Differential device

Abstract

To provide a differential device capable of improving off-road performance while maintaining turning performance. [Solution] A differential device (1) includes a rotatably arranged differential case (7), a pinion gear (11) supported rotatably within the differential case (7) and revolving as the differential case (7) rotates, and a pair of side gears (13, 15) that mesh with the pinion gear (11) and are rotatable relative to each other. The pinion gear (11) and the side gears (13, 15) form a bevel gear set, and a first flat portion (39) perpendicular to the rotation axis is provided on the back side of the gear portion of the side gears (13, 15). The differential case (7) is provided with a second flat portion (41) perpendicular to the rotation axis and arranged opposite the first flat portion (39) so that it can abut against the first flat portion (39). A first abutment force is applied between the first flat portion (39) and the second flat portion (41) by a biasing member (43), and a second abutment force is applied between the first flat portion (39) and the second flat portion (41) due to the meshing reaction force between the pinion gear (11) and the side gears (13, 15).

Description

Technical Field

[0001] The present invention relates to a differential device.

Background Art

[0002] Conventionally, as a differential device, a differential case arranged rotatably and a pinion gear rotatably supported in the differential case and revolving by the rotation of the differential case are provided. Also, a device provided with a pair of side gears that mesh with the pinion gear and are relatively rotatable is known (see Patent Document 1). In this differential device, the pinion gear and the side gear are composed of a bevel gear set. A pressing member composed of a conical spring washer is arranged between the axial directions of the differential case and the side gear.

[0003] The pressing member presses the side gear toward the pinion gear side, making the backlash between the side gear and the pinion gear zero. For this reason, every time the teeth that mesh with the pinion gear of the side gear are changed one by one, the side gear reciprocates in the rotational axis direction and vibrates slightly in the rotational axis direction. The slight vibration of the side gear is transmitted to the tire, and slight vibration is imparted in the width direction of the tire. The tire to which slight vibration is imparted increases the friction coefficient in the rotational direction with respect to the road surface, and the wheel spin of the tire is suppressed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the differential device of Patent Document 1, if the biasing force of the pressing member, that is, the initial torque, is increased, the region of the differential limiting characteristic can be expanded, but the running resistance of the left and right wheels increases, making it difficult for the vehicle to turn and reducing the turning performance.

[0006] This invention has been made in view of the problems of the prior art. The object of this invention is to provide a differential device that can improve off-road capability while maintaining turning ability. [Means for solving the problem]

[0007] The differential device according to this embodiment comprises a rotatably arranged differential case, a pinion gear rotatably supported within the differential case and revolving by the rotation of the differential case, and a pair of side gears that mesh with the pinion gear and are rotatable relative to it. The pinion gear and the side gear are made of a bevel gear assembly, the back side of the gear portion of the side gear is provided with a first planar portion perpendicular to the axis of rotation, the differential case is provided with a second planar portion perpendicular to the axis of rotation and positioned opposite to the first planar portion so as to be in contact with it, a first contact force is applied between the first planar portion and the second planar portion by a biasing member, and the meshing reaction force between the pinion gear and the side gear applies a second contact force between the first planar portion and the second planar portion. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a differential device that can improve off-road capability while maintaining turning ability. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view of a differential device according to the first embodiment. [Figure 2] This is a perspective view of the biasing member and plate of the differential device according to the first embodiment. [Figure 3] This diagram shows the torque characteristics of the differential device according to this embodiment, the torque characteristics of a comparative example, and the initial torque. [Figure 4] This is a cross-sectional view of a differential device according to a second embodiment. [Figure 5] This is a cross-sectional view of a differential device according to the third embodiment. [Modes for carrying out the invention]

[0010] The differential device according to this embodiment will be described in detail below with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios.

[0011] (First Embodiment) The first embodiment will be described using Figures 1 to 3.

[0012] As shown in Figure 1, the differential device 1 according to this embodiment is positioned between a drive source (not shown), such as an engine or electric motor, and the left and right wheels (not shown). The driving force from the drive source is transmitted to the differential device 1 via a transmission (not shown), and the driving force is distributed to the left and right wheels (not shown) via a pair of output shafts.

[0013] As shown in Figures 1 and 2, the differential device 1 comprises a differential mechanism 3 and a differential limiting unit 5.

[0014] The differential mechanism 3 comprises a differential case 7, a pinion shaft 9, a pinion gear 11, and a pair of side gears 13 and 15.

[0015] The differential case 7 is rotatably supported by stationary components (not shown), such as a carrier, via bearings 21 and 23 on the outer circumference of boss portions 17 and 19 formed on both axial sides. The differential case 7 has a flange portion 27 to which a ring gear 25 is fixed. The ring gear 25 meshes with a power transmission gear (not shown) that transmits driving force, and the driving force is transmitted to rotate the differential case 7. Inside the differential case 7 are a pinion shaft 9, a pinion gear 11, and a pair of side gears 13 and 15, among others.

[0016] The pinion shaft 9 engages with a hole formed in the differential case 7 at its end and is prevented from coming off and rotating by a pin, and is rotationally driven integrally with the differential case 7. The pinion shaft 9 is accommodated in a block member 29 that positions the axial positions of the pair of side gears 13, 15 so that both axial ends are exposed to the outside. Pinion gears 11 are respectively supported on both axial end sides of the pinion shaft 9.

[0017] A plurality (here, two) of pinion gears 11 are arranged at equal intervals in the circumferential direction of the differential case 7. The plurality of pinion gears 11 are respectively supported on the end side of the pinion shaft 9 and revolve by the rotation of the differential case 7. The pinion gears 11 are rotatably supported on the pinion shaft 9 so as to be rotationally driven when relative rotation occurs between the pair of meshing side gears 13, 15. The pinion gears 11 transmit the driving force input to the differential case 7 to the pair of side gears 13, 15.

[0018] The pair of side gears 13, 15 are accommodated in the differential case 7 so as to be relatively rotatable. The pair of side gears 13, 15 are respectively meshed with the pinion gears 11. The pinion gears 11 and the pair of side gears 13, 15 are constituted by a bevel gear set. On the inner peripheral sides of the pair of side gears 13, 15, spline-shaped output portions 31, 33 for outputting the driving force transmitted to the pair of side gears 13, 15 are provided. A pair of output shafts 35, 37 integrally rotatably connected to the left and right wheels are integrally rotatably connected to the output portions 31, 33.

[0019] The differential limiting portions 5 are respectively arranged between the differential case 7 and the pair of side gears 13, 15. The differential limiting portions 5 have a first flat portion 39 and a second flat portion 41 that slide relative to each other, and a biasing member 43.

[0020] The first flat portion 39 is provided on the back side of the gear portions of the side gears 13, 15. The first flat portion 39 extends in a plane direction orthogonal to the rotation axes of the side gears 13, 15. The first flat portion 39 is arranged to be capable of abutting against the second flat portion 41 in the rotation axis direction. The inner diameter side from the inner end portion of the first flat portion 39 is a concave portion 40 recessed toward the pinion gear 11 side so as to be axially separated from the second flat portion 41. For this reason, the inner diameter side from the inner end portion of the first flat portion 39 does not slide with the second flat portion 41 and does not affect the differential limiting characteristics of the differential limiting portion 5.

[0021] The second flat portion 41 is provided on a single plate 45 arranged to be rotatable integrally with the differential case 7. Note that the second flat portion 41 is configured to rotate in conjunction with the differential case 7 directly or indirectly, and is configured to abut against each other so that relative rotation with the first flat portion 39 occurs. By providing the second flat portion 41 on the plate 45, the design of the second flat portion 41 can be performed independently of the design of the differential case 7. The plate 45 is formed in an annular shape so as to have an opening 47 penetrating in the rotation axis direction. By providing the opening 47 in the plate 45, it is possible to easily supply lubricating oil to the second flat portion 41 and improve lubricity. The second flat portion 41 is an annular portion of the plate 45 and is arranged to face the first flat portion 39 so as to be capable of abutting against it in the rotation axis direction. The second flat portion 41 extends in a plane direction orthogonal to the rotation axis of the differential case 7 so as to be parallel to the first flat portion 39.

[0022] A plurality (here, six) of engaging convex portions 49 are arranged at equal intervals in the circumferential direction of the second flat portion 41 on the plate 45 and protrude from the second flat portion 41 toward the inner diameter side. The engaging convex portions 49 are engaged with a plurality (here, six) of engaging concave portions 50 formed in the differential case 7. The engaging convex portions 49 and the engaging concave portions 50 constitute a connecting portion 51 and enable the plate 45 to rotate integrally with the differential case 7. The connecting portion 51 is arranged on the inner diameter side of the first flat portion 39 and the second flat portion 41. For this reason, the connecting portion 51 does not project outward in the radial direction, and the differential case 7 can be miniaturized in the radial direction.

[0023] The biasing member 43 is formed as a single continuous member with respect to the plate 45. The biasing member 43 has multiple (six in this case) elastic parts on the plate 45 at the point connecting the second flat portion 41 and the engaging projection 49. The pressing force from these elastic parts acts as a whole to exert the biasing force of the biasing member 43. The pressing portion 53 of the biasing member 43, which is connected to the second flat portion 41, is inclined so that it is located on the pinion gear 11 side of the engaging projection 49 with respect to the rotation axis. The pressing portion 53 of the biasing member 43 is positioned on the outer diameter side of the connecting portion 51 when the plate 45 is placed in the differential case 7. When the plate 45 is placed in the differential case 7, the biasing member 43 abuts against an annular pivot member 57 housed in a housing groove 55 that is formed circumferentially and continuously on the outer diameter side of the connecting portion 51 of the differential case 7. The pivot member 57 is prevented from rotating at multiple points in the circumferential direction within the housing groove 55. However, the annular support member 57 is not mandatory; the axial end on the inner diameter side of the plate 45 and the axial end of the engaging recess 50 formed in the differential case 7 may come into contact and receive the reaction force of the biasing force.

[0024] The biasing member 43 uses the contact point with the pivot member 57 as a fulcrum and applies a first contact force such that the second flat portion 41 presses against the first flat portion 39. The first contact force of the biasing member 43 brings the first flat portion 39 and the second flat portion 41 into contact, generating frictional resistance against the differential limiting portion 5 and applying an initial torque. By applying an initial torque to the differential limiting portion 5, the differential limiting characteristics can be stabilized. The first contact force of the biasing member 43 is input to the block member 29 positioned between the pair of side gears 13 and 15. By receiving the first contact force of the biasing member 43 with the block member 29, backlash can be ensured in the gear portions of the pinion gear 11 and the side gears 13 and 15.

[0025] In the differential limiting section 5, the first planar portion 39 and the second planar portion 41 are subjected to a second contact force from a pair of side gears 13 and 15 that are moved axially by the meshing reaction force with the pinion gear 11, in accordance with the magnitude of the driving force (driving torque) input to the differential case 7. As a result of the second contact force applied to the first planar portion 39 and the second planar portion 41 of the differential limiting section 5, the first planar portion 39 and the second planar portion 41 slide against each other, limiting the differential of the differential mechanism 3. This differential limiting section 5 is a torque-sensitive friction clutch.

[0026] In conventional differential devices, a biasing member biases the side gears 13 and 15 toward the pinion gear 11, thereby eliminating backlash in the gear sections of the pinion gear 11 and the side gears 13 and 15. As a result, the side gears 13 and 15 reciprocate in the direction of rotation each time one tooth that meshes with the pinion gear 11 is replaced, causing minute vibrations in the direction of rotation. These minute vibrations of the side gears 13 and 15 are transmitted to the wheels, imparting minute vibrations in the width direction of the wheels. The wheels, subjected to these minute vibrations, increase the coefficient of friction in the rotational direction relative to the road surface, suppressing wheel slippage. In such differential devices, increasing the biasing force of the biasing member, i.e., the initial torque, can expand the range of differential limiting characteristics. However, if the initial torque is increased too much, the difference in rotation between the left and right wheels is easily absorbed, increasing driving resistance, making it difficult for the vehicle to turn, and reducing its turning ability.

[0027] In contrast, the differential device 1 has a first flat section 39 and a second flat section 41 between the differential case 7 and the side gears 13 and 15. A first contact force, which is an initial torque, is applied between the first flat section 39 and the second flat section 41 by a biasing member 43. The meshing reaction force between the pinion gear 11 and the side gears 13 and 15 applies a second contact force between the first flat section 39 and the second flat section 41. The first flat section 39 and the second flat section 41, to which the second contact force is applied, can obtain a differential limiting characteristic that limits the differential of the differential mechanism 3 (a pair of side gears 13 and 15) through mutual sliding. Therefore, the first contact force of the biasing member 43 can be adjusted to match the desired differential limiting characteristic, and the initial torque will not become too high. Consequently, the differential limiting characteristic will not become too high, and the vehicle's off-road capability can be improved by suppressing wheel slippage while maintaining the vehicle's turning ability.

[0028] In the differential limiting section 5, the first contact force due to the biasing member 43 is input from the second planar section 41 to the first planar section 39, and the second contact force due to the meshing reaction force is input from the first planar section 39 to the second planar section 41. Therefore, in the rotation axis direction, the directions in which the initial torque and the torque-sensitive differential limiting characteristics are generated are opposite, so stable performance can be obtained by making the most of each characteristic.

[0029] A friction material 59 is provided on the surface of at least one of the first flat portion 39 and the second flat portion 41 (in this case, the second flat portion 41). By providing the friction material 59 between the first flat portion 39 and the second flat portion 41, the friction characteristics between the first flat portion 39 and the second flat portion 41 are stabilized and wear is suppressed, thereby stabilizing the differential limiting characteristics. The friction material 59 may also be integrally fixed to the first flat portion 39 side.

[0030] An oil groove (not shown) is provided on the surface of at least one of the first flat portion 39 and the second flat portion 41 (in this case, the first flat portion 39). Lubricating oil that has flowed into the differential case 7 flows through the oil groove. By providing an oil groove between the first flat portion 39 and the second flat portion 41, the friction characteristics between the first flat portion 39 and the second flat portion 41 can be stabilized and wear can be suppressed, thereby stabilizing the differential limiting characteristics. Alternatively, the oil groove may be provided on the surface of the friction material 59 which is directly or indirectly integrally fixed to the second flat portion 41.

[0031] Here, the differential limiting characteristics of the differential limiting unit 5 are evaluated by the torque ratio (torque bias ratio: TBR) of the pair of side gears 13 and 15. TBR is expressed as the ratio of the torque at low rotation to the torque at high rotation. The locking ratio of the differential limiting unit 5 required to achieve the target TBR can be calculated by the formula (TBR-1) / (TBR+1). The clutch torque in the differential limiting unit 5 can be calculated by the formula T×C when the input torque is T and the locking ratio of the differential limiting unit 5 is C.

[0032] For example, suppose that in the differential limiting section 5, the two sliding surfaces that slide against each other are conical sliding surfaces that are inclined to intersect with the axis of rotation. On the conical sliding surfaces, the second contact force due to the meshing reaction force between the pinion gear 11, which is made up of bevel gears, and the side gears 13 and 15 is excessive, causing the TBR (differential limiting characteristic) to become too high. If the TBR becomes too high, the first contact force of the biasing member 43, which acts as the initial torque, must also be increased.

[0033] In contrast, in the differential limiting section 5, the first planar portion 39 and the second planar portion 41, which slide against each other, are sliding surfaces perpendicular to the axis of rotation, so the TBR (differential limiting characteristic) does not become too high. Therefore, the differential limiting characteristic of the differential limiting section 5 is not excessively increased, and there is no need to excessively increase the first contact force of the biasing member 43.

[0034] Here, Figure 3 shows the characteristic curves of the torque characteristics 61 of the differential limiting unit 5 of this embodiment and the torque characteristics 63 of a differential limiting unit as a comparative example. In the differential limiting unit 5 of this embodiment, the TBR is set to 1.5, and in the differential limiting unit of the comparative example, the TBR is set to 1.3. Also in Figure 3, the initial torque 65 of the differential limiting unit 5 of this embodiment, the initial torque 67 of the differential limiting unit of the comparative example, and the initial torque 69 when the initial torque is increased are shown. Note that the initial torques of the differential limiting unit 5 of this embodiment and the differential limiting unit of the comparative example are set to the same value.

[0035] As is clear from Figure 3, setting the initial torque to the same value and the TBR to 1.5 yields a greater effect than increasing the initial torque to expand the effective range. In addition, there are no side effects such as the vehicle becoming more difficult to turn. On the other hand, if you try to increase only the initial torque, such as to an initial torque of 69, you are likely to encounter side effects such as poor cornering performance, making it difficult for the vehicle to turn at low torque levels.

[0036] Such a differential device 1 includes a rotatably arranged differential case 7 and a pinion gear 11 that is rotatably supported within the differential case 7 and revolves by the rotation of the differential case 7. It also includes a pair of side gears 13 and 15 that mesh with the pinion gear 11 and are rotatable relative to each other. The pinion gear 11 and the side gears 13 and 15 are made of bevel gears. A first planar portion 39 perpendicular to the axis of rotation is provided on the back side of the gear portion of the side gears 13 and 15. The differential case 7 is also provided with a second planar portion 41 perpendicular to the axis of rotation and positioned opposite to the first planar portion 39 so as to be in contact with it. A first contact force is applied between the first planar portion 39 and the second planar portion 41 by a biasing member 43. The meshing reaction force between the pinion gear 11 and the side gears 13 and 15 then applies a second contact force between the first flat portion 39 and the second flat portion 41.

[0037] The first planar portion 39 and the second planar portion 41, to which a second contact force is applied, can obtain differential limiting characteristics that restrict the differential movement of the pair of side gears 13 and 15 through their mutual sliding. Therefore, the first contact force of the biasing member 43 can be adjusted to match the desired differential limiting characteristics, and the initial torque will not become too high. Consequently, the differential limiting characteristics will not become too high, and the vehicle's maneuverability will be maintained while wheel slippage will be suppressed, thereby improving the vehicle's off-road capability. Furthermore, since the first planar portion 39 and the second planar portion 41 are sliding surfaces perpendicular to the axis of rotation, the differential limiting characteristics will not become too high. Therefore, the differential limiting characteristics will not be excessively increased, and there will be no need to excessively increase the first contact force of the biasing member 43.

[0038] Therefore, such a differential device 1 can improve off-road capability while maintaining turning ability.

[0039] Furthermore, the second planar portion 41 is provided on a single plate 45 that is arranged to rotate integrally with the differential case 7. On the inner diameter side between the first planar portion 39 and the second planar portion 41, a connecting portion 51 is arranged to connect the differential case 7 and the plate 45 so that they can rotate integrally.

[0040] By providing the second planar portion 41 on the plate 45, the design of the second planar portion 41 can be carried out independently of the design of the differential case 7. Furthermore, the connecting portion 51 is located on the inner diameter side of the first planar portion 39 and the second planar portion 41. As a result, the connecting portion 51 does not protrude radially outward, and the differential case 7 can be made smaller in the radial direction.

[0041] Furthermore, the biasing member 43 is formed as a single continuous member with respect to the plate 45, and the pressing portion 53 that applies the first contact force is positioned on the outer diameter side of the connecting portion 51.

[0042] Therefore, a biasing member 43, formed from a single continuous member with respect to the plate 45, can apply a first contact force between the first flat portion 39 and the second flat portion 41. In addition, the number of parts can be reduced.

[0043] Furthermore, the inner diameter side of the inner end of the first planar portion 39 is spaced apart from the second planar portion 41 in the direction of the rotation axis.

[0044] Therefore, the inner diameter side of the inner end of the first planar portion 39 does not slide against the second planar portion 41, and thus does not affect the differential limiting characteristics.

[0045] Furthermore, the plate 45 is provided with an opening 47 that penetrates in the direction of the rotation axis.

[0046] Therefore, it becomes easier to supply lubricating oil to the second flat surface 41, thereby improving lubrication.

[0047] Furthermore, a block member 29 is positioned between the pair of side gears 13 and 15. The first contact force of the biasing member 43 acts on the pair of side gears 13 and 15 via the block member 29.

[0048] By receiving the first contact force of the biasing member 43 with the block member 29, backlash can be ensured in the gear portions of the pinion gear 11 and the side gears 13 and 15. Furthermore, the first contact force from the biasing member 43 is input from the second flat portion 41 to the first flat portion 39, and the second contact force due to the meshing reaction force is input from the first flat portion 39 to the second flat portion 41. As a result, in the rotation axis direction, the directions in which the initial torque and the differential limiting characteristics are generated are opposite, so stable performance can be obtained by making the most of each characteristic.

[0049] Furthermore, a friction material 59 is provided on at least one of the surfaces of the first flat portion 39 and the second flat portion 41.

[0050] Therefore, the friction characteristics between the first flat portion 39 and the second flat portion 41 can be stabilized, wear can be suppressed, and the differential limiting characteristics can be stabilized.

[0051] Furthermore, oil grooves are provided on at least one of the surfaces of the first flat portion 39 and the second flat portion 41.

[0052] Therefore, the friction characteristics between the first flat portion 39 and the second flat portion 41 can be stabilized, wear can be suppressed, and the differential limiting characteristics can be stabilized.

[0053] (Second Embodiment) A second embodiment will be described using Figure 4.

[0054] In this embodiment, the differential device 101 has a biasing member 103 positioned between at least one of the pair of side gears 13 and 15 and the block member 29.

[0055] In addition, the same symbols are used for components similar to those in the first embodiment, and the functional descriptions are omitted as they refer to the first embodiment. However, since the components are similar, the resulting effects and benefits are equivalent.

[0056] As shown in Figure 4, the biasing member 103 is made of a disc spring. The biasing member 103 is positioned between the pair of side gears 13 and 15 and the block member 29 in the rotation axis direction. The biasing member 103 is radially supported by the block member 29. The biasing member 103 biases the side gears 13 and 15 toward the inner surface of the differential case 7 and applies a first contact force, which is an initial torque, between the first flat portion 39 and the second flat portion 41. The first contact force from the biasing member 103 is input from the first flat portion 39 to the second flat portion 41. On the other hand, the second contact force due to the meshing reaction force is input from the first flat portion 39 to the second flat portion 41. Therefore, in the rotation axis direction, the direction in which the initial torque and the differential limiting characteristic are generated are the same, so a large TBR (differential limiting characteristic) can be generated with a small biasing force of the biasing member 103.

[0057] In such a differential device 101, the biasing member 103 is positioned between at least one of the pair of side gears 13, 15 and the block member 29. The individual plates 45 that form the second planar portion 41, which is provided opposite the first planar portion 39 of the pair of side gears 13, 15, are positioned separately from the biasing member 103 as described above. Therefore, the plates 45 can be formed from flat plates with a planar shape, and the complexity of the inner structure of the differential case 7 can be suppressed.

[0058] The first contact force from the biasing member 103 is input from the first planar portion 39 to the second planar portion 41, and the second contact force due to the meshing reaction force is input from the first planar portion 39 to the second planar portion 41. Therefore, in the rotation axis direction, the direction in which the initial torque and the differential limiting characteristics are generated are the same, so that a large differential limiting characteristic can be generated with a small biasing force of the biasing member 103.

[0059] (Third embodiment) A third embodiment will be described using Figure 5.

[0060] In this embodiment, the differential device 201 has a biasing member 203 positioned between the differential case 7 and the plate 45, and is radially supported by the differential case 7.

[0061] In addition, components similar to those in other embodiments are indicated by the same symbols, and the functional descriptions are omitted as they refer to other embodiments. However, since the configurations are similar, the resulting functions and effects are equivalent.

[0062] As shown in Figure 5, the biasing member 203 is made of a disc spring. The biasing member 203 is positioned between a flat plate 45, which is a single planar shape located on the back side of the gear portion of a pair of side gears 13 and 15, and the rotation axis of the differential case 7. The biasing member 203 is radially supported at a point where its inner diameter is located on the outer diameter side of the connecting portion 51 of the differential case 7. The biasing member 203 biases the plate 45 toward the side gears 13 and 15, and applies a first contact force, which is an initial torque, between the first planar portion 39 and the second planar portion 41. The first contact force due to the biasing member 203 is input from the second planar portion 41 to the first planar portion 39. On the other hand, the second contact force due to the meshing reaction force is input from the first planar portion 39 to the second planar portion 41. Therefore, in the rotation axis direction, the directions in which the initial torque and the differential limiting characteristics are generated are opposite, so stable performance can be obtained by making the most of each characteristic. By making the biasing member 203 separate from the plate 45, the plate 45 on which the second planar portion 41 is provided and the biasing member 203 that applies the first contact force can be designed independently. As a result, the structure is simplified, the degree of design freedom is increased, the setting and modification of characteristics is easy, and it can be constructed at low cost.

[0063] In such a differential device 201, the biasing member 203 is positioned between the differential case 7 and the plate 45 and is radially supported by the differential case 7. The plates 45, each forming a second planar portion 41 opposite the first planar portion 39 of the pair of side gears 13 and 15, are positioned separately from the biasing member 103 as described above. Therefore, the plates 45 can be formed from flat plates with a planar shape, and the complexity of the inner structure of the differential case 7 can be suppressed.

[0064] By making the biasing member 203 separate from the plate 45, the plate 45, which is provided with the second planar portion 41, and the biasing member 203, which applies the first contact force, can be designed independently. This simplifies the structure, increases design flexibility, makes it easy to set and change characteristics, and allows for low-cost construction.

[0065] Although this embodiment has been described above, this embodiment is not limited to these, and various modifications are possible within the scope of the gist of this embodiment.

[0066] For example, an oil groove is provided on the first flat surface and a friction material is provided on the second flat surface, but this is not the only option. Any combination of friction material and oil groove is acceptable, such as providing friction material or oil grooves on both surfaces, or providing friction material or oil grooves on only one surface.

[0067] Furthermore, while the biasing member uses a disc spring that offers good biasing force and space efficiency, other elements can be used as components that provide biasing force, taking into account their shape and number as appropriate. In that case, the arrangement with the differential case can be appropriately selected, taking into account the structure of the differential case, such as protrusions, holes, pores, adhesive, welding, or engagement using fixing members. [Explanation of Symbols]

[0068] 1,101,201 Differential device 7 Differential Case 11 Pinion Gear 13,15 Side gear 29 Block members 39 1st plane part 41 Second plane part 43,103,203 biasing member 45 Plates 47 Aperture 51 Connecting part 53 Pressing part 59 Friction material

Claims

1. A rotatably positioned differential case, A pinion gear is supported within the differential case so as to be able to rotate, and revolves around the rotation of the differential case, A pair of side gears that mesh with the aforementioned pinion gear and are rotatable relative to each other, Equipped with, The pinion gear and the side gear are made of a bevel gear assembly. A first planar portion perpendicular to the rotation axis is provided on the back side of the gear portion of the side gear. The differential case is provided with a second planar portion that is perpendicular to the axis of rotation and positioned opposite to the first planar portion so as to be able to contact it. A differential limiting portion, consisting of the first planar portion and the second planar portion, is arranged on the rear side of the gear portion of the side gear. The differential limiting portion is subjected to a first contact force by a biasing member, The meshing reaction force between the pinion gear and the side gear applies a second contact force to the differential limiting portion. The second planar portion is provided on a plate that is rotatably arranged integrally with the differential case, A connecting portion is provided on the inner diameter side of the differential limiting portion, which connects the differential case and the plate so that they can rotate together as a single unit. The connecting portion is a differential device having an engaging projection provided on the plate and projecting toward the inner diameter side, and an engaging recess provided on the differential case into which the engaging projection engages.

2. The differential device according to claim 1, wherein the biasing member is formed from a single member continuous with the plate, and the pressing portion that applies the first contact force is arranged on the outer diameter side of the connecting portion.

3. The differential device according to claim 1 or 2, wherein a recess is provided on the back side of the gear portion of the side gear, in the portion on the inner diameter side from the inner end of the first flat portion, so as to be spaced apart from the second flat portion in the direction of the rotation axis.

4. The differential device according to claim 1 or 2, wherein the plate is provided with an opening that penetrates in the direction of the rotation axis.

5. A block member is arranged between the pair of side gears, The differential device according to claim 1 or 2, wherein the first contact force of the biasing member acts on a pair of side gears via the block member.

6. The differential device according to claim 1 or 2, wherein the biasing member is disposed between the differential case and the plate and is radially supported by the differential case.

7. The differential device according to claim 5, wherein the biasing member is disposed between at least one of the pair of side gears and the block member.

8. The differential device according to claim 1 or 2, wherein a friction material is provided on at least one of the surfaces of the first planar portion and the second planar portion.

9. The differential device according to claim 1 or 2, wherein an oil groove is provided on at least one of the surfaces of the first planar portion and the second planar portion.

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