KR20020091048A - Anti-backlash sprag - Google Patents

Abstract

A drive shaft assembly is provided to allow rotation of the drive shaft only in one direction. The drive shaft assembly includes a housing, a drive shaft and an overrunning clutch. The overrunning clutch includes an inner race having an outer annular contact surface and an outer race having an inner annular contact surface radially spaced from the inner race. The inner annular contact surface and the outer annular contact surface form an annular space therebetween. Within this annular space a number of sprags are provided which allow the inner race to rotate in the first direction relative to the outer race while preventing the inner race from rotating in the second direction relative to the outer race. When the drive housing is fixed to the outer race and the drive shaft is fixed to the inner race so that the rotational force is provided to the drive shaft in the first direction, the drive shaft rotates. Is transmitted to, thereby preventing the drive shaft from rotating in the second direction. In a preferred embodiment, the drive shaft is coupled to a piston assembly that converts linear operation of the piston into rotational movement of the drive shaft.

Description

Anti-Backlash Sprags {ANTI-BACKLASH SPRAG}

In the prior art, it is known to mechanically couple the piston to rotate the drive shaft. In a conventional internal combustion piston type device, the crankshaft is used to transmit the linear motion of the piston to the rotational motion of the crankshaft. However, the operation of the crankshaft requires a number of pistons to be connected to one crankshaft to fully rotate the crankshaft.

By adding multiple piston assemblies both the initial and maintenance costs are increased. It is also much more likely that one of the multiple pistons will fail than one piston will fail on its own.

Therefore, it would be necessary to provide a device for converting linear motion into rotational motion without using multiple pistons. The problems encountered in the prior art discussed above are almost eliminated by the present invention.

The present invention relates generally to a drive shaft assembly, and more particularly to a drive shaft assembly that prevents backlash and reverse rotation of the drive shaft.

1 is a side view showing the valve assembly and the piston assembly of the present invention in a cross-sectional state.

FIG. 2 is a perspective view of the valve assembly and piston assembly of FIG. 1. FIG.

3 is an exploded view of the valve assembly and piston assembly of FIG. 2.

4 is a plan view of the arm and shaft assembly of FIG. 1 in a cross-sectional view.

5 is an exploded view showing a part of the overrunning clutch assembly of the present invention.

The present invention is a drive shaft assembly having a housing, a drive shaft and an overrunning clutch assembly. The overrunning clutch assembly has an inner race with an outer annular contact surface and an outer race with an inner annular contact surface. The inner annular contact surface and the outer annular contact surface form an annular space therebetween. The overrunning clutch assembly also has a plurality of sprags provided inside the annular space, the plurality of sprags allowing rotation of the inner race in a first direction relative to the outer race, while the inner race with respect to the outer race. Rotation in the second direction is impeded. The overrunning clutch assembly also has means for maintaining a plurality of sprags in the annular space. In the drive shaft assembly of the present invention, the housing is fixed to the outer race and the drive shaft is fixed to the inner race.

In a preferred embodiment of the invention, the piston and swing arm assembly is fixed to the drive shaft to rotate the drive shaft in the first direction. An overrunning clutch fixed to the housing prevents the drive shaft from rotating in reverse, ensuring that the drive shaft is driven in only one direction.

In the figure, the variable stroke motor is indicated by reference numeral 10 in FIG. As shown in FIG. 3, the variable stroke motor includes a valve housing 12. In a preferred embodiment, the valve housing 12 is made of aluminum and a hollow cylinder 14 is provided to receive the valve shaft 16. The valve housing 12 includes a first fluid inlet 18 in communication with the hollow cylinder 14 and a first fluid outlet 20 in communication with the hollow cylinder 14 as well. 1, a second fluid inlet 22 and a second fluid outlet 24 are also formed in the valve housing 12.

As shown in FIG. 3, the valve shaft 16 is provided with a first slot 26 and a second slot 28. The valve shaft 16 is also provided with a first ring seat 30, a second ring seat 32, and a third ring seat 34. The first ring seat 30, the second ring seat 32, and the third ring seat 34 are provided with three Teflon rings 36, 38, and 40, which are hollow with the valve shaft 16 and the hollow shaft. Prevents fluid from leaking between cylinders 14.

As shown in FIG. 2, a shaft rotator 42 is fixed to the valve housing 12, which is operably fixed to a key 44 extending from the valve shaft 16 shown in FIG. 3. The shaft rotator 42 may be a small electric motor or any similar rotating device known.

As shown in FIG. 3, the first slot 26 and the second slot 28 of the valve shaft 16 are arranged on opposite sides of the valve shaft 16. Thus, when the valve shaft 16 is located in the hollow cylinder 14 of the valve housing 12 as shown in FIG. 1, the second slot is between the second fluid inlet 22 and the second fluid outlet 24. Let the fluid through. As shown in FIG. 1, when the second slot 28 allows fluid to flow between the second fluid inlet 22 and the second fluid outlet 24, the first slot 26 is the valve housing 12. Completely covered by (FIGS. 1 and 3). The portion opposite the first slot 26 of the valve shaft 16 prevents fluid communication between the first fluid inlet 18 and the first fluid outlet 20.

Similarly, when the shaft rotator 42 rotates the valve shaft 16 by 180 °, the first slot 26 allows the first fluid inlet 18 and the first fluid outlet 20 to communicate with each other, The part opposite the second slot 28 of the valve shaft 16, on the other hand, closes the fluid communication between the second fluid inlet 22 and the second fluid outlet 28. In a preferred embodiment, the slots 26, 28 and the inlets 18, 22 and the outlets 20, 24 have a second fluid inlet when the first fluid inlet 18 and the first fluid outlet 20 are through. It is sized to prevent fluid from passing between the 22 and the second fluid outlet 22. Similarly, when there is a connection between the second fluid inlet 24 and the second fluid outlet 24, the fluid communication between the first fluid inlet 18 and the first fluid outlet 20 is closed.

The drive housing 46 is fixed to the valve housing 12, which forms the drive cylinder 48 as shown in FIG. 1. In a preferred embodiment, the drive housing 46 is made of a seamless stainless steel tube. The drive housing 46 is fixed to the drive box 50, preferably made of aluminum. In the drive cylinder 48 a piston 52 is provided. The piston 52 is preferably composed of an aluminum cap 54 and an aluminum base 56. The piston 52 is provided with a plastic sealing ring 58, as it is wobble-type, which will cause the piston 52 to pivot 2 ° from its normal position with respect to the central axis of the drive cylinder 48. While maintaining a seal between the sealing ring 58 and the drive housing 46.

The piston rod 60 is made of hardened steel and is fixed to the piston 52 by a securement screw 61 (FIG. 1). As shown in FIG. 3, the piston rod 60 is provided with an eyelet 62, which is mounted in the yoke 64 of the swing arm 66. In the eyelet 62, a needle roller bearing 68 or similar known bearing is installed to reduce friction. The needle roller bearing 68 is located in the eyelet 62, the eyelet 62 is located in the yoke 64, and a dowel pin 70 made of heat-treated steel is the first of the yoke 64. It is located through the outlet 72, the needle roller bearing 68, and the second outlet 74 of the yoke 64. The dowel is made of heat treated steel, which withstands the high pressure exerted on the piston rod 60. The swing arm 66 is made of hardened steel and preferably provided with a large hole 76 to receive a pair of drive sprags 78. The drive sprag 78 is fixed to the drive shaft 80 in such a manner as to transmit rotational energy from the swing arm 66 to the drive shaft 80 during the drive stroke, and the drive shaft 80 is coupled to the swing arm during the recovery stroke. "Freewheel" for 66, so that drive shaft 80 does not rotate in the opposite direction. As shown in FIG. 2, the drive shaft 80 extends through the drive box 50 to power a vehicle or any other driveable device.

The fluid pressure generator 82 is operably connected in fluid communication with the first fluid inlet 18. In a preferred embodiment, the pressure generator 82 is a steam generator, but can of course be any similar device. The fluid pressure generator 82 is connected to the first fluid inlet 18 via a delivery hose 84 (FIGS. 2 and 3). In a preferred embodiment, the second fluid outlet 24 is also connected to the fluid pressure generator 82 by an auxiliary delivery hose 86.

As shown in FIG. 2, the variable stroke motor 10 is also provided with an auxiliary valve and piston assembly 88. The auxiliary valve and piston assembly 88 is almost similar in design to the assembly described above. However, as shown in FIG. 3, in the valve shaft 16, the third slot 90 and the fourth slot 92 are located opposite the positions of the first slot 26 and the second slot 28. By setting the positions of the slots 26, 28, 90, 92, the piston described above is driven when the piston assembly 88 and the piston 94 of the auxiliary valve are restored, and the piston assembly 88 and the auxiliary valve Causes the piston 94 to recover when the piston 94 is driven. By the complementary operation of these pistons 52, 94, the drive shaft 80 is driven substantially continuously by one of these pistons 52, 94.

As shown in FIG. 4, two restoring springs 96, 98 are provided to restore the swing arm 66 and the swing arm 100 of the piston assembly 88 and the auxiliary valve to the starting position. Each swing arm 66, 100 alternately moves to its starting position, so that each piston 52, 94 also moves to its starting position. Restoration rings 96 and 98 are fixed around drive shaft 80 in drive box 50. Each of the restoring springs 96, 98 is provided with restoring arms 102, 104 and fixing fingers 106, 108. Once restoring springs 96, 98 are coupled to drive box 50, fingers 106, 108 are located in holes 110, 112 provided in swing arms 66, 100. As shown in FIG. 4, the drive shaft 80 is fixed to the inner circumference of the pair of drive sprags 114, and the outer circumference of the drive sprag 114 is fixed to the swing arm 100. The drive sprag 114 is set in a direction such that the swing arm 100 is driven by the piston 94 so that the rotational movement of the swing arm 100 can be transmitted to the drive shaft 80. During the restoring stroke, the drive sprag 114 rotates elastically so that the restoring spring 96 can restore the swing arm 100 to its starting position without transferring large energy to the drive shaft 80. Make sure

An anti-backlash sprag 116 is fixed to the drive shaft 80 between the swing arms 66 and 100 to further transmit rotational energy between the swing arms 66 and 100 and the drive shaft 80. Decrease. As shown in FIG. 4, the anti-backlash sprag 116 is coupled to the drive box 50 in the drive shaft opening 118 provided in the drive box 50, between the swing arms 66 and 100.

The anti-backlash sprag 116 is fixed to the drive box 50 by welding or other similar fixing method. The anti-backlash sprag 116 is similar in structure to the drive sprag 114 but is coupled to the drive shaft 80 in an operating direction opposite to the drive sprag 114. Thus, when the swing arm 100 is in the drive stroke, the drive sprags 114 transmit rotational energy of the swing arm 100 to the drive shaft 80. During this drive stroke, the anti-backlash sprag 116 is in its "freewheel" direction, allowing the drive shaft 80 to rotate freely. Once the swing arm 100 has finished its drive stroke, the restoring spring 96 restores the swing arm 100 to its starting position. As the restoring spring 96 rotates the swing arm 100, the drive sprags 114 are in the "elastic rotation" direction, thereby transferring rotational energy from the swing arm 100 to the drive shaft 80. Limited to reduce the deflection of the restoring spring 96.

As shown in FIG. 5, the anti-backlash sprag 116 is provided with an outer race 120 and an inner race 122. Both the outer race 120 and the inner race 122 are preferably made of hardened steel to increase the life of the anti-backlash sprag 116. The outer race 120 is formed with an inner annular contact surface 124. The outer race 120 is also provided with an exterior surface 126, which is fixed to the drive housing 50 as shown, by welding or other method (FIGS. 4 and 5). As shown in FIG. 5, the inner race 122 is provided with an inner annular surface 128 with a key for connection with the drive shaft 80, which is similarly provided from the drive shaft 80. A keyed face (not shown) may or may not be formed, which facilitates torque transfer to the inner race 122. The inner race 122 may also be provided with an outer annular contact surface 130.

A sprag assembly 132 is provided between the outer race 120 and the inner race 122 (FIG. 5). As shown in FIG. 5, the sprag assembly 132 includes a sprag retainer 134, a pair of coil springs 136, and a plurality of sprags 138. When the sprag assembly 132 is removed from the anti-backlash sprag 116, the coil spring 136 causes the sprag 138 to be biased to an upright position. However, when the sprag 138 is in the upright position, there is not enough distance between the outer race 120 and the inner race 122 to sandwich the sprag assembly 122. Thus, the sprag 138 must be tilted slightly so that the anti-backlash sprag 116 can be assembled. Each sprag 138 is formed with a body 140 for contacting the outer annular contact surface 130 of the inner race 122 and a head 142 for contacting the inner annular contact surface 124 of the outer race 120. It is desirable to be. The body 140 is preferably slightly wider and narrower than both the opening 144 and the head 142 provided in the sprag retainer 134. The width of the body 140 prevents the sprag 138 from falling out of the sprag retainer 134. The length of the body 140 provides sufficient clearance for placing the coil spring 136 between the body 140 and the side wall 146 of the sprag retainer 134. Because the body 140 is shorter than the head 142, the coil spring 136 can bias the overhanging portion 148 of the head 142 outwards, thus biasing the sprag 138 to its upright position. Can be biased.

When the anti-backlash sprag 116 is fully assembled, the sprag assembly 132 lies in the outer race 124 and the inner race 122 lies in the sprag assembly 132 (FIGS. 4 and 5). . Thus the inner race 122 can rotate relative to the outer race 120 in a first direction (counterclockwise as shown), which will cause the sprag 138 to tilt from its upright position. Because it can. Thus, the drive shaft 80 fixed to the inner race 14 can freely rotate counterclockwise with respect to the anti-backlash sprag 116, which rotation causes the sprag 138 to move away from its upright position. . Conversely, if an attempt is made to rotate the drive shaft clockwise, the coil spring 136 biases the sprag 138 toward its upright position, thus biasing the torsional force of the inner race 122 to the outer race 120. To pass). Since the outer race 120 is welded to the drive box 50, clockwise rotation of the drive shaft 80 is prevented by the anti-backlash sprag 116.

The anti-backlash sprag 116 prevents any further rotation of the drive shaft in the swing arm 100 recovery direction. If the friction between the drive sprag 114 and the drive shaft 80 is large enough to transfer the amount of rotational energy from the drive sprag 114 to the drive shaft 80 during the restoring stroke of the swing arm 100, the backlash The prevention sprag 116 prevents the rotation of the drive shaft 80. Since the anti-backlash sprag 116 is welded to the drive box 50, any " backward " rotational energy of the drive shaft 80 is transmitted to the drive box 50 so that the drive shaft 80 can swing the swing arm ( 100) Prevent rotation in the recovery direction.

The anti-backlash sprag 116 prevents rearward rotation of the drive shaft 80 until one of the swing arms 66, 100 in the drive stroke starts to rotate the drive shaft 80. In this way, the anti-backlash sprag 116 allows the drive shaft 80 to rotate in only one direction.

To operate the variable drive motor 10 of the present invention, the shaft rotator 42 is operated to rotate the valve shaft 16 in the hollow cylinder 14. The fluid pressure generator 82 is then operated to provide pressurized fluid, such as steam, to the first fluid inlet 18 and the auxiliary valve and piston assembly 88. The valve shaft 16 is thus rotated at a constant speed. When fluid is applied to the first fluid inlet 18 at low pressure, only a small amount, as the first slot 26 communicates the fluid between the first fluid inlet 18 and the first fluid outlet 20. Of fluid enters the drive cylinder 58. Introducing fluid into the drive cylinder 48 causes the piston 52 to move away from the valve housing 12. As the swing arm 66 rotates, the eyelet 62 of the piston rod 60 pivots slightly as the swing arm 66 reciprocates. In order to reduce the amount of tilting, the piston 52 is arranged to tilt slightly in both the starting position and the ending position. This reduces the degree of tilt when the piston 52 is at the center of the full stroke. The swing arm 66 and the piston rod 60 are designed with a length sufficient to place the piston 52 in the starting position so that the piston 52 is tilted 2 ° from the normal with respect to the central axis of the drive cylinder 48. Lose.

In order to examine how the piston 52 is tilted, it is preferable to inspect the full stroke of the piston 52. As the drive cylinder 48 begins to fill with fluid, the piston 52 moves toward the swing arm 66, pushing the swing arm 66 away from the valve housing 12 and thus starting to rotate. As the swing arm 66 rotates, the piston rod 60 pivots within the yoke 64 of the swing arm 66. The piston 52 pivots until it is in a normal direction with respect to the central axis of the drive cylinder 48. This occurs when the piston 52 is at one quarter of its previous stroke.

As more fluid enters the drive cylinder 48, the piston 52 begins to pivot from the drive shaft 80 until half of the full stroke, as shown in FIG. 1. At this point, the piston 52 is 2 ° away from the normal with respect to the axis of the drive cylinder 48, but is opposite the 2 ° direction of the starting point. As the drive cylinder 48 continues to fill the fluid, the swing arm 66 rotates further until the piston 52 reaches three quarters of the previous stroke. At this point, the swing arm 66 is sufficiently rotated so that the piston 52 is again normal to the central axis of the drive cylinder 48. As the drive cylinder 48 continues to be filled with fluid, the swing arm 66 continues to rotate, and the piston 52 moves toward a position 2 ° away from the normal to the central axis of the drive cylinder 48. This 2 ° incline is in the same direction as 2 ° away from the normal direction of the piston 52 at the start of the full stroke. At full fluid pressure, this previous stroke occurs each time fluid is brought into the first fluid inlet 18 and the first fluid outlet (FIG. 3).

Thus, in the starting position, the piston 52 is directed in the normal direction to the central axis of the drive cylinder 48, and as the swing arm 66 rotates through its cycle, the piston 52 rotates through a large angle, The position is 2 degrees away from the normal position with respect to the starting position. In this way the piston 52 starts at a position 2 ° away from the normal, 2 ° away from the normal position, 2 ° away from the opposite normal position, and 2 ° from the normal at the same position as the starting position finally through another normal position. Circulated to a remote location. Therefore, the total amount of deviation from the normal position is kept to a minimum throughout the entire stroke.

The variable stroke motor 10 can be cycled with the full stroke described above, but the full stroke is realized only under full fluid pressure. When only a small amount of pressure is applied to the first fluid input 18, the piston 52 moves in a much smaller stroke cycle. As the pressure of the fluid provided by the hydraulic generator 82 increases, a larger amount of fluid is driven from the first fluid input 18 through the first fluid output 20 at each rotation of the valve shaft 16. Is transmitted to the cylinder 48. This large amount of fluid entering the drive cylinder 48 moves the piston 52 faster, resulting in longer and longer strokes. Swing arm 66 transforms this long stroke into a large rotation of drive shaft 80. Since the axial rotor 42 rotates the valve shaft 16 at a constant speed, each cycle takes the same time regardless of the pressure of the fluid applied. Thus, greater rotation of the drive shaft 80 at the same time means faster speed of the drive shaft 80.

For each rotation of the valve shaft 16, a second slot 28 provided on the valve shaft 16 momentarily connects fluid communication between the second fluid input 22 and the second fluid output 24 (FIG. One). During this period, the force of the return spring 96 causes the swing arm 66 to push the piston rod 60 to the piston 52, thereby driving fluid from the drive cylinder 48 to the second fluid input 22 and to the second. 2 Push out through the fluid output (24). The fluid is then returned to the hydraulic generator 82 through the auxiliary delivery hose 86, and the fluid is again compressed and recycled through the motor 10 (FIG. 2). As the piston 52 is driven, the auxiliary valve and piston assembly 88 work in a reciprocating manner to drive the drive shaft 80 when the piston 52 returns to stroke. As described above, the anti-backlash sprag 116 prevents the swing arms 66 and 100 from transmitting rotational energy to the drive shaft 80 during the return stroke.

Since the valve shaft 16 rotates at a constant speed, adjusting the amount of hydraulic pressure flowing into the first fluid input 18 causes the piston 52 to travel a longer distance, thereby further driving the drive shaft 80 during the same interval. Drive a lot of distance. The hydraulic generator 82 may be provided with a heat regulation control 150, such as a propane valve, to change the amount of heat delivered to the hydraulic generator 82, thereby changing the pressure of the fluid. Accordingly, the variable stroke motor 10 can directly convert a large amount of thermal energy into faster rotation of the drive shaft 80.

The foregoing description and drawings merely illustrate and illustrate the invention, and the invention is not limited thereto, unless the claims are equally limited, and those skilled in the art, having understood the disclosure, Modifications and variations can be made without departing from the scope.

For example, any number of auxiliary valves and piston assemblies may be coupled to drive shaft 80, and it is foreseeable that a wide range of dimensions may be applied to the fluid input and fluid output of the valve housing and the slots in the valve shaft.

Claims (8)

In the drive shaft assembly, (a) housing; (b) the drive shaft, (c) a first overrunning clutch assembly, (i) a first inner race having a first outer annular contact surface; (ii) a first outer race having a first inner annular contact surface radially spaced from the first inner race, the first inner annular contact surface and the first outer annular contact surface forming a first annular space therebetween; ; (iii) a plurality of first sprags provided in the first annular space, the plurality of first sprags allowing the first inner race to rotate in a first direction relative to the first outer race while the inner Rotation of the race in a second direction with respect to the first outer race has a structure and arrangement which can be prevented; (iv) first sprag retaining means for retaining the plurality of first sprags in the first annular space; It includes a first overrunning clutch assembly comprising a, (d) the housing is secured to the first outer race; (e) the drive shaft is fixed to the first inner race; (f) means further coupled to the drive shaft for driving the drive shaft; (g) the drive means is coupled to the drive shaft by a second overrunning clutch, and the second overrunning clutch is (i) a second inner race having a second outer annular contact surface; (ii) a second outer race having a second inner annular contact surface radially spaced from the second inner race, the second inner annular contact surface and the second outer annular contact surface forming a second annular space therebetween; ; (iii) a plurality of second sprags provided in the second annular space, the plurality of second sprags allowing the second inner race to rotate in a first direction relative to the second outer race while the first The rotation of the second inner race in the second direction with respect to the second outer race has a structure and arrangement which can be prevented; (iv) second drive sprag retaining means for retaining the plurality of second sprags in the second annular space; It is made, including (v) the second overrunning clutch is coupled to the drive shaft to transmit a rotational movement of the drive means to the drive shaft via the second overrunning clutch; and (h) the first overrunning clutch and the second overrunning clutch are secured to the drive shaft in opposite overrunning directions. The drive shaft assembly of claim 1, wherein the drive means comprises a swing arm. 3. The driveshaft assembly of claim 2 wherein the swing arm is pivotally coupled to the piston. 4. The drive shaft assembly of claim 3, further comprising means for reciprocating the piston. The method of claim 4, wherein the reciprocating means, (a) a valve housing, (i) a hollow cylinder; (ii) a first fluid inlet in fluid communication with the hollow cylinder; (iii) a first fluid outlet in fluid communication with the hollow cylinder; (iv) a second fluid inlet in fluid communication with the hollow cylinder; (v) a second fluid outlet in fluid communication with the hollow cylinder; A valve housing forming a; (b) a valve shaft located within the hollow cylinder, the valve shaft being in a first position substantially blocking fluid communication between the first fluid inlet and the first fluid outlet, the second fluid inlet and the second Rotatable between second positions substantially blocking fluid communication between the fluid outlets, (c) the valve shaft is provided with a first slot and a second slot; (d) the first slot is oriented on the valve shaft to open fluid communication between the first fluid inlet and the second fluid outlet when the shaft is in the first position, (e) the second slot is oriented on the valve shaft to open fluid communication between the first fluid input and the first fluid output when the valve shaft is in the second position, (f) means coupled to said valve shaft for rotating said valve shaft between said first and second positions. 6. The drive shaft assembly of claim 5, further comprising means for biasing the piston to push fluid from the drive cylinder. 7. The drive shaft assembly of claim 6, wherein the biasing means is a spring. An anti-backlash drive device for a drive shaft, (a) a variable stroke motor, (i) a. piston; b. A piston rod having one end connected to the piston; And c. A swing arm connected to the other end of the piston rod; A drive cylinder comprising a; (ii) valve means for supplying fluid at a desired interval to the drive cylinder to drive the piston in one direction during a drive stroke; (iii) biasing means for urging said piston in a direction opposite to said one direction in a return stroke; Variable stroke motor having a; (b) coupling to the drive shaft and the swing arm to transfer rotational energy from the drive cylinder to the drive shaft during the drive stroke of the piston and to allow the shaft to inertia with respect to the swing arm during the return stroke; Drive sprag assembly; And (c) an anti-backlash sprag assembly fixed to the drive shaft in an opposite operating orientation with respect to the drive sprag assembly to prevent the drive shaft from rotating in the opposite direction to the drive direction during the drive stroke during the return stroke. Anti-backlash drive device comprising a.