JP2010164103A - Vehicle differential - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle differential capable of providing differential limiting torque suiting the driving condition of a vehicle by suppressing friction torque generated between a gear back face of a pinion gear and a gear support face of a differential case. <P>SOLUTION: The vehicle differential is equipped with side gears 3L, 3R respectively connected to a pair of output shafts, pinion gears 4, 5 meshing with the pair of side gears 3L, 3R by orthogonalizing gear shafts, the differential case 2 housing the pinion gears 4, 5 and the side gears 3L, 3R in an interior and having pinion gear support faces 10b, 11b respectively slidably supporting the pinion gears 4, 5, respectively and an electromagnetic force generator 6 for generating friction force between the differential case 2 and the pinion gears 4, 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle differential, and more particularly, to a vehicle differential equipped with a pinion gear that receives a rotational driving force from a drive side, and a side gear that meshes with the pinion gear with a gear shaft orthogonal to each other.

  As a conventional vehicle differential device, a differential case that rotates by receiving engine torque, a pair of side gears that are parallel to each other along the rotation axis of the differential case, a pair of pinion gears that mesh with the pair of side gears, Some have a pinion gear shaft through which the pair of pinion gears are inserted (for example, Patent Document 1).

  The differential case is provided with an accommodation space for accommodating a pair of side gears and a pair of pinion gears, and a pair of axle insertion holes that communicate with the accommodation space and open in a direction parallel to the axis of the pair of side gears. Yes. In addition, the differential case is provided with a pair of shaft support holes that respectively support both ends of the pinion gear shaft, and a pair of gear support surfaces that slidably support the back surfaces of the pair of pinion gears.

  The pair of side gears is composed of a bottomless cylindrical bevel gear having a boss portion and a gear portion, and is arranged so as to be movable on the rotation axis of the differential case, and each boss portion faces each axle insertion hole. It is rotatably supported in the differential case. In the pair of side gears, left and right axles are spline-fitted through the axle insertion holes.

  The pair of pinion gears is made up of bottomless cylindrical bevel gears each having a shaft insertion hole through which the pinion gear shaft is inserted. The inner peripheral surface of each shaft insertion hole is at each end of the pinion gear shaft, and the back surface of each gear is a differential case. Each of the gear support surfaces is slidably supported. The pair of pinion gears is constantly given an elastic force by a coil spring to press the back surface of each gear against each gear support surface of the differential case. A shaft insertion hole through which the pinion gear shaft is inserted is provided in the shaft center portion of the pair of pinion gears.

  The pinion gear shaft is disposed between the pair of side gears and disposed in the accommodating space of the differential case, and both ends thereof are supported by a pair of shaft support holes.

  With the above configuration, when torque from the engine side of the vehicle is input to the differential case via the drive pinion and the ring gear, the differential case is rotated about its rotational axis. Next, when the differential case is rotated, this rotational force is transmitted to the pair of pinion gears via the pinion gear shaft, and further transmitted from the pair of pinion gears to the pair of side gears. Since the axles are connected to the pair of side gears by spline fitting, the torque from the engine side is distributed according to the driving condition of the vehicle, and the drive pinion, ring gear, differential case, pinion gear shaft, pair of pinion gears, It is transmitted to the left and right axles via a pair of side gears.

  In this case, when a pair of pinion gears rotate while torque is applied to the differential case, sliding occurs on the support surfaces at both ends of the pinion gear shaft, so that frictional resistance is generated between each of these support surfaces and each pinion gear, These frictional resistances limit the differential rotation of the pair of side gears.

  Further, the rotation of the pair of pinion gears generates a thrust force on the meshing surfaces with the pair of side gears, and the thrust force moves the pair of side gears away from each other to the peripheral edge of the inner opening of each axle insertion hole. Because of the pressure contact, a frictional resistance is generated between the pair of side gears and the inner opening periphery of the pair of axle insertion holes, and the differential rotation of the pair of side gears is also limited by these frictional resistances.

  Further, when the pair of pinion gears rotates while torque is applied to the differential case, the gear back surface (gear sliding surface) of the pair of pinion gears slides on the gear support surface of the differential case, so that the gear sliding of the pair of pinion gears. A frictional resistance is generated between the moving surface and each gear support surface of the differential case, and the differential rotation of the pair of side gears is also limited by the frictional resistance.

JP 2008-164125 A

  However, according to the vehicle differential shown in Patent Document 1, the friction torque generated between the gear sliding surface of the pinion gear and the gear support surface of the differential case cannot be electrically controlled. There has been a problem that it is not always possible to obtain a differential limiting torque suitable for the running state such as the rotational speed of the wheel, the throttle opening, the steering angle, and the yaw rate.

  Accordingly, an object of the present invention is to control the friction torque generated between the gear back surface of the pinion gear and the gear support surface of the differential case, thereby obtaining a differential limiting torque suitable for the running state of the vehicle. The object is to provide a differential for a vehicle.

(1) In order to achieve the above object, the present invention provides a pair of side gears respectively connected to a pair of output shafts, and a plurality of pinion gears meshed with the pair of side gears so that the gear shafts are orthogonal to each other; A plurality of pinion gears and the pair of side gears are housed inside, and a differential case having a plurality of pinion gear support portions that slidably support the plurality of pinion gears, and friction between the differential case and the plurality of pinion gears. Provided is a vehicle differential apparatus including an electromagnetic force generator for generating torque.

(2) According to the present invention, in order to achieve the above object, a pair of side gears respectively connected to a pair of output shafts are meshed with the pair of side gears so that the gear shafts are orthogonal to each other, and a shaft insertion hole is formed. A differential case having a plurality of pinion gears in an axial center portion, a plurality of first pinion gear support portions that house the plurality of pinion gears and the pair of side gears, and slidably support the plurality of pinion gears; A pinion gear shaft having a plurality of second pinion gear support portions slidably supported in the differential case by being inserted through the shaft insertion hole and slidably supported on the inner peripheral surface of the shaft insertion hole, the pinion gear shaft, and the plurality of the plurality of pinion gear shafts An electromagnetic force generator for generating a friction torque between a pinion gear and between the differential case and the plurality of pinion gears; To provide a vehicle differential apparatus provided.

  According to the present invention, it is possible to control the friction torque generated between the gear back surface of the pinion gear and the gear support surface of the differential case, and it is possible to control the differential limiting torque according to the traveling state of the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view for explaining the entirety of a vehicle differential device according to a first embodiment of the present invention. Sectional drawing shown in order to demonstrate the whole vehicle differential device which concerns on the 1st Embodiment of this invention. Sectional drawing shown in order to demonstrate the principal part of the differential for vehicles which concerns on the 1st Embodiment of this invention. Sectional drawing shown in order to demonstrate the whole vehicle differential device which concerns on the 2nd Embodiment of this invention. Sectional drawing shown in order to demonstrate the principal part of the differential for vehicles which concerns on the 2nd Embodiment of this invention.

[First embodiment]
FIG. 1 is an exploded perspective view for explaining the entire vehicle differential device according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view for explaining the entire vehicle differential device according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view for explaining a main part of the vehicle differential device according to the first embodiment of the present invention.

(Overall configuration of vehicle differential)
In FIG. 1, a vehicle differential device denoted by reference numeral 1 includes a differential case 2 that rotates in response to engine torque, a pair of side gears 3L and 3R that are parallel to each other along a rotational axis O of the differential case 2, and these 1 A pair of pinion gears 4 and 5 meshing with the pair of side gears 3L and 3R with their gear axes orthogonal to each other, and an electromagnetic force generator for generating friction torque between the pair of pinion gears 4 and 5 and the differential case 2 6 is roughly constituted.

(Configuration of differential case 2)
As shown in FIG. 2, the differential case 2 has an accommodation space 2a for accommodating the side gears 3L, 3R, the pinion gears 4, 5 and the thrust washers 7L, 7R, and has pinion gear support portions 10, 11 (described later) as a whole. It is formed by a four-piece member consisting of a pair of cases 20 and 21 that are divided into two in the direction of the rotation axis O and parallel to each other, and a pair of spacers 22 and 22 interposed between the pair of cases 20 and 21. ing.

  The differential case 2 is provided with a pair of pinion gear support portions 10 and 11 located across both cases 20 and 21. Further, the differential case 2 has side gear passage holes 12L, 12R (in FIG. 1) that are symmetrical regions with respect to the rotation axis O and are located at positions spaced apart from the pinion gear support portions 10, 11 around the rotation axis O at equal intervals. Only the side gear passage hole 12L is shown).

  One case 20 has an axle insertion hole 9L that opens along the rotation axis O, is disposed on the left side of the differential case 2, and is entirely formed of a structure made of a magnetic material such as graphite cast iron. The left axle (not shown) of the left and right axles is inserted through the axle insertion hole 9L. A thrust washer receiving portion 9La made of a spherical surface that receives the thrust washer 7L is provided on the inner opening periphery of the axle insertion hole 9L. On the left axle side of the case 20, an annular ring gear mounting flange 13 is integrally provided along the circumferential direction in a plane perpendicular to the rotation axis O.

  The other case 21 has an axle insertion hole 9R that opens along the rotation axis O, and is disposed on the right side of the differential case 2, and the entire case 21 is a structure made of a magnetic material such as graphite cast iron, as with the case 20. Is formed by. The right axle (not shown) of the left and right axles is inserted through the axle insertion hole 9R. A thrust washer receiving portion 9Ra made of a spherical surface that receives the thrust washer 7R is provided on the inner opening periphery of the axle insertion hole 9R.

  The spacers 22, 22 are welded to the opening ends of the cases 20, 21 at both opening ends, and the whole has a magnetic resistance higher than that of the cases 20, 21 and the pinion gears 4, 5, such as stainless steel. Is formed by.

  The pinion gear support portions 10 and 11 slide on the pinion gear support surfaces 10a and 11a that slidably and rotatably support the gear outer peripheral surfaces 4a and 5a of the pinion gears 4 and 5, and the gear back surfaces 4b and 5b of the pinion gears 4 and 5. It consists of a concave hole having pinion gear support surfaces (first pinion gear support portions) 10 b and 11 b that are rotatably supported, and is formed across the cases 20 and 21.

  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 axis direction of the pinion gears 4 and 5.

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

(Configuration of side gears 3L, 3R)
As shown in FIG. 2, the side gears 3L and 3R are substantially annular gears having boss portions 3La and 3Ra and gear portions 3Lb and 3Rb having different outer diameters (having an outer diameter larger than the outer diameter of the pinion gears 4 and 5). And a bevel gear having a single tooth tip cone angle, and is rotatably supported in the differential case 2 and meshed with the pinion gears 4 and 5. The number of teeth of the side gears 3L and 3R is set to 2.1 or more times the number of teeth of the pinion gears 4 and 5 (for example, the number of teeth of the side gears 3L and 3R is 17 with respect to the number of teeth 8 of the pinion gears 4 and 5). Yes. The outer diameters of the side gears 3L and 3R are set to be larger than the outer diameters of the pinion gears 4 and 5.

  Sliding portions 3Lc and 3Rc made of spherical surfaces that are fitted to the thrust washer receiving portions 9La and 9Ra via the thrust washers 7L and 7R are provided on the rear surfaces of the side gears 3L and 3R. In the side gears 3L and 3R, left and right axles are inserted into axle insertion holes 9L and 9R, respectively, and are spline-fitted. As shown in FIG. 2, an axle spacer 14 as an axle movement restricting member is interposed between the side gears 3L and 3R.

  The axle spacer 14 has recesses 14a and 14b into which the tip portions of the left and right axles are fitted at both ends, and is disposed on the rotation axis O of the differential case 2, and is entirely formed of a substantially cylindrical body. Thereby, the connection (spline fitting) between the side gears 3L and 3R and the left and right axles is performed smoothly and reliably. The bottom surfaces of the recesses 14a and 14b of the axle spacer 14 are formed by engaging surfaces 140a and 140b with which the front end surface of the axle is engaged.

(Configuration of pinion gears 4 and 5)
Since the pinion gears 4 and 5 have substantially the same configuration, only the pinion gear 4 will be described, for example. In addition, about the pinion gear 5, the code | symbol of each site | part is attached | subjected corresponding to the code | symbol of each site | part of the pinion gear 4 (5a corresponding to the gear outer peripheral surface 4a of the pinion gear 4 on the gear outer peripheral surface of the pinion gear 4, and pinion gear) 5b is attached to the gear back surface of the pinion gear 4 corresponding to the gear back surface 4b of the pinion gear 4, respectively, and the description thereof is omitted.

  As shown in FIG. 2, the pinion gear 4 is formed of a substantially cylindrical shaftless gear having a gear outer peripheral surface 4 a and a gear rear surface 4 b, and the gear outer peripheral surface 4 a is a pinion gear support surface of a pinion gear support portion (concave hole) 10. 10a and the gear back surface 4b are slidably and rotatably supported on the pinion gear support surface 10b, respectively, and the whole is formed of a magnetic material made of, for example, graphite cast iron. The pinion gear 4 is configured to form a magnetic path M of magnetic flux generated by the electromagnetic force generator 6 together with the cases 20 and 21 of the differential case 2.

(Configuration of electromagnetic force generator 6)
As shown in FIG. 3, the electromagnetic force generator 6 includes an electromagnetic coil 6 </ b> A that generates magnetic flux, and a cover 6 </ b> B that covers the electromagnetic coil 6 </ b> A, and around the cases 20 and 21 and the spaces 22 and 22 in the differential case 2. Arranged and formed entirely by an annular structure. The electromagnetic force generator 6 is configured to generate a friction torque between the cases 20 and 21 of the differential case 2 and the pinion gears 4 and 5.

  The electromagnetic coil 6 </ b> A includes a coil holder portion 60 </ b> A and a coil winding portion 61 </ b> A, is accommodated in the cover 6 </ b> B, and is disposed across the outer peripheral surfaces of the cases 20, 21 and the spacer 22.

  The cover 6B is made of a member having a U-shaped cross section along the outer peripheral surface of the spacer 22, is disposed on the outer periphery of the differential case 2, and is fixed to the vehicle side. The cover 6B is configured to form a magnetic path M together with the pinion gears 4 and 5 and the cases 20 and 21. The cover 6B is provided with an accommodation space 60B that is open to the differential case side and is formed of a concave groove that accommodates the electromagnetic coil 6A. An air gap G is formed between the inner peripheral surface of the cover 6B and the outer peripheral surface of the differential case 2 (cases 20, 21). As the material of the cover 6B, for example, graphite cast iron is used similarly to the cases 20 and 21.

(Configuration of thrust washers 7L and 7R)
As shown in FIG. 2, the thrust washers 7L and 7R are annular washers that receive the thrust force of the side gears 3L and 3R, and are interposed between the back surfaces of the side gears 3L and 3R and the thrust washer receiving portions 9La and 9Ra. ing. The thrust washers 7L, 7R are configured to adjust the meshing between the side gears 3L, 3R and the pinion gears 4, 5.

[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 is rotated about the rotation axis O. Next, when the differential case 2 is rotated, this rotational force is transmitted to the pinion gears 4 and 5, and further transmitted from the pinion gears 4 and 5 to the side gears 3L and 3R. In this case, since the axles are spline fitted to the left and right side gears 3L and 3R, the torque from the engine side is applied to the left and right side via the drive pinion and the ring gear, differential case 2, pinion gears 4, 5 and side gears 3L and 3R. Transmitted to the axle.

  Here, when the loads applied to the wheels on the left and right axles are equal, when torque from the engine side is transmitted to the differential case 2, the pinion gears 4, 5 revolve on the side gears 3L, 3R, and the pinion gears 4, 4 5 and the side gears 3L, 3R are rotated together with the differential case 2, so that torque from the engine side is equally transmitted to the left and right axles, and the left and right wheels are rotated at the same rotational speed.

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

  In this case, when the pinion gears 4 and 5 rotate while torque is applied to the differential case 2, the gear outer peripheral surfaces 4a and 5a slide on the pinion gear support surfaces 10a and 11a, and therefore the gear outer peripheral surfaces 4a and 5a and the pinion gear support surface 10a. , 11a, and frictional resistance is generated, and the differential rotation of the side gears 3L, 3R is limited by these frictional resistances.

  Further, a thrust force in the direction of the rotation axis of each gear is generated at the meshing surfaces of the pinion gears 4 and 5 and the side gears 3L and 3R. Since the side gears 3L and 3R are moved away from each other by the thrust force generated in the side gears 3L and 3R and the thrust washers 7L and 7R are pressed against the thrust washer receiving portions 9La and 9Ra, the thrust washers 7L and 7R and the thrust washer receiver Friction resistance is generated between the portions 9La and 9Ra, and the differential rotation of the side gears 3L and 3R is also limited by these frictional resistances.

  Furthermore, since the gear sliding surfaces 4b and 5b of the pinion gears 4 and 5 are in pressure contact with the pinion gear support surfaces 10b and 11b of the differential case 2 due to the thrust force generated in the pinion gears 4 and 5, frictional resistance against rotation of the pinion gears 4 and 5 is generated. This also limits the differential rotation of the side gears 3L and 3R.

  In the present embodiment, the magnetic path M is formed in the cases 20 and 21, the pinion gears 4 and 5 and the cover 6B when the electromagnetic coil 6A is energized, so that the pinion gears 4 and 5 When rotating, the pinion gears 4 and 5 are attracted to the cases 20 and 21 by a magnetic attraction force, and the gear sliding surfaces 4b and 5b of the pinion gears 4 and 5 are in pressure contact with the pinion gear support surfaces 10b and 11b of the differential case 2. Friction resistance with respect to the rotation of 5 is generated, and this also restricts differential rotation of the side gears 3L and 3R. That is, when the vehicle travels straight on a low μ road or the like, the electromagnetic coil 6A is energized to increase the differential limiting force of the left and right axles, thereby suppressing wheel slip and enabling more stable traveling.

  Further, for example, in the case of a left turn, the brake of the left wheel is operated and the electromagnetic coil 6A is energized to increase the driving force distributed to the right wheel on the outside of the turn rather than the left wheel on the inside of the turn. It is also possible to improve the turning performance. In this case, the energization amount to the electromagnetic coil 6A is determined by calculation based on the vehicle running state such as the wheel side and the yaw rate.

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

  Friction torque generated between the gear back surfaces 4b and 5b of the pinion gears 4 and 5 and the pinion gear support surfaces 10b and 11b of the differential case 2 can be controlled, and a differential limiting torque suitable for the running state of the vehicle can be obtained. it can.

[Second Embodiment]
FIG. 4 is a cross-sectional view for explaining the whole of the vehicle differential device according to the second exemplary embodiment of the present invention. FIG. 5 is a cross-sectional view for explaining the main part of the vehicle differential apparatus according to the second embodiment of the present invention. 4 and 5, the same or equivalent members as those in FIGS. 2 and 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, a vehicle differential 31 according to the second embodiment of the present invention includes a pinion gear shaft 32 that slidably supports pinion gears 4, 5, and the pinion gear shaft 32 and the pinion gears 4. 5 and an electromagnetic force generator 33 for generating a friction torque between the differential case 2 (case main body 23) and the pinion gears 4 and 5.

  Therefore, shaft insertion holes 4c and 5c that open along the gear axis and through which the pinion gear shaft 32 is inserted are provided in the axial center of the pinion gears 4 and 5.

  The shaft insertion holes 4c and 5c are formed by stepped holes having two large and small inner surfaces with different inner diameters. Of the inner surfaces of the shaft insertion holes 4c and 5c, the inner surface having a smaller inner diameter is formed by gear sliding surfaces 40c and 50c that slide on the pinion gear support surfaces (second pinion gear support surfaces) 32a and 32b of the pinion gear shaft 32. . Of the inner surfaces of the shaft insertion holes 4c and 5c, the inner surface having a larger inner diameter is formed by gear non-sliding surfaces 41c and 51c that do not slide on the outer peripheral surface of the pinion gear shaft 32.

  The differential case 2 is interposed between a case body 23 having shaft insertion holes 23 a and 23 b for inserting both ends of the pinion gear shaft 32 therein, and an inner peripheral surface of the shaft insertion holes 23 a and 23 b and an outer peripheral surface of the pinion gear shaft 32. The side gears 3L, 3R and the pinion gears 4, 5 and the pinion gear shaft 32 are accommodated inside.

  The case body 23 is made of a material made of, for example, graphite cast iron, and the spacers 24, 24 are made of a material made of, for example, stainless steel having a magnetic resistance higher than that of the pinion gears 4, 5 and the case body 23 / pinion gear shaft 32. Has been. Of the outer diameter of the outer periphery of the case body 23, the outer diameter of the peripheral portion of the spacer 24 that forms the magnetic path M is larger than the outer diameter of the other portion facing the inner peripheral side of the electromagnetic force generator 33. Large dimensions are set. As a result, the spacer 24 is more effective than the air gap between the outer peripheral portion of the case body 23 and the electromagnetic force generator 33 (the electromagnetic coil 33A and the cover 33B) in the portion around the spacer 24 that forms the magnetic path M. The air gap between the outer peripheral portion of the case main body 23 and the electromagnetic force generator 33 (the electromagnetic coil 33 </ b> A and the cover 33 </ b> B) of the outer peripheral portion of the case main body 23 where the magnetic path M is not formed increases. Yes. Accordingly, only a small amount of magnetic flux is generated in the portion other than the peripheral portion of the spacer 24 of the case body 23, and most of the magnetic flux generated by the electromagnetic force generator 33 occupies the peripheral portion of the spacer 24 in the case main body 23. The magnetic path M is formed by passing through the differential case 23 in the thickness direction and further passing through the pinion gear 4 and the pinion gear shaft 32.

  The case body 23 is provided with pinion gear support holes 23c and 23d communicating with the shaft insertion holes 23a and 23b. The inner peripheral surfaces of the pinion gear support holes 23c, 23d are formed by pinion gear support surfaces 230c, 230d that slidably and rotatably support the gear outer peripheral surfaces 4a, 5a of the pinion gears 4, 5. The bottom surfaces of the pinion gear support holes 23c and 23d are formed by pinion gear support surfaces (first pinion gear support portions) 231c and 231d that slidably and rotatably support the gear back surfaces 4b and 5b of the pinion gears 4 and 5, respectively.

  The spacers 24, 24 are disposed between the outer peripheral surface of the pinion gear shaft 32 and the inner peripheral surfaces of the shaft insertion holes 23 a, 23 b of the case body 23.

  The pinion gear shaft 32 has a pair of pinion gear support surfaces (second pinion gear support portions) 32 a and 32 b that slidably and rotatably support the inner peripheral surfaces of the shaft insertion holes 4 c and 5 c, and the pinion gear 4 is provided in the differential case 2. , 5 are inserted through the shaft insertion holes 4c, 5c, and the whole is formed of a magnetic material such as graphite cast iron, like the case main body 23 and the pinion gears 4 and 5. A spherical bulging portion 32 c protruding in the shaft radial direction is integrally provided at a substantially central portion in the axial direction of the pinion gear shaft 32. The pinion gear shaft 32 is provided with an axle spacer 34 as an axle movement restricting member including spacer elements 34A and 34B arranged in parallel between the side gears 3L and 3R via the bulging portion 32c.

  The axle spacer 34 has recesses 34a and 34b in which the spacer elements 34A and 34B are fitted to the tip portions of the left and right axles, respectively, and is disposed on the rotation axis O of the differential case 2.

  As shown in FIG. 4, the electromagnetic force generator 33 includes a pair of electromagnetic coils 33 </ b> A that generate magnetic flux and a pair of covers 33 </ b> B that respectively cover the pair of electromagnetic coils 33 </ b> A, and the case main body 23 in the differential case 2. And the outer periphery of the spacer 24, and the whole is formed by an annular structure. The electromagnetic force generator 33 is configured to generate a friction torque between the pinion gear shaft 32 and the pinion gears 4 and 5 and between the case body 23 and the pinion gears 4 and 5.

  As shown in FIG. 5, each electromagnetic coil 33 </ b> A includes a coil holder portion 330 </ b> A and a coil winding portion 331 </ b> A, is disposed at a position facing each other via the pinion gear shaft 32, and is accommodated in the cover 33 </ b> B. Yes.

  Each cover 33B is formed of an annular body having an axis on the rotation axis O of the differential case 2, is fixed to the vehicle side, and one end portion in the direction of the rotation axis O is on one end surface in the axial direction of the pinion gear shaft 32, and the rotation axis The other end in the O direction is disposed at a position facing the outer peripheral surface of the case body 23. Each cover 33 </ b> B is configured to form a magnetic path M together with the pinion gears 4 and 5 and the case body 23 and the pinion gear shaft 32. Each cover 33 </ b> B is provided with an accommodation space 330 </ b> B that is open to the differential case side and is formed by a concave groove that accommodates a pair of electromagnetic coils 33 </ b> A. An air gap G is formed between the end surface of each cover 33 </ b> B on the differential case side and the outer peripheral surface of the differential case 2. As the material of the cover 33B, for example, graphite cast iron is used similarly to the pinion gears 4 and 5 and the case main body 23 / pinion gear shaft 32.

  In the vehicle differential device 31 configured as described above, the magnetic path M is formed in the case main body 23 and the pinion gears 4 and 5, the cover 33 </ b> B, and the pinion gear shaft 32 when the electromagnetic coil 33 </ b> A is energized. When the pinion gears 4 and 5 rotate while torque is applied, the pinion gears 4 and 5 are attracted to the case main body 23 and the pinion gear shaft 32 by the magnetic attractive force, and the gear sliding surfaces 4b and 5b of the pinion gears 4 and 5 are formed on the differential case 2. Since the pinion gear support surfaces 231c and 231d and the gear sliding surfaces 40c and 50c of the pinion gears 4 and 5 are in pressure contact with the pinion gear support surfaces 32a and 32b of the pinion gear shaft 32, friction resistance against rotation of the pinion gears 4 and 5 is generated. This limits the differential rotation of the side gears 3L and 3R. That.

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

  The differential case 2 is not divided and formed in the direction of the rotation axis O, and the mechanical strength of the differential case 2 can be increased.

  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 each embodiment, the case where two (one pair) pinion gears 4 and 5 meshing with the side gears 3L and 3R are disposed in the differential case 2 has been described, but the present invention is not limited to this, By setting the gear diameter to a small size, three or more pinion gears can be arranged in the differential case.

(2) In each embodiment, the case 20, 21 and the pinion gears 4, 5, and the cover 6B (the case main body 23 and the pinion gears 4, 5, the pinion gear shaft 32, the cover 33B) are made of a material made of graphite cast iron, and the spacer 22 ( The case where the spacers 24) are respectively formed of a material made of stainless steel has been described. However, the present invention is not limited to this, and the case and the pinion gear cover (case body and pinion gear / pinion gear shaft cover) are made of carbon for mechanical structure. The spacer may be formed of a material made of steel, and the spacer may be made of a material made of copper or the like.

  DESCRIPTION OF SYMBOLS 1,31 ... Differential gear for vehicles, 2 ... Differential case, 2a ... Accommodating space, 3L, 3R ... Side gear, 3La, 3Ra ... Boss part, 3Lb, 3Rb ... Gear part, 3Lc, 3Rc ... Sliding part, 4, 5 ... Pinion gear, 4a, 5a ... Gear outer peripheral surface, 4b, 5b ... Gear back surface, 4c, 5c ... Shaft insertion hole, 40c, 50c ... Gear sliding surface, 41c, 51c ... Gear non-sliding surface, 6, 33 ... Electromagnetic Force generator, 6A, 33A ... electromagnetic coil, 60A, 330A ... coil holder part, 61A, 331A ... coil winding part, 6B, 33B ... cover, 60B, 330B ... accommodation space, 7L, 7R ... thrust washer, 9L, 9R: Axle insertion hole, 9Lb, 9Rb ... Thrust washer receiving portion, 10, 11 ... Pinion gear support portion, 10a, 11a, 10b, 11b ... Pinion gear support surface, 12L, 12R ... Id gear passage hole, 13 ... Ring gear mounting flange, 14 ... Axle spacer, 14a, 14b ... Recess, 140a, 140b ... Engagement surface, 23 ... Case body, 23a, 23b ... Shaft insertion hole, 23c, 23d ... Pinion gear support hole , 230c, 230d, 231c, 231d ... pinion gear support surface, 32 ... pinion gear shaft, 32a, 32b ... pinion gear support surface, 34 ... axle spacer, 34a, 34b ... recess, 34A, 34B ... spacer element, G ... air gap, M ... Magnetic path, O ... Rotation axis

Claims (6)

A pair of side gears respectively connected to a pair of output shafts;
A plurality of pinion gears meshing with the pair of side gears with a gear axis orthogonal thereto;
A differential case having a plurality of pinion gear support portions that house the plurality of pinion gears and the pair of side gears therein and slidably support the plurality of pinion gears;
A vehicle differential device comprising: an electromagnetic force generator for generating a friction torque between the differential case and the plurality of pinion gears.   The differential case includes a pair of cases that bisect the plurality of pinion gear support portions in the direction of the rotation axis thereof, and a pair of spacers that are interposed between the pair of cases, and the pair of spacers 2. The vehicle differential device according to claim 1, wherein the differential gear is formed of a material having a magnetic resistance higher than that of the pair of cases and the plurality of pinion gears.   2. The plurality of pinion gears, wherein a rear surface of the plurality of pinion gears is slidably supported by the plurality of pinion gear support portions, and forms a magnetic path of magnetic flux generated by the electromagnetic force generator together with the pair of cases. Vehicle differential. A pair of side gears respectively connected to a pair of output shafts;
A plurality of pinion gears meshed with the pair of side gears with a gear shaft orthogonal to each other, and having a shaft insertion hole at an axial center;
A differential case having a plurality of first pinion gear support portions that house the plurality of pinion gears and the pair of side gears therein and slidably support the plurality of pinion gears;
A pinion gear shaft having a plurality of second pinion gear support portions that are accommodated in the differential case through the shaft insertion hole and slidably support the inner peripheral surface of the shaft insertion hole;
A vehicle differential device comprising: an electromagnetic force generator for generating a friction torque between the pinion gear shaft and the plurality of pinion gears and between the differential case and the plurality of pinion gears.   The differential case includes a case main body having a plurality of shaft insertion holes into which end portions of the pinion gear shaft are inserted, and a plurality of the differential cases interposed between an inner peripheral surface of the plurality of shaft insertion holes and an outer peripheral surface of the pinion gear shaft. The vehicle-use vehicle according to claim 4, wherein the plurality of annular spacers are formed of a material having a magnetic resistance higher than that of the case main body, the plurality of pinion gears, and the pinion gear shaft. Differential device.   The plurality of pinion gears are slidably supported by the plurality of first pinion gear support portions, and a magnetic path of magnetic flux generated by the electromagnetic force generator is formed together with the case body and the pinion gear shaft. Item 5. The vehicle differential device according to Item 4.

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