JP5145952B2 - Differential case and vehicle differential equipped with the same - Google Patents

Description

  The present invention relates to a differential case and a vehicle differential device including the differential case, and more particularly to a differential case that receives a rotational driving force from a drive side and a vehicle differential device including the differential case.

  Conventionally, for example, such a vehicle differential device as shown in FIG. 4 is known (Patent Document 1). The vehicle differential device will be described with reference to FIG. 4. In FIG. 4, 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 an accommodating space 72A for accommodating the side gears 73L, 73R and the pinion gear 74. The differential case 72 is provided with a pinion gear insertion hole 75 that communicates with the accommodation space 72A and inserts the pinion gear 74, and axle insertion holes 76L and 76R that open in a direction perpendicular to the axis of the pinion gear insertion hole 75.

  The side gears 73L and 73R are bottomless cylindrical bevel gears having boss portions 79L and 79R and gear portions 80L and 80R. The side gears 73L and 73R are arranged so as to be movable along the rotation axis of the differential case 72. Each of them 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, the left and right 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 back plate 83, and is rotatably supported in the pinion gear insertion hole 75. A shaft insertion hole 74 </ b> A through which the pinion gear shaft 84 for preventing gear falling is inserted is provided in the shaft center portion of the pinion gear 74.

  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 via the pinion gear shaft 84 and further transmitted from the pinion gear 74 to the side gears 73L and 73R. In this case, since the axles 81L and 81R are connected to the side gears 73L and 73R by spline fitting, the torque from the engine side is distributed according to the driving situation of the vehicle, and the drive pinion, ring gear, differential case 72, and pinion gear. It is transmitted to the left and right axles via the shaft 84, pinion gear 74, and side gears 73L, 73R.

  In this case, when the pinion gear 74 rotates, it slides on the support surfaces of the pinion gear insertion hole 75 and the pinion gear shaft 84, so that friction resistance is generated between these support surfaces, and the differential rotation of the side gear is generated by these friction resistances. Is limited.

Further, the rotation of the pinion gear 74 generates a thrust force on the meshing surfaces with the side gears 73L and 73R, and these thrust forces cause the side gears 73L and 73R to move away from each other to move the sliding members 82L and 82R to the axle insertion holes 76L. , 76R is in pressure contact with the inner peripheral edge of the inner opening, and frictional resistance is generated between the sliding members 82L, 82R and the inner peripheral edge of the axle insertion holes 76L, 76R, and the differential rotation of the side gear is also limited by these frictional resistances. Is done.
Utility Model Registration No. 2520728 (FIG. 1)

  By the way, in the vehicle differential device of Patent Document 1, the meshing portion of the pinion gear 74 and the side gears 73L and 73R is a sliding portion on the outer peripheral surface of the pinion gear 74 with respect to the inner peripheral surface of the pinion gear insertion hole 75 (at the tooth tip of the pinion gear 74). The differential case 72 is disposed in a position closer to the rotational axis of the differential case 72 than a part of the outer peripheral surface. As a result, the sliding portion on the outer peripheral surface of the pinion gear 74 slides with the inner peripheral surface of the pinion gear insertion hole 75 during driving (rotation of the differential case 72).

  The pinion gear 74 is formed with its gear diameter set to be larger than the gear diameters of the side gears 73L and 73R, and the entire inner peripheral surface of the shaft insertion hole 74A is rotatably supported by the pinion gear shaft 84. .

  If only the configuration in which the meshing portion of the pinion gear 74 is disposed closer to the rotational axis of the differential case 72 than the sliding portion (the outer peripheral surface of the pinion gear 74), the side gears 73L and 73R are rotated when the differential case 72 rotates. The reaction force from the differential case 72 (inner peripheral surface of the pinion gear insertion hole 75) against the pinion gear 74 generated by the engagement of the pinion gear 74 acts in a direction in which the pinion gear 74 is inclined, and thus the pinion gear 74 is maintained in an inclined state. Since the inner peripheral surface of the pinion gear insertion hole 75 slides and there is a risk that seizure or uneven wear may occur on the sliding portion of the pinion gear 74 or the inner peripheral surface of the pinion gear insertion hole 75. The differential case 72 of the pinion gear 74 (the inner peripheral surface of the pinion gear insertion hole 75) is generated. Considered configuration to try to avoid the support by the pinion gear shaft 84.

  On the other hand, in order to obtain a sufficiently large differential limiting torque, it is important for the pinion gear 74 to frictionally slide in the pinion gear insertion hole 75 with the gear axis parallel to the axis thereof. The radial dimension of the gap (first gap) between the inner peripheral surface of the pinion gear shaft 84 and the outer peripheral surface of the pinion gear shaft 84 is the same as the gap between the outer peripheral surface (sliding portion) of the pinion gear 74 and the inner peripheral surface of the pinion gear insertion hole 75. It is considered that it cannot be made smaller than the radial dimension of (second void).

  Thus, according to the vehicle differential of Patent Document 1, since the radial dimension of the first gap is set to be larger than the radial dimension of the second gap, the pinion gear 74 is the pinion shaft 84 in a normal state. It is not supported. If the pinion gear 74 is supported by the pinion gear shaft 84, it is when the pinion gear 74 is tilted. Therefore, the above-described configuration (sliding on the outer peripheral surface of the meshing portion of the pinion gear 74 with the side gears 73L and 73R) is performed. The inclination of the pinion gear 74 cannot be reliably eliminated even by disposing it at a position closer to the rotational axis of the differential case 72 than the portion, and supporting the entire inner peripheral surface of the shaft insertion hole 74A on the pinion gear shaft 84). In particular, the pinion gear 74 and the side gears 73L, 73R can not only be prevented from being seized or unevenly worn at the end portion (edge portion) in the gear axial direction of the sliding portion of the pinion gear 74 with respect to the inner peripheral surface of the pinion gear insertion hole 75. There is a problem that a good meshing state cannot be obtained.

  Accordingly, an object of the present invention is to provide a differential case capable of suppressing the occurrence of seizure and uneven wear of the sliding portion of the pinion gear or its support surface and obtaining a good meshing state between the pinion gear and the side gear. An object of the present invention is to provide a vehicle differential device provided with the vehicle.

(1) In order to achieve the above object, the present invention is provided with a case main body that rotates by receiving torque from a drive source, and projects inwardly inside the case main body, and includes a plurality of pinion gears. The same number of pinion gear insertion portions as the pinion gears respectively inserted into shaft holes that open in the gear axial direction, and the plurality of pinion gear insertion portions are included in the plurality of pinion gears by sliding on the inner peripheral surface of the shaft hole. Each of the plurality of pinion gears has a pinion gear support surface that rotatably supports a corresponding pinion gear, and the pinion gear support surface is formed by a curved surface having an outer diameter that gradually increases from the free end side toward the base end side. The opening portion of the shaft hole that opens in the axial direction is formed so as to gradually widen from the front end surface side in the gear axial direction toward the rear side in the gear axial direction. Both the inner peripheral surface forms a sliding surface for generating a frictional resistance by sliding is pressed against the pinion gear supporting surface by the thrust force of the gear axial direction, the pinion gear supporting surface and said opening, A differential case is provided that overlaps with a gear portion of the pinion gear in an axial direction of the pinion gear.

(2) In order to achieve the above object, the present invention provides a pair of side gears, a plurality of pinion gears meshed with the pair of side gears with a gear shaft orthogonal thereto, the plurality of pinion gears, and the pair of side gears. The differential case for a vehicle including a differential case that rotatably accommodates the differential case, wherein the differential case is rotated by receiving a torque from a drive source, and the case main body is provided with a gear axis of a plurality of pinion gears. And the same number of pinion gear insertion portions as the pinion gears respectively inserted into the shaft holes that open in the direction, and the plurality of pinion gear insertion portions correspond to each other among the plurality of pinion gears by sliding on the inner peripheral surface of the shaft hole. Each has a pinion gear support surface that rotatably supports the pinion gear, and whether the pinion gear support surface is a free end side. An opening portion of the shaft hole formed in a curved surface having an outer diameter gradually increasing toward the base end side and opening in the gear axial direction of the plurality of pinion gears is directed from the front end surface side in the gear axial direction toward the rear side in the gear axial direction. gradually while being formed extends, the inner circumferential surface forms a sliding surface for generating a frictional resistance by sliding is pressed against the pinion gear supporting surface by the thrust force of the gear axial Te, the pinion gear supporting surface And the opening portion overlaps the gear portion of the pinion gear and the axial direction of the pinion gear.

  According to the present invention, it is possible to suppress the occurrence of seizure and uneven wear of the sliding portion of the pinion gear or its support surface, and to obtain a good meshing state between the pinion gear and the side gear.

[Embodiment]
FIG. 1 is an exploded perspective view for explaining a vehicle differential according to an embodiment of the present invention. FIG. 2 is a cross-sectional view shown for explaining the vehicle differential according to the embodiment of the present invention. FIG. 3 is a perspective view for explaining a pinion gear insertion portion of the vehicle differential according to the 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 upon receiving engine torque from a drive source, and a differential case 1 that is parallel to each other on an axis perpendicular to the rotational axis O of the differential case 2. A pair of pinion gears 3, 4, a pair of side gears 5 L, 5 R meshing with the pair of pinion gears 3, 4 orthogonal to each other, and an axle movement restriction member interposed between the pair of side gears 5 L, 5 R And a pair of spherical thrust washers 6L, 6R arranged in parallel via the axle spacer 23 and a pair of side gears 5L, 5R.

(Configuration of differential case 2)
As shown in FIGS. 1 and 2, the differential case 2 includes a case main body (case main body portion) 2A that receives engine torque, and pinion gear insertion members (pinion gear insertion portions) 2B and 2C that are rotated by the engine torque together with the case main body 2A. The whole is formed of a rotating structure.

  The case main body 2A has a space portion 20A for accommodating the pinion gears 3 and 4 and the side gears 5L and 5R, the axle spacer 23, and the thrust washers 6L and 6R, and is entirely formed of a one-piece member.

  The case main body 2A includes a pair of upper and lower pinion gears having a pair of left and right axle insertion holes 9L and 9R that open along the rotation axis O and an axis perpendicular to the axis of the pair of axle insertion holes 9L and 9R. Holes 10 and 11 are provided. The case main body 2A has a pair of side gears located in a region that is symmetrical with respect to the rotation axis O and spaced apart from the pinion gear back holes 10 and 11 in the circumferential direction (around the rotation axis O) at equal intervals. Passing holes 12L and 12R are provided. An annular ring gear mounting flange 13 that extends along the circumferential direction in a plane orthogonal to the rotation axis O is integrally provided at the end on the left axle side of the case body 2A.

  The axle insertion holes 9L, 9R are formed by through holes that penetrate the differential case 2 and 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 for receiving the thrust washers 6L and 6R are provided on the inner peripheral edges of the axle insertion holes 9L and 9R.

  The pinion gear back holes 10 and 11 are formed by through holes (round holes) that penetrate the differential case 2 and open in a direction orthogonal to the rotation axis O. The opening size of the pinion gear back holes 10 and 11 is set to an inner diameter slightly smaller than the outer diameter of the pinion gear insertion members 2B and 2C (base end portions 20B and 20C).

  The inner peripheral surfaces of the pinion gear back holes 10 and 11 are formed by mounting surfaces 10B and 11B that attach the pinion gear insertion members 2B and 2C so that they cannot rotate around the axis and cannot move in the axial direction.

  The side gear passage holes 12L and 12R are formed by through holes having a planar non-circular opening. The opening size is set to such a size that the pinion gears 3 and 4 and the side gears 5L and 5R can be inserted into the differential case 2.

  Since the pinion gear insertion members 2B and 2C have substantially the same configuration, only one pinion gear insertion member 2B will be described. In addition, about the other pinion gear insertion member 2C, the code | symbol of each site | part is attached | subjected corresponding to the code | symbol of each site | part of the pinion gear insertion member 2B (For example, the base end part of the pinion gear insertion member 2C is attached to the base of the pinion gear insertion member 2B. 20C corresponding to the end portion 20B, and 21C corresponding to the pinion gear support portion 21B of the pinion gear insertion member 2B are attached to the pinion gear support portion of the pinion gear insertion member 2C.

  The pinion gear insertion member 2B includes a columnar base end portion 20B and a frustoconical pinion gear support portion 21B as shown in FIG. 3, and is attached to the case body 2A as shown in FIG. And it is comprised so that it may insert in the shaft hole 30 (after-mentioned) of the pinion gear 3. FIG.

  The base end portion 20B is press fitted into the pinion gear back hole 10 of the case body 2A. The outer peripheral surface of the base end portion 20B is formed by a mounted surface 200B that is in close contact with the inner peripheral surface (mounting surface 10B) of the pinion gear back hole 10.

  The pinion gear support portion 21B is disposed so as to be exposed in the space portion 20A of the case main body 2A. The outer peripheral surface of the pinion gear support portion 21B rotatably supports the pinion gear 3 by sliding with the inner peripheral surface of the shaft hole 30 of the pinion gear 3, and has an outer diameter that gradually increases from the free end side toward the base end side. It is formed by a pinion gear support surface 210B having a tapered surface (a predetermined taper angle θ) as a curved surface. The back surface of the pinion gear support portion 21 </ b> B is formed by a substantially flat surface that comes into contact with the inner peripheral edge of the pinion gear back surface hole 10.

  The pinion gear insertion member 2B is provided with a plurality of oil supply recesses 211B formed of linear grooves that open to the pinion gear support surface 210B.

(Configuration of pinion gears 3 and 4)
Since the pinion gears 3 and 4 have substantially the same configuration, only one pinion gear 3 will be described. In addition, about the other 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, 4A corresponding to the gear trunk | drum 3A of the pinion gear 3 is attached to the gear trunk | drum of the pinion gear 4. , And 4B corresponding to the gear flange 3B of the pinion gear 3 are attached to the gear flange of the pinion gear 4, respectively, and the description thereof is omitted.

  As shown in FIG. 2, the pinion gear 3 includes a gear barrel 3A having a central axis as a gear axis C, a gear flange 3B protruding from the outer periphery of the gear barrel 3A, and the gear barrel 3A and the gear flange. 3B includes a bottomless cylindrical bevel gear having a gear portion 3C (meshing portion with each side gear 5L, 5R) located on the side gear side of 3B, and a differential case on the pinion gear support surface 210B of the pinion gear insertion member 2B (pinion gear support portion 21B). 2 is rotatably supported at a predetermined distance from the inner surface of the two.

  The gear body portion 3A has a shaft hole 30A into which the pinion gear insertion member 2B is inserted in an axial center portion (a portion including the central axis), and the whole is formed by a substantially truncated cone.

  The shaft hole 30A is formed by a through hole that is opened in the central axis direction and includes two hole portions 300A and 301A having different inner diameters.

  The hole 300A is disposed at a position closer to the rotation axis O of the differential case 2 than the hole 301A. The inner diameter of the hole 300A is set to a size that is not larger than the inner diameter of the hole 301A.

  The hole 301A is arranged at a position farther from the rotation axis O of the differential case 2 than the hole 300A. The opening of the hole 301A is formed by an opening that gradually widens from the front end surface side in the gear axial direction toward the rear side in the gear axial direction. The inner peripheral surface of the hole portion 301A is fitted with a pinion gear support surface 210B of the pinion gear insertion member 2B (pinion gear support portion 21B), and has a tapered surface (predetermined taper angle θ) that slides with the pinion gear support surface 210B. It is formed by a sliding surface 301a as a support portion.

  Here, the “gear back surface” refers to an end surface disposed at a position far from the rotation axis O of the differential case 2 among both end surfaces in the gear axial direction of the pinion gear 3.

  The gear flange portion 3B is integrally formed on the outer peripheral surface of the gear back surface of the gear body portion 3A over the entire circumference, and is formed by a tapered annular body having a dimension with different outer diameters along the gear axial direction. Has been. And it is comprised so that it may function as a gear base part (site | part except the gear part 3C in the pinion gear 3) in the pinion gear 3 with the gear trunk | drum 3A.

  The gear portion 3C does not include a sliding portion as a supported portion with respect to the differential case 2, and is disposed at a position closer to the rotational axis O of the differential case 2 than the gear flange portion 3B. A part of the gear back side edge of the gear portion 3C is integrally provided on the gear tip side end surface of the gear flange portion 3B.

(Configuration of side gears 5L, 5R)
As shown in FIGS. 1 and 2, the side gears 5L and 5R are substantially annular gears having outer boss portions 5La and 5Ra and gear portions 5Lb and 5Rb having different outer diameters (the outer diameter larger than the outer diameter of the pinion gears 3 and 4). It has a diameter and a bevel gear having a single tooth tip cone angle, and is rotatably supported in the differential case 2 and is configured to mesh with the pinion gears 3 and 4 with their axes orthogonal to each other. The number of teeth of the side gears 5L and 5R is set to 1.7 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 12 with respect to the number of teeth 7 of the pinion gears 3 and 4). Yes.

  Sliding portions 5Lc and 5Rc made of spherical surfaces that are fitted to the thrust washer receiving portions 9La and 9Ra via the spherical thrust washers 6L and 6R are provided on the rear surfaces of the side gears 5L and 5R.

  The side gears 5L and 5R have spline fitting holes 500L and 500R that are fitted to the left and right axles (not shown), respectively, and positioning fitting holes 501L that are rotatably fitted to both ends of the axle spacer 23. , 501R axle shaft insertion holes 50L, 50R are provided.

(Configuration of axle spacer 23)
As shown in FIG. 2, the axle spacer 23 has recesses 23 </ b> A and 23 </ b> B 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. Is formed. Then, the front ends of the left and right axles inserted through the axle insertion holes 9L, 9R of the differential case 2 and the spline fitting holes 500L, 500R and the positioning fitting holes 501L, 501R of the side gears 5L, 5R are formed on the bottom surfaces of the recesses 23A, 23B. It is configured to abut and restrict movement of the left and right axles in the insertion direction with respect to the axle insertion holes 9L and 9R. Thereby, the connection (spline fitting) between the side gears 5L and 5R and the left and right axles is smoothly and reliably performed.

(Structure of spherical thrust washers 6L and 6R)
As shown in FIGS. 1 and 2, the spherical thrust washers 6L and 6R are annular washers that receive the thrust force of the side gears 5L and 5R, and the back surfaces (sliding portions 5Lc and 5Rc) of the side gears 5L and 5R and the thrust washers. It is interposed between the receiving portions 9La and 9Ra. 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. The spherical thrust washers 6L and 6R are provided with a lubricating oil introduction path (not shown) for introducing lubricating oil from the inner peripheral portion of the washer to the outer peripheral portion 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 insertion members 2B and 2C, and further transmitted from the pinion gears 3 and 4 to the side gears 5L and 5R. In this case, left and right axles (not shown) are spline-fitted to the left and right side gears 5L and 5R, respectively, so that torque from the engine side is driven by the drive pinion, ring gear, differential case 2, pinion gear insertion members 2B, 2C, It is transmitted to the left and right axles via pinion gears 3, 4 and side gears 5L, 5R. Further, when torque is transmitted from the pinion gears 3 and 4 to the side gears 5L and 5R, the pinion gears 3 and 4 are engaged with each other and are pressed against the pinion gear support portions 21B and 21C of the pinion gear insertion members 2B and 2C.

  Here, when the vehicle is in a straight traveling state and no slip occurs between the left and right wheels and the road surface, if torque from the engine side is transmitted to the differential case 2, the pinion gears 3 and 4 do not rotate. Revolving around the axis of the side gears 5L, 5R, and the pinion gears 3, 4 and the side gears 5L, 5R rotate together with the differential case 2 and the pinion gear shaft 7, so torque from the engine side is equally transmitted to the left and right axles, The left and right wheels rotate at the same speed.

  On the other hand, for example, when the right wheel falls into a muddy state and slips 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 are rotated while torque is applied to the differential case 2, the inner peripheral surfaces (sliding surfaces 301a and 401a) of the shaft holes 30A and 40A are pinion gear insertion members 2B and 2C (pinion gears). In order to slide the pinion gear support surfaces 210B and 210C of the support portions 21B and 21C), a frictional resistance is generated between the slide surfaces 301a and 401a and the pinion gear support surfaces 210B and 210C. These frictional resistances limit the differential rotation of the side gears 5L and 5R and suppress slipping.

  Further, the rotation of the pinion gears 3 and 4 generates a thrust force in the gear axial direction on the meshing surfaces with the side gears 5L and 5R. Among these, the side gears 5L and 5R are moved away from each other by the thrust force in the side gear axial direction and the spherical thrust washers 6L and 6R are pressed against the thrust washer receiving portions 9La and 9Ra, so that the spherical thrust washers 6L and 6R and the thrust washer Friction resistance is generated between the receiving portions 9La and 9Ra, and the differential rotation of the side gears 5L and 5R is also limited by these frictional resistances.

  Further, the inner peripheral surfaces (sliding surfaces 301a and 401a) of the pinion gears 3 and 4 (the hole portions 301A and 401A of the shaft holes 30A and 40A) are caused by the thrust force in the pinion gear axial direction generated in the pinion gears 3 and 4 to the pinion gear insertion member 2B. , 2C (pinion gear support portions 21B, 21C) are in pressure contact with the pinion gear support surfaces 210B, 210C, so that frictional resistance against rotation of the pinion gears 3, 4 occurs, and this also restricts differential rotation of the side gears 5L, 5R. .

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

(1) The sliding surfaces 301a and 401a of the shaft holes 30A and 40A (hole portions 301A and 401A) in the pinion gears 3 and 4 are pinion gear support surfaces 210B and 210C of the pinion gear insertion members 2B and 2C (pinion gear support portions 21B and 21C). Since the pinion gears 3 and 4 are supported rotatably, the inclination of the pinion gears 3 and 4 can be reliably suppressed, and the occurrence of seizure and uneven wear of the pinion gears 3 and 4 or the support surface thereof (particularly the edge portion of the pinion gear) is suppressed. In addition, a good meshing state between the pinion gears 3 and 4 and the side gears 5L and 5R can be obtained.

(2) Being able to suppress the inclination of the pinion gears 3 and 4 can widen the meshing area between the pinion gears 3 and 4 and the side gears 5L and 5R, and can disperse the stress generated in the pinion gears 3 and 4 during torque transmission. Accordingly, it is not necessary to set the size of the entire pinion gear to a large size in order to increase the gear strength of the pinion gears 3 and 4, and an increase in size of the differential case 2 can be prevented.

  As mentioned above, although the vehicle differential gear of this invention was demonstrated based on said embodiment, this invention is not limited to said embodiment, In various aspects in the range which does not deviate from the summary. For example, the following modifications are possible.

(1) In the present embodiment, the case where the pinion gear support surfaces 210B and 210C of the pinion gear insertion members 2B and 2C (pinion gear support portions 21B and 21C) have a predetermined taper angle θ has been described, but the present invention is not limited thereto. However, the taper angle can be changed as appropriate. In this case, the inner peripheral surface of the shaft hole in the pinion gear is formed by a sliding surface made of a taper that fits the pinion gear support surface of the pinion gear insertion member and slides on the pinion gear support surface as in the present embodiment. . As a result, the frictional resistance generated between the inner peripheral surface of the shaft hole and the pinion gear support surface of the pinion gear insertion member is varied by the thrust force in the pinion gear axial direction generated in the pinion gear during torque transmission, and the torque bias ratio (Torque Bias Ratio: TBR) can be adjusted.

(2) In the present embodiment, the case where the oil supply recesses 211B and 211C of the pinion gear insertion members 2B and 2C are formed of straight grooves has been described. However, the present invention is not limited to this, and curved grooves such as spiral grooves, for example. An oil supply recess made of may be used. Further, the number of oil supply recesses in the present invention is not particularly limited.

(3) In the present embodiment, the case where the oil supply recesses 211B and 211C are provided in the pinion gear insertion members 2B and 2C has been described, but the present invention is not limited to this, and the oil supply recess in the pinion gear insertion member Alternatively, the oil supply recess may be provided in the pinion gear, and the oil supply recess may be provided in both the pinion gear insertion member and the pinion gear.

(4) Although the case where the pinion gear insertion members 2B and 2C are separate members from the case main body 2A has been described in the present embodiment, the present invention is not limited to this, and the pin main body insertion member is provided integrally with the case main body. (It may be integrally formed).

(5) In the present embodiment, the case where the pair of pinion gears 3 and 4 are disposed in the differential case 2 has been described. However, the present invention is not limited to this, and three or more pinion gears are disposed in the differential case. May be.

(6) In the present embodiment, the case main body 2A has been described as being formed of one piece of member. However, the present invention is not limited to this, and may be a case main body made up of a plurality of elements. .

The disassembled perspective view shown in order to demonstrate the differential for vehicles which concerns on embodiment of this invention. Sectional drawing shown in order to demonstrate the differential for vehicles which concerns on embodiment of this invention. The perspective view shown in order to demonstrate the pinion gear insertion part of the differential for vehicles which concerns on embodiment of this invention. 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 ... Case main body, 20A ... Space part 2B, 2C ... Pinion gear insertion member, 20B, 20C ... Base end part, 200B, 200C ... Mounted surface, 21B, 21C ... Pinion gear support part , 210B, 210C ... pinion gear support surface, 211B, 211C ... oil supply recesses 3, 4 ... pinion gear, 3A, 4A ... gear barrel, 30A, 40A ... shaft hole, 300A, 301A, 400A, 401A ... hole, 301a , 401a ... sliding surface, 3B, 4B ... gear flange, 3C, 4C ... gear portion 5L, 5R ... side gear, 5La, 5Ra ... boss portion, 5Lb, 5Rb ... gear portion, 5Lc, 5Rc ... sliding portion, 50L , 50R: Axle insertion hole, 500L, 500R: Spline fitting hole, 501L, 501R: Positioning fitting hole 6L, 6R: Thrust washer ,
9L, 9R: Axle insertion hole, 9La, 9Ra ... Thrust washer receiving portion 10, 11 ... Pinion gear back hole, 10B, 11B ... Mounting surface 12L, 12R ... Side gear passage hole 13 ... Ring gear mounting flange 23 ... Axle spacer, 23A, 23B ... Recess O ... Rotating axis C ... Gear axis 71 ... Vehicle differential device 72 ... Differential case, 72A ... Housing space 73L, 73R ... Side gear 74 ... Pinion gear 75 ... Pinion gear insertion hole 76L, 76R ... Axle insertion hole 79L, 79R ... Boss portion 80L, 80R ... Gear portion 81L, 81R ... Axle 82L, 82R ... Sliding member 83 ... Pinion gear back plate 84 ... Pinion gear shaft

Claims (5)

A case body that rotates in response to torque from a drive source;
The same number of pinion gear insertion portions as the pinion gears, which are provided inwardly projecting from the inside of the case main body and are respectively inserted into shaft holes that open in the gear axis direction of the plurality of pinion gears,
Each of the plurality of pinion gear insertion portions has a pinion gear support surface that rotatably supports a corresponding pinion gear among the plurality of pinion gears by sliding on an inner peripheral surface of the shaft hole, and the pinion gear support surface is a free end side Formed from a curved surface having an outer diameter that gradually increases from the base end side toward the base end side,
The openings of the shaft holes that open in the gear axis direction of the plurality of pinion gears are formed so as to gradually expand from the front end surface side in the gear axis direction toward the rear side in the gear axis direction , and the inner peripheral surface thereof is in the gear axis direction. A sliding surface that generates frictional resistance by sliding while being pressed against the pinion gear support surface by the thrust force of
The differential case, wherein the pinion gear support surface and the opening overlap with each other in the axial direction of the pinion gear and the pinion gear.   2. The differential case according to claim 1, wherein the plurality of pinion gear insertion portions have an oil supply recess on a gear support side that opens on the pinion gear support surface. A pair of side gears;
A plurality of pinion gears meshing with the pair of side gears with a gear axis orthogonal thereto;
A differential for a vehicle including a differential case that rotatably accommodates the plurality of pinion gears and the pair of side gears;
The differential case is
A case body that rotates in response to torque from a drive source;
A pinion gear insertion portion of the same number as the pinion gear provided in the case main body portion and inserted into shaft holes that open in the gear axial direction of the plurality of pinion gears;
Each of the plurality of pinion gear insertion portions has a pinion gear support surface that rotatably supports a corresponding pinion gear among the plurality of pinion gears by sliding on an inner peripheral surface of the shaft hole, and the pinion gear support surface is a free end side Formed from a curved surface having an outer diameter that gradually increases from the base end side toward the base end side,
The openings of the shaft holes that open in the gear axis direction of the plurality of pinion gears are formed so as to gradually expand from the front end surface side in the gear axis direction toward the rear side in the gear axis direction , and the inner peripheral surface thereof is in the gear axis direction. A sliding surface that generates frictional resistance by sliding while being pressed against the pinion gear support surface by the thrust force of
The vehicle differential device, wherein the pinion gear support surface and the opening portion overlap each other in the axial direction of the pinion gear and the pinion gear.   The vehicle differential device according to claim 3, wherein the plurality of pinion gears are formed with curved surfaces in which an inner peripheral surface of the shaft hole is adapted to the pinion gear support surface. 4. The vehicle differential device according to claim 3, wherein the plurality of pinion gears include a gear-side oil supply recess that opens on an inner peripheral surface of the shaft hole. 5.

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