US2108547A - Gear lapping machine - Google Patents

Description

Feb. 15, 1938. 'NYLAND 2,108,547

GEAR LAPPING MACH INE Filed Feb. 13, 1935 6 Sheets-Sheet 1 E. R. NYLAND 2,108,547

GEAR LAPPING MACHINE Feb. 15, 1938.

Filed Feb. 13, 1935 6 Sheets-Sheet 2 Feb. 15, 1938.

E. R. NYLAND 2,108,547

GEAR LAPPING MACHINE Filed Feb. 13, 1935 6 Sheets-Sheet 4 A?! lid Feb. 15, 1938. E. R. NYLAND mew GEAR LAPPING MACHINE Filed Feb. 13, 1935 6 Sheets-Sheet 5 Feb. 15, ms.

rzawaraimL Patented Feb. 15, 1938 PATENT OFFlCE 2,108,547 GEAR LAPPING MACHINE Edward R. Nyland, Detroit, Mich assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application February 13, 1935, Serial No. 6,288

19 Claims.

This invention relates to a machine for smoothing up gear teeth by a method known as lapping to. take ofi the high spots on the teeth and to make all the teeth of a gear more nearly of identical configuration.

The heat treatment of gears after they have been cut causes different amounts of warping throughout the length of the gear teeth which must be trued up, and it is the purpose of this invention to provide means to accurately and speedily lap: the gears after heat treatment to makeflthem all practically identical in configuration. r

My invention resides in the construction as described in the specification, claimed in the claims and illustrated in the accompanying drawings, in which: i

Figure 1 is a side elevation of my machine as a whole.

I Figure 2 is an enlarged vertical section through the work holding head of the machine. 7

Figure 3 is a sectional view taken on the line 3--3 of Figure 2.

Figure 4 is an enlarged vertical section through the lap ring holding head.

Figure 5 is a side elevation of the oscillatory drive and brake for the lap: supporting sleeve, parts being broken away. 7

Figure 6 is a detail view of the brake adjusting means.

Figure 7 is a sectional view taken substantially on the line l'! of Figure 4.

Figure 8 is a sectional View taken on the line 8- 8 of Figure 6. I

Figures 9 and 10 are enlarged vertical sections through the work holding head and a portion of the lap holding head, respectively, of a modified form of my invention. 7

Figure 11 is a top plan View of the driving mechanism shown in'Figure 10 "illustrating its connection to the lap supporting housing.

Figure 12 is a detail View of an intermediate idler gear for preventing backlash; and

Figures 13 and 14 are sectional views" taken on lines |3-l3 and l4-|4 of Figure 12 respectively.

The machine comprises a base 2 having a hol low cylindrical standard 4 secured in a vertical position on the base. Slidably supported on the upper end of the standard is the work supporting and driving head designated generally at 6. This head is composed of a short cylinder 8 larger than the standard, in one side of which is rotatably secured a gear, it which meshes with a rack I 2 vertically secured to the standard 4. The shaft M on which the gear I0 is mounted projects through the side of the cylinder 8 and may be turned to cause the cylinder to move up and down 'on the standard for adjusting purposes. A rope I6 is secured to one side of the cylinder by a suitable clamp means l8 which rope runs up over a pulley secured to the top of the standard and is connected to a weight inside of the standard (not shown) which acts. as a counmr balance for the weight of the head so that it may be moved up and down more easily, 10

Supported on one side of the cylinder 8 by bracket 22 is a motor 24. Supported diametrically opposite is an irregular shaped casing 26 which houses the work holding and driving head. The casing supports a horizontal worm: 28 driven by a pulleytfl which is in turn driven by belt 32 from the motor 24. The casing 26 has a pair of vertically aligned openings in the top and bottom which are surrounded by upstanding flanges 34 and 36, respectively. Within these 20 openings are secured suitable flanged glands 38 and 40 respectively. An irregular hollow member 42 fits snugly within the glands 3B and 40 and has its: outer end secured by suitable clamp ing nuts 44. The central section of the member has a cylindrical opening 36 therein and the lower extremity has a larger circular opening 48. Fitting snugly within the opening is is a solid stub shaft 52 in whose upper end is drilled and tapped a hole 54. A bolt 56 extends through the center of the member 42 and is threaded into the threaded opening 54 to secure the assembly together.

Rotatably mounted on the central enlarged portion of the hollow member is a worm. wheel 58 which is driven by the worm 2a. Extending upward from the top face of the'wheel 58 at diametrically spaced points are two lugs 60. An X-shaped member 62 keyed to the hollow member just above the enlarged lower portion forms a flexible driving unit with the worm wheel. The ends of a pair of the X arms 64 of the member are positioned on either side of the lugs 68. Springs 66 fitted in openings 68 in each of the arms as abut the sides: of the lugs to which have a slightly countersunk opening so the springs will not slip. The tension on the springs may be adjusted by screws 10 which are finally held in cally opposite the motor is a casing 80 which is bolted to the cylinder I4. The vertical position of this casing may be adjusted by turning a threaded rod 82 which engages a lip 84 of the cylinder. Any horizontal rotation desired to bring the lapping ring into alignment with the work may be made by loosening the clamp lever arm 8I and rotating the whole assembly around standard 4.

In the top of the casing 80 is a circular opening 88 through which projects a vertical hollow sleeve 88, and which latter is supported by a bearing 80 in the opening. The top of the sleeve projects above the casing and has an inner circumferential notch in which is clamped the lapping ring 92 by a ring 94 and bolts 96. The sleeve is inwardly offset below the bearing 80 and shoes 98 are mounted on the sleeve adjacent this portion. Two diametrically opposite pins I00 extend through the shoes and are threaded on the outer ends. A yoke member I02 has diverging arms which engage these pins and are secured thereto by nuts I04. After engagement with the pins the arms then converge again until they meet on the other side of the sleeve where they are pivoted at I06 to the casing. In the front end of the yoke member there is a longitudinal cylindrical opening I08 in which is slidably carried a peg IIO having a small hole I I2 at right angles to its axis. A stub shaft H4 is supported in an extension from the casing and has thereon at its outer end drive pulleys I I6 which are driven from the motor I8 by belt II 8. From the inner end of the stub shaft projects a pin I20 eccentric to the axis of the shaft and which engages the hole H2 in the slidable peg. It will be evident from this disclosure that as the shaft rotates the yoke will be moved vertically up and down, the side motion of the peg I I0 being taken up by its relative motion within the opening I08. This action causes vertical reciprocation of the sleeve 88.

Pivotally connected to the lower portion of the yoke below the slidable peg is a bolt I22 which extends through the casing and has a spring I28 coaxially surrounding the outer end. The extremity of the bolt carries a circular disc I24 secured thereon by nuts I26 against which one end of the compression spring bears, the opposite end bearing against the outer face of the casing. The purpose of the spring is to bias the reciprocatory movement of the sleeve and yoke.

Below the shoes 98 is positioned a ring I30 on the outside surface of the sleeve adjacent which is a band of braking material I32. The lower edge of the latter is supported by a ring I34 clamped to the sleeve by set screws I36. Surrounding the circular band of brake material is a brake band I38 which also fits in between the rings I30 and I34. The ends of the brake band are bent outwardly to form short flanges and connected together by a bolt I40 which passes through both flanges and has a spring I42 surrounding the outer portion and bearing against one flange and also against a washer I44 held on the bolt by a nut I46.

Integral with the brake band and positioned below the pivot I06 is an extending stud I48 upon which is rotatably placed a roller I50 and secured thereon by a washer and nut I52. In the wall of the casing 80 in alignment with the stud I48 is a circular opening I54. A flanged cylinder I56 is projected through this opening and secured therein by bolts I58 which extend through holes I60 in the flanged portion. These holes I60 are not round but elongated so that the angular position of the cylinder may be varied. The inner end of the cylinder carries two diametrically opposite arms I62 which contact the opposite sides of the roller and by varying the position of these arms the angularity of the braking action may be varied for the vertical reciprocation.

Below the brake the sleeve 88 passes through a bearing I64 in the lower part of the casing 80 and has its lower extremity exteriorly threaded upon which a ball bearing supporting ring I66 is secured. A matching annular member I68 acts to complete the race for the balls I70 and also has a rim portion which extends up around the lower extended part of the casing. Springs I12 in this lower extended part bear against the annular member and tend to keep the two apart, thus damping the oscillation of the sleeve. To the casing surrounding this latter assembly is secured a thin cylinder I14 to protect the same.

Below the cylinder I'I4 on the standard 4 is a third supporting cylinder I16 whose distance from the base 2 is regulated by the screw thread I78. Pivoted to the lower corner is a waste pot I80 which may be swung to position below the sleeve. Supported by the cylinder I'I6 above the pot I80 is an angle bracket I82 which in turn supports a dished member I84 below the sleeve and casing. The outer end of the bracket is formed into a vertical circular hollow member I86 which extends up through an opening in the center of the dished member and then up through the center of the hollow sleeve. Slidable within this member I80 is a smaller member I88 within an opening in the lower end of which is positioned a spring I90, the lower end of which bears against a plate I92 secured across the bottom of the opening in the member I86. A rod I04 extends through a central opening in the plate I92 and up through the center of the spring and is threaded into the member I88. The lower exterior end of the rod has a Y-shaped yoke I96 thereon which receives the lever arm I98 pivoted to the side of the bracket at 260. A pin 202 goes through the arms of the yoke and an elongated hole 204 in the lever to secure them together. The purpose of this structure is to move the member I88 up and down at will. A locking means to keep the member at any desired place is provided which consists of a rotary screw 206 that contracts the split casing I86 about the outer surface of the member I88 and is operated by the lever 208.

The top of the member I88 is hollowed out and supports therein a short hollow shaft 2I0 having an exterior flange 2| 2 at the top which engages the member I 88 and limits its movement into the same. The hollow shaft 2I0 and the member I 88 are keyed together as at 2 I4. A stub shaft 2 I6 having a pointed tip is positioned within the hollow shaft. Secured in the top end of the hollow shaft is a roller bearing assembly 2I8 between the hollow shaft and the stub shaft so that the latter may rotate freely therein. A cap 220 is screwed onto the upper end of the hollow shaft to enclose the roller bearing. An inverted cup-shaped member 222 is secured on the stub shaft 2I6 to protect the roller bearing from foreign matter and extends down over the capped end. A second similar member 224 is secured to the upper end of the member I88 and extends down around the outside of the hollow member I 86 to keep the foreign matter from the contact surface between I86 and I83.

Between the pointed end of the stub shaft 2 I6 and the pointed end of the upper stub shaft 52 is carried a shaft 226 which carries the gear 228 to impart vertical oscillations to the sleeve.

to be lapped. Rotary motion is imparted to the shaft from the upper stub shaft by a depending eccentric lug 235 which cooperates with "a clamped piece 232 on the shaft to turn thelatter.

The operation of the machine will now be briefly described. The work and lap supporting heads are properly positioned upon the standard by moving them up or down and then secured. The supporting cylinder I86 is then positioned on the standard so that the member I88 may be moved up to clamp the shaft 226. Shaft226 is then inserted within the sleeve having its lower endresting on the end of the stub shaft 2 I 5. The shaft is then swung into alignment with the upper stub shaft and the lever I98 raised until it contacts the pointed end thereof, at'which time the locking lever 258 is pulled up to lock the shaft in place. The shaft is free to rotate upon these two pointed shaftsas it would be in a lathe, the depending lug 235 from the top stub shaft driving the same through contact with the clamp 232. When the shaft is in this position, the gear should be opposite the lapping ring. The upper shaft is driven by the motor 24 at any desired speed through the belt 32, which drives a pulley directly connected to a worm 28. The worm drives a worm wheel having a pair of upstanding lugs that impart rotary movement to an X-shaped member through springs 66, the X-shaped member being connected to the stub shaft. In this manner the shaft is rotated at any desired speed through a resilient connection.

At the same time the sleeve 88 is reciprocated verticallyat a desired rate by a second independent motor E8 through belt IIB, pulleys H6, shaft II and eccentric I28, which causes the yoke I52 The tension on the spring I28 is carried to any desired tension to pre-load the reciprocation of the sleeve to avoid roughness of operation at certainspeeds. The sleeve is also mounted within the housin on springs I12 to damp the oscillations for the same purpoe. A brake I32, I38 is provided to give a drag to the rotation to give friction necessary for lapping, and its action may angularly be adjusted by loosening bolts I58 and turning the flange dependent upon the helical angle of the teeth. The tension of the brake may also be varied by the spring I 42.

In this manner when the machine is operating the teeth of the gear are sliding up and down on the teeth of the lapping ring and the gear is being rotated'to bring different teeth into engagement, and also to turn the ring. Pressure is applied by the drag of the brake on the sleeve which opposes the turning thereof. The teeth of the gear are less than the teeth of the lapping ring by an odd number so that the relative position of the work will be changed in relation to the lap. The speeds of the two motors may be relatively regulated to the proper ratio.

Since it is only essential in my machine to provide rotary motion and relative reciprocation between the two members, my invention may be carried out as well by the modified form shown in Figures 9-14. In this modified form the sleeve supporting the lapping ring is both rotatably driven and vertically reciprocated, and the upper work supporting shaft merely has the brake applied thereto to give the proper frictional contact.

In Figure 9 is shown the work holding head which is the same as in the previous form, except that the teeth on the worm wheel have been removed and a brake -liningj234 inserted in the side ofthe wheel 236. The resilient connection from the wheel to the central shaft is identical to the former connection. A brake shoe 238 supported in any desired manner on the casing will give the desired braking force.

The rotary drive for the lap sleeve is shown in Figure 10. An external ring gear 240 is supported on and keyed to the sleeve 88 by a key 242 in place of the brake lining of the previous disclosure. This ring gear is wide and has two parallel sets of helical teeth, 244 and 246, about its periphery, one of which is right-handed and the other left-handed, for lapping different gears. A supporting casing 248 for a driving gear train has a portion fitting within the opening in the housing for the brake adjusting yoke of the previous disclosure, which supports a double gear 250 on a stub shaft 252 held in place'by set screw 253. One portion 255 of gear 250 meshes with the ring gear 248. The other portion 256 meshes with an idler gear 258 on shaft 260. This idler meshes in turn with a wide faced gear 262 supported on shaft 284 on which shaft is also supported a worm wheel 266, which is driven from the pulley wheel 1 268 outside the casing.

The casing 248 is pivotally supported on the housing 85 by an arm 21!) which engages a pivot pin 212 supported by a lug on the housing. In this manner, it may be swung out from the housing, withdrawing the gear 250 from engagement with the ring gear 245. Attached to the casing at a point opposite to the arm 21B is a second arm 214 upon which is pivotally mounted a hook 216 by a pin 218. The hook has a handle 280 integral therewith for turning the hook to desired positions. Secured to the housing adjacent the position of the hook when the casing is in normal driving position is a pin 282 around which the point of the hook passes to clamp the casing to the housing by pushing on the handle. A piece of packing material 284 surrounds the opening in the housing and fits between the housing and casing to insure a tight joint,

In order to change the drive from the left-hand teeth to the right-hand, the handle 280 is moved clockwise, as seen in Figure 11, which disengages the hook from the pin and allows the casing 'to swing out. The set screw 253 is then loosened, allowing the shaft 252 to be withdrawn and then gear 256 may be slid to the left from the casing.

A slotted latch 288 pivoted to the top of the casing is then swung out of engagement with the axial locking groove 2% of the shaft 259 and the latter is pulled up by taking hold of the knurled end 263 until the groove 265 is in position to be latched by the member 288, which is again moved into place. The new pair of gears is then slid into the case, the lower gear meshing with gear 245 and the upper with gear 258 in its raised position. Shaft 255 is reinserted and set screw 253 tightened. The face of gear 252 is'wide enough to remain in driving contact with gear 253 in either of its positions. The casing is then swung to closed position and latched. Projecting from an opening in the forward portion of the casing adjacent the hook 215 is an adjustable stop pin 21! which engages the face of casing 80 and varies the engagement of the gear 250 with the gear 240 to adjust the backlash of the gears. The position of the pin is locked by set screw 213.

'To further reduce backlash in the gear train, the idler gear 253 is made up of twothin gears 290 and 292 placed side by side and secured together by cap screws 294 as best shown in Figure 14.

The head and enlarged portion of the screw does not fit tightly with the opening in the gear 290,

so that a small amount of relative circumferential movement is possible. Between the screws, circular openings 296 are cut in the matching faces of the gears, half in the body of each gear in which are placed springs 298. In opposite ends of the openings, plugs 300 are secured, one plug secured to one gear and the other to the remaining gear, which will tend to cause relative rotation of the two in one direction and oppose the relative rotation in the opposite direction. This allows certain flexibility of engagement between the teeth of gears 250 and 258, and tends to keep them in contact without backlash.

It will be evident that if the sleeve be rotated in this manner and also reciprocated as before with the load on the teeth being regulated by the brake in the work head, that the same lapping action will be given to the teeth.

It is to be understood that while this invention has been described with the internal ring gear referred to as the lapping member and the external or spur gear as the gear to be lapped, it is not intended to limit the invention to this form and it would lie within the scope of my invention to have the spur gear, the lapping member and the internal gear the member upon which it operates.

I claim:

1.. A gear lapping machine comprising, a base, a lapping ring supported on the base, means for reciprocating the ring vertically, means supporting a gear having a smaller number of teeth in mesh inside the ring, means for driving the gear and resilient means between the drive and the gear to absorb any uneven forces.

2. In a gear lapping machine, a support for a gear comprising a rotatable shaft, a second shaft in alignment therewith having a driving connection to the first shaft, means on the second shaft to impart rotation thereto, a driving motor and resilient means between the driving motor and said first mentioned means to impart rotation tothe gear.

3. In a lapping machine, a sleeve for supporting a lapping ring, a yoke member pivotally connected to the sleeve, eccentric means connected to the yoke member, means for driving the eccentric means to reciprocate the sleeve vertically and spring biasing means connected to the yoke to dampen the oscillations.

4. In a lapping machine, a sleeve for supporting a lapping ring, a yoke member pivotally connected to the sleeve, eccentric means connected to the yoke member, means for driving the eccentric means to reciprocate the sleeve vertically, a band of friction material secured to the sleeve and a brake band cooperating therewith to limit the motion of the sleeve.

5. In a lapping machine, a lapping ring, a sleeve for supporting the ring, a yoke member pivotally connected to the sleeve, eccentric means connected to the yoke member, means to drive the eccentric means to reciprocate the sleeve vertically, a casing surrounding the sleeve, a member connected to the yoke and projecting through the casing and a spring to keep the member under tension to damp the vibrations of the sleeve.

6. In a lapping machine, a lapping ring, a sleeve for supporting the ring, a movable yoke member pivoted to the sleeve to impart movement thereto, a friction band on the sleeve, a brake band cooperating therewith and means to adjust the angular resistivity of the brake band in its action on the sleeve.

'7. In a lapping machine, a lapping ring, a sleeve supporting the lapping ring, means to reciprocate the sleeve vertically, braking means for the sleeve, and adjustable means for the braking means so that the angularity of its resistivity may be varied.

8. In a gear lapping machine, a lapping ring, means supporting the lapping ring, means to reciprocate the supporting means vertically, adjustable braking means for the supporting means, spring damping means for the supporting means, means for supporting a gear in mesh within the ring and resilient means for driving the gear.

9. A gear lapping machine comprising, a lapping ring, a sleeve supporting said ring, a casing, spring biased means supporting said sleeve on said casing, means for reciprocating said sleeve vertically, braking means on said sleeve, means for adjusting the angular resistivity of the braking means, means for supporting a gear in mesh within the ring, a drive shaft for the gear sup port, an X-shaped member on the shaft, a drive member supported by a second shaft having lugs that fit between the arms of the X- shaped member, springs between the lugs and arms to form a resilient connection and drive means for the second shaft.

10. A gear lapping machine comprising, a lapping ring, a spring biased rotatable sleeve supporting the ring, means for reciprocating the sleeve vertically, a braking means for limiting the motion of the sleeve, supporting means for a gear inside the ring, driving means for the supporting means including a resilient connection whereby as the gear rotates it will drive the ring and the reciprocation of the ring will lap the gear teeth.

11. A gear lapping machine, comprising a lapping ring having internal teeth, a sleeve supporting said ring, a casing, means to reciprocate the sleeve within the casing, resilient means between the sleeve and casing to dampen vibration caused by the reciprocation, means supporting a gear having a fewer number of teeth than the lapping ring in mesh therewith, the axis of the last mentioned means being parallel with the axis of the sleeve, means for rotating the gear and the ring together and braking means to apply certain pressure between the teeth of the lapping ring and gear.

12. In a gear lapping machine, a lapping ring, a sleeve for supporting the ring, means for rotating the sleeve, means for reciprocating the sleeve vertically, a casing around the sleeve, resilient means between the sleeve and the casing, means supporting a gear within the ring which is rotatable upon the teeth of the ring and braking means applied to the supporting means to cause a given pressure between the teeth of the gear and those of the ring.

13. In a gear lapping machine, a sleeve for supporting a lapping ring, means for reciprocating said sleeve, damping means for the sleeve to prevent undue vibration, adjustable braking means for the sleeve, means supporting a gear within the ring, and means to rotate the gear including a resilient connection to absorb uneven drive.

14. In a gear lapping machine, a sleeve for supporting a lapping ring, a casing rotatably supporting the sleeve, means for rotating the sleeve pivotally secured to the casing and comprising a gear train, one of the gears of which is composed of two parts relatively resiliently movable to reduce the backlash in the gear train.

15. In a gear lapping machine, a sleeve for sup- 7 porting a lapping ring, a casing rotatably supporting the sleeve, means for rotating the sleeve secured to the casing comprising a gear train, said train having a plurality of double gears so that the sleeve may be driven through either one of two gears. l

16. In a gear lapping machine, a lapping ring, a sleeve supporting the ring, a casing for support.- ing the sleeve, means for reciprocating the sleeve, means for rotating the sleeve pivotally connected on the casing, means rotatably supporting a gear in mesh with the ring, and braking means to prevent free rotation of the gear when driven by the rmg.

1'7. A gear lapping machine comprising a lapping ring, means for reciprocating said lapping ring, means supporting a gear having a smaller number of teeth in mesh inside the ring, means for driving the gear and resilient means between the drive and gear to absorb any uneven forces.

18. In a gear lapping machine, means for supporting a lapping ring, means supporting a gear having a smaller number of teeth in mesh inside the ring, means for rotating one of said means to thereby rotate the other including a resilient member to absorb any uneven forces and means to reciprocate said gear with respect to said lapping ring.

19. In a gear lapping machine, means to support a lapping ring, means to support a gear to be lapped having a fewer number of teeth in mesh within the ring, means to reciprocate one of said means with respect to the other, driving means to turn the gear and ring including a resilient member to absorb any uneven forces and braking means to limit rotary movement of the lapping ring with respect to said gear.

EDWARD R. NYLAND.

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