Differential device

Abstract

To provide a differential device capable of improving running performance while maintaining turning performance.SOLUTION: A differential device 1 includes a differential case 7 that is rotatably disposed, a pinion gear 11 that is rotatably supported in the differential case 7 and revolves by rotation of the differential case 7, and a pair of side gears 13,15 that mesh with the pinion gear 11 and are relatively rotatable. the pinion gear 11 and the side gears 13,15 form a bevel gear set, and a first flat surface portion 39 orthogonal to a rotation axis is provided on a back surface side of a gear portion of each of the side gears 13,15. The differential case 7 is provided with the second flat surface portion 41 orthogonal to the rotation axis and disposed to face the first flat surface portion 39 so as to be able to abut against the first flat surface portion 39, the first abutment force is applied between the first flat surface portion 39 and the second flat surface portion 41 by the biasing member 43, and the meshing reaction force between the pinion gear 11 and the side gear 13,15 is applied as the second abutment force between the first flat surface portion 39 and the second flat surface portion 41.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Conventionally, a differential device includes a rotatably arranged differential case and a pinion gear that is rotatably supported within the differential case and revolves as the differential case rotates. A differential device that includes a pair of side gears that mesh with the pinion gear and are rotatable relative to each other is known (see Patent Document 1). In this differential device, the pinion gear and the side gear are configured as a bevel gear set. A pressing member made of a conical spring washer is disposed axially between the differential case and the side gear.

[0003] The pressing member presses the side gear toward the pinion gear, eliminating backlash between the side gear and pinion gear. As a result, the side gear reciprocates in the direction of the rotation axis each time a tooth meshes with the pinion gear, causing minute vibrations in the direction of the rotation axis. The minute vibrations of the side gear are transmitted to the tire, imparting minute vibrations in the tire's width direction. The tire to which minute vibrations are imparted increases the coefficient of friction in the direction of rotation with respect to the road surface, suppressing tire spin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-247300 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in the differential device of Patent Document 1, if the biasing force of the pressing member, i.e., the initial torque, is increased, the range of the differential limiting characteristics can be expanded, but this increases the running resistance of the left and right wheels, making it difficult for the vehicle to turn and reducing cornering performance.

[0006] The present invention has been made in view of the problems inherent in the prior art, and an object of the present invention is to provide a differential device that can improve off-road performance while maintaining turning performance. [Means for solving the problem]

[0007] The differential device according to this embodiment includes a rotatably arranged differential case, a pinion gear rotatably supported in the differential case and revolving with the rotation of the differential case, and a pair of side gears meshing with the pinion gear and rotatable relative to each other. The pinion gear and the side gear are configured as a bevel gear set, and a first flat portion perpendicular to the rotation axis is provided on the back side of the gear portion of the side gear, and a second flat portion perpendicular to the rotation axis and arranged opposite the first flat portion so as to be able to abut against the first flat portion is provided on the differential case, and a first abutment force is applied between the first flat portion and the second flat portion by a biasing member, and a meshing reaction force between the pinion gear and the side gear applies a second abutment force between the first flat portion and the second flat portion. [Effects of the Invention]

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

[0009] [Figure 1] 1 is a cross-sectional view of a differential device according to a first embodiment. [Figure 2] FIG. 2 is a perspective view of a biasing member and a plate of the differential device according to the first embodiment. [Figure 3] FIG. 4 is a characteristic diagram showing the torque characteristics of the differential device according to the present embodiment, the torque characteristics of a comparative example, and the initial torque. [Figure 4] FIG. 6 is a cross-sectional view of a differential device according to a second embodiment. [Figure 5] FIG. 10 is a cross-sectional view of a differential device according to a third embodiment. DETAILED DESCRIPTION OF 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 proportions in the drawings are exaggerated for the sake of explanation and may differ from the actual proportions.

[0011] (First embodiment) The first embodiment will be described with reference to FIGS.

[0012] 1, a differential device 1 according to this embodiment is disposed between a drive source (not shown), such as an engine or an electric motor, and left and right wheels (not shown). 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 FIGS. 1 and 2, the differential device 1 includes a differential mechanism 3 and a differential limiting unit 5.

[0014] The differential mechanism 3 includes 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 a stationary member (not shown) such as a carrier via bearings 21 and 23 at the outer peripheries of bosses 17 and 19 formed on both axial sides. A flange 27 to which a ring gear 25 is fixed is formed on the differential case 7. 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. A pinion shaft 9, a pinion gear 11, a pair of side gears 13 and 15, etc. are housed and arranged within the differential case 7.

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

[0017] A plurality of pinion gears 11 (two in this example) are arranged at equal intervals around the circumferential direction of the differential case 7. Each of the plurality of pinion gears 11 is supported on the end side of the pinion shaft 9 and revolves with the rotation of the differential case 7. The pinion gear 11 is rotatably supported on the pinion shaft 9 so as to be rotationally driven when a differential rotation occurs between the pair of meshed side gears 13, 15. The pinion gear 11 transmits 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 housed in the differential case 7 so as to be rotatable relative to one another. The pair of side gears 13, 15 are each meshed with the pinion gear 11. The pinion gear 11 and the pair of side gears 13, 15 are configured as a bevel gear set. Spline-shaped output portions 31, 33 that output the driving force transmitted to the pair of side gears 13, 15 are provided on the inner periphery of the pair of side gears 13, 15. A pair of output shafts 35, 37 that are connected to the left and right wheels so as to be rotatable together are connected to the output portions 31, 33 so as to be rotatable together.

[0019] The differential limiting unit 5 is disposed between the differential case 7 and the pair of side gears 13, 15. The differential limiting unit 5 has a first flat portion 39 and a second flat portion 41 that slide against each other, and a biasing member 43.

[0020] The first flat portion 39 is provided on the back side of the gear portion of the side gears 13, 15. The first flat portion 39 extends in a plane direction perpendicular to the rotation axis of the side gears 13, 15. The first flat portion 39 is arranged so as to be able to abut against the second flat portion 41 in the rotation axis direction. The portion of the first flat portion 39 radially inward from its inner end forms a recess 40 that is recessed toward the pinion gear 11 so as to be spaced apart from the second flat portion 41 in the axial direction. Therefore, the portion of the first flat portion 39 radially inward from its inner end does not slide against the second flat portion 41, and does not affect the differential limiting characteristics of the differential limiting unit 5.

[0021] The second flat portion 41 is provided on a single plate 45 arranged to be rotatable integrally with the differential case 7. The second flat portion 41 is configured to rotate interlocked with the differential case 7, directly or indirectly, and abuts against the first flat portion 39 to cause relative rotation. 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 with an opening 47 penetrating in the rotational axis direction. Providing the opening 47 in the plate 45 makes it easier to supply lubricating oil to the second flat portion 41, thereby improving lubrication. The second flat portion 41 is an annular portion of the plate 45 and is arranged opposite the first flat portion 39 so as to be able to abut against it in the rotational axis direction. The second flat portion 41 extends in a planar direction perpendicular to the rotational axis of the differential case 7 so as to be parallel to the first flat portion 39.

[0022] The plate 45 is provided with a plurality (six in this example) of engaging protrusions 49 arranged at equal intervals in the circumferential direction of the second flat surface 41 and protruding radially inward from the second flat surface 41. The engaging protrusions 49 are engaged with a plurality (six in this example) of engaging recesses 50 formed in the differential case 7. The engaging protrusions 49 and the engaging recesses 50 form connecting portions 51 that allow the plate 45 to rotate integrally with the differential case 7. The connecting portions 51 are arranged on the radially inner side of the first flat surface 39 and the second flat surface 41. Therefore, the connecting portions 51 do not protrude radially outward, and the differential case 7 can be made smaller in the radial direction.

[0023] The biasing member 43 is formed as a single member continuous with the plate 45. The biasing member 43 is provided as a plurality (six in this example) of elastic portions on the plate 45 at a portion connecting the second flat portion 41 and the engaging protrusion 49. The pressing force of these elastic portions acts as a whole to exert the biasing force of the biasing member 43. The biasing member 43 is inclined so that the pressing portion 53 connected to the second flat portion 41 is located closer to the pinion gear 11 than the engaging protrusion 49 with respect to the rotational axis direction. When the plate 45 is disposed in the differential case 7, the pressing portion 53 of the biasing member 43 is located on the outer diameter side of the connecting portion 51. When the plate 45 is disposed in the differential case 7, the biasing member 43 abuts against an annular fulcrum member 57 housed in a housing groove 55 formed continuously in the circumferential direction on the outer diameter side of the connecting portion 51 of the differential case 7. The fulcrum member 57 is prevented from rotating at multiple points in the circumferential direction in the housing groove 55. However, the annular fulcrum member 57 is not required, and the axial end portion on the inner diameter side of the plate 45 and the axial end portion of the engagement recess 50 formed in the differential case 7 may come into contact with each other to receive the reaction force of the biasing force.

[0024] The biasing member 43 applies a first contact force, with the second flat portion 41 pressing against the first flat portion 39, using the contact portion with the fulcrum member 57 as a fulcrum. The first contact force of the biasing member 43 causes the first flat portion 39 and the second flat portion 41 to contact each other, generating frictional resistance in the differential limiting unit 5 and applying initial torque. Applying initial torque to the differential limiting unit 5 stabilizes the differential limiting characteristics. The first contact force of the biasing member 43 is input to a block member 29 disposed between the pair of side gears 13, 15. By having the first contact force of the biasing member 43 received by the block member 29, backlash in the gear portions of the pinion gear 11 and the side gears 13, 15 can be ensured.

[0025] A second contact force is applied to the first flat portion 39 and the second flat portion 41 of the differential limiting unit 5 from the pair of side gears 13, 15, which are moved axially in response to a meshing reaction force with the pinion gear 11, depending on the magnitude of the driving force (driving torque) input to the differential case 7. When the second contact force is applied to the first flat portion 39 and the second flat portion 41, the first flat portion 39 and the second flat portion 41 of the differential limiting unit 5 slide against each other, thereby limiting the differential movement of the differential mechanism 3. This type of differential limiting unit 5 is a torque-sensitive friction clutch.

[0026] In a conventional differential, a biasing member biases the side gears 13 and 15 toward the pinion gear 11, eliminating backlash between the pinion gear 11 and the side gears 13 and 15. Therefore, the side gears 13 and 15 reciprocate in the direction of the rotation axis each time a tooth meshing with the pinion gear 11 is replaced, causing minute vibrations in the direction of the rotation axis. The 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 to which the minute vibrations are applied increase the coefficient of friction in the direction of rotation with respect to the road surface, thereby suppressing wheel spin. In such a differential, the range of the limited slip differential characteristic can be expanded by increasing the biasing force of the biasing member, i.e., the initial torque. However, if the initial torque is increased too much, the differential rotation between the left and right wheels is easily absorbed, increasing running resistance, making it difficult for the vehicle to turn, and reducing cornering performance.

[0027] In contrast, the differential device 1 has a first flat portion 39 and a second flat portion 41 between the differential case 7 and the side gears 13, 15. A first contact force, which is an initial torque, is applied between the first flat portion 39 and the second flat portion 41 by the biasing member 43. The meshing reaction force between the pinion gear 11 and the side gears 13, 15 applies a second contact force between the first flat portion 39 and the second flat portion 41. The first flat portion 39 and the second flat portion 41 to which the second contact force is applied slide against each other, thereby achieving a differential limiting characteristic that limits the differential motion of the differential mechanism 3 (the pair of side gears 13, 15). Therefore, the first contact force of the biasing member 43 can be adjusted to match the desired differential limiting characteristic, and the initial torque does not become too high. Therefore, the differential limiting characteristic does not become too high, and wheel spin is suppressed while maintaining the vehicle's turning performance, thereby improving the vehicle's off-road performance.

[0028] In the differential limiting unit 5, the first contact force by the biasing member 43 is input from the second flat portion 41 to the first flat portion 39, and the second contact force by the meshing reaction force is input from the first flat portion 39 to the second flat portion 41. As a result, the directions in which the initial torque and the torque-sensitive differential limiting characteristic are generated are opposite in the direction of the rotation axis, making it possible to obtain stable performance that makes the most of the characteristics of each.

[0029] A friction material 59 is provided on the surface of at least one of the first flat surface portion 39 and the second flat surface portion 41 (here, the second flat surface portion 41). By providing the friction material 59 between the first flat surface portion 39 and the second flat surface portion 41, the friction characteristics between the first flat surface portion 39 and the second flat surface portion 41 are stabilized and wear is suppressed, thereby stabilizing the differential limiting characteristics. Note that the friction material 59 may be fixed integrally to the first flat surface 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 (here, the first flat portion 39). Lubricating oil that flows into the inside of the differential case 7 flows through the oil groove. By providing the 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 are stabilized and wear can be suppressed, stabilizing the differential limiting characteristics. Note that the oil groove may also be provided on the surface of the friction material 59 that is integrally fixed directly or indirectly to the second flat portion 41.

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

[0032] For example, suppose that the two sliding surfaces of differential limiting unit 5 that slide against each other are conical sliding surfaces that are inclined so as to intersect with the rotation axis. The conical sliding surfaces receive too much of the second contact force caused by the meshing reaction force between pinion gear 11 and side gears 13 and 15, which are made up of a bevel gear set, and the TBR (differential limiting characteristic) becomes too high. If the TBR becomes too high, the first contact force of biasing member 43, which serves as the initial torque, must also be increased.

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

[0034] FIG. 3 shows a characteristic diagram of torque characteristics 61 in the differential limiting unit 5 of this embodiment and torque characteristics 63 in a differential limiting unit of a comparative example. Note that the TBR is 1.5 in the differential limiting unit 5 of this embodiment, and 1.3 in the differential limiting unit of the comparative example. FIG. 3 also shows initial torque 65 in the differential limiting unit 5 of this embodiment, initial torque 67 in the differential limiting unit of the comparative example, and initial torque 69 when the initial torque is increased. Note that the initial torque is set to the same value in the differential limiting unit 5 of this embodiment and the differential limiting unit of the comparative example.

[0035] As is clear from Figure 3, setting the TBR to 1.5 while keeping the initial torque constant provides a greater effect than increasing the initial torque to expand the effective range. In addition, there is no side effect of making the vehicle harder to turn. In contrast, if you try to increase only the initial torque, as in the case of initial torque 69, it is likely to have a side effect of worsening cornering performance, making it harder for the vehicle to turn on the low torque side.

[0036] The differential device 1 includes a rotatably disposed differential case 7 and a pinion gear 11 that is rotatably supported within the differential case 7 and revolves as the differential case 7 rotates. The differential device 1 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 form a bevel gear pair. A first flat portion 39 that is perpendicular to the rotation axis is provided on the rear side of the gear portion of the side gears 13 and 15. The differential case 7 also includes a second flat portion 41 that is perpendicular to the rotation axis and is positioned opposite the first flat portion 39 so as to be able to 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. The meshing reaction force between the pinion gear 11 and the side gears 13, 15 applies a second contact force between the first flat portion 39 and the second flat portion 41.

[0037] The first flat portion 39 and the second flat portion 41, to which the second contact force is applied, slide against each other to obtain a differential limiting characteristic that limits the differential between the pair of side gears 13, 15. Therefore, the first contact force of the biasing member 43 can be adjusted to match the desired differential limiting characteristic, and the initial torque does not become too high. Therefore, the differential limiting characteristic does not become too high, and wheel spin is suppressed while maintaining the vehicle's turning performance, thereby improving the vehicle's off-road performance. Furthermore, because the first flat portion 39 and the second flat portion 41 form sliding surfaces perpendicular to the rotation axis, the differential limiting characteristic does not become too high. Therefore, the differential limiting characteristic is not excessively increased, and there is no need to excessively increase the first contact force of the biasing member 43.

[0038] Therefore, with such a differential device 1, it is possible to improve off-road performance while maintaining turning performance.

[0039] The second flat portion 41 is provided on a plate 45 that is arranged to be rotatable integrally with the differential case 7. A connecting portion 51 that connects the differential case 7 and the plate 45 to be rotatable integrally is arranged on the inner diameter side of the first flat portion 39 and the second flat portion 41.

[0040] By providing the second flat portion 41 on the plate 45, the second flat portion 41 can be designed independently of the design of the differential case 7. Furthermore, the connecting portion 51 is disposed on the inner diameter side of the first flat portion 39 and the second flat portion 41. Therefore, the connecting portion 51 does not protrude radially outward, and the differential case 7 can be made smaller in the radial direction.

[0041] Moreover, the biasing member 43 is formed of one member that is continuous with the plate 45, and the pressing portion 53 that applies the first contact force is disposed on the outer diameter side of the connecting portion 51.

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

[0043] The inner diameter side of the inner end of the first flat surface portion 39 is spaced apart from the second flat surface portion 41 in the rotation axis direction.

[0044] Therefore, the portion of the first flat portion 39 on the inner diameter side from the inner end portion does not slide against the second flat portion 41, and the differential limiting characteristic is not affected.

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

[0046] This makes it easier to supply lubricating oil to the second flat portion 41, thereby improving lubrication.

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

[0048] By having the first contact force of the biasing member 43 received by the block member 29, it is possible to ensure backlash in the gear portions of the pinion gear 11 and the side gears 13, 15. Furthermore, the first contact force by 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. Therefore, the directions in which the initial torque and the limited slip differential characteristic are generated are opposite to each other in the rotational axis direction, thereby making the most of the respective characteristics and achieving stable performance.

[0049] 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.

[0050] This stabilizes the friction characteristics between the first flat portion 39 and the second flat portion 41, suppresses wear, and stabilizes the differential limiting characteristics.

[0051] In addition, an oil groove is provided on the surface of at least one of the first flat surface portion 39 and the second flat surface portion 41.

[0052] This stabilizes the friction characteristics between the first flat portion 39 and the second flat portion 41, suppresses wear, and stabilizes the differential limiting characteristics.

[0053] (Second embodiment) The second embodiment will be described with reference to FIG.

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

[0055] Note that the same symbols are used for the same configurations as in the first embodiment, and the functional explanations will be omitted as reference will be made to the first embodiment, but since the configurations are similar, the actions and effects obtained are the same.

[0056] As shown in FIG. 4 , the biasing member 103 is made of a disc spring. The biasing member 103 is disposed between the pair of side gears 13, 15 and the block member 29 in the rotational axis direction. The biasing member 103 is supported radially by the block member 29. The biasing member 103 biases the side gears 13, 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 by the biasing member 103 is input from the first flat portion 39 to the second flat portion 41. Meanwhile, 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, the initial torque and the differential limiting characteristic are generated in the same direction in the rotational axis direction, 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 disposed between at least one of the pair of side gears 13, 15 and the block member 29. Each plate 45 forming the second flat portion 41 provided opposite the first flat portion 39 of the pair of side gears 13, 15 is disposed separately from the biasing member 103, as described above. Therefore, the plate 45 can be formed of a flat plate having a planar shape, which prevents the structure of the inner surface of the differential case 7 from becoming complicated.

[0058] The first contact force by the biasing member 103 is input from the first flat portion 39 to the second flat portion 41, and the second contact force by the meshing reaction force is input from the first flat portion 39 to the second flat portion 41. Therefore, the directions in which the initial torque and the differential limiting characteristic are generated are the same in the rotational axis direction, so a small biasing force from the biasing member 103 can generate a large differential limiting characteristic.

[0059] (Third embodiment) The third embodiment will be described with reference to FIG.

[0060] In the differential device 201 according to this embodiment, the biasing member 203 is disposed between the differential case 7 and the plate 45 and is supported by the differential case 7 in the radial direction.

[0061] Note that the same symbols are used for configurations similar to those in other embodiments, and functional descriptions will be omitted as reference will be made to other embodiments, but since the configurations are similar, the actions and effects obtained are equivalent.

[0062] As shown in FIG. 5 , the biasing member 203 is made of a disc spring. The biasing member 203 is disposed between the differential case 7 and a flat, planar plate 45 located on the rear side of the gear portions of the pair of side gears 13, 15 in the rotational axis direction. The inner diameter side of the biasing member 203 is supported radially by a portion 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, 15 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 by the biasing member 203 is input from the second flat portion 41 to the first flat portion 39. Meanwhile, 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, the directions in which the initial torque and the differential limiting characteristic are generated are opposite in the direction of the rotation axis, and stable performance can be obtained by taking advantage of the respective characteristics. By making the biasing member 203 separate from the plate 45, the plate 45 provided with the second flat portion 41 and the biasing member 203 that applies the first contact force can be designed independently. This simplifies the structure, increases the degree of freedom in design, makes it easy to set and change characteristics, and allows for a low-cost configuration.

[0063] In such a differential device 201, the biasing member 203 is disposed between the differential case 7 and the plate 45 and is supported radially by the differential case 7. Each plate 45 forming the second flat surface 41 provided opposite the first flat surface 39 of the pair of side gears 13, 15 is disposed separately from the biasing member 103, as described above. Therefore, the plate 45 can be formed of a flat plate having a planar shape, which prevents the structure of the inner surface of the differential case 7 from becoming complicated.

[0064] By making the biasing member 203 separate from the plate 45, it is possible to design the plate 45 provided with the second flat portion 41 and the biasing member 203 that applies the first contact force independently. This simplifies the structure, improves the degree of freedom in design, makes it easy to set and change the characteristics, and allows for a low-cost configuration.

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

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

[0067] Although the biasing members are disc springs, which have good biasing force and space efficiency, other elements can be used as long as they are functional components that provide a biasing force, taking into consideration the shape and number of the elements. In this case, the placement relationship with the differential case can be appropriately selected based on the structure of the differential case, such as projections, recesses, holes, adhesives, 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 2nd plane part 43,103,203 Biasing member 45 plates 47 Aperture 51 Connecting part 53 Pressing section 59 Friction material

Claims

1. A rotatably arranged differential case; a pinion gear rotatably supported in the differential case and revolving with the rotation of the differential case; a pair of side gears that mesh with the pinion gear and are rotatable relative to each other; Equipped with the pinion gear and the side gear are a bevel gear set, a first flat portion perpendicular to the rotation axis is provided on a rear surface side of the gear portion of the side gear, The differential case is provided with a second flat portion that is perpendicular to the rotation axis and is arranged opposite to the first flat portion so as to be able to abut against the first flat portion, a first contact force is applied between the first flat portion and the second flat portion by a biasing member; A differential device in which a meshing reaction force between the pinion gear and the side gear applies a second contact force between the first flat portion and the second flat portion.

2. The second flat portion is provided on a plate arranged to be rotatable integrally with the differential case, The differential device according to claim 1 , wherein a connecting portion that connects the differential case and the plate so as to be rotatable together is disposed on an inner diameter side of the first flat portion and the second flat portion.

3. 3. The differential device according to claim 2, wherein the biasing member is formed of a single member that is continuous with the plate, and a pressing portion that applies the first contact force is disposed radially outward of the connecting portion.

4. 4. The differential device according to claim 1, wherein an inner diameter side of an inner end of the first flat portion is spaced apart from the second flat portion in the rotational axis direction.

5. 4. The differential device according to claim 2, wherein the plate is provided with an opening penetrating in the direction of the rotation axis.

6. A block member is disposed between the pair of side gears, 3. The differential device according to claim 1, wherein the first contact force of the biasing member acts on the pair of side gears via the block member.

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

8. 7. The differential device according to claim 6, wherein the biasing member is disposed between at least one of the pair of side gears and the block member.

9. 4. The differential device according to claim 1, wherein a friction material is provided on a surface of at least one of the first flat portion and the second flat portion.

10. 4. The differential device according to claim 1, wherein an oil groove is provided on a surface of at least one of the first flat portion and the second flat portion.

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