US2899829A

US2899829A - H smith

Info

Publication number: US2899829A
Authority: US
Publication date: 1959-08-18
Anticipated expiration: 1976-08-18

Description

Aug. 18, 1959 J. H.'SMITH 2,899,829

ENGINE STARTER Filed April 12, 1957 2 Sheets-Sheet 1 Fig. 4

K INVENTOR.

John H Smith BY Ck. Z. H/s Aflorn y Fig.3

1959 J. H. SMITH 2,899,829

ENGINE STARTER Filed April 12, 1957 2 Sheets- Sheet 2 Fig.9 F/gJQ F/g.// Fig/2 INVENTOR. Job/7 H Sm/fh His Alforn y United States Patent ENGINE STARTER John H. Smith, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware I Application April 12, 1957, Serial No. 652,556

12 Claims. (Cl. 74-6) invention relates to engine starter drives and is more particularly concerned with the type of engine starter drives wherein the pinion gear and other starter drive parts are bodily moved to cause meshing engagement, between the pinion gear and the gear member of the engine to 'be started.

In the conventional starting systems for internal combustion engines, a pinion gear is moved into meshing engagement with the ringgear of the engine to be started. After the meshing engagement is accomplished, the pinion gear is rotated by a starting motor which may 'be either electric or fluid actuated. In all of the starting apparatuses used, an overrunning clutch is provided to permit the pinion gear to overrun the starter motor shaft after the engine becomes self-operative. Further, in the conventional starter drive arrangements, the ring and pinion gear teeth are provided with chamfered ends to aid in achieving the meshing engagement. These chamfered surfaces may have any number of dilferent shapes each of which is selected to achieve the best possible meshing conditions for the particular starting equipment used. I The present invention is directed to a starter drive wherein a meshing engagement will result even if unmatched, or reverse, chamfers are provided between the pinion'and ring gears. This condition frequently arises when the original starting equipment of an internal combustion engine is replaced by service parts. As for an example, when a starter drive, as shown in the Critchfi eld Patent 2,245,431, replaces the starter drive which is shown in the Dyer Patent 1,799,042. When this com- .bination of starter drives is used, tooth abutment will frequently occur and the tooth abutment will not be selfrelieving as is the usual case when normal chamfered teeth are used.

, It is an object of the present invention to provide a ICC Another object of "the present invention is to incorporate means in aone-way clutch type starter drive 'whih Willhpe'rmit the drive to be used with any type ring gear teet Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown. r

In the drawings:

' Figure 1 shows a starting motor with a broken away portion illustrating one form of a starting motor drive according to the present invention.

Figure 2 is a sectional view of one form of a starting motor drive according 'to the present invention.

Figure 3 is a perspective view of a biasing washer, as used in the starter drive in Figure 2.

Figure -4 is a perspective view of a coil spring as used in the starter drive in Figure 2.

Figure 5 is a cross-sectional side view of the starter drive according to the present invention showing the drive parts in a "normal position.

Figure 6 is a sectional view taken along 1ine'6-6 in Figure 5. p

Figure 7 is a View showing the drive parts in Figure 5 as rotated according to the present invention. 7

.Figure '8 is a sectional view taken along line 8-8 in Figure 7. I

Figures 9-12 diagrammatically show some of the various combinations of pinion and ring gear teeth that may be used with the starter drive according to the present invention.

In :the drawings, the starter drive 20 includes a pinion gear 22 which .is driven through a suitable overrunning clutch 24 by means of a starting motor 26. This starting motor may be of the fluid type or of the conventional electromotive type as shown. The starting motor 26 is arranged to rotate a shaft 28 when energized. The shaft 28 is provided with splined teeth 30 along its outer surface which are spaced as shown and may be either straight or helically disposed along the outer surface of the shaft 28. The sleeve 32 most clearly shown in Figure 2, is pro: vided with teeth 34 which are separated by grooves that are straight or helically disposed depending upon the shape of the teeth on the shaft. The grooves or teeth 30 g on the sleeve 32 are spaced to provide a backlash starter drive which may be used with any type of engine ring gear.

A further object of the present invention is to incorporate into a starter drive a means which will enable the starter motor pinion gear to pass into meshing engagement with the ring gear regardless of the shape of the two gears.

Another object of the present invention is to provide a one-way running clutch type starting motor drive with a means which will enable the pinion gear to mesh with the ring gear of the engine to be started regardless of the shape of the ring gear.

A still further object of the present invention is to incorporate a means .in a starter drive which has a oneway clutch and a pinion gear that is bodily movable into mesh with a member of the engine to be started which tween teeth 34 on the sleeve '32 and the teeth 30 on the shaft 28. A torque washer 36, shown in Figure 3, has a single tooth 38. This torque washer 36 is normally biased by means of the torsion spring 40 so the tooth 38 constantly engages one side of one of the teeth 30 on the shaft 28.

The torque washer 36 is held in position bya retainer 39 which presses the washer against a shoulder on the sleeve so the tooth 38 may extend througha notch 4:1 in the sleeve 32. The retainer 39-, in turn, is held in position by the snap ring 43-which is received in a groove in the sleeve 32. The clutch 24 may be of any of the well-known overrunning types, such as a Sprague clutch, a dog-tooth clutch, see Patent 1,912,061 to Bertsche, or'a roller type clutch as is shown in the Critchfield Patent 2,245,431. A study of the Critchfield patent will reveal that when'the engine is to be started, the entire drive'assembly 20 ismoved to the right on shaft 28 by the lever 42 which operates in the shift collar 44, to cause the meshing engagement to occur between the pinion gear 22 and the ring gear 46. After the meshing engagement is accomplished, the starting motor is energized so that the cranking force of shaft 28 is applied to the engine to be started. 7 A

Occasionally, however,- tooth abutment may occur when the pinion gear 22 is slid forward on a smooth surface portion 29 of shaft 28 toward the meshing engagement. The shape of the various types of gear teeth which are normally used on ring gears are shown in Figures 9-12 of the drawings. The clutch drive, according to the present invention, may be used with any of the ring gear teeth shown. This is not possible with the drives now known. The improvement in this drive assembly which permits the drive to be used with the various ring gear teeth includes the use of the torsion spring 40 and the washer 36 together with the backlash spacing between

teeth

30 and 34. Specifically, the use of the washer 36 and the other parts will permit the drive to overcome the condition shown in Figure 9. When the drive 20 is moved forward and the tooth abutment occurs, as shown in Figure 9, the continued forward movement of the collar 44 will cause the spring 48 to be slightly compressed. At this time the pres-' sure of the tooth 50 on the pinion gear and the tooth 52 on the ring gear will overcome the force exerted by the spring 40 so that the sleeve 32 will rotate relative to shaft 28 in the direction of the arrow 54, shown in Figure 9, and will take up the backlash between

teeth

30 and 34. This will permit the pinion gear teeth 50 to rotate in a direction of arrow 54 so that the pinion teeth 50 may pass into full meshing engagement with the ring gear teeth 52. After the teeth are fully meshed, the teeth are rotated in the direction of arrow 56 to crank the engine. In Fig- .ures 10 and 11 two other of the ring gear teeth 52A and B are shown. When these teeth are used, the use of the torsion spring 40 and a washer 36 will be unnecessary. In Figure 12 of the drawing another condition of tooth abutment is shown. When this condition arises, the shift collar 44 will be moved forward against the force of spring 48 to its greatest point of travel. When this occurs a bleed valve in an hydraulic starter will open or an electric switch in an electric starter will be closed to cause the drive to be rotated in the direction of arrow 56. This will permit the spring 48 to cause the tooth 50C to move from its end abutment into full meshing engagement with the tooth 52C of the ring gear.

The arrangement of the

teeth

34 and 30 on the sleeve 32 and shaft 28 respectively, together with the location of the tooth 38 on the washer 36 are most clearly seen in Figures 6 and 8. The starter drive is arranged to be driven in the direction of rotation as represented by the arrow 58 in Figures and 7. The torsion spring 40 has one of its ends hooked in an opening 60 in washer 36 and its other end disposed in a suitably located opening 62 in the sleeve 32. The torsion spring 40 normally surrounds the sleeve and is under slight compression. Thus, whenever the tooth-end abutment occurs, as shown in Figure 5, the continued forward force caused by the movement of collar 44 will overcome the compression exerted by spring 40. The tooth 38 will remain in constant engagement with the tooth 34 of the shaft 28 as shown in Figures 6 and 8. The sleeve 32 will rotate in the direction-of arrow 64 in Figure 8. The clutch shell 66 of course is secured to sleeve 32. The continued forward movement of the drive will permit the pinion gear 22 to rotate with the sleeve in the direction of arrow 64. In other words, the pinion gear 22 will rotate a slight degree in'reverse from its normal direction of rotation to relieve the tooth abutment and cause the meshing engagement. This result is accomplished by the spacing between the teeth on the shaft 28 and sleeve 32 which will permit the starter drive to be used with any type of engine ring gear.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. An engine starting apparatus comprising: a motor, a shaft rotated by the motor, a pinion gear movable into mesh with a gear of the engine to be started, said pinion gear and said engine gear having reverse chamfers, means for transmitting rotation between said shaft and pinion gear in one direction of rotation only, means for bodily moving said pinion and rotation transmitting means axially on said shaft, and means comprising a backlash connection between said motion transmitting means and said shaft for permitting limited'rotative movement between the rotation transmitting means and the shaft in a direction opposite to said one direction of rotation when the pinion gear is prevented from meshing with the gear of the engine to be started.

2. An engine starting apparatus comprising: a motor, a shaft rotatable by said motor, a pinion gear slidable on said shaft and movable into mesh with a member of the engine to be started, means for transmitting rotation between the shaft and pinion gear in only one direction, means for bodily moving the pinion gear and motion transmitting means axially on said shaft, and means comprising a backlash connection between said motion transmitting means and said shaft for permitting limited reverse rotative relative movement between the motion transmitting means and the shaft when the pinion gear is prevented from meshing with said member.

3. An engine starting apparatus comprising: a motor, a splined shaft rotatable by said motor, a pinion gear bodily movable on said shaft into mesh with a member of the engine to be started, a one way clutch axially movable on said shaft and having a driven member connected with said pinion and a driving member, a member connected with the driving member of said clutch having internal splines cooperable with the splines on said shaft for transmitting rotative movement between said shaft and driving member, means for bodily moving said member, clutch and pinion gear axially on said shaft so the pinion is moved into mesh with the engine member, and means comprising a backlash connection between the splines on said shaft and the splines on said driving member for permitting relative .rotative movement between said driving member and shaft when the pinion is prevented from meshing with said engine member.

4. An engine starting apparatus comprising: a motor, a shaft rotatable by said motor, a splined and a smooth surface portion on said shaft, a pinion gear slidable on 'the smooth surface portion of said shaft into mesh with a member of the engine to be started, a one way clutch arranged for rotating said pinion gear in one direction of rotation only, a member having internal splines cooperable with the splined portion of said shaft for transmitting rotary motion between said shaft and clutch and a lost motion connection between said splined member and shaft for permitting the splined member to rotate in the direction opposite to said one direction when the pinion gear is prevented from moving into mesh with the engine member.

5. An enginestarting apparatus comprising: a motor, a shaft rotatable by said motor, a splined and smooth surface portion on said shaft, a pinion gear slidable on the smooth surface portion into mesh with a member of the engine to be started, a one way clutch arranged for rotating said pinion gear in one direction of rotation only, a member having internal splines cooperable with the splined portion of said shaft for transmitting rotary motion between the shaft and clutch, means for bodily moving the splined member, the clutch and pinion on said shaft into mesh with the engine member, and a lost motion connection between said splined member and shaft for permitting said splined member, clutch and pinion to rotate relative to said shaft in a direction opposite to said one direction when the pinion is prevented from moving into mesh with said engine member.

6. An engine starting apparatus comprising: a motor, a. shaft having a splined portion rotatable by said motor, a. pinion slidable on said shaft into mesh with an engine to be started, a clutch arranged to rotate the pinion gear in only one direction of rotation, a member having internal grooves cooperable with and having a greater width than i 16 Width of the splines on said shaft for transmitting rotary motion between the shaft and clutch and constituting a backlash connection between said grooved member and said shaft, a means for bodily moving said grooved member, the clutch and pinionon said shaft into mesh with said engine member, and means arranged to normally urge said gooved member in said one direction relative to said shaft and permitting said grooved member to rotate in the opposite direction relative to said shaft when said pinion is prevented from meshing with the engine member.

7. An engine starting apparatus, comprising: a motor, a shaft having a splined portion rotatable by said motor, a member having grooves therein of greater width than the splines arranged to receive the splines of said shaft and constituting a backlash connection between said grooved member and said shaft, a pinion slidable on a smooth surface portion of the shaft into mesh with a member of the engine to be started, a one way overrunning clutch arranged to transmit rotation between said grooved member and pinion when the shaft is rotated in one direction, a means for bodily moving the grooved member, the clutch and the pinion with said engine member, and means for permitting said grooved member to rotate a predetermined distance relative to said shaft in the direction opposite to said one direction when the pinion is bodily moved and prevented from meshing with said engine member.

8. An engine starting apparatus comprising: a starting motor, a shaft having a splined portion driven by said motor, a sleeve having internal grooves cooperating with the splines of said shaft to provide a driving connection therebetween, said grooves being of substantially greater width than the splines of said shaft and constituting a backlash connection between said sleeve and said shaft, a pinion gear slidable on said shaft into meshing engagement with a member of the engine to be started, a one way clutch arranged to transmit rotation between said sleeve and pinion in one direction of rotation only, means for bodily moving said sleeve, clutch and pinion axially on the shaft so the pinion is moved into meshing engagement with said engine member, and a means including a spring and a toothed washer for constantly urging the sleeve in said one direction on said shaft and arranged to permit the sleeve to rotate in the opposite direction on said shaft when said pinion is moved by said means and the pinion is prevented from moving into said meshing engagement.

9. The combination as set forth in claim 7 wherein the splines of said shaft are straight and extend longitudinally along a portion of the outer surface thereof.

10. An engine starting apparatus comprising: a starting motor, a shaft having a splined portion rotatable by said motor, a pinion slidable on a smooth portion of said shaft into mesh with a member of the engine to be started, a sleeve having internal grooves of greater width than the splines telescoped over the splined portion of said shaft and constituting a backlash connection between said sleeve and said shaft, a one way clutch having a driving member attached to said sleeve and a driven member attached to said pinion, said clutch being adapted to rotate said pinion in one direction of rotation only when the sleeve is rotated in said direction by the shaft, a collar slidable on said sleeve, a spring between said collar and clutch, a means for bodily moving said collar toward said pinion whereby said sleeve, spring, clutch and pinion are bodily moved toward said engine member, and a means operable between said shaft and sleeve arranged to normally urge the sleeve in said one direction and permit said sleeve to rotate in the opposite direction on said shaft when the pinion is bodily moved and prevented from moving into mesh with the engine member.

11. The combination as set forth in claim 10 wherein the means operable between the splined shaft and pinion includes a torsion spring and a washer having an inwardly extending tooth on its inner periphery.

12. The combination as set forth in claim 11 wherein the splines on the shaft are straight and extend axially along a portion of the surface of the shaft.

References Cited in the file of this patent UNITED STATES PATENTS 1,870,075 Sutter Aug. 2, 1932 1,892,056 Jackson et a1. Dec. 27, 1932 2,173,983 Sekella Sept. 26, 1939 2,235,076 McGrath Mar. 18, 1941 2,305,219 Jones Dec. 15, 1942 2,332,864 Martin Oct. 26, 1943 2,523,151 Schneider et a1 Sept. 19, 1950 2,554,445 Miller May 22, 1951 2,782,643 Miller Feb. 26, 1957