JP2019143652A - Differential device - Google Patents

Abstract

To provide a differential device which enables an influence of abrasion powder to be minimized as much as possible in a torque sensitive type LSD having a sealed structure.SOLUTION: A differential device includes: a differential case 3; a pair of side gears 5, 7; a pinion gear 9; friction clutches 49, 51 for limiting differential rotation of the pair of side gears 5, 7 according to fastening force; pressure rings 55, 57 which apply fastening force to the friction clutches 49, 51; a first sealing part P1 for sealing an exterior and an interior of the differential case 3; and a second sealing part P2 of the side gears 5, 7 against a shaft separately formed. The friction clutches 49, 51 are disposed at an outer periphery side relative to engagement parts of the side gears 5, 7 and the pinion gear 9. A space part 59a which can accumulate lubrication oil is formed on an inner peripheral surface of the differential case 3. The space part 59a is disposed at the outer periphery side of the friction clutches 49, 51.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a differential device used for an automobile or the like.

  In general, a differential device with a torque-sensitive differential limiting function (hereinafter referred to as “torque-sensitive LSD”) shares a differential carrier or transaxle lubricant.

  For this reason, CVT oil or ATF is used for torque-sensitive LSD, which causes judder noise due to stick-slip in the friction part.

  Further, when performing differential transmission while transmitting torque, wear powder is generated, and there is a risk that the host unit on which the differential device is mounted is affected by contamination.

  For example, since the differential device for the left and right front wheels of the FF vehicle is mounted in the A / T unit, the wear powder generated from the differential device is mixed with the A / T oil.

  The A / T unit is not limited to wear powder, but it is apt to contaminate, and those having a certain particle size or more cause malfunction of the A / T valve.

  Some have provided a partition between the actuator mounting part and the A / T mechanism part to make it a completely separate room so that the wear powder does not adversely affect the A / T mechanism part. In such a configuration, the oil must be injected separately, and two sets of injection and drainage plugs and breathers are required, which increases the number of parts, complicates management as a unit, and adversely affects vehicle costs. There was a problem to affect.

  On the other hand, Patent Document 1 proposes a torque-sensitive LSD that can prevent the generation of wear powder to the outside and eliminate the influence of contamination on the host unit.

  This torque-sensitive LSD has a structure in which a rotational seal is provided between a casing (also referred to as a “difference case”) and an output shaft so that a mechanism portion is sealed and lubricating oil is sealed inside.

  However, no consideration is given to the dispersion of the wear powder in the casing, and there is a problem that the wear powder tends to cause judder noise by affecting the frictional portion at the time of differential restriction.

JP 2000-205375 A

  The problem to be solved is that the torque-sensitive LSD with a sealed structure in which lubricating oil is enclosed is not considered for the dispersion of the wear powder in the casing, and the friction of the wear powder at the time of differential restriction is not considered. It is a point that it is easy to invite judder sound by affecting the part.

  The present invention provides a differential case that inputs or outputs torque, and is rotatably supported and inserted in the differential case in order to minimize the influence of wear powder in a torque-sensitive LSD having a sealed structure. A pair of side gears for outputting or inputting torque via a shaft, a pinion gear rotatably supported by a pinion shaft in the differential case and meshing with the side gears, and disposed between the differential case and the side gear. A friction member for limiting the differential rotation of the pair of side gears according to the fastening force, and engaging the differential case and the pinion shaft to enable the torque transmission by rotating the differential case as the pinion gear revolves. A pressing member that moves according to the pressure and applies a fastening force to the friction member, and the differential case A first sealing portion disposed between the side gear and sealing the inside and outside of the differential case; and a second sealing portion of the side gear with respect to the separate shaft or a second sealing portion between the side gear and the pinion shaft. Or a second sealing portion between the side gears or a second sealing portion between the side gears, and the friction member is disposed on the outer peripheral side of the meshing portion of the side gear and the pinion gear, A space that can store lubricating oil is formed on the peripheral surface, and the space is disposed on the outer peripheral side of the friction member.

  Since this invention is the said structure, internal wear powder can be collected in a space part by centrifugal force by rotation of a differential case, and the influence on a friction member etc. can be suppressed as much as possible.

FIG. 3 is a cross-sectional view of the differential device taken along line II in FIG. 2. (Example 1) FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1 of the differential device. (Example 1) FIG. 5 is a cross-sectional view of the differential device taken along line III-III in FIG. 4. (Example 2) FIG. 4 is a cross-sectional view of the differential device taken along line IV-IV in FIG. 3. (Example 2) It is principal part sectional drawing which shows the 1st, 2nd sealing part. (Example 3) It is principal part sectional drawing which shows the 1st, 2nd sealing part. (Example 4) It is principal part sectional drawing which shows the sealing part of the side gear with which a shaft is integral. (Example 5)

  In order to achieve the object of making it possible to suppress the influence of wear powder as much as possible in a torque-sensitive LSD having a sealed structure, the present invention is provided with a differential case for inputting torque, and is rotatably supported in the differential case. A pair of side gears that output torque via a shaft that is inserted and coupled, a pinion gear that is rotatably supported by a pinion shaft in the differential case and meshes with the side gears, and is disposed between the differential case and the side gear. A friction member for limiting the differential rotation of the pair of side gears according to the fastening force, and engaging the differential case and the pinion shaft to enable torque transmission by rotating the differential case as the pinion gear revolves. A pressing member that moves according to transmission and applies a fastening force to the friction member; A first sealing portion that is disposed between the first gear and the side gear and seals the inside and outside of the differential case; and a second sealing portion of the side gear with respect to the separate shaft, and the friction member includes the side gear and This is realized by arranging a space part that can store lubricating oil on the inner peripheral surface of the differential case, and arranging the space part on the outer peripheral side of the friction member. .

  The friction member may be arranged separately for each of the pair of side gears, and the space may extend over the friction members arranged separately.

  The side gear may include a coupling hole through which the separate shaft is inserted and coupled, and the second sealing portion of the side gear may be a cap that closes the inner end of the coupling hole.

  The cap includes an opening that allows the coupling hole to communicate with the inside of the differential case, and the opening includes a removable plug, and the pinion shaft passes through the space and the center side of the differential case. A hole may be provided.

  A differential case that inputs or outputs torque, a pair of side gears that are rotatably supported in the differential case and that outputs or inputs torque via an integral shaft, and a pinion shaft that is rotatably supported in the differential case by the pinion shaft A pinion gear meshing with each side gear; a friction member disposed between the differential case and the side gear for limiting differential rotation of the pair of side gears according to a fastening force; and engaging the differential case and the pinion shaft. Sealing between the differential case and the integral shaft, and a pressing member that enables torque transmission by rotating the differential case as revolution of the pinion gear and moves in accordance with the torque transmission and applies a fastening force to the friction member And the friction member is formed from a meshing portion of the side gear and the pinion gear. Is disposed on the outer peripheral side, the inner peripheral surface of the differential case, to form a space capable sump lubricating oil, the space was realized by disposed on the outer peripheral side of the friction member.

  A permanent magnet may be provided in the space portion.

  FIG. 1 is a cross-sectional view of the differential apparatus according to the embodiment of the present invention taken along line I-I in FIG. 2 is a cross-sectional view of the differential device taken along the line II-II in FIG.

  In the following description, the axial direction means the direction of the rotational axis of the differential case, and the rotational direction means the rotational direction of the differential case.

  As shown in FIG. 1, the differential device 1 is a torque-sensitive LSD having a sealed structure that is disposed, for example, between front wheels of an FF vehicle in an A / T unit.

  The differential device 1 includes a differential case 3, a pair of side gears 5 and 7, and a pinion gear 9.

  The differential case 3 receives an input of torque within A / T, for example, and includes a main body portion 11 and a lid portion 13.

  Note that the differential device 1 can be configured as a center differential and output from the differential case 3.

  The main body portion 11 is integrally provided with a main body flange portion 15 on one side of the main body peripheral wall portion 14 and a main body end wall portion 17 on the other side. A boss portion 19 for supporting the shaft is integrally provided on the end wall portion 17 of the main body, and an outer peripheral surface of the boss portion 19 serves as a bearing support portion 19a. A helical groove 19b for shaft lubrication is formed on the inner peripheral surface of the boss portion 19.

  A fastening receiving surface 17a and a relief surface 17b are provided on the inner surface in the axial direction of the main body end wall portion 17, and the fastening receiving surface 17a protrudes relatively inward in the axial direction with respect to the relief surface 17b. A side gear sliding surface 17f is formed on the inner surface of the main body end wall portion 17 on the inner diameter side of the flank 17b. The side gear sliding surface 17f is a flat surface along the radial direction.

  The inner peripheral side of the main body end wall portion 17 is formed thick in the axial direction, and a concave portion 17c for rotation support is formed in a circular shape. On the inner peripheral side of the main body end wall portion 17, a seal accommodating recess 17 d that accommodates the seal of the first sealing portion P <b> 1 in the recess 17 c is formed in a circular shape. The seal housing recess 17d is formed in a stepped shape in the axial direction. At the base of the boss portion 19, a through-hole 17e for lubrication that communicates with the concave portion 17c is formed.

  The lid portion 13 is integrally provided with a lid flange portion 23 on the outer peripheral side of the lid peripheral wall portion 21 and is integrally provided with a lid end wall portion 25 on the inner peripheral side. A boss portion 27 is integrally projected on the lid end wall portion 25, and an outer peripheral surface of the boss portion 27 serves as a bearing support portion 27a. On the inner peripheral surface of the boss portion 27, a spiral groove 27b for shaft lubrication is formed.

  A fastening receiving surface 25a and a relief surface 25b are provided on the inner surface of the lid end wall portion 25, and the fastening receiving surface 25a protrudes inward in the axial direction with respect to the relief surface 25b. The fastening receiving surface 25a is formed on the inner end surface of the protruding portion 25c. The fastening receiving surface 25 a is disposed at a position facing the fastening receiving surface 17 a of the main body end wall portion 17. The projecting portion 25 c is formed in a circular shape on the inner surface of the lid end wall portion 25.

  The inner peripheral side of the lid body end wall portion 25 is formed thick in the axial direction, and a side gear sliding surface 25d is formed. The side gear sliding surface 25d is a cone-shaped protruding surface.

  On the inner periphery of the lid body end wall portion 25, a concave portion 25e for rotation support is formed in a circular shape. On the inner peripheral side of the lid end wall portion 25, a seal accommodation recess 25f for accommodating the seal of the first sealing portion P1 is formed in a circular shape in the recess 25e. The seal housing recess 25f is formed in a stepped shape in the axial direction. At the base of the boss portion 27, a through-hole 25e for lubrication communicating with the concave portion 25e is formed.

  On the inner periphery of the lid body end wall portion 25, a concave portion 25c for rotation support is formed in a circular shape. On the inner peripheral side of the lid body end wall portion 25, a seal housing recess 25f constituting the first sealing portion P1 is formed in a circular shape in the recess 25c. The seal housing recess 25f is formed in a stepped shape in the axial direction. At the base of the boss portion 27, a through hole 25g for lubrication communicating with the concave portion 25e is formed.

  A lid flange portion 23 is fitted to the main body flange portion 15 via an O-ring 30 and fastened and fixed by a flat bolt 28. As a result, the lid 13 is attached to the main body 11, and the sealed differential case 3 is configured. A ring gear that receives torque input from the drive pinion gear in the A / T is fastened and fixed to the flange portion including the main body flange portion 15 and the lid flange portion 23.

  As shown in FIGS. 1 and 2, a pin insertion groove 29 having a semicircular cross section is provided on the inner peripheral surface of the main body peripheral wall portion 14, and the pin insertion grooves 29 are arranged at predetermined intervals in the rotational circumferential direction of the differential case 3. A plurality are provided.

  The side gears 5 and 7 output torque to an axle shaft, which is a shaft that is rotatably supported in the differential case 3 and is inserted and coupled separately. In the case where the differential device 1 is configured as a center differential, the output of the drive shaft of the transmission can be input from one of the side gears 5 and 7.

  The side gears 5 and 7 are provided with gear portions 39 and 41 on the front side of the circumferential gear main body portions 35 and 37 and are bevel gears. Boss portions 35a and 37a for rotational fitting are formed on the back surfaces of the gear main body portions 35 and 37 in a circular shape. The boss portions 35a and 37a are rotatably supported by the recesses 17c and 25e of the differential case 3, and close the inner peripheries of the seal housing recesses 17d and 25f.

  The back surface of the side gear 5 is formed as a flat surface along the radial direction. With the boss 39a of the side gear 5 supported by the recess 17c of the differential case 3, the back surface of the side gear 7 faces the side gear sliding surface 17f of the main body end wall 17 of the differential case 3.

  The back surface of the side gear 7 is formed in a concave shape and has a cone-shaped concave surface. In a state where the boss portion 37 a of the side gear 7 is supported by the recess 25 e of the differential case 3, the cone-shaped concave surface of the side gear 7 faces the side gear sliding surface 25 d of the lid end wall portion 25 of the differential case 3.

  In the seal housing recesses 17d and 25f, an X ring 20a is housed together with the seal seat 20b as a seal, and constitutes the first sealing portion P1. The X ring 20a is configured as a seal that can withstand high temperatures and high pressures. However, other general seals such as O-rings can also be applied. The first sealing portion P1 is disposed between the differential case 3 and the side gears 5 and 7, and seals the inside and outside of the differential case 3.

  The gear body portions 35 and 37 of the side gears 5 and 7 are provided with coupling holes 35b and 37b penetrating the inner periphery thereof. The coupling holes 35b and 37b are for inserting and coupling the axle shaft, and inner splines are formed in the coupling holes 35b and 37b. An attachment recess 35c and an attachment projection 37c are formed on the inner peripheral portion of the gear main body portions 35, 37 on the opposite side in the axial direction.

  Caps 40 and 46 constituting the second sealing portion P2 are attached to the attachment recess 35c. The caps 40 and 46 are positioned at the inner ends of the gear main body portions 35 and 37 in the axial direction, and close the inner end portions of the coupling holes 35b and 37b on the inner periphery of the gear main body portions 35 and 37 to form a bag structure. It is.

  That is, the second sealing portion P2 is configured on the side gears 5 and 7 side with respect to a separate axle shaft.

  The inside of the differential case 3 is sealed by the first and second sealing portions P2, and lubricating oil is sealed in the sealed space. As this lubricating oil, a dedicated LSD oil can be adopted, and unlike CVT oil, ATF, etc., stick slip or the like hardly occurs when a friction clutch described later is engaged.

  Engaging members 43 and 45 are integrally provided on the outer periphery of the gear main body portions 35 and 37 by precision forging or the like. The engaging members 43 and 45 have a shape that protrudes from the gear main body portions 35 and 37 to the outer peripheral surface of the pinion gear 9.

  The inner peripheral surfaces of the engaging members 43 and 45 have a gap between them and the outer peripheral surface of the pinion gear 9. At the inner ends of the engaging members 43 and 45 in the axial direction, engaging portions for engaging friction plates are formed. The outer end portions in the axial direction of the engaging members 43 and 45 are opposed to the flank surfaces 17b and 25b of the differential case in the axial direction.

  A pair of axle shafts that pass through the boss portions 19 and 27 of the differential case 3 and are inserted into the coupling holes 35b and 37b are splined to the side gears 5 and 7.

  The pinion gear 9 is a four-pinion type including four pieces, and is rotatably supported by a cross-shaped pinion shaft 47. Each pinion gear 9 meshes with each side gear 5, 7. This engagement constitutes a differential gear, which allows torque transmission between the differential case 3 and the side gears 5 and 7 and allows relative rotation between the side gears 5 and 7.

  The pinion shaft 47 is not in the form of an integral spider, but is configured by combining two shaft members 48 and 50 in a cross shape. The intermediate portions 48a and 50a of each member are formed in a thin plate shape and intersect to form a cross. Four pinion shafts 47a are formed on the pinion shaft 47 as the tip of the cross, and each pinion gear 9 is fitted and supported in a loosely fitted state. The four gear support shaft portions 47a have bottomed shaft holes 47aa for weight reduction.

  In addition, although demonstrated also in Example 2, the shaft hole 47aa of any gear support shaft part 47a can also be formed as a through hole for oil exchange. The pinion shaft 47 is a specification of a 4-pinion type, but can be configured as a 2-pinion type. The same applies to other embodiments.

  In the intermediate portions 48a and 50a of the pinion shaft 47 assembled in a cross shape, a cross-shaped concave portion 47b facing the side gear 7 is formed. The cap 46 is loosely fitted in the recess 47b. On the opposite side of the recess 47b in the axial direction, the intermediate portions 48a and 50a of the pinion shaft 47 are assembled in a substantially flat shape and face the cap 40.

  Between the side gears 5 and 7 and the differential case 3, multi-plate friction clutches 49 and 51 as friction members are disposed adjacent to each other in the axial direction of the fastening receiving surfaces 17a and 25a. A pressure receiving ring 52 is interposed between the friction clutch 49 and the fastening receiving surface 17a, and the friction clutch 51 directly faces the fastening receiving surface 25a.

  The friction clutches 49 and 51 limit the differential rotation between the side gears 5 and 7 according to the fastening force.

  The inner plates of the friction clutches 49 and 51 are engaged with the engaging portions for engaging the friction plates of the engaging members 43 and 45 in the rotational direction, and are movable in the direction along the rotational axis. The outer plates of the friction clutches 49 and 51 are engaged with the pin 53 in the rotational direction, and are movable in the direction along the rotational axis of the differential case 3. The friction clutches 49 and 51 are configured to engage with the differential case 3 by engaging with the pins 53.

  With this structure, the friction clutches 49 and 51 that are friction members are arranged on the outer peripheral side of the meshing portions of the side gears 5 and 7 and the pinion gear 9.

  The pin 53 is fitted in the pin insertion groove 29. One end of the pin 53 is supported in the radial direction by the outer periphery of the pressure receiving ring 52, and the other end of the pin 53 is supported in the radial direction by the outer periphery of the protruding portion 25 c of the lid end wall portion 25. .

  Pressure rings 55 and 57 as pressing members are provided adjacent to the friction clutches 49 and 51 in the axial direction. The pressure rings 55 and 57 are engaged with the differential case 3 and the pinion shaft 47 to enable torque transmission as the revolution of the differential case 3 revolves around the pinion gear 9 and move according to the torque transmission, and are friction members that are the friction members. A fastening force is applied to the clutches 49 and 51.

  That is, the friction clutches 49 and 51 can be fastened with the fastening receiving surfaces 17a and 25a by the movement of the pressure rings 55 and 57.

  The pressure rings 55 and 57 have a plurality of semicircular recesses on the outer peripheral surface engaged with the pins 53 in the rotational direction, respectively, and can move in the direction along the rotational axis. The pressure rings 55 and 57 are engaged with the differential case 3 by engaging with the pin 53.

  Each of the pressure rings 55 and 57 is provided with a cam surface on the side facing the pinion shaft 47. The cam surface is formed in, for example, a concave shape, and is configured to engage with the outer peripheral surface of the pinion shaft 47.

  The pressure rings 55 and 57 are provided with spherical portions on the inner periphery, and support the back surface of the pinion gear 9.

  A coil spring 63 is supported between the opposing surfaces of the pressure rings 55 and 57.

  The coil spring 63 is elastically brought into contact with the opposing surfaces of the pressure rings 55 and 57 and applies preload to the friction clutches 49 and 51 via the pressure rings 55 and 57.

[Space]
In the embodiment of the present invention, in addition to sealing the inside of the differential case 3, spaces 59a and 59b capable of storing lubricating oil are formed on the inner peripheral surface of the differential case 3, and the spaces 59a and 59b are the friction members. The friction clutches 49 and 51 are arranged on the outer peripheral side.

  As described above, the friction clutches 49 and 51 are separately disposed on the pair of side gears 5 and 7, and the space portions 59 a and 59 b are formed so as to extend over the friction clutches 49 and 51, respectively. .

  That is, as shown in FIG. 1, the space portion 59a is formed on the inner peripheral surface of the main body peripheral wall portion 14 of the differential case 3 in the axial direction, and the outer peripheral portions of the friction clutches 49 and 51 are coupled in the axial direction by the space portion 59a. In addition, the configuration extends over the friction clutches 49 and 51 arranged separately. The same applies to the space 59b.

  In addition, the friction clutches 49 and 51 can be configured by only one of them, and in this structure, the space portions 59a and 59b can be formed short in the axial direction. Even when only one of the friction clutches 49 and 51 is configured, a space portion having a length extending over both the side gears 5 and 7 can be formed as in FIG.

  In the spaces 59 a and 59 b, a guide surface that is inclined in the axial direction can be formed on the inner peripheral surface of the main body peripheral wall portion 14. In the form of FIG. 1, it can be a guide surface that is gradually inclined toward the outer peripheral side from the gear support shaft portion 47a side toward both friction clutches 49 and 51, or a guide surface that is inclined in the opposite direction.

  When only one of the friction clutches 49 and 51 is configured, the guide surface gradually inclines outward from one axial end side of the space portions 59a and 59b toward the friction clutch 49 or the friction clutch 51 side, or in the opposite direction. The guide surface can be inclined.

  By such a guide surface, the abrasion powder is guided together with the lubricating oil by centrifugal force, and the abrasion powder can be collected.

  A plurality of spaces 59 a and 59 b are arranged at regular intervals in the circumferential direction of the inner peripheral surface of the main body peripheral wall 14 of the differential case 3. In the present embodiment, it is provided at a total of eight locations with a 45 degree arrangement. The four space portions 59a are disposed so as to face the gear support shaft portion 47a of the pinion shaft 47 in the radial direction, and are relatively wide in the circumferential direction. The remaining four space portions 59b are arranged between the space portions 59a, and are formed with a relatively narrow width in the circumferential direction. However, the space portions 59a and 59b can be formed to have the same circumferential width.

  The spaces 59a and 59b have a flat, semi-cylindrical shape in the cross-section of FIG. 2 and have a wide opening on the inner diameter side, and have a permanent magnet 61 inside. Both sides in the circumferential direction of the spaces 59a and 59b are formed as curved surfaces and reach the inside fixing portion.

  The permanent magnet 61 adsorbs wear powder. Two permanent magnets 61 are arranged side by side in the circumferential direction in the relatively wide space 59a. One permanent magnet 61 is disposed in the circumferential direction in the relatively narrow space 59b. Four permanent magnets 61 in the space portions 59a and 59b are provided in the axial direction. However, the number of permanent magnets 61 is arbitrary.

  The thickness dimension of the permanent magnet 61 is slightly smaller than the depth dimension of the space portions 59a and 59b. For this reason, the permanent magnet 61 is accommodated in the space parts 59a and 59b.

[Action]
The differential device 1 includes a ring gear attached to a flange portion including a main body flange portion 15 and a lid flange portion 23, in which bearing support portions 19 a and 27 a of the differential case 3 are rotatably supported in the A / T via bearings. Engage with the drive pinion gear.

  The axle shaft is inserted into the coupling holes 35b and 37b of the side gears 41 and 39 from the left and right boss portions 27 and 19, and is splined.

  When torque is input from the drive pinion gear through the ring gear, the differential case 3 rotates. As the differential case 3 rotates, torque is transmitted to the pressure rings 55 and 57 engaged with the pin 53, and torque is transmitted to the pinion shaft 47 via the cam surface. By this torque transmission, the pinion gear 9 and the side gears 5 and 7 rotate together with the differential case 3. Torque is transmitted from the side gears 5 and 7 via the left and right axle shafts, and the left and right wheels are rotationally driven.

  Lubrication between the axle shaft, the boss portions 19 and 27, and the coupling holes 35b and 37b is performed by the lubricating oil in the A / T. The lubricating oil is supplied from the spiral grooves 19b and 27b and the through holes 17e and 25g, and is distinguished from the lubricating oil inside the differential case 3.

  When the cam surfaces of the pressure rings 55 and 57 abut on the pinion shaft 47 in the rotational direction, the pressure rings 55 and 57 are moved toward the friction clutches 49 and 51 by the cam action. By this movement, the friction clutches 49 and 51 are fastened between the pressure rings 55 and 57 and the fastening receiving surfaces 17a and 25a.

  In this case, as the torque transmitted from the differential case 3 to the pressure rings 55 and 57 increases, the cam force of the cam surfaces of the pressure rings 55 and 57 increases. Strengthen. The engaging members 43 and 45 and the differential case 3 are frictionally engaged by the fastening force of the friction clutches 49 and 51, and differential restriction between the side gears 5 and 7 is performed. As described above, the differential limiting force increases as the torque increases.

  At the same time, when the side gears 5 and 7 are moved in the axial direction by the meshing reaction force with the pinion gear 9, the flat back surface of the side gear 5 slides against the side gear sliding surface 17f and slides on the other side. The cone-shaped concave surface slides in pressure contact with the cone-shaped side gear sliding surface 25d.

  The frictional force of the friction clutches 49 and 51 and the direct sliding with the side gears 5 and 7 and the differential case 3 cooperate to ensure a differential limiting force.

  Torque is transmitted to the left and right wheels while performing differential restriction in accordance with torque increase.

  In addition, since the preload is applied to the friction clutches 49 and 51 via the pressure rings 55 and 57 by the urging force of the coil spring 63, torque transmission can be performed while obtaining a differential limiting force from the beginning.

  During the differential rotation of the left and right wheels, the pinion gear 9 rotates around the gear support shaft portion 47a of the pinion shaft 47. By this rotation, the differential rotation between the side gears 5 and 7 can be allowed, and the differential rotation can be limited by the friction force according to the preload and torque of the friction clutches 49 and 51.

  Therefore, stable cornering traveling or the like is enabled by a reliable differential limiting force during cornering traveling or the like.

  At the time of such differential limitation, wear powder is generated from each portion that slides frictionally. In particular, wear powder generated from the friction clutches 49 and 51 is mainly used, and the wear powder collects in the spaces 59a and 59b on the outer peripheral side of the friction clutches 49 and 51 by centrifugal force.

  The abrasion powder collected in the spaces 59a and 59b is held by the permanent magnet 61 and the like, and the influence on each functional part such as the differential gear and the friction clutches 49 and 51 inside the differential case 3 can be suppressed.

  In addition, the spaces 59a and 59b become oil reservoirs, which can increase the amount of lubricating oil to the friction clutches 49 and 51, etc., improving durability and improving reliability.

[Effect of Example]
In the embodiment of the present invention, a differential case 3 for inputting or outputting torque, and a pair of side gears 5 and 7 for outputting torque via an axle shaft that is rotatably supported in the differential case 3 and inserted and coupled separately. A pinion gear 9 that is rotatably supported by a pinion shaft 47 in the differential case 3 and meshes with the side gears 5, 7, and the pair of side gears 5 disposed between the differential case 3 and the side gears 5, 7, 7 is engaged with the friction clutches 49 and 51 for limiting the differential rotation according to the fastening force, and the differential case 3 and the pinion shaft 47, and the rotation of the differential case 3 can be transmitted as the revolution of the pinion gear 9. And a pressure ring 55 that moves according to the torque transmission and applies a fastening force to the friction clutches 49, 51, 7, the X ring 20a of the first sealing portion P1 that is disposed between the differential case 3 and the side gears 5 and 7 and seals the inside and outside of the differential case 3, and the side gears 5 and 7 with respect to the separate axle shaft The caps 40 and 46 of the second sealing portion P2 are provided.

  Therefore, the inside of the differential case 3 is sealed by the first and second sealing portions P2, and the dedicated LSD oil can be sealed in the sealed space. The dedicated LSD oil, unlike CVT oil, ATF, and the like, can hardly cause stick-slip or the like when the friction clutches 49 and 51 are engaged.

  Further, during cornering traveling, differential rotation is allowed, and the LSD function by the friction clutches 49, 51, etc. is exhibited, and stable cornering traveling or the like is enabled by differential limitation.

  In addition, the friction clutches 49 and 51 are disposed on the outer peripheral side of the meshing portion of the side gear 3 and the pinion gear 9, and space portions 59 a and 59 b that can store lubricating oil are formed on the inner peripheral surface of the differential case 3. The space portions 59a and 59b are disposed on the outer peripheral side of the friction clutches 49 and 51.

  At the time of differential limitation, wear powder is generated from each part that slides frictionally. In particular, wear powder generated from the friction clutches 49 and 51 is mainly used. The abrasion powder is also generated from the meshing portion between the pinion gear 9 and the side gears 5 and 7 and the sliding portion between the side gears 5 and 7 and the differential case 3.

  The wear powder collects in the space portions 5959a and 59b on the outer peripheral side of the friction clutches 49 and 51 by centrifugal force. The wear powder collected in the space portions 5959a and 59b is held by the permanent magnet 61, and the influence on each functional portion such as the differential gear and the friction clutches 49 and 51 in the differential case 3 can be suppressed.

  Since the influence of the wear powder on the friction part of the LSD can be suppressed, the generation of judder noise can be suppressed.

  Since the wear powder is not discharged out of the differential case 3, the influence on the transmission hydraulic pressure control unit can be prevented.

  In addition, the space 59 becomes an oil reservoir, and the amount of lubricating oil to the friction clutches 49 and 51 can be increased, so that durability is improved and reliability is increased.

  Since the space 59 extends between the pair of friction clutches 49, 51, the space 59 is wide and a sufficient oil reservoir can be formed, and both friction clutches 49, 51 can be formed with the lubricating oil accumulated in the space 59. Can be sufficiently lubricated.

  The second sealing portions P2 of the side gears 5 and 7 are caps 40 and 46 that close the inner ends in the axial direction of the coupling holes 35b and 37b.

  For this reason, before the axle shaft is inserted and coupled, the coupling holes 35b and 37b of the side gears 5 and 7 can be put into a bag state and the differential case 3 can be independently sealed together with the X ring 20a.

  Therefore, the LSD oil can be sealed with the differential device 1 alone, and handling is easy.

  Permanent magnets 61 are provided in the spaces 59a and 59b.

  For this reason, the abrasion powder collected by the centrifugal force in the space 59 on the outer peripheral side of the friction clutch 49, 51 is held by the permanent magnet 61, and each functional part such as the differential gear inside the differential case 3, the friction clutch 49, 51, etc. The influence on can be suppressed.

  3 and 4 show a differential apparatus according to Embodiment 2 of the present invention. 3 is a cross-sectional view of the differential device taken along line III-III in FIG. 4 is a cross-sectional view of the differential device taken along the line IV-IV in FIG. 3.

  The basic configuration is the same as that of the first embodiment, and the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

  The differential device 1 according to the second embodiment has a structure that facilitates oil exchange inside.

  As shown in FIGS. 3 and 4, in the differential device 1 according to the second embodiment, the cap 40 includes an opening 65. The opening 65 allows the coupling hole 35 a to communicate with the inside of the differential case 3. The opening 65 is provided with a detachable plug 67.

  The cap 40 is formed such that the inner end side is thick in the axial direction, and the opening 65 is formed in a stepped shape at the axial center. A female screw portion is formed in the opening 65, and a plug 67 is detachably screwed to the opening 65 by the female screw portion.

  The pinion shaft 47 is formed in a spider shape, and each gear support shaft portion 47a is fixed to the ring portion 47c by fitting such as press fitting. One of the gear support shaft portions 47a is provided with a through hole 47ab communicating with the space portion 59a and the inner peripheral side of the ring portion 47c, which is the center side in the differential case 3.

  The gear support shaft portion 47a provided with the through hole 47ab is formed to be relatively longer than the other gear support shaft portions 47a, and the end portion is located in the space portion 59a. In the space 59a where the end is located, the magnet is not disposed or disposed on both sides of the gear support shaft portion 47a in the axial direction of the differential case 3.

  The ring portion 47c is fitted to the outer peripheral surfaces of the caps 40 and 46, and supports the axially inner end sides of the side gears 5 and 7 so as to be relatively rotatable. The end surface in the axial direction of the ring portion 47 c is opposed to the front surfaces of the side gears 5 and 7.

  A plurality of circumferential grooves 47ca in the axial direction are formed on the inner periphery of the ring portion 47c with respect to the caps 40 and 46. The circumferential groove 47 ca forms a labyrinth packing with respect to the caps 40 and 46.

  Therefore, in the second embodiment, the second sealing portion P2 includes the ring portion 47c including the plurality of circumferential grooves 47ca, the caps 40 and 46, and the plug 67.

  Other configurations are substantially the same as those in the first embodiment.

  Also in the second embodiment, the same effects as those of the first embodiment can be achieved by the first sealing portion P1 formed by the X ring 20a and the like and the second sealing portion P2 formed by the plurality of circumferential grooves 47ca and the like. .

  In the second embodiment, when the LSD oil sealed in the differential case 3 is deteriorated, the oil can be easily changed by the following procedure.

  The differential device 1 adjusts the rotational position so that the through-hole 47ab is downward.

  The axle shaft is pulled out from the coupling hole 35b on the side gear 5 side of the differential device 1.

  The plug 67 of the cap 40 is screwed back and removed, and a suction pump is connected to the boss portion 19.

  Due to the operation of the suction pump, a negative pressure is generated on the boss portion 19 side which is the outside with respect to the sealed inside of the differential case 3. Due to this negative pressure, a pressure difference is generated between the sealed case and the air pressure inside the differential case 3. Due to this pressure difference, the deteriorated LSD oil in the differential case 3 is sucked into the through hole 47ab, reaches the coupling hole 35b side through the opening 65 between the caps 40, 46, and is sucked out to the suction pump side.

  At this time, since the inside of the differential case 3 is sealed by the action of the labyrinth packing by the circumferential groove 47ca, the LED oil in the differential case 3 can be sucked out smoothly from the through hole 47ab side.

  Since the through hole 47ab of the gear support shaft portion 47a faces the bottom of the space 59a located at the lowermost portion, the remaining amount of deteriorated LSD oil in the differential case 3 can be minimized.

  When injecting new LSD oil, the rotational position of the differential device 1 is adjusted so that the through-hole 47ab faces upward.

  A suction pump and a fuel tank are connected to the boss portion 19 via a switching valve.

  The inside of the differential case 3 is sucked into a negative pressure by operating the suction pump.

  At this time, since the inside of the differential case 3 is sealed by the action of the labyrinth packing by the circumferential groove 47ca, the air in the differential case 3 can be sucked out smoothly from the through hole 47ab side.

  When the switching valve is switched, new LSD oil is sucked into the differential case 3 from the oil supply tank by the negative pressure in the differential case 3.

  The suction pump and the oil supply tank are detached from the boss portion 19, and the plug 67 is screwed into the coupling hole 35 to seal the differential case 3.

  The axle shaft is inserted from the boss portion 19 and splined to the coupling hole 35b to complete the replacement of the LSD oil.

  Therefore, in the second embodiment, the LSD oil replacement work of the differential device 1 can be performed very easily.

  FIG. 5 is a cross-sectional view of main parts showing first and second sealing portions of the differential apparatus according to the third embodiment.

  The basic configuration is the same as that of the first embodiment, and the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 5, in the differential shaft device according to the third embodiment, the second sealing portion P <b> 2 is disposed between the side gears 5 and 7 and the pinion shaft 47.

  In the third embodiment, the caps 40 and 46 employed in FIG. 1 of the first embodiment are omitted.

  The pinion shaft 47 is formed in an integral spider shape, and the boss portion 47d is fitted to the inner boss portions 35d and 37d of the side gears 5 and 7 so as to be relatively rotatable. A seal accommodating recess is formed on the inner periphery of the boss portion 47d, and the seal 69 is accommodated.

  Accordingly, the second sealing portion P2 of the third embodiment is constituted by the boss portion 47d provided with the seal housing recess of the pinion shaft 47, the inner boss portions 35d and 37d of the side gears 5 and 7, and the seal 69. .

  Other configurations are substantially the same as those in the first embodiment.

  Also in the third embodiment, the same effects as those of the first embodiment can be achieved by the first sealing portion P1 formed by the X ring 20a or the like and the second sealing portion P2 formed by the seal 69 or the like.

  In the third embodiment, the structure can be simplified.

  FIG. 6 is a cross-sectional view of main parts showing first and second sealing portions of the differential apparatus according to the fourth embodiment.

  As shown in FIG. 6, in the differential shaft device according to the fourth embodiment, the second sealing portion P <b> 2 is disposed between the side gears 5 and 7.

  In the fourth embodiment, the caps 40 and 46 employed in FIG. 1 of the first embodiment are omitted.

  The pinion shaft 47 is formed in an integral spider shape, and the boss portion 47d is fitted to the inner boss portions 35d and 37d of the side gears 5 and 7 so as to be relatively rotatable. A seal accommodation recess is formed on the inner periphery of the inner boss portion 37d, and the seal 69 is accommodated. As the seal 69, an O-ring, an X-ring or the like can be adopted. The seal 69 is in close contact with the outer peripheral surface of the inner boss portion 35d.

  Therefore, the second sealing portion P2 of the fourth embodiment is configured by the inner boss portion 37d having the seal housing recess of the side gear 7, the inner boss portion 35c of the side gear 5, and the seal 69.

  Other configurations are substantially the same as those in the first embodiment.

  Also in the third embodiment, the same effects as those of the first embodiment can be achieved by the first sealing portion P1 formed by the X ring 20a or the like and the second sealing portion P2 formed by the seal 69 or the like.

  In the third embodiment, the structure can be simplified.

  FIG. 7 is a cross-sectional view of a principal part showing a sealing portion of a side gear with a shaft integrated with a differential apparatus according to a fifth embodiment.

  The basic configuration is the same as that of the first embodiment, and the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 7, in the differential shuffler device according to the fifth embodiment, the sealing portion P is disposed between the shaft 71 integral with the side gear 7 and the boss portion of the differential case through which the shaft 71 passes. A similar sealing portion is provided between the other side gear and the differential case.

  The sealing portion P is composed of a seal 7 such as an X ring, etc., is accommodated in the seal accommodating recess of the boss portion on the differential case side, and is in close contact with the shaft 71.

  Accordingly, the sealing portion P is constituted by a boss portion having a seal housing recess on the differential case side and a seal 73 such as an X ring. The same applies to the side gear 5 side.

  Other configurations are substantially the same as those in the first embodiment.

  Also in the fifth embodiment, the inside of the differential case can be hermetically sealed by a sealing portion P such as an X ring, and the same effects as those of the first embodiment can be achieved.

  In the fifth embodiment, the structure can be simplified.

1 differential device 3 differential case 5, 7 side gear 9 pinion gear 20a X ring (seal)
35, 37 Gear body part 39, 41 Gear part 49, 51 Friction clutch (friction member)
55, 57 Pressure ring (pressing member)
59a, 59b Space portion 61 Permanent magnet 69, 73 Seal P Seal portion P1 First seal portion P2 Second seal portion

Claims (6)

A differential case for inputting or outputting torque, and
A pair of side gears for outputting or inputting torque via a shaft rotatably supported and inserted in the differential case;
A pinion gear rotatably supported by a pinion shaft in the differential case and meshing with each side gear;
A friction member disposed between the differential case and the side gear for limiting differential rotation of the pair of side gears according to a fastening force;
A pressing member that engages with the differential case and the pinion shaft, enables rotation of the rotation of the differential case as a revolution of the pinion gear, and moves according to the torque transmission and applies a fastening force to the friction member;
A first sealing portion that is disposed between the differential case and the side gear and seals the inside and outside of the differential case;
A second sealing portion of the side gear with respect to the separate shaft or a second sealing portion between the side gear and the pinion shaft or a second sealing portion between the side gears,
The friction member is disposed on the outer peripheral side of the meshing portion of the side gear and the pinion gear,
On the inner peripheral surface of the differential case, a space that can store lubricating oil is formed,
The space portion is disposed on the outer peripheral side of the friction member.
A differential device characterized by that. The differential device according to claim 1,
The friction members are separately disposed on the pair of side gears,
The space portion extends over the friction members arranged separately.
A differential device characterized by that. A differential device according to claim 1 or 2,
The side gear includes a coupling hole through which the separate shaft is inserted and coupled,
The second sealing portion of the side gear is a cap that closes the inner end portion of the coupling hole.
A differential device characterized by that. A differential device according to claim 3, wherein
The cap includes an opening that allows the coupling hole to communicate with the inside of the differential case;
The opening has a detachable plug,
The pinion shaft is provided with a through hole that communicates the space and the center side of the differential case.
A differential device characterized by that. A differential case for inputting or outputting torque, and
A pair of side gears that are rotatably supported in the differential case and output or input torque via an integral shaft;
A pinion gear rotatably supported by a pinion shaft in the differential case and meshing with each side gear;
A friction member disposed between the differential case and the side gear for limiting differential rotation of the pair of side gears according to a fastening force;
A pressing member that engages with the differential case and the pinion shaft, enables rotation of the rotation of the differential case as a revolution of the pinion gear, and moves according to the torque transmission and applies a fastening force to the friction member;
A sealing portion between the differential case and the integral shaft,
The friction member is disposed on the outer peripheral side of the meshing portion of the side gear and the pinion gear,
On the inner peripheral surface of the differential case, a space that can store lubricating oil is formed,
The space portion is disposed on the outer peripheral side of the friction member.
A differential device characterized by that. A differential device according to any one of claims 1 to 5,
The space portion is provided with a permanent magnet,
A differential device characterized by that.

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