JPH04266623A - Rotation transmitting device - Google Patents

Abstract

PURPOSE:To provide a rotation transmitting device possible to mechanically conduct the transmission and change of a driving torque and control the transmitting direction of the torque only in one direction. CONSTITUTION:Engaging surfaces 4, 5 are formed on the opposed surfaces of an outer ring 1 and an input shaft 2, and a sprag 9 engaged with the engaging surface by the relative rotation between the input shaft and a retainer 6, and an elastic member for holding the sprag in neutral state are integrated into the pocket of retainers 6, 7 provided between both the engaging surfaces. The retainer 6 and the input shaft 2 are connected to a control shaft 12 through pins 15, 17, a rotating directional clearance is provided in the connecting part between the pin 17 and the input shaft 2, and a differential bearing 20 for decelerating the rotation of the control shaft 12 is connected to the top end of the pin 17. When the input shaft 2 is rotated, the rotation of the control shaft 12 is later than the input shaft 2 by the clearance portion of the connecting part, and the sprag 9 is laid in engaging operating state by the relative movement of the retainers 6, 7. When the rotation of the outer ring 1 is faster than the input shaft 2 in this state, the outer ring is overrun, and in the reverse case, the sprag is engaged with the engaging surfaces to transmit the torque to the outer ring.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation transmission device, and is used, for example, to switch between transmission and interruption of drive torque between the drive shaft and wheels of an automobile.

0002

[Prior Art and its Problems] When turning a corner in a car, the turning radius of the front wheels becomes larger than the turning radius of the rear wheels, so when turning a tight corner with the front and rear wheels directly connected, the front wheels trying to turn quickly will The vehicle slips, causing the phenomenon as if the brakes had been applied.

Due to this braking phenomenon, in conventional four-wheel drive vehicles, the driver disconnects the front and rear wheels when driving around tight corners or in urban areas, and switches between two-wheel drive and four-wheel drive depending on the driving condition. The problem was that it was necessary to use different drives, and switching operations were time-consuming.

On the other hand, as shown in FIG. 11, between the drive shaft C branched from the engine transfer B and the front differential E provided on the front wheels D,
It is known that full-time four-wheel drive is achieved by interposing a rotation transmission device A consisting of a viscous coupling and absorbing the difference in rotation between the front and rear wheels by the resistance inside the high viscous fluid in the viscous coupling.

However, viscous couplings, which transmit rotational torque through the resistance of high viscosity fluid, have poor torque transmission efficiency due to loss when resistance occurs, and also have low shear resistance with small rotational differences, which causes problems with the weight of automobiles. However, it has the disadvantage that it cannot transmit a sufficiently large torque.

In addition, in order to increase the transmitted torque, it is necessary to increase the area and number of disks that shear the highly viscous fluid, which results in a problem that the drive system cannot be made compact due to the large size. Since the shear resistance of the viscous fluid increases at low speeds, drag torque occurs when turning at low speeds, and there is also the drawback that the braking phenomenon at tight corners cannot be completely eliminated.

The present invention was made in view of the above-mentioned problems, and its purpose is to enable efficient torque transmission by mechanically switching between transmission and cutoff of drive torque, and to It is an object of the present invention to provide a rotation transmission device that transmits force in only one direction and absorbs rotation differences in the opposite direction, thereby enabling complete full-time four-wheel drive when applied to automobiles.

[0008]

[Means for Solving the Problems] In order to solve the above problems, the rotation transmission device of the present invention rotatably supports an input shaft inside an outer ring, and has an engager on a surface facing the outer ring and the input shaft. An engaging element is formed in a pocket of a retainer that forms an engaging surface and is rotatably provided between the two engaging surfaces, and that engages with both of the engaging surfaces by relative rotation of the input shaft and the retainer in forward and reverse directions. and an elastic member that holds the engager in an unengaged position, and the retainer and the input shaft are connected so that rotational force can be transmitted by a control shaft that is rotatably disposed coaxially with the input shaft. , a rotational clearance is provided between the control shaft and the input shaft, one of the control shaft or the input shaft is connected to the fixed member by a differential bearing, and the input shaft or the control shaft is connected to the differential bearing. The structure provides greater rotational resistance than the rotational resistance of the supporting portion.

[0009]

[Operation] In the above structure, when a differential bearing is connected to the control shaft and the input shaft is rotated, the rotation of the control shaft, which is decelerated by the rotational resistance of the differential bearing, is the rotation of the connecting part relative to the input shaft. After a delay corresponding to the directional clearance, the retainer connected to the control shaft rotates relative to the input shaft. Due to this movement of the retainer,
The engager moves to an engaged position where it contacts the engagement surface.

[0010] In this state, when a rotation difference occurs such that the input shaft rotates faster than the outer ring, the engager immediately engages with the engagement surface, causing the outer ring to rotate together with the input shaft.

Conversely, when the rotation of the outer ring becomes faster than the rotation of the input shaft, the outer ring overruns the engager, so the engager does not engage, and the outer ring and the input shaft rotate in a separated state. do. Therefore, the driving force is transmitted only in the direction from the input shaft to the outer ring, and rotation from the outer ring to the input shaft is blocked.

Note that the same effect as described above can be obtained even if a differential bearing is connected to the input shaft to create a speed difference between the input shaft and the control shaft.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings.

1 to 4 show a first embodiment. As shown in the figure, one end of the input shaft 2 is inserted into the outer ring 1, and the input shaft 2 is rotatably supported by two bearings 3, 3 installed between the two bearings.

Cylindrical engagement surfaces 4 and 5 are formed on the inner diameter surface of the outer ring 1 and the outer diameter surface of the input shaft 2 opposing thereto. A control cage 6 with a possible large diameter and a small diameter fixed cage 7 pinned to the input shaft 2 are incorporated.

A plurality of opposing pockets 8, 8 are formed on the circumferential surfaces of both retainers 6, 7, and each pocket 8
, 8 includes a sprag 9 as an engager and an elastic member 10.
is included. This sprag 9 is formed with an arcuate surface 11 having a center of curvature on the center line of the sprag on the outer diameter side and the inner diameter side.
5 to integrate the outer ring 1 and the input shaft 2. Also,
Normally, both sides of each sprag 9 are pressed by elastic members 10 supported by the control retainer 6, and the arcuate surfaces 11 are held in a neutral state in which they do not engage with the engagement surfaces 4, 5.

On the other hand, inside the input shaft 2, a control shaft 12 disposed on the central axis of the input shaft is rotatably supported via a pair of bearings 13, 13. A control retainer 6 is integrally fixed to the center of the control shaft 12 by a connecting pin 15 inserted into a pin hole 14 of the input shaft 2 with a gap in the circumferential direction.

Furthermore, an input shaft 2 is provided at the tip of the control shaft 12.
A connecting pin 17 inserted through the pin hole 16 on the tip side with a rotational clearance 18 is fixed, and a sleeve 19 press-fitted into the differential bearing 20 is integrally connected to the tip of the connecting pin 17. This rotational direction clearance 18 is set to be larger than the distance at which the sprag 9 contacts the engagement surfaces 4 and 5 via the elastic member 10 from the neutral position.

The differential bearing 20 is a single-row deep groove ball bearing, and the inner ring 21 fits into the sleeve 19, and the outer ring 22 has a fixing arm 23 connected to an external fixing member (not shown). is mated to. This differential bearing 20 is formed so that the outer ring is press-fitted into the fixing arm 23 to make the radial clearance of the bearing negative, and the rotational resistance during rolling becomes large. The rotational resistance is set to be greater than the rotational resistance of the bearings 3, 3 that support the input shaft 2, and a braking force is applied to the control shaft 12 connected to the connecting pin 17 so that the rotation is slower than the rotation of the input shaft 2.

Further, an input flange member 26 having a mounting hole 25 for the drive shaft is integrally fixed to the tip of the input shaft 2 via a press-fitted spline 24. The circumferential clearance 28 created between the pin hole 27 provided in the flange member 26 and the connecting pin 17 is set larger than the rotational clearance 18 between the pin hole 16 of the input shaft 2 and the connecting pin 17 described above. has been done.

In the rotation transmission device of the embodiment having the above structure, when the input shaft 2 rotates in one direction, the differential bearing 2
The rotation of the control shaft 12 decelerated by 0 is delayed, and the control retainer 6 rotates relative to the input shaft 2 and fixed retainer 7 by the rotational clearance 18 . Due to this relative movement between the retainers 6 and 7, the sprag 9 tilts in the opposite direction to the rotational direction (arrow) of the input shaft 2 as shown in FIG. 4, contacts the engagement surfaces 4 and 5, and engages. becomes active.

In this case, since the elastic member 10 attached to the control retainer 6 holds the sprag 9 in a pressed state,
All sprags 9 are removed before the connecting pin 17 and pin hole 16 come into contact.
can be placed on standby in an engaged state.

In this state, when a rotational difference occurs between the input shaft 2 and the outer ring 1 that causes the input shaft to speed up, the sprag 9 in the engagement operation state immediately engages the engagement surfaces 4 and 5. Then, the outer ring 1 and the input shaft 2 are rotated together.

Conversely, when the outer ring 1 rotates faster than the input shaft 2, the outer ring 1 overruns and the sprags 9 are contacted by the outer ring in the direction of being disengaged. Therefore, the sprag 9 does not engage with the engaging surfaces 4 and 5, and the outer ring 1 and the input shaft 2 continue to rotate in a separated state.

In this way, the driving force is transmitted in the input shaft 2.
There is only one direction from outer ring 1 to outer ring 1, and from outer ring 1 to input shaft 2.
Rotational torque directed toward is cut off.

On the other hand, when the input shaft 2 rotates in the opposite direction from the above-mentioned state, the retainer 6 rotates relative to the input shaft in the opposite direction, and the sprag 9 is tilted to become engaged. That is,
Since the inclination of the sprag 9 changes depending on the direction of rotation of the input shaft 2 and waits in the engaged state, rotational torque can be transmitted and interrupted in the same manner in both forward and reverse directions.

The rotation transmission device A of the above embodiment is shown in FIG.
To install it on a four-wheel drive vehicle in which the rear wheel F is the driving wheel as shown in Figure 2, the input shaft 2 is connected to the drive shaft C that is separated from the transfer B, and the outer wheel is connected to the shaft of the front wheel axle D that goes toward the front differential E. Connect 1.

In the above structure, when the vehicle is normally traveling straight, the rear wheels F are two-wheel drive, and the front wheels G rotate together with the rear wheels.
Since there is no difference in rotation between the input shaft 2 and the outer ring 1, the sprags 9 do not engage with each other, and the input shaft and the outer ring rotate separately.

Now, when the rear wheels slip and the vehicle speed decreases, the rotation of the drive shaft C exceeds that of the decelerating front wheels, so the input shaft 2 rotates faster than the outer wheel 1. Therefore, in the rotation transmission device A, the sprag 9 engages with the engagement surfaces 4 and 5, the torque of the drive shaft C is transmitted to the front wheel axle D, and the state is switched to a four-wheel drive state.

On the other hand, when switching to four-wheel drive mode while turning a tight corner, the outer wheel 1 tries to rotate faster than the input shaft 2 due to the movement of the front wheels trying to turn faster than the rear wheels, but in this state, Since the outer ring 1 overruns, the sprags 9 do not engage the engagement surfaces 5 and 6. Therefore, the movement of the front wheels is not restricted by the movement of the rear wheels, and no braking phenomenon occurs.

In this way, with the above structure, if the rear wheel, which is the drive wheel, slips while driving, the system automatically switches to four-wheel drive, and when the front wheels rotate faster than the rear wheels, such as when turning a tight corner, The overrunning of the outer wheel absorbs the difference in rotation between the front and rear wheels, allowing smooth and stable driving.

FIG. 5 shows a second embodiment. In this example, the differential bearing 31 is formed by two rolling bearings 32 and 33 arranged in parallel, and an axial preload is applied to the rolling bearings 32 and 33 by a thrust press plate 34 to create the necessary rotational resistance. giving.

By using multiple rolling bearings in this way, compared to the case where one bearing provides rotational resistance,
The resistance applied to each bearing can be reduced, allowing use at higher speeds. Note that the other structures are similar to those in the first embodiment, and the same parts are given the same reference numerals and explanations will be omitted.

FIG. 6 shows a third embodiment. In this example, the differential bearing 41 is one radial bearing, and its inner ring 4
2 is attached to the input flange member 26, and the outer ring 43 is fixed to the fixing arm 44. Further, a retainer 46 of a ball 45 incorporated between the inner and outer rings 42 and 43 and a rotating member 47 integrally connected to the connecting pin 17 are brought into sliding contact via a sliding member 48.

Furthermore, the differential bearing 41 has a radial clearance set close to zero, and a highly viscous lubricant such as traction grease is sealed inside to prevent slippage between the balls 45 and the retainer 46.

In the above structure, the outer ring 43 of the differential bearing 41
is fixed, the rotation of the cage 46 is reduced to about 1/2.5 compared to that of the inner ring 42. For this reason, a decelerating force is applied to the rotating member 47 that slides into contact with the retainer 46 to cause a rotation delay with respect to the input flange member 26, and the control shaft 1
2 is delayed compared to the input shaft 2.

FIG. 7 shows a fourth embodiment. In this example, the differential bearing 51 is formed by two rolling bearings 52 and 53 with different raceway diameters, and the balls 54 of both of them are
A retainer 55 is integrally formed to connect both bearings 52 and 53.

Further, the inner ring 52a of the bearing 52 on the small diameter side is fixed to the input flange member 26, the inner ring 53a of the bearing 25 on the large diameter side is rotatable relative to the flange member 26, and a side surface of the inner ring 53a is provided with a A rotating member 57 connected to the connecting pin 17 via an elastic member 56 is brought into sliding contact.

Further, as in the third embodiment, each of the rolling bearings 52 and 53 has a radial clearance set to zero or less, and traction grease or the like is sealed inside the ball 5.
4 is prevented from slipping and rotating relative to the retainer 55.

In the above structure, the input flange member 26
When rotates, the rotation is transmitted to the large diameter bearing 53 via the cage 55, but due to the difference in raceway diameter, the small diameter bearing 5
The rotation of the inner ring 53a of the large-diameter bearing 53 is slower than that of the inner ring 52a of No. 2. This rotational delay is transmitted to the connecting pin 17 via the pressing force of the elastic member 56, causing the control shaft 12 to lag behind the input shaft 2.

FIG. 8 shows a fifth embodiment, in which two rolling bearings 64 and 65 with different raceway diameters are installed in a space 63 provided in a fixing arm 62, with an inner ring and an inner ring, respectively. The outer rings are connected together and assembled in a multi-layered structure.

Furthermore, the retainer 66 of the bearing 64 on the small diameter side is fixed to the input flange member 26, and the rotating member 68 connected to the connecting pin 17 is brought into sliding contact with the retainer 67 of the bearing 64 on the large diameter side. There is. This rotating member 68 has elastic force and is in a state of being pressed against the retainer 67, thereby reducing the speed difference between the rotary member 68 and the retainer 67 due to slippage.

Note that 69 is a bearing for positioning the fixing arm 62 and the input flange member 26.

In the differential bearing 61 having the above structure, the input flange member 26 is connected to the retainer 6 of the small diameter bearing 64.
6 rotates, due to the difference in raceway diameter, the larger diameter bearing 65
Since the rotation of the retainer 67 is delayed compared to the retainer 66, the rotation delay is transmitted to the control shaft 12 via the rotating member 68 and the connecting pin 17.

In the fourth and fifth embodiments described above, the differential bearing may be constructed using three or more rolling bearings.

FIGS. 9 and 10 show a sixth embodiment,
In this example, a differential bearing is connected to the input shaft side. That is, one end of the control shaft 71 is integrally fixed to the input flange member 73 by screwing a nut 72, and the other end is rotatably supported by the input shaft 75 by a bearing 74.

Furthermore, the input flange member 73 and the input shaft 7
5 are connected via a spline 76 having a clearance in the rotational direction, and a differential bearing 77 is fitted to the outer peripheral surface of the input shaft 75. This differential bearing 77 has an outer ring forcibly press-fitted into a fixing arm 78 in the same way as in the first embodiment, and a rotational resistance greater than the resistance of the support portion of the control shaft 71 is obtained by preloading. This applies deceleration force to the input shaft 75.

Furthermore, the central part of the control shaft 71 and the connecting pin 1
A control retainer 79 connected through the sprag 5 is disposed on the inner diameter side of the sprag 9, and a fixed retainer 80 fixed to the input shaft 75 is disposed on the outer diameter side of the sprag 9.

In the above structure, the input flange member 73
When the control shaft 71 rotates, the control shaft 71 rotates as a unit, but the input shaft 75, which is decelerated by the differential bearing 77, is delayed in rotation by the rotational clearance of the spline 76. As a result, the control retainer 79 and the fixed retainer 80 rotate relative to each other, but since the control retainer 79 is on the inner diameter side, the sprag 9 is moved toward the input shaft 75.
is tilted in the opposite direction to the direction of rotation, and transitions to the engaged state.

In each of the embodiments described above, sprags were used as the engagers, but rollers may also be used.

[0051]

[Effect] As described above, the rotation transmission device of the present invention mechanically switches the transmission of drive torque by engaging the engager between the input shaft and the outer ring, so that efficient torque transmission can be performed. This allows for accurate torque transmission between the input and output sides.

Furthermore, since a rotation speed difference is created between the input shaft and the control shaft, and the engager is always kept in the engaged state, even if there is a slight difference in rotation between the input side and the output side, the engagement is immediately caused. Since the couplings engage and do not require large relative slips unlike viscous couplings that use high viscosity fluids, the rotation can be switched with good responsiveness.

Furthermore, when the rotation on the output side exceeds the rotation on the input side, the transmission of the rotation can be cut off by overrunning the outer ring, and the transmission direction of the drive torque can be controlled in only one direction. .

Therefore, if the rotation transmission device of the present invention is used in the drive unit of an automobile, braking will not occur even when turning a tight corner with four wheels directly connected, and two-wheel drive and four-wheel drive can be automatically switched. This makes it possible to achieve full-time direct-coupled four-wheel drive.

[Brief explanation of the drawing]

[Fig. 1] Longitudinal front view of the first embodiment

[Figure 2] Cross-sectional view taken along line II-II in Figure 1

[Figure 3] Cross-sectional view taken along line III-III in Figure 1

[Figure 4] Figure 2
Enlarged cross-sectional view of main parts

[Fig. 5] Longitudinal front view of the second embodiment

[Fig. 6] Vertical front view of the third embodiment

[Fig. 7] Longitudinal front view of the fourth embodiment

[Fig. 8] Longitudinal front view of the fifth embodiment

[Fig. 9] Vertical front view of the sixth embodiment

[Fig. 10] Cross-sectional view taken along line X-X in Fig. 9

[Fig. 11] A diagram showing an example of mounting a rotation transmission device on a car.

[Explanation of symbols]

1 Outer ring 2, 75 Input shaft 4, 5 Engagement surface 6, 79 Control retainer 7, 80 Fixed retainer 8 Pocket 9 Sprag 10 Elastic member 12, 71 Control shaft 18 Rotational direction clearance 20, 31, 41, 51, 61, 77 Differential bearing 46
, 55, 66, 67 Cage A Rotation transmission device

Claims (2)

[Claims] [Claim 1] An input shaft is rotatably supported inside an outer ring, an engaging surface of an engager is formed on the opposing surface of the outer ring and the input shaft, and a rotatable member is provided between the two engaging surfaces. Incorporating in the pocket of the retainer an engager that engages with both of the engagement surfaces by relative rotation of the input shaft and the retainer in forward and reverse directions, and an elastic member that holds the engager in a non-engaged position. The retainer and the input shaft are connected so that rotational force can be transmitted by a control shaft that is rotatably arranged on the same axis as the input shaft, and a clearance in the rotational direction is provided at the connection portion between the control shaft and the input shaft, and A rotation transmission device in which one of a control shaft or an input shaft and a fixed member are connected by a differential bearing, and a rotational resistance greater than the rotational resistance of a support portion of the input shaft or control shaft is imparted to the differential bearing. 2. The rotation transmission device according to claim 1, wherein the differential bearing includes a plurality of rolling bearings having different raceway diameters, and a retainer of a rolling element of each rolling bearing is used as a rotational resistance extraction member.