JP2008115971A - Differential device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a differential device capable of suppressing the occurrence of seizure by a lubrication shortage, by forcibly supplying lubricating oil to a tapered roller bearing on the distant side from a ring gear. <P>SOLUTION: A pinion gear 32 is fixed to the rear end of a pinion shaft 31 constituting a liquid lubricating mechanism 30, and the lubricating oil L in a differential case 34 is splashed up by the rotation of the ring gear 33 driven by being meshed with the pinion gear 32. The liquid lubricating mechanism 30 comprises a rotary vane 41 for forcibly making the lubricating oil L by the rotation of the ring gear 33 flow to a further separated position in a bearing housing 35 of the differential case 34, more concretely, a midway position of an oil feeding passage 35a going along the inner wall surface of the bearing housing 35, and a belt 42 for rotatingly driving its rotary vane 41 based on the rotation of the pinion shaft 31. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a differential apparatus.

  In general, in a differential device (differential gear device) of a vehicle such as an automobile, a pinion shaft having a pinion gear fixed to one end is supported by a pair of tapered roller bearings that are combined in the axial direction and separated from each other by a predetermined distance. Yes. The tapered roller bearing is lubricated by a so-called splashing method in which the lubricating oil in the differential case is sprung up with the rotation of the ring gear driven by the pinion gear (see, for example, Patent Document 1).

  Specifically, in the FR (front engine rear wheel drive) system shown in FIG. 5, the power of the engine (not shown) mounted in front of the vehicle (right side in FIG. 5) is transmitted from the propeller shaft 101 which is long in the front and rear directions. It is transmitted to the drive shaft 102 via the device 103, and the left and right rear wheels (drive wheels; not shown) are rotated. In the differential device 103, the rotation of the propeller shaft 101 is transmitted to the pinion shaft 131 via the companion flange 138. The pinion shaft 131 is supported in a rear combination by a pair of tapered roller bearings 110 and 120 having a predetermined interval in the axial direction. In these tapered roller bearings 110 and 120, a plurality of tapered rollers 113 and 123 (rolling elements) are arranged between the raceways formed by the inner rings 111 and 121 and the outer rings 112 and 122.

  A pinion gear 132 is fixed to the rear end of the pinion shaft 131 constituting the liquid lubrication mechanism 130, and the lubricating oil L in the differential case 134 jumps up by the rotation of the ring gear 133 that is engaged with the pinion gear 132 and driven. It is done. In many cases, the lubricating oil L bounced up by the ring gear 133 passes through the oil supply passage 135a formed in the bearing housing portion 135, and the inner rings 111, 121 in the axial direction with respect to the pair of tapered roller bearings 110, 120. Supplied from the small brim portion 111b, 121b side.

Regarding the lubrication of the tapered roller bearings 110 and 120 by such a splashing method, there are the following contradictory circumstances and requirements of the times.
(1) For example, during high-speed rotation, the amount of lubricating oil L that is spun up by the ring gear 133 and supplied to the tapered roller bearings 110 and 120 tends to increase, and the agitation resistance by the bearing tends to increase. As a result, the rotational torque of the bearing is increased and the transmission efficiency is lowered, so that the energy consumption is increased and the fuel consumption of the vehicle is deteriorated. Further, when the supply amount of the lubricating oil L is increased, the inflow (mixing) amount of foreign matters is also increased, and the wear and damage of the tapered roller bearings 110 and 120 is promoted and the life may be shortened.

(2) On the other hand, if the supply amount of the lubricating oil L is limited in order to improve the fuel efficiency of the vehicle, there is a possibility that seizure may occur due to insufficient lubrication. At that time, the amount of the lubricating oil L flowing into the tapered roller bearings 110 and 120 is likely to decrease in a low temperature state such as when the engine is started. Further, since the ring gear 133 is formed only on one side (for example, the right side) of the left and right sides, when turning to the installation side (for example, the left side) of the ring gear 133, centrifugal force is applied to the opposite side (for example, the right side) from the turning center. Acts and the amount of scraping of the lubricating oil L by the ring gear 133 tends to decrease. For this reason, the large collar portion 111a of the inner ring 111 of the tapered roller bearing 110 on the front side is far from the ring gear 133, so that the supply amount is insufficient, and seizure due to insufficient lubrication is particularly likely to occur.

  Therefore, an introduction path (oil supply path) and an opening for supplying lubricating oil directly at a position corresponding to the large collar part of the inner ring of the tapered roller bearing on the front side are provided, and the lubricating oil is supplied to the large collar part through the opening. And the technique which suppresses generation | occurrence | production of the seizure by insufficient lubrication and aims at the lifetime improvement is disclosed (for example, refer patent document 2).

Japanese Patent Laid-Open No. 11-51159 JP-A-8-210472

  According to Patent Document 2, the lubricating oil can be directly supplied to the large collar portion of the inner ring of the tapered roller bearing on the front side. However, although the introduction path and the opening for supplying the lubricating oil scraped up (bounced up) by the ring gear to the large brim portion are formed, no positive supply means are provided and sufficient Lubrication oil may not be supplied.

  An object of the present invention is to provide a differential device that can forcibly supply lubricating oil to a tapered roller bearing on the side far from the ring gear and suppress the occurrence of seizure due to insufficient lubrication.

Means for Solving the Problems and Effects of the Invention

In order to solve the above problems, the differential device of the present invention is:
A pinion shaft with a pinion gear fixed to one end side is supported by a pair of tapered roller bearings in which a plurality of tapered rollers are arranged between the raceway surfaces of the inner ring and the outer ring, with a back combination having a predetermined interval in the axial direction. And a differential device having a liquid lubrication path for supplying lubricating oil in the differential case from the large collar side of the inner ring in the axial direction to a tapered roller bearing far from the ring gear driven by the pinion gear. Because
Oil flow means disposed inside or outside the bearing housing portion of the differential case, forcibly flowing lubricating oil, and the pinion shafts for rotating the oil flow means as the pinion shaft rotates. A liquid lubrication mechanism having a rotary transmission member interposed between the oil flow means,
The liquid lubrication mechanism forcibly supplies the lubricating oil in the differential case to the tapered roller bearing through the liquid lubrication path.

  As described above, the oil for forcibly lubricating the tapered roller bearing through the liquid lubrication path for supplying the lubricating oil in the differential case from the large collar side of the inner ring in the axial direction to the inside or outside of the bearing housing portion of the differential case. A liquid lubrication mechanism having a flow means and a rotary transmission for rotating the oil flow means as the pinion shaft rotates is provided. Accordingly, since the lubricating oil can be forcibly supplied to the tapered roller bearing (on the large collar portion side of the inner ring) through the liquid lubrication path, the occurrence of seizure due to insufficient lubrication can be suppressed or prevented. In addition, because it is forced lubrication by the liquid lubrication mechanism, by controlling the rotation of the oil flow means and the rotating transmission body, the increase in rotational torque due to the stirring resistance is suppressed, improving fuel efficiency and the life of the tapered roller bearing (durability) ) Can be improved.

  The oil flow means is rotationally driven with the rotation of the pinion shaft via the rotary transmission. That is, since it is driven by utilizing the rotation of the pinion shaft, the number of parts can be reduced. For example, when it is arranged inside the bearing housing portion, it can be arranged in the limited space.

  By the way, as a rotational transmission body, a viscous transmission force is transmitted between the rolling elements pressed against each other, in addition to a winding transmission body (belt, chain, wire, rope, etc.), a contact transmission body (gear, friction wheel, etc.). An elastic fluid film transmission mechanism (traction drive mechanism) or the like can be used. By using these rotary transmission bodies, the oil flow means can be arranged at a position away from the pinion shaft, that is, a position corresponding to the liquid lubrication path, and the lubricating oil (for example, ring gear splashes) efficiently and forcibly. The raised lubricating oil) can be guided to the liquid lubrication path, and the lubricating oil can be supplied to the tapered roller bearing. In addition, as an oil flow means, a rotary blade and a pump are mainly used.

For example, the oil flow means is a rotor blade that is arranged in the middle of the liquid lubrication path and is driven via a rotary transmission body by rotation of a pinion shaft,
Based on the rotation of the pinion shaft, along with the rotation of the ring gear driven through the pinion gear, the lubricating oil in the differential case is splashed up and introduced into the liquid lubrication path, while being driven through the rotating transmission. With the rotation of the rotary blade, the lubricating oil can be supplied from the large collar portion side of the inner ring in the axial direction to the tapered roller bearing on the side far from the ring gear.

  As a result, the oil flow means composed of the rotor blades is arranged in the middle of the liquid lubrication path, and the rotor blades are rotated based on the rotation of the pinion shaft, so that a flow of lubricating oil is generated along the liquid lubrication path. Therefore, the lubricating oil splashed up by the ring gear can be easily supplied to the tapered roller bearing on the side far from the ring gear from the side of the large collar portion of the inner ring. That is, the lubricating oil splashed by the ring gear is introduced into the liquid lubrication path, passes through the rotor blades, and is sent to the tapered roller bearing as it is, so that the driving force (driving torque) for operating the liquid lubrication mechanism is small. Tesumu.

Further, the oil flow means is a pump that is driven through the rotary transmission body by rotation of the pinion shaft (as well as disposed in the middle of the liquid lubrication path),
Along with the operation of the pump (based on the rotation of the pinion shaft), the lubricating oil in the differential case is pumped up and introduced into the liquid lubrication path, and the tapered roller bearing on the side far from the ring gear On the other hand, the lubricating oil may be supplied from the large collar portion side of the inner ring in the axial direction.

  As a result, the oil flow means including the pump is arranged in the middle of the liquid lubrication path, and the pump is driven based on the rotation of the pinion shaft to pump up the lubricating oil in the differential case and introduce it into the liquid lubrication path. Accordingly, the supply of the lubricating oil to the tapered roller bearing does not depend on the spring-up supply of the ring gear, and the arrangement position of the liquid lubricating mechanism can be set without being bothered by the difference in reach due to the centrifugal force. As a result, by adjusting the pump discharge position (introduction position), it is possible to supply directly to the tapered roller bearing (large collar side of the inner ring), and the pump discharge amount (lubricant supply amount) By appropriately adjusting, it is possible to suppress or prevent an increase in rotational torque due to agitation resistance due to excessive lubricating oil and image sticking due to insufficient lubrication.

  Further, in these liquid lubrication mechanisms, the rotational transmission body can be configured by a winding transmission body that is disposed at an intermediate portion in the axial direction with respect to the pair of tapered roller bearings and is rotationally driven by a pinion shaft.

  According to this, power can be taken out easily and smoothly in a limited space by arranging the winding transmission (for example, a belt) in the middle part of the pair of tapered roller bearings. Also, the oil flow means is driven without obstructing the supply of the lubricating oil to the tapered roller bearing on the side close to the ring gear (pinion gear), and the lubricating oil is supplied to the tapered roller bearing on the side far from the ring gear. Can be done.

(Example 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view showing an example of a differential device according to the present invention, and FIG. 2 is an enlarged view of a main part in FIG. 1 shows a case where the first tapered roller bearing 10 on the front side (the side far from the ring gear 33) is lubricated.

  In the FR (front engine rear wheel drive) system shown in FIG. 1, the power of an engine (not shown) mounted in front of the vehicle (right side in FIG. 1) is driven from a propeller shaft 1 that is long in the front and rear direction through a differential device 3. It is transmitted to a shaft (not shown), and the left and right rear wheels (drive wheels; not shown) are rotated. In the differential device 3, the rotation of the propeller shaft 1 is transmitted to the pinion shaft 31 via the companion flange 38. The pinion shaft 31 is supported by a cylindrical spacer 39 in a back surface combination by first and second tapered roller bearings 10 and 20 (tapered roller bearings; rolling bearings) having a predetermined interval in the axial direction. These tapered roller bearings 10 and 20 are composed of a plurality of tapered rollers 13 between races formed by inner rings 11 and 21 rotating integrally with the pinion shaft 31 and outer rings 12 and 22 fixed to the bearing housing portion 35 of the differential case 34. , 23 (rolling elements) are arranged by the retainers 14 and 24 while maintaining a predetermined interval in the circumferential direction.

  Specifically, the inner rings 11 and 21 are made of bearing steel or the like, have an inner ring raceway surface formed in a conical surface, and have small collar portions 11b and 21b and large collars on both ends in the axial direction of the inner ring raceway surface. The parts 11a and 21a are arranged in a distributed manner. The inner rings 11 and 21 are made of bearing steel or the like and have outer ring raceway surfaces formed in a conical shape so as to face the inner ring raceway surfaces. The tapered rollers 13 and 23 are made of bearing steel or the like, and are disposed between both race rings. The large end surfaces of the tapered rollers 13 and 23 are in sliding contact with the inner side surfaces of the large collar portions 11a and 21a.

  A pinion gear 32 is fixed to the rear end of the pinion shaft 31 constituting the liquid lubrication mechanism 30, and the lubricating oil L in the differential case 34 jumps up by the rotation of the ring gear 33 that is engaged with the pinion gear 32 and driven. It is done. In addition, the liquid lubrication mechanism 30 rotates the ring gear 33 in the bearing housing portion 35 of the differential case 34, specifically in the middle of the oil supply passage 35 a (liquid lubrication route) along the inner wall surface of the bearing housing portion 35. A rotating blade 41 (oil flow means) forcibly flowing the lubricating oil L sprung up by a further distant position, and a belt 42 (winding transmission) for rotating the rotating blade 41 based on the rotation of the pinion shaft 31 Body; rotating transmission body).

  The rotor blade 41 shown in FIG. 2 is a part of a shaft portion 41a that is rotatably fixed to shaft support portions 41b and 41b that are disposed opposite to each other along the axial direction of the pinion shaft 31 at an intermediate position in the oil supply passage 35a. It is a screw propeller attached integrally to the shaft portion 41a. The rotating blade 41 generates a flow F of the lubricating oil L that moves in a direction away from the pinion gear 32 when rotated along with the rotation of the pinion shaft 31. Therefore, below the rotary blade 41, a conveying rod 35 b parallel to the shaft portion 41 a is installed inside the bearing housing portion 35 so as to face the rotary blade 41.

  The belt 42 interposed between the pinion shaft 31 and the shaft portion 41a is wound around the pair of first and second tapered roller bearings 10 and 20 at an intermediate portion in the axial direction. In other words, by forming the rotary blade 41 at a position closer to the ring gear 33 than the first tapered roller bearing 10, the lubricating oil L can be efficiently supplied to the first tapered roller bearing 10, and the rotation thereof By wrapping in the vicinity of the wing 41, it contributes to space saving.

  Thereby, in the present embodiment, most of the lubricating oil L bounced up by the ring gear 33 flows down the oil supply passage 35 a along the inner wall surface of the bearing housing portion 35. Then, due to the rotation of the rotary blade 41 formed in the middle of the oil supply passage 35a, it is further pushed forward along the conveying rod 35b (side far from the ring gear 33) as indicated by an arrow F in the figure. The lubricating oil L pumped by the rotary blade 41 and the conveying rod 35b passes through the oil supply hole 35c in the wall portion of the bearing housing portion 35, and is on the large collar portion 11a side of the inner ring 11 of the first tapered roller bearing 10 on the front side. Is forcibly supplied.

  The other part of the lubricating oil L bounced up by the ring gear 33 passes through the oil supply passage 35d along the outer periphery of the ring gear 33, and the second tapered roller bearing 20 on the rear side (side closer to the ring gear 33). Is also supplied to the large collar portion 21a side of the inner ring 21. At this time, in the second tapered roller bearing 20, the lubricating oil L supplied to the large collar portion 21a side of the inner ring 21 flows down between the inner ring 21 and the outer ring 22 toward the small collar portion 21b side. Further, a part of the lubricating oil L splashed up by the ring gear 33 flows down the oil supply passage 35a along the inner wall surface of the bearing housing portion 35 as in the conventional case (see FIG. 7), and is indicated by an arrow f in the figure. In this way, there is also a case where the pair of tapered roller bearings 10 and 20 are supplied from the small collar portions 11b and 21b side of the inner rings 11 and 21 in the axial direction.

  The companion flange 38 (connection joint) connects the propeller shaft 1 and the pinion shaft 31 and presses the back surface 11c of the inner ring 11 by tightening (screwing) the nut 38a (tightening member) to apply preload. is doing. The annular oil seal 36 is fixed to the inner peripheral surface of the bearing housing portion 35 and slides on the companion flange 38 to temporarily store the lubricating oil L. An annular deflector 37 (protective member) is fixed to the companion flange 38, extends radially outward to reach the outer peripheral surface of the bearing housing portion 35, and covers from the outer side so that foreign matter does not enter the oil seal 36.

(Example 2)
FIG. 3 is a side sectional view showing another example of the differential device according to the present invention. In the following description, parts different from those in the first embodiment will be mainly described, and overlapping parts will be denoted by the same reference numerals, and description thereof will be omitted or simplified. In the differential device 3 of FIG. 3 according to the second embodiment, a pinion gear 32 is fixed to the rear end of the pinion shaft 31 constituting the liquid lubrication mechanism 30, and the ring gear 33 that is driven by meshing with the pinion gear 32 is rotated. The lubricating oil L in the differential case 34 is splashed up. Further, the liquid lubrication mechanism 30 pumps up the lubricating oil L in the differential case 34 separately from the lubricating oil L splashed up by the rotation of the ring gear 33 and supplies the oil supply hole 35c (liquid lubrication) in the wall portion of the bearing housing portion 35. A pump 51 (oil flow means) that is directly introduced (discharged) into the path), and a belt 42 (wound transmission body; rotation transmission body) for driving the pump 51 based on the rotation of the pinion shaft 31. ing.

  A part of the lubricating oil L splashed up by the ring gear 33 flows down the oil supply passage 35a along the inner wall surface of the bearing housing portion 35 as in the conventional case (see FIG. 7), as indicated by an arrow f in the figure. Are supplied to the pair of tapered roller bearings 10 and 20 from the small collar portions 11b and 21b of the inner rings 11 and 21 in the axial direction. Further, another part of the lubricating oil L bounced up by the ring gear 33 passes through the oil supply passage 35d along the outer periphery of the ring gear 33, and the large collar of the inner ring 21 in the axial direction with respect to the second tapered roller bearing 20. It is also supplied to the part 21a side.

  Specifically, the pump 51 includes an impeller (not shown), a casing 51a including the impeller, a suction portion 51b (suction port) for sucking the lubricating oil L in the differential case 34, and a suction thereof. A discharge portion 51c (discharge port) for introducing the lubricating oil L into the oil supply hole 35c is provided. The impeller in the casing 51a is, for example, as a part of the shaft portion 41a that is rotatably fixed to the shaft support portions 41b and 41b that are opposed to each other along the axial direction of the pinion shaft 31 at an intermediate position of the oil supply passage 35a. Or it is a rotary vane attached to the axial part 41a integrally.

  Accordingly, in this embodiment, the pump 51 pumps up and discharges the lubricating oil L separately from the lubricating oil L bounced up by the ring gear 33, so that the large inner ring 11 of the first tapered roller bearing 10 on the front side is large. Oil is forcibly supplied to the collar portion 11a side.

(Example 3)
FIG. 4 is a side sectional view showing still another example of the differential device according to the present invention. In the following description, parts different from the second embodiment will be mainly described, and overlapping parts will be denoted by the same reference numerals, and description thereof will be omitted or simplified. In the differential device 3 of FIG. 4 according to the third embodiment, a pinion gear 32 is fixed to the rear end of the pinion shaft 31 constituting the liquid lubrication mechanism 30, and the ring gear 33 driven by meshing with the pinion gear 32 is rotated. The lubricating oil L in the differential case 34 is splashed up. Further, the liquid lubrication mechanism 30 pumps the lubricating oil L in the differential case 34 outside the bearing housing portion 35 of the differential case 34, separately from the lubricating oil L splashed up by the rotation of the ring gear 33. The first tapered roller bearing 10 has a pump 51 (oil flow means) that is directly introduced into the large collar portion 11 a side of the inner ring 11 in the axial direction, and a belt that drives the pump 51 based on the rotation of the pinion shaft 31. 42 (one-dot chain line; winding transmission body; rotation transmission body).

  Specifically, the pump 51 is disposed outside the bearing housing portion 35. On the other hand, the belt 42 is interposed between a shaft portion 41 a extending from the casing 51 a (pump 51) along the pinion shaft 31 and the companion flange 38. By disposing the pump 51 outside the bearing housing portion 35, there is no space limitation, so that the pump 51 can be made relatively large and the pumping force of the lubricating oil L can be secured. That is, the lubricating oil L in the differential case 34 that is far away can be easily pumped up, and the lubricating oil L can be supplied to the large flange portion 11a side of the first tapered roller bearing 10 on the front side by the discharge portion 51c. it can.

  In the above embodiment, only the differential device used for the FR type vehicle has been described. However, the differential device may be used for a FF (front engine front wheel drive) type or 4WD (four wheel drive) type vehicle.

Side surface sectional drawing which shows an example of the differential apparatus which concerns on this invention. The principal part enlarged view in FIG. Side surface sectional drawing which shows the other example of the differential apparatus which concerns on this invention. Side surface sectional drawing which shows the further another example of the differential apparatus which concerns on this invention. Side surface sectional drawing which shows the conventional differential apparatus.

Explanation of symbols

1 Propeller Shaft 3 Differential Device 10 1st Tapered Roller Bearing (Tapered Roller Bearing; Rolling Bearing)
DESCRIPTION OF SYMBOLS 11 Inner ring 11a Large brim part 11b Small brim part 11c Back surface 12 Outer ring 13 Tapered roller (rolling element)
14 Cage 20 Second Tapered Roller Bearing (Tapered Roller Bearing; Rolling Bearing)
21 Inner ring 21a Large brim part 21b Small brim part 22 Outer ring 23 Tapered roller (rolling element)
24 Cage 30 Liquid Lubrication Mechanism 31 Pinion Shaft 32 Pinion Gear 33 Ring Gear 34 Differential Case 35 Bearing Housing 35a Oil Supply Path (Fluid Lubrication Path)
35c Oil supply hole (fluid lubrication path)
36 Oil seal 37 Deflector (protective member)
38 Companion flange (connection joint)
41 Rotating blade (oil flow means)
42 Belt (wound transmission body; rotating transmission body)
51 Pump (oil flow means)
L Lubricating oil

Claims (2)

A pinion shaft with a pinion gear fixed to one end side is supported by a pair of tapered roller bearings in which a plurality of tapered rollers are arranged between the raceway surfaces of the inner ring and the outer ring, with a back combination having a predetermined interval in the axial direction. And a differential device having a liquid lubrication path for supplying lubricating oil in the differential case from the large collar side of the inner ring in the axial direction to a tapered roller bearing far from the ring gear driven by the pinion gear. Because
Oil flow means disposed inside or outside the bearing housing portion of the differential case, forcibly flowing lubricating oil, and the pinion shafts for rotating the oil flow means as the pinion shaft rotates. A liquid lubrication mechanism having a rotary transmission member interposed between the oil flow means,
A differential apparatus characterized in that the liquid lubrication mechanism forcibly supplies the lubricating oil in the differential case to the tapered roller bearing through the liquid lubrication path. The oil flow means is a pump that is driven via the rotary transmission body by rotation of the pinion shaft,
Along with the operation of the pump, the lubricating oil in the differential case is pumped up and introduced into the liquid lubrication path, and from the large collar portion side of the inner ring in the axial direction with respect to the tapered roller bearing far from the ring gear. The differential apparatus of Claim 1 which supplies lubricating oil.

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