JP5109453B2 - Vehicle differential - Google Patents

Description

  The present invention relates to a vehicle differential device, and more particularly to a vehicle differential device including a pinion gear shaft for preventing a pinion gear that receives a rotational driving force from a drive side from falling down.

  Conventionally, a vehicle differential device as shown in FIG. 15 is known (for example, Patent Document 1). The vehicle differential device will be described with reference to FIG. 15. In FIG. 15, the vehicle differential device denoted by reference numeral 71 includes a differential case 72 that rotates upon receiving engine torque, and a rotational axis of the differential case 72. Side gears 73L and 73R that are parallel to each other, and a pinion gear 74 that meshes with these side gears 73L and 73R.

  The differential case 72 is provided with a pinion gear insertion hole 75 and axle insertion holes 76L and 76R whose axes are orthogonal to each other. In addition, the differential case 72 is provided with a concave groove 78 that opens to the inner surface of the pinion gear insertion hole 75 and for attaching the snap ring 77.

  The side gears 73L and 73R are bottomless cylindrical bevel gears having boss portions 79L and 79R and gear portions 80L and 80R, are arranged so as to be movable in the rotational axis direction of the differential case 72, and the boss portions 79L and 79R are respectively disposed. It is rotatably supported in the differential case 72 so as to face the axle insertion holes 76L and 76R. In the side gears 73L and 73R, axles 81L and 81R are spline-fitted with their parts positioned in the axle insertion holes 76L and 76R. Between the gear portions 80L, 80R (rear surface) of the side gears 73L, 73R and the inner opening peripheral edge of the axle insertion holes 76L, 76R, annular sliding members 82L, 82R positioned around the boss portions 79L, 79R are interposed. It is disguised.

  The pinion gear 74 is formed of a bottomless cylindrical bevel gear, is prevented from coming off by a pinion gear holding plate 83 interposed between the snap ring 77 and the pinion gear 74, and is rotatably supported in the pinion insertion hole 75. A pinion gear shaft 84 is inserted through the shaft core portion of the pinion gear 74 to prevent the gear from collapsing.

With the above configuration, when torque from the engine side of the vehicle is input to the differential case 72 via the drive pinion and the ring gear, the differential case 72 is rotated about the rotation axis. Next, when the differential case 72 is rotated, this rotational force is transmitted to the pinion gear 74 and further transmitted from the pinion gear 74 to the side gears 73L and 74R. In this case, since the left and right axles are connected to the side gears 73L, 74R by spline fitting, the torque from the engine side is distributed according to the driving condition of the vehicle, and the drive pinion, ring gear, differential case 72, pinion gear 74 are distributed. And it is transmitted to the left and right axles via the side gears 73L and 73R.
Utility Model Registration No. 2520728 (FIG. 1)

  However, in the vehicle differential of Patent Document 1, the meshing portion between the pinion gear 74 and the side gears 73L and 73R is located only on the rotational axis side of the differential case 72 relative to the sliding portion between the pinion gear 74 and the pinion gear insertion hole 75. . Therefore, a reaction force from the differential case 72 (pinion gear support surface) against the pinion gear 74 generated by meshing of the side gears 73L, 73R and the pinion gear 74 when the differential case 72 rotates acts in a direction in which the pinion gear 74 is inclined, and the pinion gear 74 or the pinion gear is inserted. There is a risk that seizure or uneven wear may occur in the hole 75. In the vehicle differential device of Patent Document 1, an attempt is made to avoid this problem by forming the pinion gear 74 larger in diameter than the side gears 73L and 74R and inserting the pinion gear shaft 84 through the shaft core portion of the pinion gear 74. It is thought that there is. However, in order to obtain a sufficient differential limiting force, the pinion gear 74 is not pivotally supported by the pinion shaft 32 but is frictionally slid in a state where the outer peripheral surface of the pinion gear 74 is parallel to the inner peripheral surface of the pinion gear insertion hole 75. Therefore, the gap between the inner peripheral surface of the pinion gear 74 and the outer peripheral surface of the pinion gear shaft 84 should be made smaller than the gap between the outer peripheral surface of the pinion gear 74 and the inner peripheral surface of the pinion gear insertion hole 75. Can not. That is, the pinion gear 74 is not pivotally supported by the pinion shaft 84 in a normal state, but if it is pivotally supported, the pinion gear 74 is tilted. Inclination cannot be eliminated reliably, and in particular, seizure and uneven wear cannot be prevented from occurring at the edge portion in the axial direction of the pinion gear shaft 84 at the sliding portion between the pinion gear 74 and the pinion gear insertion hole 75. it is conceivable that. Further, in such a structure, since the diameters of the side gears 20L and 20R cannot be increased, the surface pressure of the meshing portion between the side gears 20L and 20R and the pinion gear 74 at the time of torque transmission to the axle is increased, resulting in high strength. It is thought that another problem will occur. Conversely, if sufficient strength is to be ensured, the entire differential limiting device 10 must be enlarged. Further, since the pinion gear 74 has a large diameter, the side gears 20L and 20R are separated from each other in the axle direction, and the length of the differential limiting device 10 in the axle direction cannot be shortened.

  Therefore, the object of the present invention is to sufficiently exhibit the effect of preventing the inclination of the pinion gear by the pinion gear shaft without incurring an increase in the size of the device, and thus it is possible to obtain a good meshing state between the pinion gear and the side gear. The object is to provide a differential for a vehicle.

(1) In order to achieve the above object, the present invention meshes at right angles with a differential case, a pair of side gears rotatably accommodated in the differential case, and the pair of side gears, And at least one pair of pinion gears provided with shaft insertion holes, and a pinion gear shaft that is inserted through the shaft insertion holes and supported by the differential case. The differential case is rotatable on the outer peripheral surface of the at least one pair of pinion gears. The pinion gear shaft is supported by the differential case so as not to rotate about its axis, and the at least one pair of pinion gears is rotatable by sliding with the inner surface of the shaft insertion hole. A second pinion gear support portion for supporting the second pinion gear support portion; Disposed to the rotational axis side of the from the support portion the differential case, at least a portion of the first pinion gear supporting portion, from the engagement center point of the side gears of the pinion gear and the pair of said at least one pair in the axial direction of the pinion gear shaft Is located on the opposite side of the rotation axis of the differential case, and at least a part of the second pinion gear support portion is located at a center of engagement between the at least one pair of pinion gears and the pair of side gears in the axial direction of the pinion gear shaft. And the first pinion gear support portion and the second pinion gear support portion are arranged at a predetermined interval in the axial direction of the pinion gear shaft. Provide a moving device.

  According to the present invention, the effect of preventing the inclination of the pinion gear by the pinion gear shaft can be sufficiently exhibited, and a good meshing state between the pinion gear and the side gear can be obtained.

[First embodiment]
FIG. 1 is an exploded perspective view for explaining a vehicle differential according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view for explaining the vehicle differential according to the first embodiment of the present invention. FIG. 3 is a perspective view for explaining the differential case of the vehicle differential device according to the first embodiment of the present invention. FIG. 4 is a cross-sectional view showing the pinion gear assembly state of the vehicle differential device according to the first embodiment of the present invention cut at right angles to the rotation axis of the differential case. FIG. 5 is a cross-sectional view for explaining a stable operation of the pinion gear in the vehicle differential device according to the first exemplary embodiment of the present invention. FIG. 6 is a cross-sectional view for explaining the differential case of the vehicle differential device according to the first embodiment of the present invention. FIG. 7 is a perspective view for explaining the pinion gear of the vehicle differential device according to the first embodiment of the present invention.

(Overall configuration of vehicle differential)
1 and 2, a vehicle differential device denoted by reference numeral 1 includes a differential case 2 that rotates by receiving engine torque, a pinion gear shaft 50 that is positioned on an axis perpendicular to the rotational axis O of the differential case 2, A pair (upper and lower) of a pair of pinion gears 3 and 4 parallel to each other on the pinion gear shaft 50, a pair of (right and left) side gears 5L and 5R meshing at right angles with these upper and lower two pinion gears 3 and 4, and these It is generally composed of thrust washers 6L and 6R located on the back side of the left and right side gears 5L and 5R.

(Configuration of differential case 2)
As shown in FIGS. 3 and 4, the differential case 2 includes a space 2A for accommodating the pinion gears 3 and 4 and the side gears 5L and 5R and thrust washers 6L and 6R, and a sliding surface of the pinion gears 3 and 4 (described later). The first supported portions 3a, 4a of the base end portions 3M, 4M and the second supported portions 3b, 4b of the gear portions 3N, 4N) and the pinion gear support surfaces of the pinion gear support portions 10, 11 (pinion gear back holes 10A, described later) 11A, the first pinion gear support surfaces 10a, 11a of the 11A and the second pinion gear support surfaces 10b, 11b of the extension portions 10B, 11B) are internally provided with lubricating oil introducing portions 7, 8 for introducing the lubricating oil, The whole is formed by a one-piece member.

  As shown in FIGS. 4 and 6, the lubricating oil introduction portions 7 and 8 are constituted by protrusions 7 a and 8 a that lift up the lubricating oil (diff oil) by rotation of the differential case 2 and pinion gears 3 and 4. The protrusions 7a and 8a are integrally formed by extending from the second pinion gear support surfaces 10b and 11b to the rotation axis side of the differential case 2 on extension portions 10B and 11B (described later), respectively. Placed in position. Spaces 7b and 8b formed by the protrusions 7a and 8a and the pinion gears 3 and 4 are configured to open around the rotation axis side of the differential case 2 and the axis of the pinion gear support portions 10 and 11 and introduce lubricating oil. Yes.

  1, 2 and 6, the differential case 2 has two left and right axle insertion holes 9L, 9R that open along the rotation axis O, and a direction perpendicular to the axis of these axle insertion holes 9L, 9R. A pair of upper and lower pinion gear support portions 10 and 11 each having an axis are provided. 2 and 3, the differential case 2 is a region that is symmetrical with respect to the rotation axis O, and that is located in a portion that is spaced apart from the pinion gear support portions 10 and 11 at equal intervals in the circumferential direction. Holes 12L and 12R are provided. As shown in FIGS. 1 to 3, an annular ring gear mounting flange 13 is integrally provided on the left axle side of the differential case 2 along the circumferential direction in a plane perpendicular to the rotation axis O.

  As shown in FIG. 2, the axle shaft insertion holes 9 </ b> L and 9 </ b> R are formed by through holes that open in a direction along the rotation axis O. Left and right axles (not shown) are inserted through the axle insertion holes 9L and 9R, respectively. Thrust washer receiving portions 9La and 9Ra made of spherical surfaces that receive the thrust washers 6L and 6R are provided on the inner opening peripheral edges of the axle shaft insertion holes 9L and 9R.

  As shown in FIG. 4, the pinion gear support portions 10 and 11 are formed by pinion gear back holes 10A and 11A and extending portions 10B and 11B.

  The pinion gear back holes 10A and 11A are stepped through holes that open to the inside and outside of the differential case 2 and have an inner diameter of the differential case 2 that expands with an axis perpendicular to the rotational axis O, as shown in FIGS. It is formed by a hole. And it is comprised so that it may function also as a hole for processing of a pinion gear support hole. The inner opening size of the pinion gear back holes 10A and 11A is set to a size having an inner diameter substantially equal to the outer diameter of the pinion gears 3 and 4 (an inner diameter smaller than the outer diameters of the side gears 5L and 5R). The inner surfaces of the pinion gear back holes 10A and 11A are provided with first supported portions (second supported portions 3b and 4b, which are outer peripheral surfaces of portions where gear tooth surfaces are provided) as sliding portions of the pinion gears 3 and 4, respectively. (Excluding portions) 3a and 4a are formed by first pinion gear support surfaces 10a and 11a that rotatably support and slide relative to them.

  The first stepped surfaces of the pinion gear back holes 10A and 11A are formed of spherical surfaces that receive the pinion gears 3 and 4 on which centrifugal force acts and have a predetermined curvature, as shown in FIGS. Pinion gear receiving portions (top portions) 10M and 11M are provided. Washer receiving portions 10C and 11C for receiving annular washers 21 and 22 as plug bodies are provided on the second stepped surfaces of the pinion gear back holes 10A and 11A. As shown in FIGS. 5 and 6, the washers 21 and 22 are interposed between the back surfaces of the pinion gears 3 and 4 (fourth supported portions 3B and 4B) and the washer receiving portions 10C and 11C.

  As shown in FIG. 4, extending portions 10 </ b> B extending in parallel with the circumferential direction at equal intervals and extending toward the rotation axis side (inside the case) of the differential case 2, 11B is provided integrally. Second pinion gear support surfaces 10b and 11b are provided on the extending portions 10B and 11B. The second pinion gear support surfaces 10b and 11b support the second supported portions 3b and 4b corresponding to the outer peripheral surface of the portion where the tooth surfaces of the pinion gears 3 and 4 are formed. The second pinion gear support surfaces 10b and 11b are connected to the first pinion gear support surfaces 10a and 11b. The second pinion gear support surfaces 10b and 11b correspond to the “first pinion gear support portion” of the present invention together with the first pinion gear support surfaces 10a and 11a. The second pinion gear support surfaces 10b and 11b are at least partially disposed on the opposite side of the rotation axis O of the differential case 2 from the meshing portion of the pinion gears 3 and 4 and the side gears 5L and 5R in the axial direction of the pinion gear shaft 50. Yes.

  As shown in FIGS. 3 and 4, the side gear passage holes 12 </ b> L and 12 </ b> R are formed by through holes having a planar non-circular opening. The opening size is set such that the pinion gears 3 and 4 and the side gears 5L and 5R can be inserted into the differential case 2.

(Configuration of pinion gear shaft 50)
2 and 4, the pinion gear shaft 50 includes pinion gear support surfaces 50A and 50B that rotatably support the pinion gears 3 and 4, and the pinion gears 3 and 4 (shaft insertion holes 3A and 4A) and the washer 21. , 22 are inserted into the pinion gear back holes 10A, 11A of the differential case 2. The pinion gear support surfaces 50A and 50B correspond to the “second pinion gear support portion” of the present invention. At least a part of the pinion gear support surfaces 50A and 50B is arranged on the rotation axis O side with respect to the meshing portion between the pinion gears 3 and 4 and the side gears 5L and 5R in the axial direction of the pinion gear shaft 50.

  Further, the pinion gear support surfaces 50A and 50B are disposed on the rotation axis O side of the differential case 2 from the pinion gear support portions 10 and 11. More specifically, the pinion gear support surfaces 50A and 50B are arranged at a predetermined interval from the second pinion gear support surfaces 10b and 11b to the rotation axis O side in the axial direction of the pinion gear shaft 50. A spherical bulge 50C protruding in the shaft radial direction is integrally provided at a substantially central portion in the axial direction of the pinion gear shaft 50.

(Configuration of pinion gears 3 and 4)
Since the pinion gears 3 and 4 have substantially the same configuration, only the pinion gear 3 will be described, for example. In addition, about the pinion gear 4, the code | symbol of each site | part is attached | subjected corresponding to the code | symbol of each site | part of the pinion gear 3 (For example, 4M corresponding to the base end part 3M of the pinion gear 3 is attached to the base end part of the pinion gear 4, Further, 4N is attached to the gear portion of the pinion gear 4 corresponding to the gear portion 3N of the pinion gear 3), and the description thereof is omitted.

  As shown in FIGS. 1 and 7, the pinion gear 3 includes a base end portion 3M having a peripheral surface having a predetermined outer diameter, and a gear portion 3N having convex teeth C1 and tooth grooves C2 alternately arranged in the circumferential direction. As shown in FIG. 4, the first pinion gear support surface 10a of the pinion gear back hole 10A, the second pinion gear support surface 10b of the extension portion 10B, and the pinion gear shaft 50 of the pinion gear shaft 50 are formed. The support surface 50A is rotatably supported. In the pinion gear 3, the side located on the side of the rotation axis O of the differential case 2 when defined on the differential case 2 is defined as the gear front end side, and the side located on the opposite side is the gear base end. Define as side.

  The pinion gear 3 is provided with a plurality of concave grooves 3C, 3C,... Serving as lubricating oil inflow portions that open to the first supported portion 3a as sliding surfaces of the pinion gear back hole 10A with respect to the first pinion gear support surface 10a. Yes.

  A shaft insertion hole 3 </ b> A through which the pinion gear shaft 50 is inserted is provided in the axial center portion of the pinion gear 3. The shaft insertion hole 3A is formed by a stepped hole having two large and small inner surfaces with different inner diameters. An inner surface having a smaller inner diameter among both inner surfaces of the shaft insertion hole 3A is formed by a third supported portion 3m that slides on the pinion gear support surface 50A of the pinion gear shaft 50. Of the inner surfaces of the shaft insertion holes 3A and 4A, the inner surface having a larger inner diameter (the portion other than the third supported portion 3m) is formed by a non-sliding portion 30m that does not slide on the outer peripheral surface of the pinion gear shaft 50.

  As shown in FIGS. 1 and 7, the base end portion 3M is an end portion on the opposite side of the side gear side end portion of the pinion gear 3, and is formed at a portion excluding the side gear meshing portion meshing with the side gears 5L and 5R. Yes. As shown in FIGS. 7 and 8, on the outer peripheral surface of the base end portion 3M, the first supported portion 3a corresponding to the first pinion gear supporting surface 10a of the pinion gear back hole 10A and the second pinion gear of the extending portion 10B are provided. A second supported portion 3b corresponding to the support surface 10b is provided. On the back surface of the pinion gear 3, a fourth supported portion 3B formed of a spherical surface that fits the pinion gear receiving portion 10M of the pinion gear back surface hole 10A is provided.

  As shown in FIG. 7, the gear portion 3N includes a straight portion Cs including the second supported portion 3b of the pinion gear 3 and a tapered portion Ct connected to the straight portion Cs, and the side gear 5L on the rotation axis side of the differential case 2. , 5R. As shown in FIG. 2, the gear portion 3N meshes with the gear portions of the side gears 5L and 5R, and the portion (meshing center point) where the surface pressure is highest during torque transmission from the pinion gear 3 to the side gears 5L and 5R is the gear portion 3N. It is located near the center point of the tooth surface. A tooth tip surface c of the convex tooth C1 in the straight portion Cs (a part of the tooth tip surface of the gear meshing portion continuous with the outer peripheral surface of the base end portion 3M) is formed of a peripheral surface having a predetermined outer diameter. The tooth tip surface c of the convex tooth C1 in the taper portion Ct is formed by a circumferential surface that decreases from the gear base end portion toward the gear tip end portion.

(Configuration of side gears 5L, 5R)
As shown in FIG. 2, the side gears 5L and 5R are substantially annular gears having boss portions 5La and 5Ra and gear portions 5Lb and 5Rb having different outer diameters (having an outer diameter larger than the outer diameter of the pinion gears 3 and 4). And a bevel gear having a single tooth tip cone angle, and is rotatably supported in the differential case 2 and meshed with the pinion gears 3 and 4. The number of teeth of the side gears 5L and 5R is set to 2.1 or more times the number of teeth of the pinion gears 3 and 4 (for example, the number of teeth of the side gears 5L and 5R is 15 with respect to the number of teeth 7 of the pinion gears 3 and 4). Yes. The outer diameters of the side gears 5L and 5R are set to be larger than the outer diameter of the pinion gears 3 and 4 and the dimension between the extending portions 10B and 11B.

  Sliding portions 5Lc and 5Rc made of spherical surfaces that are fitted to the thrust washer receiving portions 9Lc and 9Rc via the thrust washers 6L and 6R are provided on the rear surfaces of the side gears 5L and 5R. In the side gears 5L and 5R, left and right axles (not shown) are respectively inserted into the axle insertion holes 9L and 9R and are spline-fitted. As shown in FIG. 2, an axle spacer 23 as an axle movement restriction member is interposed between the side gears 5L and 5R.

  As shown in FIGS. 1 and 2, the axle spacer 23 has recesses 24 and 25 into which the front ends of the left and right axles are fitted at both ends, and is disposed on the rotation axis O of the differential case 2. And the whole is formed by the substantially cylindrical body which combines a pair of spacer elements 23A and 23B. Thereby, the connection (spline fitting) between the side gears 5L and 5R and the left and right axles is smoothly and reliably performed. The bottom surfaces of the recesses 24 and 25 are formed by engagement surfaces 26 and 27 with which the front end surfaces of the axles are engaged.

  The axle spacer 23 is provided with a cylindrical shaft insertion hole 28 through which the pinion gear shaft 50 is inserted, and a spherical inner space 29 in which the bulging portion 50C of the pinion gear shaft 50 is fitted and fixed. The shaft insertion hole 28 is formed by providing substantially semi-cylindrical spaces 28A and 28B in the spacer elements 23A and 23B, respectively. The internal space 29 is formed by providing substantially hemispherical space portions 29A and 29B in the spacer elements 23A and 23B, respectively. The shaft insertion hole 28 and the internal space 29 are configured to prevent the position of the pinion gear shaft 50 from being displaced.

(Configuration of thrust washers 6L and 6R)
As shown in FIGS. 1 and 2, the thrust washers 6L and 6R are annular washers having washer bodies 6La and 6Ra that receive the thrust force of the side gears 5L and 5R. It is interposed between 9Lc and 9Rc. And it is comprised so that mesh | engagement with the side gears 5L and 5R and the pinion gears 3 and 4 may be adjusted. On the outer peripheral edges of the thrust washers 6L, 6R, planar substantially T-shaped locking pieces 30, 31 are integrally provided that can be plastically deformed. The locking pieces 30 and 31 are plastically deformed and locked to the outer peripheral surfaces of the side gears 5L and 5R, and are disposed at positions where the side gears 5L and 5R are allowed to rotate. And it is comprised so that the position shift of the radial direction of the thrust washers 6L and 6R with respect to the side gears 5L and 5R may be prevented. The thrust washers 6L and 6R are provided with a lubricating oil introduction path 32 (only one is shown) for introducing lubricating oil from the inner periphery of the washer to the outer periphery of the washer.

[Operation of the differential 1 for a vehicle]
When torque from the engine side of the vehicle is input to the differential case 2 via the drive pinion and the ring gear, the differential case 2 rotates about the rotation axis O. When the differential case 2 rotates, this rotational force is transmitted to the pinion gears 3 and 4 via the pinion gear shaft 50 and further transmitted from the pinion gears 3 and 4 to the side gears 5L and 5R. In this case, since the axles (not shown) are spline-fitted to the left and right side gears 5L and 5R, the torque from the engine side is driven by the drive pinion, ring gear, differential case 2, pinion gear shaft 50, pinion gears 3, 4,. It is transmitted to the left and right axles via the side gears 5L and 5R.

  Here, when the vehicle is in a straight traveling state and no slip occurs between the left and right wheels and the road surface, when torque from the engine side is transmitted to the differential case 2, the pinion gears 3 and 4 are connected to the side gears 5L and 5R. Since the pinion gears 3 and 4 and the side gears 5L and 5R rotate together with the differential case 2 and the pinion gear shaft 50, the torque from the engine side is equally transmitted to the left and right axles. The left and right wheels rotate at the same rotational speed.

  On the other hand, for example, when the right wheel falls into a muddy state and slip occurs with the road surface, the pinion gears 3 and 4 rotate while meshing with the side gears 5L and 5R, and the torque from the engine side is adjusted to the left and right axles ( Differential distribution between the wheels). That is, the left wheel rotates at a speed lower than the rotational speed of the differential case 2, and the right wheel rotates at a speed higher than the rotational speed of the differential case 2.

  In the present embodiment, when the pinion gears 3 and 4 rotate while torque is applied to the differential case 2, the first supported portions 3a and 4a and the second supported portions 3b and 4b are moved to the first pinion gear support surfaces 10a and 11a. And the second pinion gear support surfaces 10b, 11b, and the third supported portions 3m, 4m slide on the pinion gear support surfaces 50A, 50B of the pinion gear shaft 50, so that the first supported portions 3a, 4a and the first supported portions 3a, 4a Friction resistance is generated between the pinion gear support surfaces 10a and 11a and between the second supported portions 3b and 4b and the second pinion gear support surfaces 10b and 11b, and the third supported portions 3m and 4m and the pinion gear support surface. Friction resistance is generated between 50A and 50B. These frictional resistances limit the differential rotation of the side gears 5L and 5R, and the slip generated between the left and right wheels and the road surface is suppressed. At this time, as shown in FIG. 5, when the load L acts on the pinion gears 3 and 4 from the side gears 5L and 5R due to the engagement of the side gears 5L and 5R and the pinion gears 3 and 4, the differential case 2 (the first first pinion gear support surface 10a). , 11a and second second pinion gear support surfaces 10b, 11b) and reaction forces R1, R2 from the pinion gear shaft 50 (pinion gear support surfaces 50A, 50B) act on the pinion gears 3, 4, and the pinion gears 3, 4 are pinion gear shafts 50. It will slide in a stable (not inclined) state.

  Further, the rotation of the pinion gears 3 and 4 generates a thrust force in the direction of the rotation axis of each gear on the meshing surfaces with the side gears 5L and 5R. Due to this thrust force, the side gears 5L, 5R move away from each other and press the thrust washers 6L, 6R against the thrust washer receiving portions 9Lc, 9Rc. Therefore, the thrust washers 6L, 6R and the thrust washer receiving portions 9Lc, 9Rc Friction resistance is generated between them, and the differential rotation of the side gears 5L and 5R is also limited by these friction resistances. Further, since the fourth supported portions 3B and 4B of the pinion gears 3 and 4 are pressed against the pinion gear receiving portions 10M and 11M of the differential case 2 by the thrust force generated in the pinion gears 3 and 4, the friction resistance against the rotation of the pinion gears 3 and 4 is increased. This also limits the differential rotation of the side gears 5L and 5R.

[Effect of the first embodiment]
According to the first embodiment described above, the following effects can be obtained.

  The pinion gear shaft 50 is inserted into the pinion gears 3 and 4 and the washers 21 and 22 and is supported by the pinion gear back holes 10A and 11A of the differential case 2. Further, the pinion gear support surfaces 50A and 50B are connected to the pinion gear support portions 10 and 11 by the rotation axis of the differential case 2 Since it is arranged on the O side, the pinion gears 3 and 4 slide on the pinion gear shaft 50 in a stable state. Thereby, the effect of preventing the inclination of the pinion gears 3 and 4 by the pinion gear shaft 50 can be sufficiently exhibited, and a good meshing state between the pinion gears 3 and 4 and the side gears 5L and 5R can be obtained.

  In the present embodiment, the case where the fitting state between the axle spacer 23 and the pinion gear shaft 50 is obtained by the spherical inner space 29 and the spherical bulged portion 50C has been described, but the present invention is not limited to this. As shown in FIG. 8, it can also be obtained by a cylindrical internal space (only a semi-cylindrical space 61 formed in the spacer element 23B is shown) and a cylindrical bulge 62. The shape of the internal space and the bulging portion can be changed as appropriate as long as the fitting structure can fix the pinion gear shaft 50 to the axle spacer 23. Further, a notch extending in the axial direction may be provided in the pinion gear shaft 50, and an engaging portion that engages with the notch and restricts the axial movement of the pinion gear shaft 50 may be formed in the axle spacer 23. In addition, the pinion gear shaft 50 may not be fixed to the axle spacer 23, but a part of the pinion gear back holes 10A and 11A may be reduced in diameter or closed to fix the pinion gear shaft 50 to the differential case 2.

  In the present embodiment, the case where the pinion gears 3 and 4 meshing with the side gears 5L and 5R are a pair of pinion gears is described. However, the present invention is not limited to this, and the case where the pinion gears are a plurality of pairs of pinion gears is also described. The same effect as the present embodiment can be obtained. For example, when two pairs of pinion gears are used, three or four pinion gear shafts are supported on the differential case, and the end opposite to the support side end of the pinion gear shaft is fixed to the axle spacer and integrated. .

[Second Embodiment]
FIG. 9 is a cross-sectional view showing the pinion gear assembly state of the vehicle differential device according to the second embodiment of the present invention cut in parallel to the rotation axis of the differential case. FIG. 10 is a perspective view showing the differential case and the pinion gear with a part cut away in order to explain the vehicle differential according to the second embodiment of the present invention. 9 and 10, the same or equivalent members as those in FIGS. 1 to 7 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 9 and 10, in the vehicle differential apparatus according to the second embodiment of the invention, the pinion gear shaft 50 does not have a bulging portion, and the outer diameter is set to a substantially uniform dimension. It is formed by the cylindrical body made. The pinion gear shaft 50 is provided with a pin insertion hole 50D that opens in the radial direction. At both ends of the pinion gear shaft 50, a pair of notch recesses 50E and 50E that open along the rotation axis O are provided at portions of the outer peripheral surface facing the gear portions 5Lb and 5Rb of the side gears 5L and 5R, respectively. ing. A pair of notch recesses 50E and 50E at each end of the pinion gear shaft 50 are arranged in parallel positions at equal intervals (180 °) in the circumferential direction. The pair of cutout recesses 50E and 50E are set such that the axial dimension is larger than the axial dimension of the shaft insertion holes 3A and 4A. Thereby, between the outer peripheral surface of the pinion gear shaft 50 and the inner peripheral surface of the shaft insertion holes 3A, 4A (between the outer peripheral surface of the pinion gear shaft 50 and the third supported portions 3m, 4m of the shaft insertion holes 3A, 4A and An oil passage is formed between the outer peripheral surface of the pinion gear shaft 50 and the non-sliding portions 30m and 40m of the shaft insertion holes 3A and 4A, and the outer peripheral surface of the pinion gear shaft 50 and the inner peripheral surfaces of the pinion gears 3 and 4 are lubricated. Is done.

  In the differential case 2, the inner diameters of the pinion gear back holes 10 </ b> D and 11 </ b> D are set to be substantially the same as the outer diameter of the pinion gear shaft 50. Thereby, the radial operation of the pinion gear shaft 50 is restricted by the contact between the outer peripheral surface of the pinion gear shaft 50 and the inner peripheral surfaces of the pinion gear back holes 10D and 11D. The differential case 2 is provided with pin mounting holes 2b and 2b that open along the rotation axis O on the inner peripheral surface of the pinion gear back surface hole 10D and are arranged in parallel at equal intervals (180 °) in the circumferential direction. The pin attachment holes 2b and 2b are fixed to both ends of a pin 52 through which the pin insertion hole 50D of the pinion gear shaft 50 is inserted. Thereby, the pinion gear shaft 50 is supported by the differential case 2 via the pin 52. The pinion gear shaft 50 is prevented from rotating about its axis and is prevented from coming off in the axial direction.

[Effect of the second embodiment]
According to the second embodiment described above, the following effects can be obtained in addition to the effects of the first embodiment.

  Since the pinion gear shaft 50 is prevented from rotating around the differential case 2, the rotational speeds of the pinion gears 3 and 4 with respect to the pinion gear shaft 50 coincide. As a result, the respective frictional resistances caused by the sliding of the third supported portions 3m, 4m of the pinion gears 3, 4 are equalized, and the differential limiting force is stabilized.

  In the present embodiment, the inner peripheral surface of the differential case 2 corresponding to the back side of the fourth supported portions 3B and 4B of the pinion gears 3 and 4 is formed to be substantially flat, and the pinion gear provided in the flatly formed portion. Although the case where the pinion gear shaft 50 is supported by the inner peripheral surfaces of the back holes 10D and 11D has been described, the present invention is not limited to this, and the differential case 2 corresponding to the back side of the pinion gears 3 and 4 as shown in FIG. It is also possible to provide annular shaft support portions 100D and 110D formed by projecting the inner surface along the pinion gear shaft 50 inward, and to support the pinion gear shaft 50 by these shaft support portions 100D and 110D. In this case, a highly rigid support structure can be obtained as the support structure of the pinion gear shaft 50. Further, the surface pressure between the pinion gear shaft 50 and the shaft support portions 100D and 110D can be reduced as compared with the case where the pinion gear back holes 10D and 11D support the surface pressure.

  In the present embodiment, the case where the pinion gear shaft 51 is prevented from rotating by the pin 52 has been described. However, the present invention is not limited to this. For example, the pinion gear shaft 50 is press-fitted into a hole provided in the differential case 2. Alternatively, it may be prevented from rotating by welding. Alternatively, a part of the pinion gear shaft 50 may be cut out, and the rotation of the differential case 2 may be prevented by engaging a part of the notch.

[Third embodiment]
FIG. 12 is a cross-sectional view showing the pinion gear assembly state of the vehicle differential device according to the third embodiment of the present invention cut in parallel to the rotation axis of the differential case. 12, members identical or equivalent to those in FIGS. 1 to 7 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 12, in this embodiment, instead of the axle spacer 23 and the pinion gear shaft 50 in the first embodiment, the inner surface of the gear tip side opening of the through holes (holes) 3A, 4A of the pinion gears 3, 4 Is provided with a support member 90 having pinion gear support portions 90A and 90B as second pinion gear support portions that rotatably contact the pinion gears 3 and 4. The support member 90 is interposed between the side gears 5L and 5R and between the pinion gears 3 and 4, and at least a part of the pinion gear support portions 90A and 90B is fitted into the through holes 3A and 4A so that the rotation axis O of the pinion gears 3 and 4 is reached. It is arranged at a position that restricts movement to the side.

  With the above configuration, the movement of the pinion gears 3 and 4 toward the side approaching the rotation axis O is restricted, and the center axis of the pinion gears 3 and 4 is inclined with respect to the center axis of the inner peripheral surface of the pinion gear support portions 10 and 11. Is regulated.

  The vehicle differential device according to the present embodiment is assembled by first fitting the pinion gears 3 and 4 into the pinion gear support portions 10 and 11 and then disposing the support member 90 between the both pinion gears 3 and 4 and then the side gear 5L. , 5R, and thrust washers 6L, 6R are interposed between the side gears 5L, 5R and the differential case 2.

[Effect of the third embodiment]
According to the third embodiment described above, in addition to the effects of the first embodiment, the number of parts and the number of assembly steps can be reduced.

[Fourth embodiment]
FIG. 13 is a perspective view showing a pinion gear of a vehicle differential device according to a fourth embodiment of the present invention. FIG. 13A shows a state seen from above, and FIG. 13B shows a state seen from below. FIG. 14 is a cross-sectional view showing a state in which the pinion gear of the vehicle differential device according to the fourth exemplary embodiment of the present invention is supported by the pinion gear support portion. In FIG.13 and FIG.14, the same code | symbol is attached | subjected about the same or equivalent member as FIGS. 1-7, and detailed description is abbreviate | omitted.

  In the present embodiment, the large-diameter portion 33a that is frictionally slid with the second pinion gear support surface 10b and located on the gear proximal end side, and the small-diameter portion 33b that is formed with a smaller diameter than the large-diameter portion 33a and located on the gear distal end side. Is different from the first embodiment in that the upper outer peripheral surface of the pinion gear 33 is configured. Thereby, in the vehicle differential device of the present embodiment, only the large-diameter portion 33a of the outer peripheral surface of the pinion gear 33 slides with the second pinion gear support surface 10b. The large-diameter portion 33a on the outer peripheral surface of the pinion gear 33 is disposed on the gear base end side with respect to the meshing center point between the pinion gear 33 and the side gears 5L and 5R. The third supported portion 33m of the shaft insertion hole 3A of the pinion gear 33 is disposed on the gear tip side from the meshing center point of the pinion gear 33 and the side gears 5L and 5R. That is, in the axial direction of the pinion gear 33, the large-diameter portion 33a and the third supported portion 33m are arranged so as to sandwich the meshing center point. Note that the other pinion gear paired with the pinion gear 33 is configured substantially the same, and thus the description thereof is omitted.

[Effect of the fourth embodiment]
According to the fourth embodiment described above, the large-diameter portion 33a and the third supported portion 33m are respectively disposed on both sides of the meshing center point between the pinion gear 33 and the side gears 5L and 5R. The pressing force due to the meshing of 33 and the side gears 5L, 5R is distributed in a well-balanced manner to the large-diameter portion 33a and the third supported portion 33m, and this distribution ratio is unlikely to change due to the running state of the vehicle or wear due to long-term use. Thereby, the differential limiting force can be obtained in a more stable state.

  In the present embodiment, the large-diameter portion 33a and the small-diameter portion 33b are formed on the outer peripheral surface of the pinion gear 33, and the pinion gear 33 can freely rotate to the second pinion gear support surface 10b only on the gear base end side from the meshing center point. However, the present invention is not limited to this, and the pinion gear 33 is formed of a cylindrical body having an outer peripheral surface having a uniform outer diameter, and the rotational axis of the differential case 2 of the second pinion gear support surface 10b. By shortening the protruding amount toward the O side, the pinion gear 33 may be rotatably supported on the second pinion gear support surface 10b only on the gear base end side with respect to the meshing center point. Further, the first portion of the second pinion gear support surface on the gear proximal side from the meshing center point of the pinion gear 33 is a small diameter portion having an inner diameter a, and the second portion of the second pinion gear support surface located on the gear tip side is an inner diameter. The large-diameter portion b (b> a) may be used so that the large-diameter portion does not contact the outer peripheral surface of the pinion gear 33.

  As mentioned above, although the vehicle differential gear of the present invention has been described based on each of the above-described embodiments, the present invention is not limited to each of the above-described embodiments, and various modifications can be made without departing from the gist thereof. For example, the following modifications are possible.

In each of the above-described embodiments, the case where the differential case 2 is formed of one piece of member has been described. However, the present invention is not limited to this, and may be a differential case including a plurality of case elements.

The disassembled perspective view shown in order to demonstrate the differential for vehicles which concerns on the 1st Embodiment of this invention. Sectional drawing shown in order to demonstrate the differential for vehicles which concerns on the 1st Embodiment of this invention. The perspective view shown in order to demonstrate the differential case of the differential for vehicles which concerns on the 1st Embodiment of this invention. Sectional drawing which shows the pinion gear assembly | attachment state of the differential for vehicles which concerns on the 1st Embodiment of this invention cut | disconnected at right angles to the rotating shaft line of a differential case. Sectional drawing shown in order to demonstrate the stable operation | movement of the pinion gear in the differential for vehicles which concerns on the 1st Embodiment of this invention. Sectional drawing shown in order to demonstrate the differential case of the differential for vehicles which concerns on the 1st Embodiment of this invention. The perspective view shown in order to demonstrate the pinion gear of the differential for vehicles which concerns on the 1st Embodiment of this invention. The disassembled perspective view shown in order to demonstrate the other fitting example of the pinion gear shaft and axle movement control member of the differential for vehicles which concerns on the 1st Embodiment of this invention. Sectional drawing which shows the pinion gear assembly | attachment state of the vehicle differential gear which concerns on the 2nd Embodiment of this invention cut | disconnected in parallel with the rotating shaft line of a differential case. The perspective view which notches and shows a part of differential case and a pinion gear, in order to demonstrate the vehicle differential apparatus which concerns on the 2nd Embodiment of this invention. Sectional drawing shown in order to demonstrate the modification of the differential case in the differential for vehicles which concerns on the 2nd Embodiment of this invention. Sectional drawing which shows the pinion gear assembly | attachment state of the vehicle differential gear which concerns on the 3rd Embodiment of this invention cut | disconnected in parallel with the rotating shaft line of a differential case. (A) And (b) is a perspective view which shows the pinion gear of the differential for vehicles which concerns on the 4th Embodiment of this invention. Sectional drawing which shows the state by which the pinion gear of the vehicle differential gear which concerns on the 4th Embodiment of this invention was supported by the pinion gear support part. Sectional drawing shown in order to demonstrate the conventional vehicle differential.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle differential device, 2 ... Differential case, 2A ... Space part, 2b ... Pin mounting hole, 3, 4, 33 ... Pinion gear, 3A, 4A ... Shaft insertion hole, 3B, 4B ... 4th supported part, 3M , 4M ... Base end, 3N, 4N ... Gear, 3a, 4a ... First supported part, 3b, 4b ... Second supported part, 3C ... Concave groove, 3m, 4m, 33m ... Third supported part 33a ... large diameter portion, 33b ... small diameter portion, 5L, 5R ... side gear, 5La, 5Ra ... boss portion, 5Lb, 5Rb ... gear portion, 5Lc, 5Rc ... sliding portion, 5Ld, 5Rd ... spline fitting portion, 6L , 6R: Thrust washer, 6La, 6Ra ... Washer body, 7, 8 ... Lubricating oil introduction part, 7a, 8a ... Projection, 7b, 8b ... Space, 9L, 9R ... Axle insertion hole, 9Lc, 9Rc ... Thrust washer receiving part 10, 11 ... Pinion gear support, 10 , 11A, 10D, 11D ... pinion gear back hole, 10a, 11a ... first pinion gear support surface, 10B, 11B ... extension portion, 10C, 11C ... washer receiving portion, 10M, 11M ... pinion gear receiving portion, 10b, 11b ... first 2 pinion gear support surface, 12L, 12R ... side gear passage hole, 13 ... ring mounting flange, 21, 22 ... washer, 23 ... axle spacer, 23A, 23B ... spacer element, 24, 25 ... recess, 26, 27 ... engagement 28, shaft insertion hole, 29 ... internal space, 28A, 28B, 29A, 29B ... space, 30, 31 ... locking piece, 30m ... non-sliding part, 32 ... lubricating oil introduction path, Cs ... straight part , Ct ... tapered portion, C1 ... convex tooth, C2 ... tooth groove, c ... tooth tip surface, 50 ... pinion gear shaft, 50A, 50B ... pinion gear support , 50C: bulge portion, 50D: pin insertion hole, 50E: notch recess, 52 ... pin, 90 ... support member, 90A, 90B ... pinion gear support portion, 100D, 110D ... shaft support portion, 71 ... differential for vehicle Device: 72 ... Differential case, 73L, 73R ... Side gear, 74 ... Pinion gear, 75 ... Pinion gear insertion hole, 76L, 76R ... Axle insertion hole, 77 ... Snap ring, 78 ... Groove, 79L, 79R ... Boss, 80L, 80R ... Gear part, 81L, 81R ... Axle, 82L, 82R ... Sliding member, 83 ... Pinion gear holding plate, 84 ... Pinion gear shaft, O ... Rotation axis

Claims (4)

Differential case,
A pair of side gears rotatably accommodated in the differential case;
And at least one pair of pinion gears that mesh with the pair of side gears at right angles and that have shaft insertion holes in the axial center,
A pinion gear shaft inserted through the shaft insertion hole and supported by the differential case;
The differential case has a first pinion gear support portion that rotatably supports an outer peripheral surface of the at least one pair of pinion gears,
The pinion gear shaft is supported by the differential case so as not to rotate about its axis, and has a second pinion gear support portion that rotatably supports the at least one pair of pinion gears by sliding with an inner surface of the shaft insertion hole,
The second pinion gear support is disposed closer to the rotation axis of the differential case than the first pinion gear support ;
At least a portion of the first pinion gear support portion is located on the opposite side of the rotational axis of the differential case from the meshing center point of the at least one pair of pinion gears and the pair of side gears in the axial direction of the pinion gear shaft.
At least a part of the second pinion gear support portion is located closer to the rotation axis side of the differential case than an engagement center point of the at least one pair of pinion gears and the pair of side gears in the axial direction of the pinion gear shaft.
The first pinion gear support portion and the second pinion gear support portion are a vehicle differential device arranged at a predetermined interval in the axial direction of the pinion gear shaft .   The shaft insertion holes of the at least one pair of pinion gears are formed by stepped holes having two large and small inner surfaces with different inner diameters, and the inner surface having the smaller inner diameter slides the second pinion gear support portion out of the two large and small inner surfaces. The differential for vehicles according to claim 1 which moves. The first pinion gear support portion rotatably supports an outer peripheral surface of the at least one pair of pinion gears on a gear base end side with respect to a meshing center point between the at least one pair of pinion gears and the side gear;
2. The vehicle differential device according to claim 1 , wherein the second pinion gear support portion rotatably supports the at least one pair of pinion gears on a gear tip side with respect to the meshing center point. The outer peripheral portion of the at least one pair of pinion gears has an outer diameter set to a size smaller than the outer diameter of the large-diameter portion and a large-diameter portion located on the gear proximal end side from the meshing center point. 4. The vehicle differential device according to claim 3 , wherein the vehicle differential is formed by a small-diameter portion located on a gear tip side, and the large-diameter portion is supported by the first pinion gear support portion.

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