Camshaft grinding machine – Manufacturer GST. Camshaft grinder
US4833834A. Camshaft belt grinder. Google Patents
Publication number US4833834A US4833834A US07/115,025 US11502587A US4833834A US 4833834 A US4833834 A US 4833834A US 11502587 A US11502587 A US 11502587A US 4833834 A US4833834 A US 4833834A Authority US United States Prior art keywords camshaft belt belts cams grinding Prior art date 1987-10-30 Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Expired. Lifetime Application number US07/115,025 Inventor Henry B. Patterson Eberhard E. Wasserbaech Jae M. Lee Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.) Motors Liquidation Co Original Assignee Motors Liquidation Co Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.) 1987-10-30 Filing date 1987-10-30 Publication date 1989-05-30 1987-10-30 Application filed by Motors Liquidation Co filed Critical Motors Liquidation Co 1987-10-30 Priority to US07/115,025 priority Critical patent/US4833834A/en 1987-12-21 Assigned to GENERAL MOTORS CORPORATION, A CORP. OF DE. reassignment GENERAL MOTORS CORPORATION, A CORP. OF DE. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: LEE, JAE M., WASSERBAECH, EBERHARD E., PATTERSON, HENRY B. 1989-05-30 Application granted granted Critical 1989-05-30 Publication of US4833834A publication Critical patent/US4833834A/en 2007-10-30 Anticipated expiration legal-status Critical Status Expired. Lifetime legal-status Critical Current
Links
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- 229910003460 diamond Inorganic materials 0.000 claims description 8
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- 239000012530 fluid Substances 0.000 claims description 6
- 230000001050 lubricating Effects 0.000 claims description 6
- 238000001816 cooling Methods 0.000 claims description 4
- 230000001360 synchronised Effects 0.000 claims description 4
- 238000005461 lubrication Methods 0.000 abstract 2
- 239000000969 carrier Substances 0.000 description 14
- 238000004519 manufacturing process Methods 0.000 description 8
- 239000002826 coolant Substances 0.000 description 6
- 238000000034 method Methods 0.000 description 4
- 239000003921 oil Substances 0.000 description 4
- UONOETXJSWQNOL-UHFFFAOYSA-N Tungsten carbide Chemical compound [W]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 2
- 238000005296 abrasive Methods 0.000 description 2
- 230000000712 assembly Effects 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 239000000110 cooling liquid Substances 0.000 description 2
- 239000005068 cooling lubricant Substances 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 239000000314 lubricant Substances 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
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Images
Classifications
- B — PERFORMING OPERATIONS; TRANSPORTING
- B24 — GRINDING; POLISHING
- B24B — MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B21/00 — Machines or devices using grinding or polishing belts; Accessories therefor
- B24B21/006 — Machines or devices using grinding or polishing belts; Accessories therefor for special purposes, e.g. for television tubes, car bumpers
- B — PERFORMING OPERATIONS; TRANSPORTING
- B24 — GRINDING; POLISHING
- B24B — MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B19/00 — Single-purpose machines or devices for particular grinding operations not covered by any other main group
- B24B19/08 — Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding non-circular cross-sections, e.g. shafts of elliptical or polygonal cross-section
- B24B19/12 — Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding non-circular cross-sections, e.g. shafts of elliptical or polygonal cross-section for grinding cams or camshafts
Abstract
Various embodiments of multiple belt camshaft grinding machines each have grinding belt drive, contouring and support members carried on a feed table for separate control of cam contouring and grinding feed rate while the camshaft workpiece is carried on a fixed axis by a table providing axial motion for belt wear balancing oscillation and, optionally, camshaft indexing. Curved shoe or wheel contouring members allow reverse curve cam grinding. Special shoe materials and belt-shoe lubrication may be provided to reduce shoe wear. Other features are also disclosed.

Description
This invention relates to camshaft belt grinders and, more particularly, to multiple belt grinding machines for grinding the lobes of camshafts for engines and the like.
It is known in the art relating to camshaft manufacturing to use cam grinding and lapping machines with traditional circular grinding and lapping wheels as shown, for example in U.S. Pat. Nos. 1,660,291 Birkigt, 1,813,503 Merryweather, 1,843,301 Player et al, 2,098,438 Stubbs, 2,195,054 Wallace et al and 2,553,831 Musyl. Such grinding machines commonly require relatively expensive grinding wheels which must be dressed often.
A camshaft grinder having multiple belts which are individually movable for simultaneously grinding the profiles of a plurality of cams of an engine camshaft or the like can make use of potentially lower cost long life abrasive belts which do not require dressing and can be easily replaced. Such a machine is shown in U.S. Pat. No. 4,175,358 wherein the grinding of individual cams is performed by straight sections of separate belts tautly drawn between idler rollers of a grinding head. Cam profiling is accomplished by a roller type cam follower mechanism while the grinding stroke is provided by infeed of a separate camshaft supporting table. This arrangement limits the ability to form cam profiles to those capable of being formed by a flat grinding surface. It also introduces inaccuracies by the use of a curved roller follower with the flat grinding surface. The camshaft table feed yields dual moving assemblies and results in the lack of a fixed center for the camshaft workpiece.
Belt grinders are also known for use with workpieces other than camshafts wherein the belts are forced into grinding engagement by curved shoes as in U.S. Pat. Nos. 2,823,494 Board, Jr. et al and 3,136,097 Laird or by wheels or drums as in U.S. Pat. Nos. 2,810,480 Carroll, 3,760,537 Bovati, 4,091,573 Schmidt, 4,292,767 Fatula, 4,382,727 Schmidt, 4,309,848 Arrigoni and 4,407,096 Steinback.
The present invention provides related arrangements of camshaft belt grinders having several significant features of novel design.
In general, the invention involves multiple belt grinders having grinding belt drive, contouring and support means carried on a feed table for separate control of cam contouring and grinding feed rate. The camshaft workpiece is carried for rotation on a fixed axis by a table that may provide axial motion for indexing or belt wear balancing oscillation.
In particular embodiments, machines according to the invention may include wheels or curved shoes for contacting the belts and applying grinding pressure. The shoes may be made with long wearing hard surfaced materials and may include special wear inserts. Cooling and lubricating fluid may be sprayed not only on the grinding face of the belts to carry away heat from the grinding process but also between the shoes and the backs of the belts to lubricate and cool the sliding action of the belts on the shoes.
Alternative contouring means may include cam followers using a master cam or a preferred numerically controlled actuator arrangement using motor driven ball screws or equivalent means. In multi-belt applications involving close cam spacing, the belt engaging shoes or wheels may be closely spaced in a common plane while their associated actuators are offset in one or more planes and staggered vertically and horizontally to provide room for their mounting.
Additionally, the belt support units or contouring heads of a grinding machine may be mounted for relative lateral adjustment of one or more of the grinding and contouring mechanisms to provide variable belt spacing that allows for use of the machine with various camshafts having different axial spacing of the cams.
These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.
FIG. 1 is a pictorial view of a representative four belt camshaft grinding machine formed according to the invention;
FIG. 2 is a pictorial cross-sectional view from the plane generally indicated by the line 22 of FIG. 1 and showing details of the master cam actuated contouring mechanism;
FIG. 3 is a fragmentary pictorial view similar to FIG. 2 but showing an alternative numerically controlled ball screw actuated contouring arrangement;
FIG. 4 is a fragmentary top view of a similar two belt embodiment having adjustable belt spacing with potentially closely spaced belts and staggered actuators;
FIG. 6 is a fragmentary top view of an alternative eight belt embodiment having fixed spacing and staggered actuators for grinding simultaneously all the cams of a single camshaft;
FIG 7 is a fragmentary cross-sectional view from the plane of line 77 of FIG. 6 showing the actuators of the contouring means;
FIG. 8 is a transverse cross-sectional view from the plane of line 88 of FIG. 7 and showing the staggered relationship of the actuators and their belt engaging rollers;
CNC Camshaft grinding machine.
FIG. 9 is a transverse cross-sectional view from the plane of line 99 of FIG. 6 through the camshaft workpiece supporting table of a grinding machine and showing a ball screw traversing mechanism for oscillating or indexing the cams;
FIG. 10 is a cross-sectional view through the table supporting ways from the plane of the line 1010 in FIG. 9; and
FIG. 11 is side view of an alternative embodiment of contouring means using belt engaging curved shoes with cooling lubricant delivered on both sides of the belt.
Referring now to the drawings in detail, numeral 10 generally indicates a camshaft belt grinder formed in accordance with the invention. Grinder 10 includes base 11 on which is supported a feed table 12 that is slidably movable on ways, not shown, by a feed screw or other suitable means driven by a feed motor 14. The motion of the table 12 is longitudinal in forward and rearward directions to provide the grinding feed needed in operations performed on the grinder.
Also mounted on the base 11 forward of the table 12 is a workpiece support 15 mounting a laterally movable worktable 16 carrying centers 18, 19 for mounting a camshaft workpiece 20 having a plurality of cams 21 arranged, for example, in groups of four closely spaced cams each. A grinding steady rest 22 may also be provided. A cam drive motor 23 extends laterally from the live center 19 for rotatably driving the workpiece 20. A camshaft oscillating motor 24 is carried on the workpiece support 15 for driving the table 16 and camshaft 20 in a laterally oscillating motion during cam grinding.
On the feed table 12, there is carried a contouring head assembly generally indicated by numeral 26 and portions of which are best shown in FIG. 2. Assembly 26 in oludes a frame 27 which supports four grinding belts 28 driven by a main drive pulley 30, guided by upper and lower guide pulleys 31, 32 and tensioned by individual tensioning pulleys 34.
The belts 28 are also contacted by individual contouring shoes 35 of a contouring drive assembly generally indicated by numeral 36. This assembly further includes a master camshaft 38 with a plurality of cams 39 shaped in the form desired for the workpiece cams, a follower shoe 40 for each cam 39, a carrier block 42 carrying each follower shoe, and a pushrod 43 mounting each carrier block. The pushrods are reciprocably carried, in a body 44 fixed to the feed table, by linear ball bearing sleeves 47 which prevent rotation of the pushrods and the blocks 42 in body 44. A spring 48 acts against each pushrod 43 to urge its follower shoe 40 against its respective master cam 39.

The front end of each pushrod carries an offset shoe carrier 50 that connects its pushrod with a respective one of the contouring shoes 35 to urge the shoe 35 against an associated one of the grinding belts 28 for grinding the associated cam surfaces of a camshaft workpiece. The shoe carriers 50 are offset to permit the close spacing of the cams 21 which requires the four grinding belts to be similarly closely spaced. The contouring push rods 43 are staggered above and below, as well as beside, the positions of their 5 contouring shoes 35 in order to accommodate the wider spacing required for the contouring mechanism.
On the feed table, a main drive motor 51 is mounted and connected for driving the main drive pulley 30. A master cam drive motor 52 is also mounted thereon and connected for rotatably driving the master camshaft 38. Motor 52 is controlled to operate in synchronism with the cam drive motor 23 so that the master camshaft 38 and the workpiece camshaft 20 are driven at the same phase angles and rotational speeds. On the contouring head assembly 26, the tensioning pulleys 34 are urged against the grinding belts by any suitable devices, such as air pressure actuated pistons 53.
In operation, the main drive motor 51 rotates the main drive pulley 30, driving the grinding belts over the tensioning pulleys 34, guide pulleys 31, 32 and contouring shoes 35. The shoes 35 are formed with a face curvature preferably identical to that of the follower shoes 40 and selected to provide accurate cam grinding with a predetermined amount of reverse cam curvature if desired. The guide pulleys are placed to maintain the desired amount of belt wrap about the guide shoes, limited to minimize friction and wear.
Concurrently. the workpiece cam drive motor 23 and the master cam drive motor 52 operate to drive the camshaft workpiece 20 and the master camshaft 38 in synchronous rotation about their respective axes. The follower shoes 40 follow the profiles of their respective master cams 39 and drive their respective pushrods 43 to reciprocate the associated contouring shoes 35 so as to replicate the shapes of the master cams on the cams 21 of the workpiece 20.
From an initial position spaced from the workpiece, the grinding belts are advanced to the final cleanup grinding position by forward feed motion of the feed table 12 driven by the feed motor 14 through a drive screw or other suitable feed mechanism, not shown. During the grinding process, the work table is preferably oscillated laterally a small amount to move the cams 21 being ground back and forth over the complete faces of the slightly wider grinding belts. This provides even belt wear and a more even finish on the completed cams 21.
Referring now to FIG. 3, there is shown an alternative embodiment of grinder 54 similar to that of FIGS. 1 and 2 but using numerically controlled contouring devices. For convenience, like numerals are used for like parts.
In the FIG. 3 embodiment, the grinding belts 28 and the workpiece camshaft 20 are driven in the manner previously described. However, the contouring shoes 35 and their associated pushrods 43 are driven by directly connected ballscrews 55 actuated by numerically controlled individual contouring motors 56. The pushrods 43 and ballscrews 55 are staggered as in the earlier embodiment to provide for the close belt and cam spacing.
The operation is similar to that of the FIGS. 1 and 2 embodiment except that the contouring of the workpiece cams 21 is accomplished by numerically controlled actuation of the motor 56 in timed phase relation with the rotation of the workpiece camshaft 20 to reciprocate the shoes 35 so as to form the desired cam profiles.
In FIGS. 4 and 5 are illustrated two further embodiments of camshaft grinders 57, 58 respectively, having generally the forms previously described and for which like numerals identify like parts. Both embodiments use dual grinding belts 28 supported in a manner such that one of the belts is adjustable relative to the other to vary the spacing between the belts to accommodate differing camshaft designs. The concepts could, if desired, be equally well used in grinders having more than two belts.
In FIG. 4, the two grinding belts 28 of grinder 57 are carried by two separate frame portions of the contouring head assembly, a stationary frame 59 fixed to the feed table 12 and a movable frame 60 mounted for lateral motion on the feed table 12. To accommodate the illustrated close spacing of the belts, they are actuated by pushrods 43 through offset carriers 61. These carry belt engaging contouring wheels 62 instead of the shoes of the earlier described embodiments.
The pushrods 43 are actuated by a master cam arrangement similar to the embodiment of FIGS. 1 and 2. However, two separate cam members, not shown, are used, one driven by a master cam drive motor, not shown, mounted on the stationary frame 59 and the other driven by a second master cam drive motor 63 mounted on the movable frame 60. This second master cam and the associated pushrod and grinding belt are all laterally movable with lateral movement of the frame 60 to vary the belt spacing as desired. This adjustment is accomplished by an adjusting screw 64 driven through a chain drive 66 by suitable manual or motor drive means, not shown.
The arrangement of FIG. 5 is similar to that of FIG. 4 but differs in that the belt spacing is not so close. This allows the use of centered carriers 67 on the pushrods 43 carrying contouring wheels 62. Also, the master cam mechanism is replaced by a numerically controlled drive similar to that used in the FIG. 3 embodiment and using separate contouring motors 56 for directly driving the pushrods 43 through ballscrews, not shown. The adjusted position of the movable belt mechanism is shown by phantom lines but the mechanism for moving the movable frame 60 relative to the stationary frame 59 is not shown.
FIGS. 6-10 illustrate the differing features of a grinding machine, or grinder 68, intended for mass production of camshafts. The grinder uses eight fixed position grinding belts 28 arranged to grind simultaneously all of the cams on a typical engine camshaft 20. The grinding belts 28 are spaced with the same intervals as the camshaft cams 21 so as to contact and grind all of the cams simultaneously. Staggered pushrods 43 and numerically controlled contouring motors 56 with ballscrews 55 and linear ball bearing sleeves 47 are used as in the arrangement of FIG. 3, however the vertically offset carriers 69 optionally support belt engaging contouring wheels 62 instead of the shoes 35 of FIG. 3.
FIGS. 9 and 10 show details of the work table 16 including the ways 70 carried by the support 15 and on which the table 16 is laterally movable. An end mounted drive motor 71 and associated ballscrew 72 are used for oscillation and lateral adjustment of the worktable rather than the back mounted motor 24 of FIG. 1.
FIG. 11 illustrates an alternative arrangement wherein contouring shoes 74 with long wearing inserts 75 are substituted for the contouring wheels 62. The inserts 75 are preferably made of tungsten carbide coated with a long wearing coating, such as silicon nitrider, preferably, a man made polychrystalline diamond, known commercially as Compax diamond, fused to the wearing surface of the insert.
Coolant-lubricant distribution tubes are also provided including outer tubes 76 located to direct cooling liquid onto the cams being ground by the outer sides of the belts 28 and inner tubes 78 located to direct coolant onto the backs of the belts 28. The coolant may be water to which a soluble oil is added, such as is in common use in manufacturing operations. The oil not only protects the workpieces and machine parts from corrosion but also improves the lubricating qualities of the coolant when it is sprayed behind the belts to cool and lubricate the belt travel over the shoes 74. In this way, the wear life of the shoes is greatly extended.
While the invention has been described by reference to certain preferred embodiments, it should be understood that numerous changes could be made within the spirit and scope of the inventive concepts described. Accordingly it is intended that the invention not be limited to the disclosed embodiments, but that it have the full scope permitted by the language of the following claims.
Claims ( 19 )
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
A camshaft belt grinder having a plurality of spaced grinding belts for simultaneously grinding on a camshaft a plurality of longitudinally spaced cams, one with each belt, said grinder comprising
means for driving and tensioning said belts in paths aligned with said cams laterally of the camshaft,
actuating means operative to engage the belts and individually urge the belts into grinding contact with their respective cams, said actuating means including curved face belt engaging members, one lying adjacent each cam and engaging the opposite side of its belt therefrom, and contouring means connected with each of the belt engaging members and operative to individually advance and withdraw their respective belt engaging members to cause the belts to grind the cam surfaces in desired configurations, and
guide means engaging the belts beyond and ahead of their belt engaging members to limit the maximum angle of belt wrap about the curved faces of the belt engaging members,
wherein said belt engaging members are stationary contouring shoes, and the curved faces of said shoes have hard wearing surfaces for engaging the belts.
A camshaft belt grinder as in claim 1 wherein the hard wearing surfaces include polycrystalline diamond fixed to the curved faces.
A camshaft belt grinder as in claim 1 wherein are provided fluid delivery means operative to deliver cooling and lubricating fluid between the belts and the contouring shoes for minimizing wear on the curved faces thereof.
A camshaft belt grinder as in claim 1 wherein said plurality of grinding belts is less than the number required to simultaneously grind all the cams on a camshaft workpiece and portions of said belt driving and tensionsing and said contouring means are movable longitudinally of the camshaft to sequentially grind selected groups of the cams.
A camshaft belt grinder as in claim 1 wherein the belt driving and tensioning and the actuating means are all carried on a traveling feed table and the camshaft workpiece supporting means carries the camshaft for rotation on a fixed axis.
A camshaft belt grinder having a plurality of spaced grinding belts for simultaneously grinding on a camshaft a plurality of longitudinally spaced cams, one with each belt, said grinder comprising
means for driving and tensioning said belts in paths aligned with said cams laterally of the camshaft, and
actuating means operative to engage the belts and individually urge the belts into grinding contact with their respective cams, said actuating means including curved face belt engaging members, one lying adjacent each cam and engaging the opposite side of its belt therefrom, and contouring means connected with each of the belt engaging members and operative to individually advance and withdraw their respective belt engaging members to cause the belts to grind the cam surfaces in desired configurations,
wherein said plurality of grinding belts is less than the number required to simultaneously grind all the cams on a camshaft workpiece and portions of said belt driving and tensioning and said contouring means are movable longitudinally of the camshaft to sequentially grind selected groups of the cams.
A camshaft belt grinder having a plurality of spaced grinding belts for simultaneously grinding on a camshaft a plurality of longitudinally spaced cams, one with each belt, said grinder comprising
means for driving and tensioning said belts in paths aligned with said cams laterally of the camshaft, and
actuating means operative to engage the belts and individually urge the belts into grinding contact with their respective cams, said actuating means including curved face belt engaging members, one lying adjacent each cam and engaging the opposite side of its belt therefrom, and contouring means connected with each of the belt engaging members and operative to individually advance and withdraw their respective belt engaging members to cause the belts to grind the cam surfaces in desired configurations,
wherein the belt driving and tensioning and the actuating means are all carried on a traveling feed table and the camshaft workpiece supporting means carries the camshaft for rotation on a fixed axis.
A camshaft belt grinder as in claim I wherein the camshaft workpiece supporting means is an axially movable table capable of oscillating the camshaft along its axis.
A camshaft belt grinder having a plurality of spaced grinding belts for simultaneously grinding on a camshaft a plurality of longitudinally spaced cams, one with each belt, said grinder comprising
means for driving and tensioning said belts in paths aligned with said cams laterally of the camshaft, and
actuating means operative to engage the belts and individually urge the belts into grinding contact with their respective cams, said actuating means including belt engaging members, one lying adjacent each cam and engaging the opposite side of its belt therefrom, and contouring means connected with each of the belt engaging members and operative individually advance and withdraw their respective belt engaging members along parallel lines of motion to cause the belt to grind the cam surface in desired configurations,
the contouring means of adjacent belt engaging members being offset in generally opposite directions laterally from the lines of motion of their respective belt engaging members to allow closer spacing of the belt engaging members than is permitted of the contouring means.
A camshaft belt grinder as in claim 9 wherein said contouring means are driven by power means operative to cause movement of the associated belt engaging members in response to a control input.
means carrying a pattern cam for each cam of the camshaft and rotatable in synchronized relation to the rotating motion of the camshaft, and
follower means having a cam follower for and engaging each of the pattern cams and means connecting each of the cam followers with one of the contouring means for actuating the belt engaging members directly from their associated pattern cams.
A camshaft belt grinder as in claim 9 wherein said contouring means of adjacent belt engaging members are alternately disposed above and below the level of the camshaft to be ground to further provide for close spacing of the belt engaging members.
A camshaft belt grinder as in claim 12 wherein said contouring means of adjacent belt engaging members are also offset from the line of motion of their respective belt engaging members in generally opposite directions longitudinally of the camshaft workpiece.
A camshaft belt grinder as in claim 9 wherein said plurality of grinding belts is less than the number required to simultaneously grind all the cams on a camshaft workpiece and portions of said belt driving and tensioning and said contouring means are movable longitudinally of the camshaft to sequentially grind selected groups of the cams.
A camshaft belt grinder as in claim 9 wherein said belt engaging member is a curved shoe having a belt contacting surface made from a low wear material.
A camshaft belt grinder as in claim 16 wherein said low wear material includes polycrystalline diamond.
A camshaft belt grinder as in claim 9 wherein the belt driving and tensioning and the actuating means are all carried on a traveling feed table and the camshaft workpiece supporting means carries the camshaft for rotation on a fixed axis.
A camshaft belt grinding as in claim 18 wherein the camshaft workpiece supporting means is an axially movable table capable of oscillating the camshaft along its axis.
Priority Applications (1)
US07/115,025 US4833834A ( en ) | 1987-10-30 | 1987-10-30 | Camshaft belt grinder |
Applications Claiming Priority (1)
US07/115,025 US4833834A ( en ) | 1987-10-30 | 1987-10-30 | Camshaft belt grinder |
Family Applications (1)
US07/115,025 Expired. Lifetime US4833834A ( en ) | 1987-10-30 | 1987-10-30 | Camshaft belt grinder |
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US20140005817A1 ( en ) | 2012-06-28 | 2014-01-02 | Michael A. Brewer | Apparatus and related systems and methods for processing molded parts and similar items |
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US4382727A ( en ) | 1979-09-14 | 1983-05-10 | Maschinenfabrik Zuckermann Komm. Ges. | Contour copying machine |
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GB2073069A ( en ) | 1980-03-25 | 1981-10-14 | Thielenhaus Ernst Kg | Process for the Finishing of Camshafts |
US4407096A ( en ) | 1980-05-15 | 1983-10-04 | Acrometal Products, Inc. | Method and apparatus for surface grinding |
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Camshaft grinding machine – Manufacturer GST
You have come to the right place if you are looking for a new camshaft / cam piece grinding machine. We manufacture your machine tailor-made for your individual requirements! We look forward to your inquiry!
Your benefits
As a manufacturer of industrial grinding machines for metal, GST Grinder delivers highest precision solutions since 1992.
Berco RAC 1500 Camshaft Grinder at RT Sales
- Specialized in circular grinding ✓
- Completely individual ✓
- High-precision technology ✓
- Short retooling times ✓
- Integrated automation ✓
- Improved energy balance ✓
Tailor-made solutions
Camshafts / cam pieces are essential parts of the internal combustion engine. When it comes to processing large quantities with highest accuracy, GST is a flexible provider for your requirements. Since the highest level of precision is required for this type of grinding, GST has developed various concepts. Depending on our customers’ requirements, each machine is specially planned, designed and manufactured in Austria according to highest quality standards.
Grinding diameters, plane surfaces cam shape
- One spindle with X-axis
- Table used as Z-axis
- Grinding of cams and bearing seats is possible
Your contact person
Markus Aschauer, Dipl.W.Ing.(FH) Technical Sales GST Grinder GmbH Your grinding machine manufacturer in Austria!
Contact me: Phone: 43 (0) 2267 3250-24 Mobile: 43 (0) 650 3250 005 E-Mail: markus.aschauer@gst.at
GST Grinder GmbH, Industriepark 6, A-2011 Sierndorf Phone: 43 2267 32500, Fax: 43 2267 3250 99, office[at]gst.at
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Evolution of Performance Camshaft Grinding, Finishing
Comp Cams has made numerous improvements to its CNC camshaft grinding process. The company has also implemented what it calls its “Micro Surface Enhancement” finishing technology, which works in tandem with its enhanced grinding process to further improve camshaft longevity and durability.
By improving its CNC grinding processes and adding its new Micro Surface Enhancement (MSE) finishing technology, Comp Cams has not only improved the look of its camshafts for LS-type GM engines, but more importantly, improved their longevity.
Comp Cams has nine CNC camshaft grinding machines. Eight of these are Okuma GC-34 NH models.
One camshaft installs in each of an MSE centrifugal barrel finishing machine’s four drums. These drums contain the media that polishes the camshafts, too.
The combined rotation of the barrel and drums creates 2 tons of force on the media and camshafts in the drums. This force is distributed equally on the camshaft surfaces to evenly polish them.

All nine of Comp Cams’ CNC grinding machines now use carbon-fiber-hub cBN wheels.
They also feature scrubbers that shoot high-pressure streams of coolant across the face of the wheels during operation to prevent swarf buildup that would otherwise increase grinding pressure as well as the frequency of dressing operations.
This skidless profilometer is used to measure the roughness of camshaft journal and lobe surfaces as well as their waviness. It can determine actual surface topography to a resolution of 0.000002 inch.
This image depicts a camshaft lobe surface before the MSE process.
while this one shows it after the MSE process. The uniform force generated during the MSE removes many material “peaks” and minimizes waviness across the camshaft lobe.
Read Next
Oftentimes, grinding lobes and bearing journals is the final machining operation that completes an engine’s camshaft. This is still the case for a number of offerings from Comp Cams, a leading manufacturer of aftermarket camshafts and valvetrain components for race, show and street vehicles.
The Memphis, Tennessee-based company has continued to adopt new grinding technology over the years, and now has nine computer numerical control (CNC) grinding machines using carbon-fiber-hub, cubic-boron-nitride (CBN) wheels that are profiled and trued on the machines using rotary diamond wheel dressers. It also recently has introduced a new lobe and bearing-journal finishing process for one of its most popular roller-lifter camshaft lines that not only makes the camshafts look better, but more importantly, extends their lives by reducing abnormal, premature lobe wear. The kinetic finishing process does this by removing tiny peaks of material left behind after grinding while also minimizing the amount of side-to-side waviness across the surface of a camshaft lobe, thus increasing the effective surface-bearing area between a lobe and its mating lifter’s roller. This lowers the amount of localized stress the camshaft lobes experience during operation, minimizing the number of microscopic imperfections that could eventually propagate and become problematic on a macro scale.
Featured Content
Comp Cams calls its finishing process Micro Surface Enhancement (MSE), and it is currently available as a standard feature for the roller-lifter camshafts it offers for popular General Motors LS engines (introduced in 1995 for use in a variety of rear-wheel-drive vehicles) as well as custom racing applications for an added cost.
That said, MSE proved not to be a cure-all. In developing and refining the MSE process, the company realized it made sense to circle back to further refine its grinding process to generate a better overall camshaft lobe surface profile and finish to maximize the benefits that MSE offered.
Circling Back
Comp Cams is no stranger to the pages of Modern Machine Shop. In 2011, I visited with Billy Godbold, valvetrain engineering group manager, who explained how the company had developed a process to turn and mill custom, powder-metal camshaft cores for racing applications complete from barstock using a twin-spindle/twin-turret Okuma LT300-MY turning center. (Camshaft cores have their primary features machined, but still require subsequent heat treating and grinding operations.) After learning a bit about MSE recently, I decided a return trip was warranted.
For a number of years, Mr. Godbold and his team have been researching various finishing processes to improve camshaft-lobe and journal-surface quality. He says some camshaft manufacturers (Comp Cams included, largely for custom racing camshafts) perform belt sanding. However, it is challenging to get a belt to provide uniform pressure on a lobe. This can cause a lobe’s surface to become even more wavy and the lifter’s load to be applied only to a lobe’s high spots. Plus, belt sanding does not remove any remaining burrs on the lobes’ side edges. In addition, this is still largely a manual process requiring a skilled operator, so it is not easily scalable for higher-production applications.
It is also possible to acid-etch the surface of the lobes, which anneals and softens the iron in their surfaces, and then polish the surfaces with media to smooth them. However, the etching doesn’t affect the carbide in the iron lattice structure of the steel, so the process can leave behind peaks of carbide, which become stress risers, or points of localized stress.
A third option is micro peening. This kinetic-energy process blasts the lobe surface with micro media, but it can create tiny craters that have stress risers around their circumference. Also, it is challenging to clean out all the media from camshafts after the micro-peening process.
Ultimately, Comp Cams discovered a manufacturer of centrifugal-barrel-finishing machines and worked with the company for a couple years to tailor that type of kinetic-energy finishing process to its camshafts. (Mr. Godbold withheld the name of said equipment manufacturer.)
The machines (Comp Cams has two) operate on a Ferris-wheel-like principle. Each has four drums, or baskets, into which a single camshaft and the polishing media are manually loaded and enclosed. These drums rotate in the opposite direction of the barrel rotation. During operation (typical finishing time for a camshaft is 15 minutes), the combined rotation of the barrel and drums creates two tons of force on the media and camshafts in the drums, and this force is distributed equally on the camshaft surfaces to evenly polish them.
Although some applications of this finishing technology use organic material as the polishing media, Comp Cams determined that denser, ceramic- composite media and higher rotational speeds worked best for its steel camshafts, not only to remove any peaks and to minimize waviness across the camshaft lobe because of the uniform force that is applied, but also to provide a high luster. Plus, the process also deburrs the side edges of the lobes and journals. In addition, the company found that this process, with a very dense media, served to impart compressive stresses into the surfaces, which slightly strengthens them. MSE’s rust-preventive qualities also made it no longer necessary to coat camshafts in as thick of an oil as it used to do prior to packaging.
That said, while MSE proved to be an effective finishing process, precise measurements using an Adcole 911 camshaft inspection device and Zeiss Surfcom Flex 50A skidless profilometer showed that even further improvements could be realized by making changes to the grinding process to generate a higher-quality surface prior to MSE finishing.
Grinding Through Improvements
Today, Comp Cams’ eight Okuma GC-34 NH CNC camshaft grinding machines and single Landis 3L camshaft grinding machine use carbon-fiber-hub CBN wheels instead of steel-hub CBN wheels. Although these lightweight wheels are much costlier, they offer improved vibration damping, repeatability, predictable performance and less-frequent dressing (dressing is required after every 20 to 30 camshafts). The company found that using steel-hub CBN wheels on its rigid grinding machines sometimes caused camshafts to vibrate during grinding.
Comp Cams uses a variety of wheel brands depending on the camshaft being ground, and performs tests to measure the electrical current during a grinding operation when selecting grinding wheels for a given application. Higher current means more pressure and heat is created during grinding, which could cause burning, so it looks for wheels that grind with the least amount of current. It also added scrubbers to its grinding machines that shoot high-pressure streams of coolant across the face of the wheel during operation to remove any swarf buildup. Cleaning material out of the voids in the wheel surface reduces grinding pressure (and risk of burning the camshaft lobe and journal surfaces) as well as the frequency of dressing operations. Grinding tests proved that even less current was drawn when scrubbers were used because wheels could grind more freely when they were not loaded with swarf.
The company also settled on Castrol Syntilo 9974 heavy-duty synthetic metalworking fluid, which Mr. Godbold says is costlier than many other fluids, but it offers high, consistent lubricity with no need for a lubricity additive. In addition, the company went so far as to decouple coolant mist collectors from machines. Originally, the grinding machine mist collectors were mounted directly on the machine enclosures. However, it was determined that the mist collectors’ electric motors caused a slight amount of vibration that resulted in a small bit of measurable chatter in the ground camshafts. Now, the mist collectors are mounted on a frame separate from the machines.
Addressing the Dress
The final big change was refining and optimizing the wheel dressing process. William McIntyre, a manufacturing associate engineer for process development at Comp Cams, says the company received a good bit of input from Okuma and various grinding wheel manufacturers in developing its wheel dressing routines. As he explains, the first step in refining the dressing process was to get the speed ratio of the dressing and grinding wheels to the recommended 75 percent to minimize the risk of dressing chatter. In other words, the surface feet per minute (SFM) of the rotary diamond dresser was adjusted to be 75 percent of the normal SFM of the CBN wheels to provide the proper pressure on the wheels to enable proper surface fracturing. He says it is important not to reduce the grinding wheel speed during dressing because it can adversely affect grinding wheel concentricity, making it more difficult to balance at the normal rotational speed.
Comp Cams grinds so many types of material and surface profiles in lobes that it has multiple different dress parameters it uses depending on what’s best-suited for a given application. Mr. McIntyre notes that it can be challenging to determine the appropriate dressing wheel transverse rate across the grinding wheel. This rate is kept slow, but not so slow as to cause burning on the flanks or ramps of the camshaft. Too slow of a transverse rate will not open the wheel grains properly so the wheel will ultimately burn the cams during grinding.
In dialing in the dressing processes for each application, the company tested ground camshafts at set integrals to check for lobe surface topography, lobe profile and burning. Using a carbide disk that emulates a lifter, its two Adcole 911 camshaft inspection devices record the translating lifter motion for each lobe every 0.1 degree as it rotates the camshaft, meaning 3,600 data points are collected in a single rotation to a radial resolution of 1 micron. Comp Cams takes three measurements for each lobe (at the middle and on either side). This device records the motion of the lifter, determines if the lobe is convex or concave, and performs a fast Fourier transform (FFT) algorithm to check for grinding chatter.
While the Adcole 911 is used to determine follower motion 360 degrees around lobes, the Zeiss Surfcom Flex 50A skidless profilometer measures lobe profile and surface finish longitudinally (side-to-side) across the lobe surface. It does this using a pointed diamond stylus that drops into any valleys and moves over any peaks in the surface to determine actual surface topography to a resolution of 0.000002 inch.
The profilometer is also used to check for appropriate lobe crown on roller camshafts. Mr. Godbold says that the surface of the lobes for roller camshafts should be slightly convex (with a bit of a crown in the middle), because the rollers on the mating lifters are also slightly convex. By having both mating surfaces slightly convex, the pushrod load (which can reach approximately 2,500 pounds for LS engines) tends to cause each surface to flatten a bit. Comp Cams shoots for a lobe crown of just a 0.0001 inch.
The company also uses Profile Master data analysis software from Digital Metrology Solutions to process and report the data gathered by the profilometer. Mr. Godbold says the software’s graphical interface is valuable in clearly communicating to manufacturing and quality control personnel how changes to the grinding process affect the end product.
To check for burned surfaces, Mr. McIntyre created a test station in which camshafts are first dipped in a bath of nital, an etching solution that is a combination of alcohol and 8 percent nitric acid, and then dipped in a bath of alcohol and 8 percent hydrogen chloride to deactivate the etching. This process will cause a significant color change of any burned surfaces because different material hardnesses react differently with these solutions.
Product Improvements
The various modifications of the grinding process ultimately enabled it to serve as “pre-polish” step on lobe surfaces prior to MSE processing. This enabled Comp Cams to use smaller media in the MSE process, because not as much material removal or surface pressure (as bigger media would provide) were required to remove material peaks and minimize profile waviness. Plus, bigger media tended to create new valleys in the lobe surface anyway, which would also reduce bearing area, meaning a second MSE operation with smaller media would have been required.
MSE was put into production in October 2017 for the company’s LS-engine camshafts and introduced at the SEMA show in Las Vegas, Nevada, later that month. Comp Cams plans to offer MSE for other camshaft lines down the road. Mr. Godbold says the bearing area for the company’s camshafts was approximately 10 percent 15 years ago and 15 percent 10 years ago. Now with refined grinding and MSE processes, the company is achieving 50 to 70 percent bearing area and reduction in peak roughness by 65 percent to more effectively spread the load on camshaft lobes to lower the stress they endure during operation for improved durability and reduced valvetrain noise.
The key in all this, however, was having the capability to precisely measure various lobe features as the company worked to improve its camshaft manufacturing process. As Mr. Godbold notes, if you are trying to improve a process but cannot measure to verify that improvements are being realized, you are ultimately just guessing.
Skidded and Skidless Profilometers: What’s the Difference?
The top image shows a skidded profilometer; the bottom shows a skidless profilometer.
According to Zeiss Industrial Metrology, the primary principle of a skidded profilometer is that its diamond stylus and the skid datum are independent of each other and are in contact with the part surface when the trace is made. The surface texture is measured by the change in the diamond’s position relative to the plane of the skid that follows the surface. Because of this, any form or long wavelengths are filtered out and the remaining data is roughness only. Typical skidded profilometers are portable, cost less and incorporate short traverse movement. In addition, they are robust enough for shopfloor use, have good vibration damping characteristics and are generally easy to use.
As manufacturing techniques and surface analysis became more advanced, a more capable “skidless” profilometer was developed. The primary principle of a skidless trace is that the diamond stylus and datum are interdependent. The diamond tip is solely in contact with the part surface at the time of measurement, and surface deviations are measured in reference to the diamond’s position against a straight datum built within the instrument’s drive guide. Skidless profilometers can analyze surface profile, waviness and roughness. These devices are more accurate and repeatable than skidded models, but are also more expensive due to the precision datum guide, multi-speed driver and higher-resolution probe.
Camshaft grinder
Goodson abrasives are second to none. We work with our manufacturer ro get you the most ideal grain that’s bonded to be free-cutting, yet still shed before loading up. We stock several standard sizes, but every camshaft grinding wheel is finished in house to your exact specifications. Choose from these standard sizes or contact us for custom size or profile today.
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Order No. | Description | Price | Quantity |
GCC18X0.750X6 | 3/4″ W | 6″ Arbor Dia. | 214.99 | Add |
GCC18X0.875X6 | 7/8″ W | 6″ Arbor Dia. | 219.99 | Add |
GCC18X1.000X6 | 1″ W | 6″ Arbor Dia. | 224.99 | Add |
GCC18X1.250X6 | 1-1/4″ W | 6″ Arbor Dia. | 234.99 | Add |
information
To return an item:1. Write a brief note describing the reason for the return. Please be sure to include your name or company name or account number.
Return the item freight prepaid within 60 days from the invoice date. For best results, please ship return merchandise by UPS or Federal Express. Please keep your receipt because it may be necessary to track the package if it is lost in transit.
A 10% restocking fee applies on all returns unless the problem was the fault of Goodson. If so, the restocking charge is waived and shipping costs are reimbursed. Credits will be made to the account originally billed.
Send the completed Product Return Form along with the product to:
Goodson Shop SuppliesATTN: RETURNS156 Galewski DriveWinona, MN 55987
Goodson strives to ship orders the same day they are received. In fact, we track this on a daily basis and we are currently shipping 99.97% of orders on the same day.
We use most major carriers including FedEx, UPS, USPS and regional carrier, SpeeDee.
For more information, check out our Shipping Delivery page.
Goodson ships F.O.B. Winona, Minnesota, USA to most countries around the world. To find a distributor near you visit our Distributor Listing.
If there is not a distributor in your area, you can contact Goodson by phone (1-507-452-1830) or order online. Please note some items (such as Sunnen) are not available for shipping outside of the United States Canada. If you have these items in your shopping cart, your order cannot be processed. You must remove those items from the cart to continue.
“Proposition 65 requires businesses to provide warnings to Californians about significant exposures to chemicals that cause cancer, birth defects or other reproductive harm.”. www.p65warnings.ca.gov
So, what does this mean for Goodson customers? It means that many of common products used in manufacturing contain products known to the state of California to cause cancer and/or reproductive harm. Components such as stainless steel, galvanized wire, brass, bronze, etc. can be found in the Prop 65 list and require us to provide the warning.
You can find a complete list at the Proposition 65 website.