JPH09144770A - Cone clutch and differential gears therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve clutch seizure resistance by providing a plurality of contact parts consisting of partial elliptic shape in the peripheral direction, and forming a non-contact part in the middle of it. SOLUTION: In a cone clutch serving as the differential limit mechanism of a differential device, right and left cone parts 17, 17 are provided, in a shaft right-angled cross-section, with two contact part 17a consisting of elliptic long- diameter shape in the peripheral direction, and its top part 17c comes into contact with a facing conical surface on differential case side. A small-diameter part 17b in the middle of respective contact parts 17a comes into no contact. The top part 17c of the cone part 17 has no edge part, and while the cone clutch is sliding, it is connected to the small-diameter part 17b smoothly, thus facilitating introduction of lubricating oil into the large-diameter part from the small-diameter part of the cone part 17. The cone part 17 is elliptic, therefore, the top part 17c comes into smooth slide contact. Lubricating oil is apt to enter the top part 17c easily, therefore, it is possible to provide good oil film formation and improve seizure resistance of the cone clutch.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cone clutch and a differential device including the cone clutch as a differential limiting mechanism.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 47-10484 discloses a differential device 201 as shown in FIG.
The differential device 201 is a differential case 20.
3 is a bevel gear type differential mechanism 213 including a pinion shaft 205 fixed to No. 3, a pinion gear 207 rotatably supported on the pinion shaft 205, and a pair of side gears 209 and 211 meshing with the pinion gear 207. A pair of cone clutches 2 for motion limitation
15, 217 etc. are provided.

The cone clutches 215 and 217 are formed between a pair of clutch members 219 and 221 and the differential case 203, and these clutch members 219 and 221.
The side gears 209, 211 together with the axles 223, 22
5 is splined so as to be movable in the axial direction. Further, the cone portion (sliding portion) of the clutch members 219 and 221.
Oil grooves 219b and 221 for lubrication are provided in 219a and 221a.
b is formed. During transmission of the driving force, the clutch members 219 and 221 are pressed outward from the side gears 209 and 211 in the axial direction and frictionally engaged with the differential case 203.

When the differential case 203 is rotationally driven by the engine via the ring gear 227, the driving force is distributed to the side gears 209, 211 (axles 223, 225) via the pinion shaft 205 and the pinion gear 207. When a drive resistance difference is generated between the axles 223 and 225, the pinion gear 207 starts to rotate, and the driving force is the axles 223 and 2
It is distributed differentially among the 25. At this time, cone clutch 2
Relative rotation occurs in the cone portions 219a and 221a of the gears 15 and 217, and the differential force between the axles 223 and 225 is limited by the frictional resistance force. The cone portions 219a and 221a are lubricated by the oil introduced from the oil grooves 219b and 221b.

[0005]

With this structure, the clutch members 219 and 221 have cone portions 219.
a, 221a and oil grooves 219b, 221b are processed, whichever oil groove 219b, 221b is processed in a later step.
Since burrs are generated at the edges of 21b, a process for removing the burrs is required, and the processing is troublesome. Even if the burr is removed in the initial stage, the cone portions 219a,
When 1a is worn, the oil grooves 219b, 22 due to the wear
Burrs also occur at the edge of 1b. This burr causes galling and seizure of the cone portions 219a and 221a during operation, and the differential device 201
May deteriorate the durability of the.

The present invention has been made in view of these problems, and an object thereof is to improve the seizure resistance of a cone clutch and to provide a differential device equipped with this clutch.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is such that the members on the inner and outer sides each have a truncated cone-shaped power transmission portion, and the members on the driving side and the driven side are connected to each other. A cone clutch for intermittently transmitting power between the power transmission units, wherein the power transmission unit of at least one side member is provided with a plurality of contact units each having an elliptical partial shape in a cross section perpendicular to the axis of the truncated cone in the circumferential direction, and each contact unit. A non-contact part is provided in the middle of the above, and the contact part comes into contact with the other-side member.

Therefore, since the contact portion has a partial elliptical shape, no edge portion is formed in the contact portion. Further, since the non-contact portion in the middle of each contact portion functions as a lubricating oil passage, the seizure resistance of the cone clutch is improved. This stabilizes the sliding of the contact portion and improves the durability of the cone clutch.

According to a second aspect of the present invention, there is provided a cone clutch in which the members on the inner and outer sides each have a truncated cone-shaped power transmission portion, and the power transmission between the driving side and the driven side is interrupted and at least. The power transmission portion of the one-sided member is in contact with a circle in a cross section perpendicular to the axis of the truncated cone, and is provided with a plurality of contact portions in the circumferential direction which are arcs having a radius different from the radius of the circle and are not in contact with the middle of each contact portion And a contact portion contacting the other member.

Therefore, the same operation and effect as the invention according to claim 1 can be obtained.

According to a third aspect of the present invention, a differential gear mechanism that is rotationally driven by the driving force of the engine, a differential gear mechanism that distributes the rotation of the differential gear gear to the axle side via a pair of side gears, and a differential gear mechanism. -A differential device having a cone clutch that is formed between the gear and the side gear and that receives the meshing reaction force of the side gear and slides to limit the differential of the differential gear mechanism. The cone clutch is the cone clutch according to claim 1.

Therefore, when a driving resistance difference occurs between the pair of side gears, the driving force is differentially distributed to the side gears by the differential gear mechanism. At this time, the cone clutch slides and the differential resistance is limited by the frictional resistance. To be done. At the time of this sliding, the cone clutch acts in the same manner as the invention according to claim 1 or 2, so that the differential limiting action of the differential device is stabilized and the durability is improved.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an overall cross-sectional view of a differential device including a cone clutch of this embodiment,
2 is a view of the side gear of FIG. 1 taken along the line AA. FIG. 3 is an enlarged view of a main part of the cone clutch.

As shown in FIG. 1, a differential case (outer member) 3 of the differential device 1 is constructed by connecting a differential case body 5 and a cover 7 with bolts (not shown), and their boss portions 5a, 5a. The outer peripheral portions 5b and 7b of 7a are rotatably supported by a differential carrier (not shown) via bearings. A ring gear (not shown) is fixed to the differential case 3, and the differential case 3 is rotationally driven by the engine via the ring gear. An oil reservoir is formed on the differential carrier, and the differential device 1 is lubricated with an oil bath. In addition, the boss 5
Helical oil grooves 5c and 7c are formed on the inner circumferences of a and 7a. On the other hand, openings 5d, 7 are provided on the outer peripheral side of the differential case 3.
d is formed.

A pinion shaft 9 is fixed to the differential case 3 at right angles to its rotation axis, and the pinion shaft 9 rotates integrally with the differential case 3. Inside the differential case 3, a pair of output side gears (inner members) 11 and 13 are arranged coaxially with the differential case 3 so as to sandwich the pinion shaft 9. Also, the pinion shaft 9
A pair of pinion gears 15 are rotatably supported above,
It meshes with the side gears 11 and 13. The thrust received by the pinion gear 15 is received by the rear differential case 3. Left and right axles (not shown) are spline-connected to the inner circumferences of the side gears 11 and 13, respectively. The side gears 11 and 13 are movably arranged on this axle. Thus, the differential gear mechanism is constructed.

As shown in FIG. 1 and FIG. 2, the cone parts 17, 1 as power transmission parts on the outer circumferences of the side gears 11, 13 are formed.
7 has a cone apex outward in the axial direction, and has a cross section perpendicular to the cone axis formed in an elliptical shape. That is, the cone portions 17 and 17 are provided with two contact portions 17a having an elliptical long diameter portion shape in the circumferential direction in the cross section perpendicular to the axis, and the top portion 1 thereof is provided.
7c contacts the facing conical surface on the side of the differential case 3 described later. Intermediate short diameter portion (non-contact portion) 17b of each contact portion 17a
Does not touch.

On the other hand, on the inner circumference of the differential case 3 facing the cone portion 17, along the cone generatrix of the top portion 17c,
In addition, circular conical surfaces (power transmission portions) 19, 19 having a circular cross section circumscribing the top portion 17c are formed. In this way, the conical surface 19 of the differential case 3 is the top portion 1 of the cone portion 17.
7c (conical generatrix) contacts. Since the conical surface 19 does not contact the short diameter portion 17b at the time of contact, the conical surface 1
Two crescent-shaped columnar gaps extending in the axial direction are formed between 9 and the minor diameter portion 17b, and these gaps serve as the oil passages 21. In this way, the cone portion 17 on the side gears 11 and 13 side and the cone surface 19 on the differential case 3 side form a cone clutch 23.

Contrary to the above, the cross section perpendicular to the axis on the side of the differential case 3 may be formed into an ellipse, and in this case, the short-diameter portion on the side of the diffus 3 which is the shape of the short-diameter portion of the ellipse serves as the contact portion. The long-diameter portion on the side of the defusce 3 comes into contact with the side gears 11 and 13 and becomes the non-contact portion.

Oil passages 25, 25 are provided between the rear surfaces of the side gears 11, 13 and the differential case 3, and these oil passages 25, 25 are provided with oil grooves 5c, 7c on the inner periphery of the boss portions 5a, 7a and a cone. The oil passage 21 of the clutch 23, 23
And the openings 5d and 7d of the differential case 3 communicate with each other.

The elliptical cone portion 17 of the side gears 11 and 13 can be formed by numerically controlled turning or forging.

Next, the operation of the cone clutch 23 and the differential device 1 including the cone clutch 23 will be described.

When the engine driving force is input to the differential case 3 via the ring gear, the driving force is distributed to the left and right axles via the pinion shaft 9, the pinion gear 15 and the side gears 11 and 13. At this time, the side gear 1
When meshed with the pinion gear 15, 1 and 13 receive thrust to move outward on the axle, and their cone portions 17 are pressed against the conical surface 19 of the differential case 3. If there is no driving resistance difference between the left and right axles, the side gears 11 and 13 rotate together with the pinion gear 15 together with the differential case 3, and the cone clutch 23 is engaged.

When a driving resistance difference is generated between the left and right axles, the rotation of the pinion gear 15 allows the relative rotation between the side gears 11 and 13. At this time, the differential case 3 rotates at the average number of rotations of the left and right side gears 11 and 13, so that the cone clutch 23 relatively rotates and the cone portion 17 and the cone surface 19 slide. Since the frictional force resists the differential between the side gears 11 and 13 and the differential case 3, that is, resists the differential between the side gears 11 and 13, the left and right side gears 11 and 13 (left and right axles) rotate differentially. However, it is subject to differential limitation. In this way, for example, even if one wheel (axle) of a vehicle traveling on a rough road slips, the driving force of the frictional resistance of the cone clutch 23 is added to the other wheel to improve the running performance of the vehicle.

When the cone clutch 23 slides, the top portion 17c of the cone portion 17 has no edge portion and is smoothly connected to the short diameter portion 17b. Easy to enter (sliding part). Therefore, the lubrication is good and the sliding (differential limiting action) is stable (see FIG. 3). In addition, the introduction of lubricating oil into the oil passage 21
As shown in FIG. 1, the oil grooves 5c, 7c of the boss portions 5a, 7a
Is easily introduced through the oil passage 25 on the rear surface of the side gear or through the openings 5d and 7d. The oil that lubricates the sliding portion further lubricates the meshing portion of the pinion gear 15 and the back surface thereof.

In this way, according to this embodiment, since the oil passage 21 is formed in the cone portion 17 of the side gears 11 and 13, even if the oil groove is not machined as in the conventional example, there is no burr at the initial stage. Moreover, since it does not occur even after the operation, the risk of galling or seizure of the cone clutch 23 is eliminated.

In addition, it is easy to introduce the lubricating oil from the small diameter side to the large diameter side of the cone portion 17 (the crescent-shaped oil passage 21). Furthermore, since the cone portion 17 has an elliptical shape,
The top portion 17c makes smooth sliding contact. As a result, the lubricating oil easily enters the top portion 17c from the oil passage 21, so that an oil film is easily formed. As a result, the seizure resistance of the cone clutch 23 is improved.

As a result, the frictional force of the cone clutch 23 is stabilized and the durability is improved, and the differential limiting action of the differential device 1 equipped with the cone clutch 23 is stabilized and the durability is improved.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is an overall sectional view of the differential device 101 including the cone clutch of the present embodiment, and FIG. 5 is a view of the side gear of FIG. 4 taken along the line BB.

This embodiment is different from the first embodiment in the sectional shape of the cone portion of the cone clutch. Therefore, the members other than the different parts are designated by the same reference numerals as those in the first embodiment, and the duplicated description will be omitted.

The cone portions (power transmission portions) 117 on the outer circumferences of the side gears (inner members) 111 and 113 are shown in FIGS.
As shown in (1), it has a truncated cone shape having an apex of the cone outward in the axial direction, and has a petal-shaped cross section perpendicular to the axis. That is, the cone portion 117 is radially inscribed with five contact portions 117a which are inscribed in a circle in a cross section perpendicular to the axis and which are circular arcs having a radius smaller than the radius of the circle, and the top portion 117c of the contact portion 117a ( The maximum diameter portion) comes into contact with the facing conical surface 119 of the differential case 3 described later. Then, the concave portion (non-contact portion) 117b in the middle of each contact portion 117a does not contact.

On the other hand, on the inner circumference of the differential case 3 facing the petal-shaped cone portion 117, a conical surface 119 having a circular cross section perpendicular to the axis is formed along the conical generatrix of the top portion 117c of the contact portion 117a. . Therefore, the cone portion 1
Each top 117c (each busbar) of 17 contacts the conical surface 119 of the differential case 3. And, at the time of contact, the cone portion 1
In each of the recesses 117b of the groove 17, a substantially crescent-shaped columnar gap extending in the axial direction is formed, and the gap serves as the oil passage 121.
Thus, the cone portion 11 on the side gear 111, 113 side
7 and the conical surface 119 on the side of the differential case 3 constitute a cone clutch 123.

Contrary to the above, the differential case 3 side may be formed into a petal shape, and in that case, the differential case 3
The arc of the side contact part is a convex arc toward the conical axis,
The top portion contacts the cone portion on the side gear 111, 113 side. Then, the intermediate portion between the adjacent top portions becomes the non-contact portion.

The recess 117b of this embodiment may be formed in a continuous shape with an appropriate curvature. Further, the number of contact portions 117a is not limited to five. The cone portion 117 of the side gears 111 and 113 can be formed by turning or forging by numerical control.

With this configuration, according to the present embodiment, the same operation and effect as those of the first embodiment can be obtained, and the number of contact portions 117a of the side gears 111 and 113 is increased, so that the contact is achieved. The surface pressure of the part is reduced and wear resistance is further improved.

In each of the above embodiments, the shape of the cone portion of the present invention is applied to the side gear side.
Of course, the cone clutch shape of the present invention may be applied to another member other than the side gear and the differential case to configure the cone clutch. In that case, the shape of the present invention can be formed by pressing.

[0036]

As is apparent from the above description, according to the invention described in claim 1, since the contact portion of the cone clutch has a partial elliptical shape, the contact portion has no edge portion. Further, since the non-contact portion in the middle of each contact portion functions as a lubricating oil passage, the seizure resistance of the cone clutch is improved. This stabilizes the sliding of the contact portion and improves the durability of the cone clutch.

According to the invention described in claim 2, only the point that the contact portion of the cone clutch is an arc is different from the invention described in claim 1, so that the same effect as the invention described in claim 1 can be obtained. .

According to the invention described in claim 3, since the effect of the invention described in claim 1 or 2 is obtained in the cone clutch for limiting the differential, the differential limiting action of the differential device is stable and the durability is improved. Is improved.

[Brief description of the drawings]

FIG. 1 is an overall sectional view of a differential device according to a first embodiment.

FIG. 2 is a view of the side gear of FIG. 1 taken along the line AA.

FIG. 3 is an enlarged view of a main part of the cone clutch of the first embodiment.

FIG. 4 is an overall sectional view of a differential device according to a second embodiment.

5 is a BB arrow view of the side gear of FIG. 4. FIG.

FIG. 6 is a sectional view of a conventional example.

[Explanation of symbols]

 3 differential case (outer member) 9 pinion shaft 11, 13, 111, 113 side gear (inner member) 15 pinion gear 17, 117 cone portion (power transmission portion) 17a, 117a contact portion 17b short diameter portion (non-contact portion) 17c, 117c Top part 19,119 Conical surface of differential case (power transmission part) 21,121 Crescent-shaped oil passage 23,123 Cone clutch 117b Recessed part (non-contact part)

Claims (3)

[Claims] 1. A cone clutch, in which each of the inner and outer members has a truncated cone-shaped power transmission portion, and the power transmission between the driving side and the driven side is intermittent, the power transmission portion of at least one side member. Is provided with a plurality of contact portions in the circumferential direction, each of which has a partial shape of an ellipse in a cross section perpendicular to the axis of the truncated cone, and a non-contact portion in the middle of each contact portion, which contact portion contacts the other side member. The featured cone clutch. 2. A cone clutch, in which each of the inner and outer members has a truncated cone-shaped power transmission portion, and the power transmission between the driving side and the driven side is intermittent, the power transmission portion of at least one side member. Is provided with a plurality of contact portions in the circumferential direction which are in contact with a circle in a cross section perpendicular to the axis of the truncated cone and have a radius different from the radius of the circle, and a non-contact portion is provided in the middle of each contact portion. A cone clutch characterized in that a member contacts the other side member. 3. A differential gear which is rotationally driven by the driving force of the engine, a differential gear mechanism which distributes the rotation of the differential gear to the axle side via a pair of side gears, and between the differential gear and the side gears. And a cone clutch that is slid on receiving the meshing reaction force of the side gears to limit the differential of the differential gear mechanism, the cone clutch according to claim 1 or 2. A differential device that is a cone clutch.