JP2001349348A - Two-way differential clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-way differential clutch being high in reliability. SOLUTION: Holders 11 and 12 different in a diameter are incorporated between a rotary shaft 4 and an input gear 5 the holder 11 on the large diameter side is fixed to the input gear 5. Sprags 18 are incorporated is pockets 16 and 16 formed at the holder 11 on the large diameter side and the holder 12 on the small diameter side, respectively. A flange 22 and a ring groove 23 are situated at and formed in the end part of the holder 12 on the small diameter side, a and a friction disc 24 situated on one side of the flange 22 is pressed against the flange 22 by an elastic member attached in the ring groove 23. The elastic member to press the friction disc 24 forms a coned disc spring 25, a change in a rotation speed and switching of a rotation direction prevents dislocation of the elastic member from a mounting position, and reliability of the two-way differential clutch is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-way differential clutch using sprags.

[0002]

2. Description of the Related Art In a part-time type four-wheel drive vehicle, an overrunning type two-way differential clutch for automatically transmitting a driving force to a front wheel when a rear wheel slips and a speed is reduced is used. I have.

[0003] Japanese Patent Application Laid-Open No. 9-25959 discloses an overrunning type two-way differential clutch using sprags. This two-way differential clutch incorporates two cages having different diameters between an outer peripheral surface of a rotating shaft and an inner peripheral surface of an input gear provided on the rotating shaft. , And the small-diameter retainer is rotatably supported with respect to the rotation shaft. The frictional resistance applied to the small-diameter retainer allows the large-diameter retainer and the small-diameter retainer that rotate together with the input gear to rotate. A speed difference is generated between them, and the sprags, which are installed across the pockets of both cages, are tilted until the standby state where both ends contact the outer peripheral surface of the rotating shaft and the inner peripheral surface of the input gear. When the shaft rotation speed falls below the input gear rotation speed,
The sprags are engaged to transmit the rotation of the input gear to the rotating shaft.

In the two-way differential clutch, when the rotation direction of the input gear is switched, the inclination direction of the sprag is also automatically switched, so that both forward and reverse rotations of the input gear can be transmitted to the rotating shaft. it can.

Here, as resistance applying means for applying rotational resistance to the small-diameter side cage, a flange is provided on an outer periphery of an end portion of the small-diameter side cage that protrudes outward from a side surface of the input gear, and one side of the flange is provided. In many cases, a method is adopted in which the friction plate provided on the small-diameter side retainer is movably supported in the axial direction, and the friction plate is pressed by an elastic member and pressed against the flange.

[0006]

In the above-described two-way differential clutch, a band-shaped steel plate having a rectangular cross section is formed as a resilient member for pressing the friction plate into a ring shape so that both side edges are corrugated. When using a molded scrowave spring, the scrowave spring expands in diameter and deviates from the mounting position when the rotating shaft rotates at high speed or when the rotating shaft rotates in the direction opposite to the winding direction of the scrowave, and the two-way difference There is a possibility that the dynamic clutch becomes inoperable.

In order to prevent the above-mentioned inconveniences from occurring, it is necessary to separately provide a restricting means for restricting the diameter expansion of the scroll wave spring, which complicates the configuration and requires time for assembling the scroll wave spring. Take it.

An object of the present invention is to provide a highly reliable two-way differential clutch which can completely prevent the elastic member pressing the friction plate against the flange of the small diameter side retainer from falling off. .

[0009]

In order to solve the above-mentioned problems, according to the present invention, an input gear and an output gear are provided on a rotating shaft, and an outer periphery of the rotating shaft and an inner periphery of the input gear are provided. Two cages with different diameters were incorporated into the small diameter side cage, a flange was provided on the outer periphery of the end protruding outward from the side surface of the input gear of the small diameter side cage, and one side of this flange was prevented from rotating with the stationary member. A friction plate and an elastic member that presses the friction plate against the flange are provided, and the relative rotation of the small-diameter retainer to which the rotational resistance is given by the friction plate and the large-diameter retainer that rotates together with the input gear causes the friction plate to rotate. In a two-way differential clutch in which a sprag incorporated across a pocket of a retainer is tilted until both ends thereof come into contact with an outer peripheral surface of a rotating shaft and an inner peripheral surface of an input gear, As serial elastic member is to that the configuration using the disc spring having a plurality of slits in the circumferential direction of the smaller diameter end.

[0010] Here, the stationary member refers to a fixed member such as a gear case in which the rotating shaft is incorporated.

Further, in the present invention, a torque transmission mechanism for transmitting rotation of the rotation shaft to the output gear is provided between the rotation shaft and the output gear, and play in the rotation direction is formed in the torque transmission mechanism. A sub-gear that stops a friction ring provided on one side of the output gear with respect to a rotation shaft, and generates a differential speed corresponding to the rotation of the output gear on the outer periphery of the friction ring; An elastic member for pressing the sub-gear against a flange provided on the outer periphery of the friction ring is attached, and as the elastic member, a disc spring having a plurality of slits formed in the circumferential direction at the small-diameter end is used.

As described above, the elastic member for pressing the friction plate against the flange to apply frictional resistance to the small diameter side retainer and the elastic member for pressing the sub-gear against the flange of the friction ring to apply frictional resistance to the sub-gear. By using the spring, even if the rotating shaft rotates at a high speed or the rotation direction is switched, the disc spring is always held at the mounting position, and a highly reliable two-way differential clutch can be obtained.

Here, as the disc spring, the cross-sectional shape is a straight line, a straight tapered tube portion, and a curved line having a circular arc cross-section having a concave curved outer surface and smoothly continuing to the small diameter end of the linear tapered tube portion. When a disc spring having a tapered tube portion and a slit formed in the curved tapered tube portion is used, the disc spring forms a flat region in which the load is substantially constant in a deflection-load curve. For this reason, by incorporating the above-mentioned disc spring with a deflection amount in the flat region, a substantially constant frictional force can be applied to the small diameter side retainer and the sub gear without being affected by the dimensional error of the disc spring and the variation of the mounting position. And the two-way differential clutch can be operated with extremely high accuracy.

In order to form a substantially constant flat region in the disc spring, the slit is preferably formed from the small-diameter end of the curved tapered cylinder to the boundary of the linear tapered cylinder.
In addition, it is preferable that the rigidity of the linear tapered cylindrical portion is higher than the rigidity of the curved tapered cylindrical portion.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a bearing 3 is mounted on the opposing side wall 2 of the gear case 1, and an input gear 5 and an output gear 6 are provided on a rotating shaft 4 whose both ends are rotatably supported by the bearing 3. Is provided.

The input gear 5 is rotatably supported by a bearing 7 attached to the rotating shaft 4 and meshes with a drive gear 8 so that rotation is transmitted from the drive gear 8.

Between the cylindrical inner peripheral surface 9 of the input gear 5 and the cylindrical outer peripheral surface 10 of the rotating shaft 4, two retainers 11, 12 having different diameters are incorporated.

The large-diameter cage 11 is fixed to the input gear 5, while the small-diameter cage 12 is rotatably supported by the rotating shaft 4 via a bearing 13. The pin 14 attached to the small-diameter retainer 12 is inserted into a circumferentially long pin hole 15 formed in the large-diameter retainer 10 within a range where the pin 14 abuts both ends of the pin hole 15. The large-diameter side cage 11 and the small-diameter side cage 12 can rotate relative to each other.

A plurality of pockets 16 and 17 are formed in each of the large-diameter side cage 11 and the small-diameter side cage 12 at equal intervals in the circumferential direction so as to straddle the radially opposed pockets 16 and 17. A sprag 18 is incorporated.

As shown in FIG. 8, the sprags 18 are pressed from both sides by elastic members 19 attached to the small diameter side retainer 12. By the pressing, the sprags 18 are held in a neutral state in which the cam surfaces 20 and 21 at the outer and inner ends are disengaged from the cylindrical inner peripheral surface 9 and the cylindrical outer peripheral surface 10.

A flange 22 and a ring groove 23 on one side are provided on the outer periphery of an end of the small diameter side retainer 12 facing outward from the side surface of the input gear 5. Flange 2
The friction plate 24 provided on one side of the pair 2 is pressed against the flange 22 by pressing a disc spring 25 as an elastic member attached to the ring groove 23.

The disc spring 25 is made of a press-formed product of a steel plate. As shown in FIG. 3 and FIG.
A curved tapered cylindrical portion having a straight cross-sectional shape and a curved tapered cylindrical portion having an arcuate cross-section having a concave outer surface; A plurality of slits 25c are formed in the small-diameter end of the portion 25b at intervals in the circumferential direction. The slit 25c reaches the boundary of the linear tapered cylindrical portion 25a, and a tongue piece 25d is provided between the adjacent slits 25c.

In the illustrated example, the curved tapered tubular portion 25b is directly connected to the straight tapered tubular portion 25a. However, an arc portion having a larger radius of curvature than the curved tapered tubular portion 25b is provided between both tubular portions. The curved tapered tube portion 25b may be smoothly continuous with the linear tapered tube portion 25a.

In the disk spring 25 having the above structure,
The main deformation is controlled by the tongue piece 25d. In order to make the tongue pieces 25d more easily deformed, each tongue piece 25d is provided with an auxiliary slit 25e shorter than the slit 25c.

As a material of the disc spring 25, spring steel, for example, SK5 is used. In addition to the SK material, other materials such as S60C and SUS for mechanical structure may be used. The plate thickness is preferably about 0.2 to 1.0 mm. If it exceeds 1.0 mm, the spring load becomes excessive, and if it is 0.2 mm or less, an appropriate friction resistance cannot be provided between the flange 22 of the small diameter side retainer 12 and the friction plate 24.

FIG. 5 shows the disc spring 25 shown in FIGS.
FIG. 4 is an actual measurement diagram of a deflection amount-spring load curve of FIG. Here, the dimensions of each part of the disc spring 25 are as follows. Outer diameter D _{1 at the} large diameter end = 52 mm Outer diameter D ₂ at the small diameter end = 42 mm Pitch P of slit 25c = 30 ° Width W of slit 25c = 3 mm Taper angle α of linear tapered cylindrical portion 25a = 25 ° Curved taper The radius of curvature r of the cylindrical portion 25b is 2 mm. As shown in the deflection amount-spring load curve shown in FIG. 5, the disc spring 25 has a flat region A in which the spring load is substantially constant within a range of the deflection amount of approximately 2 to 4 mm. Have. Disc spring 25
Are attached to the ring groove 23 with the amount of deflection in the flat area A.

As shown in FIGS. 1 and 2, the friction plate 24
Is stopped by the gear case 1 as a stationary member by a rotation preventing mechanism 26 via the flange 22. Here, as the rotation preventing mechanism 26, a protruding piece 27 provided on the outer periphery of the flange 22 is engaged with a notch 29 of an engagement plate 28 attached to the inner surface of the gear case 1.

As shown in FIGS. 1 and 7, a torque transmitting mechanism 30 for transmitting the rotation of the rotating shaft 4 to the output gear 6 is provided between the rotating shaft 4 and the output gear 6. . The torque transmission mechanism 30 includes a torque transmission ring 31 between the outer peripheral surface of the rotating shaft 4 and the inner peripheral surface of the output gear 6.
The torque transmission ring 31 and the rotary shaft 4 are relatively prevented from rotating by a spline 32, and a projection 33 provided on the outer periphery of the torque transmission ring 31 is formed on the inner peripheral surface of the output gear 6. Inserted into the notch 34, a play δ in the rotational direction is provided between the notch 34 and the protrusion 33, and the rotation of the rotary shaft 4 is controlled by the engagement between the protrusion 33 and the end face of the notch 34. I'm trying to tell 6.

A friction ring 35 is provided on one side of the output gear 6. The friction ring 35 is prevented from rotating with respect to the rotation shaft 4 by the spline 32.

A flange 36 is provided on the outer circumference of the friction ring 35.
And a ring groove 37. A sub gear 38 is provided on one side of the flange 36. Sub gear 38
Is rotatably supported by a friction ring 35, and the number of teeth formed on the outer periphery thereof is smaller than the number of teeth formed on the outer periphery of the output gear 6. Each of the output gear 6 and the sub gear 38 meshes with a wheel-side gear 39, and when the output gear 6 and the sub-gear 38 are rotated from the wheel-side gear 39, the sub gear 38 is separated from the output gear 6 by a difference in the number of teeth. It rotates at a low speed.

The sub gear 38 is pressed against the flange 36 by a disc spring 40 as an elastic member attached to the ring groove 37 of the friction ring 35.

Here, the disc spring 40 presses the friction plate 24 against the flange 22 of the small diameter side retainer 12.
5 and the structure is the same as that of the disc spring 25, and a description thereof will be omitted.

Now, when the rotation is transmitted from the drive gear 8 to the input gear 5 shown in FIG. 1, the small diameter side retainer 12 to which the rotational resistance is given by the friction plate 24 and the inner peripheral surface of the input gear 5 are fixed. A rotation speed difference occurs between the large-diameter cage 11 and the large-diameter cage 11. For this reason, a gap is generated in the inner circumferential direction between the pocket 16 provided in the large diameter side cage 11 and the pocket 17 formed in the small diameter side cage 12, and both pockets 1 are formed.
The sprags 18 installed so as to straddle 6 and 17 tilt in the rotation direction of the input gear 5.

For example, when the input gear 5 rotates in the direction indicated by the arrow in FIG. 8, the sprag 18 falls down to the left side in the figure, and the cam surfaces 20 and 21 at both ends are connected to the inner peripheral surface 9 of the input gear 5 and the rotating shaft. 4 comes into contact with the outer peripheral surface 10 to enter a standby state where the clutch is established.

Here, when the part-time type four-wheel drive vehicle is traveling by two-wheel drive, rotation from the front wheels (driven wheels) is transmitted to the rotating shaft 4 so as to be in the same direction as the rotation direction of the input gear 5. The sprags 18 are not engaged with the inner peripheral surface 9 of the input gear 5 and the outer peripheral surface 10 of the rotating shaft 4 because the rotational speed is set to rotate faster than the rotational speed of the input gear 5. The rotation of the input gear 5 is not transmitted to the rotation shaft 4.

The rotational speed of the driven shaft of the four-wheel drive vehicle slips and the rotational speed of the driven wheel decreases or stops, and the rotational speed of the rotary shaft 4 rotated by the rotation transmission from the driven wheel changes the rotational speed of the input gear 5. When the rotation speed is lower than the rotation speed, the sprags 18 engage with the inner peripheral surface of the input gear 5 and the outer peripheral surface of the rotating shaft 4, and the rotation of the input gear 5 is transmitted to the rotating shaft 4. The rotation of the rotating shaft 4 is transmitted to the output gear 6 via the torque transmission mechanism 30, and the driven wheels are driven.

When the traveling direction of the vehicle is switched from forward to backward from the above state, the input gear 5 is stopped and then reversed, so that the large-diameter cage 1 is rotated.
1 and the rotation speed difference between the small diameter side cage 12 and the sprag 1
8 is tilted in the opposite direction to the state shown in FIG. 8 and comes into contact with the inner peripheral surface 9 of the input gear 5 and the outer peripheral surface 10 of the rotating shaft 4.
If the rotation speed of the rotating shaft 4 is higher than the rotation speed of the input gear 5 in the contact state, the sprag 18 does not engage with the inner peripheral surface 9 and the outer peripheral surface 10, and the rotation of the input gear 5 is not transmitted to the rotating shaft 4. It will be.

However, when the rotation direction is switched, the output gear 6 and the sub gear 3
When the gear 8 is rotated, the sub gear 38 rotates at a lower speed than the output gear 6 due to the difference in the number of teeth between the gears 6 and 38. At this time, since the sub gear 38 is pressed against the flange 36 by the pressing of the disc spring 40, the rotating shaft 4 is braked, and the rotational speed of the sub gear 38 becomes lower than the rotational speed of the input gear 5 until the play δ of the torque transmission mechanism 30 disappears.

Therefore, the sprag 18 is engaged with the inner peripheral surface 9 and the outer peripheral surface 10 to establish a clutch, and the rotation of the input gear 5 is immediately transmitted to the rotating shaft 4 via the sprag 18.

As described above, when the rotation direction of the input gear 5 is switched, the rotating shaft 4 is decelerated by the frictional resistance acting on the contact portion between the sub gear 38 and the flange 36. Can be differential.

As shown in the embodiment shown in FIG. 1, an elastic member for pressing the friction plate 24 against the flange 22 formed on the small-diameter side retainer 12 and an elastic member for pressing the sub gear 38 against the flange 36 of the friction ring 35. By using the disc springs 25 and 40, the disc springs 25 and 40 do not come out of the ring grooves 23 and 37 even if the rotating shaft 4 rotates at a high speed or the rotation direction is switched.
Always held in the mounting position.

Therefore, the two-way differential clutch can be reliably operated, and a highly reliable two-way differential clutch can be obtained.

The disc springs 25 and 40 have a flat area where the load is substantially constant in the deflection-load curve, and the ring groove 2 has a deflection amount in the flat area.
Since the friction plates 24 and the sub gear 38 are pressed with a substantially constant pressing force without being influenced by the dimensional errors of the disc springs 25 and 40 and the mounting position, they are incorporated in the insides 3 and 37.

Therefore, a substantially constant frictional force can be applied to the small diameter side retainer 12 and the sub gear 38, and the two-way differential clutch can be operated with high accuracy.

[0045]

As described above, in the present invention, since the friction plate is pressed by the disc spring, the disc spring comes off from the mounting position due to a change in the rotation speed of the rotating shaft or a change in the rotation direction. There is no inconvenience, and a highly reliable two-way differential clutch can be provided.

Also, since the disc spring always presses the friction plate with a substantially constant pressing force without being influenced by the dimensional error of the disc spring or the variation of the mounting position, the fixed diameter side retainer has a constant friction. As a result, the two-way differential clutch can be operated with extremely high precision.

Further, a torque transmitting mechanism having a play in the rotating direction is provided between the output gear and the rotating shaft, and a differential gear corresponding to the rotation of the output gear is provided on the outer periphery of the friction ring rotating integrally with the rotating shaft. Provide a sub gear that generates speed,
By pressing this sub gear against a flange provided on the outer periphery of the friction ring by pressing a disc spring to impart rotational resistance to the rotation shaft, the two-way differential clutch can be used even when the rotation direction of the input gear is switched. It can be immediately activated.

[Brief description of the drawings]

FIG. 1 is a sectional view of a two-way differential clutch according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a front view of a disc spring incorporated in the two-way differential clutch shown in FIG. 1;

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is a diagram showing a deflection-spring load curve of the disc spring shown in FIG. 3;

FIG. 6 is a sectional view taken along the line VI-VI of FIG. 1;

FIG. 7 is a sectional view taken along the line VII-VII of FIG. 1;

8 is a sectional view taken along the line VIII-VIII in FIG.

[Explanation of symbols]

 Reference Signs List 4 rotating shaft 5 input gear 6 output gear 11 large-diameter side retainer 12 small-diameter side retainer 16, 17 pocket 18 sprag 22 flange 24 friction plate 25 disc spring 25a linear tapered tube portion 25b curved tapered tube portion 25c slit 34 Torque transmission mechanism 35 Friction ring 36 Flange 38 Sub gear 40 Disc spring δ play

Claims (6)

[Claims] An input gear and an output gear are provided on a rotating shaft, and two cages having different diameters are incorporated between an outer periphery of the rotating shaft and an inner periphery of the input gear. A flange is provided on the outer periphery of the end protruding outward from the side surface of the friction plate, a friction plate that is prevented from rotating with a stationary member on one side of the flange, and an elastic member that presses the friction plate against the flange is provided. By the relative rotation of the small-diameter retainer to which rotational resistance is given by the friction plate and the large-diameter retainer that rotates with the input gear, the sprags built across the pockets of both retainers In a two-way differential clutch configured to be tilted until it comes into contact with an outer peripheral surface of a rotating shaft and an inner peripheral surface of an input gear, the elastic member has a plate having a plurality of slits formed in a circumferential direction at a small-diameter end. A two-way differential clutch comprising a spring. 2. A torque transmitting mechanism for transmitting rotation of a rotating shaft to an output gear is provided between the rotating shaft and an output gear, and the torque transmitting mechanism has a play in a rotating direction. A friction ring provided on one side of the friction ring is prevented from rotating with respect to the rotation shaft, and a sub-gear that generates a differential speed corresponding to the rotation of the output gear on the outer periphery of the friction ring; Attach the elastic member that presses to the flange provided on the outer circumference,
2. The two-way differential clutch according to claim 1, wherein said elastic member comprises a disc spring having a plurality of slits formed in a circumferential direction at a small diameter side end. 3. A belleville spring for pressing the friction plate and a belleville spring for pressing the sub-gear have a flat area where a load is substantially constant in a deflection-load curve, and the deflection in the flat area. 3. The two-way differential clutch according to claim 2, wherein the two-way differential clutch is incorporated. 4. A disk spring for pressing the friction plate and a disk spring for pressing the sub-gear smoothly have a sectional shape linearly and linearly continuous with a tapered cylindrical portion and a small-diameter end of the linear tapered cylindrical portion. The two-way differential clutch according to claim 2, further comprising: a curved tapered cylindrical portion having an arcuate cross-section having an outer surface having a concave curved surface, wherein a slit is formed in the curved tapered cylindrical portion. . 5. The two-way differential clutch according to claim 4, wherein the slit is formed from a small-diameter end of the curved tapered tubular portion to a boundary portion of the linear tapered tubular portion. 6. The two-way differential clutch according to claim 4, wherein the linear tapered cylinder has higher rigidity than the curved tapered cylinder.