US3812736A

US3812736A - Reversing mechanism

Info

Publication number: US3812736A
Application number: US00284946A
Authority: US
Inventors: G Nickstadt
Original assignee: General Electric Co
Current assignee: Amtech Inc
Priority date: 1972-08-30
Filing date: 1972-08-30
Publication date: 1974-05-28
Anticipated expiration: 1991-05-28

Abstract

A gear drive reversing mechanism is disclosed for reversing the direction of rotation of an output shaft driven by a drive shaft rotating in a contant direction. A gear drive reversing mechanism is also disclosed for driving two output shafts in mutually opposite rotary directions by means of a drive shaft rotating in a constant direction. The mechanisms include spiral angle face gears driven by pinions having both right-hand and left-hand spiral angle pinion gear teeth.

Description

United States Patent [1 1 Nickstadt REVERSING MECHANISM [75] Inventor: Gerhard Nickstadt, Oakland, NJ.

[73] Assignee: General Electric Company, Fort Wayne, Ind.

[22] Filed: Aug. 30, 1972 [21] Appl. No.: 284,946

[52] US. Cl 74/404, 74/355, 74/459.5, 74/342 [51] Int. Cl. Fl6h 57/00, Fl6h 3/14, Fl6h 55/04 [58] Field of Search 74/355, 665 GB, 665 GD, 74/459.5, 457-459, 342, 376, 404

[451 May 28, 1974 1,330,740 2/1920 Mills 74/355 1,455,706 5/1923 Bower et a1 74/459.5

1,947,853 2/1934 King 74/458 UX 2,190,856 2/1940 Young 74/355 X 2,453,656 11/1948 Bullard 74/462 X 2,878,690 3/1959 Capron et a1. 74/355 X 3,178,955 4/1965 Enders et a1 74/361 Primary ExaminerArthur T. McKeon [57] ABSTRACT A gear drive reversing mechanism is disclosed for reversing the direction of rotation of an output shaft driven by a drive shaft rotating in a contant direction. A gear drive reversing mechanism is also disclosed for driving two output shafts in mutually opposite rotary directions by means of a drive shaft rotating in a constant direction. The mechanisms include spiral angle face gears driven by pinions having both right-hand and left-hand spiral angle pinion gear teeth.

10 Claims, 7 Drawing Figures PATENTEDKAY 28 1924 sum 1 BF 3 FIG,5

PATENIEI] I" 2 8 i974 SHEET 3 BF 3 FIG BACKGROUND OF THE INVENTION This invention relates generally to drive reversing mechanisms, and particularly to drive reversing mechanisms of the types which employ one or more sets of gears. Thus, it is a general object of the invention to provide an improved drive reversing mechanism.

More specifically, it is an object of the invention to provide a mechanism for reversing the direction of rotation of an output shaft driven by a rotatable drive shaft without need for reversing the direction of rotation of the drive shaft.

Another object of the invention is to provide a mechanism for reversing the direction of rotation of an output shaft driven by a rotatable drive shaft without need for shifting the drive shaft axially or radially.

Another object of the invention is to provide a mechanism for reversing the direction of rotation of an output shaft driven by a rotatable drive shaft without need for shifting the output shaft radially.

Another object of the invention is to provide a gear drive reversing mechanism which does not require inclusion of an idle gear.

Another object of the invention is to provide a drive reversing mechanism which is inexpensive to construct consisting of a relatively few number of easily assembled parts.

Another object of the invention is to provide a gear SUMMARY OF THE INVENTION In one form of the present invention a gear drive reversing mechanism is provided for reversing the direction of rotation of an output shaft driven by a drive shaft rotating in a constant direction. The mechanism comprises a drive pinion secured to the drive shaft and having both right-hand and left-hand spiral angle gear teeth. A first face gear having spiral angle gear teeth is mounted to the output shaft facing the drive pinion. A second face gear having spiral angle gear teeth is also mounted to the output shaft facing the first face gear with the drive pinion rotatably positioned between the first and second face gears. The teeth of the first and second face gears are spaced apart a distance greater than the width of said pinion disposed between the first and second face gears wherebyonly one of the face gears may be in mesh with the pinion at any one time. Means are also provided for moving the face gears into and out of mesh with the pinion whereby the direction of rotation of the output shaft rotatably driven by the drive shaft may be reversed while the direction of rotation of the drive shaft and drive pinion remains constant.

In another form of the invention a gear drive reversing mechanism is provided comprising a first shaft mounted for rotation about a first shaft axis and a first face gear having right-hand spiral angle face gear teeth mounted to the first shaft. A second shaft is mounted for rotation about a second shaft axis and a second face gear having left-handspiral angle face gear teeth is mounted to the second shaft. The mechanism further includes a rotatably mounted pinion having right-hand spiral angle pinion gear teeth in mesh with the righthand spiral face gear teeth, and having left-hand spiral angle pinion gear teeth in mesh with the left-hand spiral angle face gear teeth.'Rotation of theapinion in a constant direction simultaneously drives the first and second shafts in mutually opposite rotary directions.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a' perspective view of a drive reversing mechanism embodying principles of the present invention.

FIG. 2 is a bottom plan view of the drive reversing mechanism shown in FIG. I mounted in a housing. The housing and bearings mounted therein are shown in cross section.

FIG. 3 is a bottom plan view of the drive reversing mechanism shown in FIG. 1 including portions of the housing illustrated in FIG. 2. Relative positions of selected mechanism components are shifted in FIG. 3 from positions assumed in FIG. 2 to effect reversing.

FIG. 4 is a side view in elevation of the drive reversing mechanism shown in FIG. 3 with a portion of the mechanism housing shown in cross section and with one face gear removed for clarity.

FIG. 5 is a side view in elevation of the .drive pinion employed in the drive reversing mechanism shown in FIG. 1.

FIG. 6 is a cross-sectional view of the drive pinion shown in FIG. 5 taken along plane 66.

FIG. 7 is a diagrammatical view of a modified form of the drive reversing mechanism shown in FIG. 1 embodying another form of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in more detail to the drawing and in particular to FIGS. 1 and 2, there is shown a drive reversing mechanism embodying principles of the present invention and including a housing 10 which may be made of aluminum, steel, cast iron or the like. Four threaded holes 12 in the housingprovide means by which a housing plate may be secured with a gasket held therebetween. A drive shaft 14 is journalled through a ball bearing in the housing. The bearing comprises a set of annularly disposed balls 15 rotatably disposed between an inner race 16 and an outer race 18. The two races are maintained in position by snap ring 20 secured to drive shaft 14, by snap ring 21 disposed within an annular recess in the housing, by shaft shoulder 22, and by housing shoulder 24. The terminal end of the drive shaft is journalled in bushing 25 mounted in a housing wall opposite that in which the ball bearing is disposed.

Drive shaft 14 includes a truncated, conic drive pinion 26, the details of which may be seen most clearly by reference to. FIGS. 5 and 6. The pinion includes both right-hand spiral angle gear teeth and left-hand spiral angle gear teeth, which are longitudinally coextensive along the pinion. Shaft 14 and pinion 26 are preferably made of carbonized and hardened steel with the pinion teeth being formed by grinding. The shaft and pinion are preferably of unitary construction.

An output shaft 30 is journalled through support bearings mounted within opposing walls of housing 10,

which bearings comprise

bronze bushings

32 and 33. Output shaft 30 passes above drive shaft 14 within the housing cavity with the axes of the two shafts oriented substantially normal to each other. Two

face gears

35 and 37 are rigidly secured to output shaft 30 with pinion 26 disposed therebetween. The two face gears are spaced apart a distance sufficiently great to insure that only one of the face gears engages the drive pinion at any given time. As will hereinafter be explained in more detail, the output shaft and face gears are adapted to be moved axially to bring

face gears

35 and 37 alternatively into mesh with drive pinion 26.

The teeth of face gear 35 are right-hand spiral angles while those of face gear 37 are left-hand spiral angles. They, as well as the output shaft to which they are secured, are formed of hardened steel. Such face gears may be purchased from the Illinois Tool Works Inc. of Chicago, Illinois which, in combination with tapered pinions, are sold under the trademark Spiroid".

With reference next to FIGS. 1, 3, and 4, means for moving

face gears

35 and 37 alternatively into and out of mesh with drive pinion 26 are shown comprising an annular cam 40 mounted to the end of control rod 42. Cam 40 is mounted to the control rod in sliding contact with

hubs

38 and 39 of

face gears

37 and 35, respectively, and with the cam axis offset from that of the control rod. Where mechanical play is desired, the cam is mounted in contact with only one face gear at one time.

Cam mounting is accomplished by means of pin 44 whichv is press fitted into aligned channels within the cam and control rod. A crosspiece 45 is press fitted in pin 44 and control rod 42 to inhibit axial movement of the pin. Rod 42 is journalled through bushing 47 mounted within housing to the housing exterior.

As a final assembly step, a housing cover is secured and the housing interior then partially filled with a lubricating oil. Lubrication is facilitated by the presence of both left-hand and right-hand spiral angle pinion gear teeth which are longitudinally coextensive.

In operation, drive shaft 14 may be rotated unidirectionally such as clockwise as indicated by arrow 50 with drive pinion in mesh with right-hand spiral angle face gear 37 as seen in FIGS. 1 and 2. The resultant torque transmitted to the face gear causes it and output shaft 30 to rotate clockwise as indicated by arrows 55. Should reverse rotation become desired, rotation of the drive pinion and output shaft is momentarily halted and rod 42 rotated a half turn. This action causes cam 40 to force the face gears and output shaft to move axially. As the face gears move, gear 37 disengages drive pinion 26. As the half turn of the rod and cam is completed, left-hand spiral angle face gear 35 engages the drive pinion, Mesh will ordinarily occur with higher gearing ratios whereas with lower ratios conventional spring bias may be applied to the face gears to'insure m'esh upon recommencenient of pinion rotation. With pinion 26 now in engagement with face gear 35, clockwise rotation is again imparted to the drive pinion causing output shaft 30 to be driven counterclockwise as indicated by arrow 51 in FIGS. 1 and 4 and with the mechanism components assuming the relative positions depicted in FIGS. 3 and 4. To return the rotation of the output shaft back to its original direction rod 42 is merely rotated another half turn causing face gear 35 to disengage the drive pinion and face gear 37 shortly thereafter to reengage the pinion while rotation of the drive pinion and face gears is momentarily arrested.

For some applications avoidanceof axial movement 7 of the output shaft may be desired. Under such circumstances face

gears

35 and 37 may be rigidly secured to a tubular sleeve about shaft 30 thereby permitting relative axial movement between the face gears and output shaft upon rotation of cam 40. In such cases rotational slippage of the face gears upon the shaft is prohibited or limited by keys and keyways, or by meshed, coaxial teeth formed on the exterior of the shaft and interior of the tubular sleeve.

FIG. 7 illustrates another embodiment of the invention which may be constructed through a modification of the drive reversing mechanism just described. Here, rather than reversing the direction of a single output shaft, two independent, coaxial,

output shafts

60 and 62 are simultaneously driven in opposite directions as indicated by arrows 5 and 55, respectively. Each is simultaneously in mesh with drive pinion 26. Again, face gear 37 is right-hand spiral angle while face gear 35 is left-hand spiral angle.

It should be understood that the just described embodiments merely illustrate principles of the invention. Many other modifications may be made thereto without departure from the spirit and scope thereof as set forth in the following claims.

What I claim as new and desire to secure by Letters Patent of the United States is: v

l. A gear drive reversing mechanism for reversing the direction of rotation of an output shaft driven by a drive shaft rotating in a constant direction, said gear drive reversing mechanism comprising a tapered drive pinion rotatable with said drive shaft, with said tapered drive pinion having both right-hand spiral angle gear teeth and left-hand spiral angle gear teeth, a first face gear drivingly connected with said output shaft and having spiral angle gear teeth facing said drive pinion; a second face gear drivingly connected with said output shaft and having spiral angle gear teeth facing said first face gear with said drive pinion rotatably positioned between said first and second face gears; the teeth of said first and second face gears being spaced apart a distance greater than the width of said drive pinion disposed between said first and second face gears whereby only one of said first and second face gears may be in mesh with said drive pinion at any one time; and means for moving said first and second face gears into and out of mesh with said drive pinion whereby the direction of rotation of said output shaft rotatably driven by said drive shaft may be reversed while the direction of rotation of said drive shaft and drive pinion remains constant. 7

2. A gear drive reversing mechanism in accordance with claim 1 wherein said first and second face gears are rigidly mounted to said output shaft.

3. A gear drive reversing mechanism in accordance with claim 1 wherein said moving means comprises a cam supported for contact with said first and second face gears.

4. A gear drive reversing mechanism in accordance with claim 1 wherein said right-hand spiral angle gear teeth and said left-hand spiral angle gear teeth are longitudinally coextensive along said pinion.

5. A gear drive reversing mechanism for reversing the direction of rotation of an output shaft being driven by a drive shaft rotating in a predetermined direction, said reversing mechanism comprising a tapered drive pinion rotatably with said drive shaft; said tapered drive pinion having a right hand spiral groove in the surface thereof, and a left-hand spiral groove in the surface thereof traversing said right-hand spiral groove to form a plurality of pinion gear teeth between said grooves; a first face gear coupled to said output shaft and having spiral gear teeth facing said pinion gear teeth; a second face gear coupled to said output shaft and having spiral gear teeth facing said pinion gear teeth; and means for holding the spiral gear teeth of said first face gear in engagement with said pinion gear teeth when the spiral gear teeth of said second face gear are disengaged from said pinion gear teeth, and for holding the spiral gear teeth of said second face gear in engagement with said pinion gear teeth when the spiral gear teeth of said first face gear are disengaged from said pinion gear teeth; said output shaft being rotatably drivable by said input shaft in opposite directions without reversing the direction of rotation of said drive shaft.

6. A gear drive reversing mechanism in accordance with claim 5 wherein said drive pinion is secured to said drive shaft for rotation about a first axis, said first and second face gears are coupled to said output shaft for rotation about a second axis, and said first and second axes overlay one another at substantially right angles.

7. A gear drive reversing mechanism in accordance with claim 5 wherein said engaging means comprises a cam supported for contact with at least one of said face gears.

8. A gear drive reversing mechanism comprising a shaft mounted for rotation about a shaft axis; a first face gear mounted to said shaft and having right-hand spiral angle gear teeth; a second face gear mounted to said shaft in spaced relation with said first face gear and having left-hand spiral angle gear teeth facing said right-hand spiral angle gear teeth of said first face gear; a tapered pinion mounted between said first and second face gears for rotation about a pinion axis disposed substantially at a right angle with said shaft axis, said tapered pinion having both right-hand spiral angle gear teeth faces that define a right-handspiral groove and left-hand spiral angle gear teeth faces that define a lefthand spiral groove; and means for alternatively engaging teeth of said pinion with the teeth of said first and second face gears.

9. A gear drive reversing mechanism in accordance with claim 8 wherein said right-hand spiral angle gear teeth and said left-hand spiral angle gear teeth are longitudinally coextensive along said pinion.

10. A gear drive reversing mechanism in accordance with claim 8 wherein said alternative engaging means comprises a cam positioned between said first and second face gears.

Claims

1. A gear drive reversing mechanism for reversing the direction of rotation of an output shaft driven by a drive shaft rotating in a constant direction, said gear drive reversing mechanism comprising a tapered drive pinion rotatable with said drive shaft, with said tapered drive pinion having both right-hand spiral angle gear teeth and left-hand spiral angle gear teeth; a first face gear drivingly connected with said output shaft and having spiral angle gear teeth facing said drive pinion; a second face gear drivingly connected with said output shaft and having spiral angle gear teeth facing said first face gear with said drive pinion rotatably positioned between said first and second face gears; the teeth of said first and second face gears being spaced apart a distance greater than the width of said drive pinion disposed between said first and second face gears whereby only one of said first and second face gears may be in mesh with said drive pinion at any one time; and means for moving said first and second face gears into and out of mesh with said drive pinion whereby the direction of rotation of said output shaft rotatably driven by said drive shaft may be reversed while the direction of rotation of said drive shaft and drive pinion remains constant.

5. A gear drive reversing mechanism for reversing the direction of rotation of an output shaft being driven by a drive shaft rotating in a predetermined direction, said reversing mechanism comprising a tapered drive pinion rotatably with said drive shaft; said tapered drive pinion having a right-hand spiral groove in the surface thereof, and a left-hand spiral groove in the surface thereof traversing said right-hand spiral groove to form a plurality of pinion gear teeth between said grooves; a first face gear coupled to said output shaft and having spiral gear teeth facing said pinion gear teeth; a second face gear coupled to said output shaft and having spiral gear teeth facing said pinion gear teeth; and means for holding the spiral gear teeth of said first face gear in engagement with said pinion gear teeth when the spiral gear teeth of said second face gear are disengaged from said pinion gear teeth, and for holding the spiral gear teeth of said second face gear in engagement with said pinion gear teeth when the spiral gear teeth of said first face gear are disengaged from said pinion gear teeth; said output shaft being rotatably drivable by said input shaft in opposite directions without reversing the direction of rotation of said drive shaft.

8. A gear drive reversing mechanism comprising a shaft mounted for rotation about a shaft axis; a first face gear mounted to said shaft and having right-hand spiral angle gear teeth; a second face gear mounted to said shaft in spaced relation with said first face gear and having left-hand spiral angle gear teeth facing said right-hand spiral angle gear teeth of said first face gear; a tapered pinion mounted between said first and second face gears for rotation about a pinion axis disposed substantially at a right angle with said shaft axis, said tapered pinion having both right-hand spiral angle gear teeth faces that define a right-hand spiral groove and left-hand spiral angle gear teeth faces that define a left-hand spiral groove; and means for alternatively engaging teeth of said pinion with the teeth of said first and second face gears.