JPH04266622A - 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 surfaces by the relative rotation between the input shaft 2 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 holding equipment 6 is connected to a control shaft 12 through a pin 15, a rotating directional clearance is provided between a pin 21 connected to the control shaft and the input shaft 12, and a gear speed reducing mechanism 23 for decelerating the rotation of the input shaft 2 and transmitting it to the control shaft 12 is connected between the pin 21 and the input shaft 2. When the input shaft 2 is rotted, 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 sate, 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. 6, a rotation transmission device A consisting of a viscous coupling is installed between a drive shaft C branched from an engine transfer B and a front differential E provided on a front wheel D. intervene,
It is known that full-time four-wheel drive is achieved by absorbing the difference in rotation between the front and rear wheels using the internal resistance of a high viscous fluid in a viscous coupling.

However, viscous couplings that transmit rotational torque through the resistance of highly viscous fluid have poor torque transmission efficiency due to loss when resistance occurs, and also have low shear resistance with small rotational differences, which reduces the weight of automobiles. The disadvantage is that a sufficiently large torque cannot be transmitted.

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 a non-engaged position, and connects the retainer to a control shaft rotatably disposed on the same axis as the input shaft so that rotational force can be transmitted thereto, and The input shaft is connected to the gear reduction mechanism via a gear reduction mechanism, and a rotational clearance is provided at the connection portion between the control shaft or the input shaft and the gear reduction mechanism.

[0009]

[Operation] In the above structure, if the gear reduction mechanism is set to decelerate the rotation of the control shaft relative to the rotation of the input shaft, the rotation of the control shaft to be decelerated will be in the rotational direction of the coupling part relative to the input shaft. After a delay corresponding to the clearance, the retainer connected to the control shaft rotates relative to the input shaft. This movement of the retainer moves the engager 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 the input shaft side is decelerated 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.

As shown in FIG. 1, 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. There is.

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, an input flange member 17 having a mounting hole 18 is integrally fixed to the tip of the input shaft via a pressure-fitted spline 16. A control shaft 12 disposed on the central axis 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 21 is fixed to be inserted into the pin hole 20 with a rotational clearance 22, and a gear reduction mechanism 23 is provided between the tip of the connecting pin 21 and the input flange member 17.

This gear reduction mechanism 23 includes a sun gear 24 fixed to the input flange member 17, and a sun gear 24 fixed to the input flange member 17.
4, the sun gear 24 and the flange member 17
a shifted gear 25 rotatably attached to the shift gear 25, a fixed gear 28 formed on an external fixed member 27, and a plurality of planetary gears 26 that mesh with the sun gear 24 and shifted gear 25.
The number of teeth of the shifted gear 25 is set to be several teeth larger than that of the sun gear 24.

Further, an elastic member 29 is provided on the side surface of the shifted gear 25.
A rotating member 30 integrally connected to the connecting pin 21 is in sliding contact with the connecting pin 21 via the connecting pin 21 . Note that 31 and 31' are side plates for guiding the gear.

In the gear reduction mechanism 23 described above, when the sun gear 24 rotates integrally with the input flange member 17, the shifted gear 25 is rotated via the planetary gear 26. Since it has a large number of teeth, it rotates slower than the sun gear 24 accordingly. This rotational delay is transmitted to the control shaft 12 via the connecting pin 21, and the control shaft 1
2 is decelerated relative to the input shaft 2.

Further, the gap 32 in the circumferential direction created between the pin hole 19 provided in the input flange member 17 and the connecting pin 21 corresponds to the gap 32 in the circumferential direction between the pin hole 20 of the input shaft 2 and the connecting pin 21.
The rotational clearance 22 is set larger than the distance between the sprag 9 and the engagement surfaces 4 and 5 via the elastic member 10 from the neutral position. 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 rotation of the control shaft 12, which is decelerated by the gear reduction mechanism 23, is delayed, and the control retainer 6 rotates. It rotates relative to the input shaft 2 and fixed retainer 7 by the amount of directional clearance 22 . Both retainers 6,
7, the sprag 9 tilts in the opposite direction to the rotational direction (arrow) of the input shaft 2 as shown in FIG. 3, contacts the engaging surfaces 4 and 5, and enters the engaged state.

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 21 and pin hole 20 come into contact.
can be placed on standby in an engaged state.

In this state, if 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 the outer ring toward the outer ring 1, and the rotational torque from the outer ring 1 toward the input shaft 2 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 be in the engaged state. 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.

In order to install the rotation transmission device A of the above embodiment in a four-wheel drive vehicle in which the rear wheel F is the drive wheel as shown in FIG. and the outer wheel 1 is connected to a shaft on the front wheel axle D facing the front differential E.

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 4 and 5. 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.

The gear reduction mechanism shown in the above embodiment is just an example, and any gear mechanism can be used as long as it has the function of creating a rotational difference between the input shaft and the control shaft using gears. can.

[0035]

[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 rotational 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]

[Figure 1] Longitudinal front view of the example

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

[Figure 3] Enlarged cross-sectional view of main parts in Figure 2

[Figure 4] Cross-sectional view taken along line IV-IV in Figure 1

[Figure 5] Cross-sectional view taken along line V-V in Figure 1

[Figure 6] Diagram showing an example of installing a rotation transmission device on a car

[Explanation of symbols]

1 Outer ring 2 Input shaft 4, 5 Engagement surface 6, 7 Cage 8 Pocket 9 Sprag 10 Elastic member 12 Control axis 22 Rotation direction clearance 23 Gear reduction mechanism A Rotation transmission device

Claims (1)

[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 is connected to a control shaft rotatably disposed on the same axis as the input shaft, and the control shaft and the input shaft are connected via a gear reduction mechanism, and the control shaft or the input shaft and the gear reduction mechanism are connected. A rotation transmission device with a rotational clearance in the connecting part.