JP2017096463A - Power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission device capable of inhibiting intrusion of a lubrication oil into a breather port without requiring assembly work of an air flow passage and a shield member having a complicated structure to a case.SOLUTION: A power transmission device includes: a ring gear 20; a drive pinion gear 10; a differential case 310; a case 100 in which a lubrication oil is stored at a bottom part; and a sleeve 50 in which one end part supports the differential case 310 via a right taper roller bearing 340, the other end part is fixed to the case 100, and a barrel part 51 supports a rear side shaft part 12 via a rear taper roller bearing 40. In the case 100, a breather chamber 2 is formed for communicating with the outside via a breather port 3. On an outer peripheral surface of the sleeve 50, a circumferential direction shield plate 5 is formed which is directed to an inner wall surface of the case 100, and which shields the lubrication oil scraped up by the ring gear 20 with respect to the breather port 3. The breather chamber 2 is formed by being surrounded by the inner wall surface of the case 100 and the outer peripheral surface of the sleeve 50 and the circumferential direction shield plate 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power transmission device.

  The final reduction gear of the FF-based four-wheel drive vehicle is disposed at the rear of the vehicle. This final reduction gear decelerates the power generated by the prime mover, decelerated by the transmission and transmitted through the propulsion shaft, and adjusts that the rotation speed of the left and right rear wheels is different when the vehicle travels a curve. It is a device that facilitates running. The final reduction gear includes a drive pinion gear that rotates integrally with the propulsion shaft, a pair of bevel gears including a ring gear that meshes at right angles with the drive pinion gear, a differential case that rotates integrally with the ring gear, and a drive shaft that is disposed inside the differential case. A differential gear comprising: a side gear that rotates integrally with the side gear; a pinion gear that meshes with the side gear and is disposed inside the differential case; and a pinion shaft that is inserted into the hole of the pinion gear and fits into the differential case; And a case (housing) that is housed inside.

  Since the final reduction gear device transmits high torque at high speed, a high load acts on the meshing portions of the gears and the bearings that support the gears. Therefore, lubricating oil is sealed in the case for lubrication and cooling, and the opening is protected by an oil seal or the like so that the lubricating oil does not leak outside.

  On the other hand, the inside of the case becomes hot due to the meshing of the gears and the rolling motion of the bearings. There is a risk of spraying outside. Therefore, for example, as in Patent Document 1, an air channel (breather channel) that releases pressure from an appropriate position to the outside is formed.

  In a reduction gear having large and small bevel gears, such as a final reduction gear or a sub-transmission, generally, an oil reservoir is formed in the vicinity of the large gear in the case, and the lubricating oil is lifted by the rotation of the large gear. Is sprayed on the bearings, the lubricating oil may be ejected even if not in the vicinity of the rotating body. On the other hand, Patent Document 2 discloses a technique in which a member that shields the splash oil that enters the air flow path is arranged in the case.

JP 2005-282733 A JP 2000-65191 A

  If the air flow path for pressure release is arranged in the vicinity of a rotating body such as a gear, the lubricating oil will be ejected out of the carrier, so attention must be paid to its position. In Patent Document 1, an air flow path having a labyrinth structure is formed in the case. However, this technique has a problem that the structure of the case becomes complicated. Moreover, in the technique of patent document 2, the assembly | attachment operation | work which assembles a shielding member to a case is required.

  The present invention was created to solve these problems, and prevents the intrusion of lubricating oil into the breather port without requiring a complicated air flow passage or shielding member assembly work in the case. It aims at providing the power transmission device which can be performed.

  In order to solve the above-described problem, the present invention includes a first bevel gear, a bevel gear body meshing with the first bevel gear, and a tooth surface side shaft portion formed on a tooth surface side of the bevel gear body. A second bevel gear, a rotating body that rotates integrally with the first bevel gear, a case that houses the first bevel gear, the second bevel gear, and the rotating body, and in which lubricating oil is stored at the bottom; A cylindrical sleeve having one end supporting the rotating body through a first bearing, the other end fixed to the case, and a peripheral wall supporting the tooth surface side shaft through a second bearing; A breather chamber that communicates with the outside via a breather port is formed inside the case, and is directed to the inner wall surface of the case on the outer peripheral surface of the sleeve, and the first bevel gear lifts up the lubricating oil An oil shielding part is formed to shield the breather mouth from the breather chamber. Characterized in that it is surrounded with the inner wall surface of over scan and the outer peripheral surface of the sleeve and the oil shield portion.

  According to such a configuration, the lubricating oil pumped up by the first bevel gear is shielded by the oil shielding portion, thereby preventing the lubricating oil from entering the breather port 3. By forming the oil shielding portion on the sleeve, there is no need to assemble the shielding portion on the case side, and it is not necessary to form a labyrinth structure for preventing the intrusion of lubricating oil on the case side.

  Further, the present invention is characterized in that the oil shielding portion includes a circumferential shielding plate extending radially outward along a circumferential direction of the sleeve.

  According to the present invention, the lubricating oil scattered in the axial direction of the sleeve can be effectively shielded by the circumferential shielding plate.

  In the invention, it is preferable that the oil shielding portion includes an axial shielding plate extending from the circumferential end of the circumferential shielding plate toward the breather chamber along the axial direction of the sleeve. .

  According to the present invention, the lubricating oil scattered in the direction orthogonal to the axial direction of the sleeve can be effectively shielded by the axial shielding plate.

  Further, the present invention is characterized in that the breather port is a pipe port of a breather pipe attached to the case, and an oil shielding rib is formed on the inner wall surface of the case so as to surround the breather pipe. And

  According to the present invention, the oil shielding rib can prevent the lubricating oil from entering the breather port. The oil shielding rib need only be formed so as to surround the breather pipe, and does not require a complicated labyrinth structure.

  Further, the present invention is suitable for a final reduction gear having a configuration in which the first bevel gear is a ring gear constituting a final reduction gear, and the rotating body is a differential case to which the ring gear is fixed.

  According to the present invention, in the power transmission device, it is possible to prevent intrusion of lubricating oil into the breather port without requiring an assembly work of an air flow path or a shielding member having a complicated structure in the case.

It is a plane sectional view of the power transmission device concerning a 1st embodiment. It is X1-X1 sectional drawing of FIG. It is an external appearance perspective view of the sleeve which concerns on 1st Embodiment. It is an external appearance perspective view around the sleeve which concerns on 1st Embodiment. It is a plane sectional view of the power transmission device concerning a 2nd embodiment. It is X2-X2 sectional drawing of FIG. It is an external appearance perspective view of the sleeve which concerns on 2nd Embodiment. It is an external appearance perspective view around the sleeve which concerns on 2nd Embodiment.

“First Embodiment”
The first embodiment will be described with reference to FIGS.
≪Configuration of final reduction gear≫
The final reduction gear 1 (power transmission device) according to the present embodiment is mounted on an FF (Front-engine Front-drive) -based four-wheel drive vehicle, and after decelerating the power from a propeller shaft (not shown). A device for transmitting to the left rear wheel and the right rear wheel.

  The final reduction gear 1 includes a drive pinion gear (second bevel gear) 10, a ring gear (first bevel gear) 20, a front taper roller bearing 30, a rear taper roller bearing 40, a sleeve 50, and a case 100. I have. The final reduction gear device 1 includes a clutch 200 and a differential device 300.

<Case>
The case 100 is a shell-like container, and in the front-rear direction, a first case 110 disposed on the front side, a second case 120 disposed on the middle, a third case 130 disposed on the rear side, And these are fastened together by bolts or the like.

  The first case 110 is a cylindrical member and generally accommodates the front half of the clutch 200. The second case 120 is a substantially cylindrical member, and has a hemispherical front case portion 121 that is open on the front side, and a rear case portion 122 that is continuous with the rear side of the front case portion 121 and is open on the rear side. And. The front case part 121 generally accommodates the rear half of the clutch 200. The rear case portion 122 generally accommodates the drive pinion gear 10, the sleeve 50, and the front half of the differential device 300. The third case 130 is a hemispherical shell-shaped member having an opening on the front side, and generally accommodates the sleeve 50 and the rear half of the differential device 300. An oil sump 150 for storing lubricating oil is formed at the bottom of the rear case portion 122 and the third case 130.

<Differential device>
The differential device 300 is a device that differentially rotates the left rear wheel and the right rear wheel. The differential device 300 includes a substantially cylindrical differential case 310 (rotary body) that rotates about an axis O2, a pinion shaft 321 that is fixed to the differential case 310 and extends in the radial direction, and a pair of pinion gears that rotate about the pinion shaft 321. 322 and 322 and a pair of side gears 323 and 323 that mesh with the pinion gears 322 and 322.

  The differential case 310 includes a spherical shell-shaped differential case body 311, a cylindrical left boss portion 312 formed on the left side of the differential case body 311, a right boss portion 313 formed on the right side of the differential case body 311, and the differential case body 311. And a ring-shaped flange portion 314 extending radially outward from the right end portion on the drive pinion gear 10 side.

  The left boss portion 312 is rotatably supported by the second case 120 and the third case 130 via a left tapered roller bearing 330. A shim 339 for adjusting a preload of the left tapered roller bearing 330 is interposed between the end surface of the left tapered roller bearing 330 and the second case 120 and the third case 130.

  The right boss portion 313 is rotatably supported by the sleeve 50 via a right tapered roller bearing 340 (first bearing). A right end of a left rear drive shaft (not shown) extending from the left rear wheel is splined to the left side gear 323. The left end of a right rear drive shaft (not shown) extending from the right rear wheel is splined to the right side gear 323. For example, when the vehicle travels on a curve, the left and right side gears 323 and 323 rotate differentially, and the pinion gears 322 and 322 rotate.

<Drive pinion gear>
The drive pinion gear 10 is a rod-like member that rotates about an axis O1 extending in the front-rear direction. The drive pinion gear 10 includes a truncated cone-shaped pinion gear 11 (bevel gear body) having a small diameter on the rear side, and a rear shaft portion 12 (tooth surface side shaft portion) formed on the rear side that is the tooth surface side of the pinion gear 11. And a front shaft portion 13 (back surface shaft portion) formed on the front side which is the back surface side of the pinion gear 11.

  The pinion gear 11 meshes with the ring gear 20, and the ring gear 20 constitutes a final reduction gear mechanism. The pinion gear 11 and the ring gear 20 are constituted by hypoid gears, for example. The rear shaft portion 12 is rotatably supported by the sleeve 50 via a rear taper roller bearing 40. The front shaft portion 13 includes a proximal end portion 13a, an intermediate portion 13b, and a distal end portion 13c from the proximal end side (rear side) that is the pinion gear 11 side toward the distal end side (front side). The base end portion 13 a is rotatably supported by the second case 120 via the front tapered roller bearing 30.

  A shaft spline 13d is formed on the outer peripheral surface of the intermediate portion 13b. The shaft spline 13d is spline-coupled with the hole spline 221 of the inner hub 220. The tip portion 13c supports the pump body 242 rotatably via a needle roller bearing 246 (radial bearing). The pump body 242 is supported by the clutch case 210 so as not to be relatively rotatable. For this reason, the front-end | tip part 13c and the clutch case 210 are relatively rotatable.

<Front taper roller bearing>
The front taper roller bearing 30 is a bearing that rotatably supports the base end portion 13 a with respect to the second case 120. A shim 39 for adjusting the meshing between the pinion gear 11 and the ring gear 20 is provided between the front taper roller bearing 30 and the pinion gear 11.

<Rear taper roller bearing>
The rear taper roller bearing (second bearing) 40 is a bearing that rotatably supports the rear shaft portion 12 with respect to the sleeve 50. Since the drive pinion gear 10 is rotatably supported by the front taper roller bearing 30 on the front side of the pinion gear 11 and the rear taper roller bearing 40 on the rear side without using a collapsible spacer, the drive pinion gear 10 is only on the front side. The base end portion 13a is shortened with respect to the configuration in which the cantilever is supported.

<Ring gear>
The ring gear 20 is a ring-shaped member that rotates about an axis O2 extending in the left-right direction. The ring gear 20 is fastened to the flange portion 314 of the differential case 310 by bolts 21 and is disposed on the radially outer side of the outer fitting portion 52 of the sleeve 50 described later. The lower part of the ring gear 20 is immersed in the oil reservoir 150, and when the ring gear 20 rotates, the lubricating oil in the oil reservoir 150 is swept up.

<Sleeve>
The sleeve 50 is a cylindrical member disposed coaxially with the ring gear 20 behind the drive pinion gear 10 and is a member that holds the rear taper roller bearing 40 and the right taper roller bearing 340.

  The sleeve 50 extends in the left-right direction with the axis O2 as a center, and includes a body portion 51 (peripheral wall portion), an outer fitting portion 52 (one end portion) formed on the left side (one end side) of the body portion 51, and a body portion. 51, and a sandwiched portion 53 (the other end portion) formed on the right side (the other end side) of 51. The body portion 51 is formed to be thicker than the outer fitting portion 52 and the sandwiched portion 53.

<Sleeve-trunk>
An insertion hole 51 a into which the outer ring of the rear taper roller bearing 40 is inserted is formed on the front side of the body portion 51. A preload adjusting shim 49 is disposed between the end surface of the outer ring of the rear tapered roller bearing 40 and the body portion 51.

<Sleeve-external fitting>
The outer fitting portion 52 is a portion that is fitted and held on the right tapered roller bearing 340. A shim 344 for adjusting the preload of the right taper roller bearing 340 is interposed between the end surface of the outer ring of the right taper roller bearing 340 and the outer fitting portion 52.

<Sleeve-sandwiched part>
The sandwiched portion 53 is a portion that is sandwiched between the right semi-cylindrical portion 123 of the second case 120 and the right semi-cylindrical portion 131 of the third case 130 in the front-rear direction. In this way, the sleeve 50 is fixed to the case 100 by the sandwiched portion 53 being sandwiched.

<Breeza room>
Inside the case 100, a breather chamber 2 is formed which communicates with the outside through a breather port 3 which is a pressure release port for the purpose of always maintaining the inside of the case 100 at atmospheric pressure. A breather pipe 4 is attached to an upper portion of the third case 130 so as to penetrate the third case 130 in the front-rear direction, and a pipe port at a front end of the breather pipe 4 located inside the third case 130 is a breather port. 3 is configured. The breather pipe 4 is disposed substantially on the axis O1 in a plan view as shown in FIG. 1, and is disposed obliquely rearward above the sleeve 50 in the direction of the axis O2 as shown in FIG. The breather chamber 2 is formed so as to be surrounded by the inner wall surface of the third case 130, the outer peripheral surface of the body portion 51 of the sleeve 50, and an oil shielding portion described later.

<Oil shielding part>
On the outer peripheral surface of the body portion 51 of the sleeve 50, a circumferential shielding plate 5 (oil shielding portion) that is directed to the inner wall surface of the case 100 and shields the lubricating oil that the ring gear 20 lifts from the breather port 3 and the axial direction. Shielding plates 6A and 6B (oil shielding portions) are formed. The circumferential shielding plate 5 is formed on the outer circumferential surface of the body portion 51 between the ring gear 20 and the breather port 3 so as to extend radially outward along the circumferential direction in the direction of the axis O2. The formation range of the circumferential shielding plate 5 in the circumferential direction in the body portion 51 is a range of about 90 degrees around the axis O2 from the upper end to the rear end of the body portion 51 as can be seen from FIG. . The outer diameter of the circumferential shielding plate 5 is substantially the same as the outer diameter of the ring gear 20, and the outer peripheral edge of the circumferential shielding plate 5 is close to the inner wall of the third case 130.

  The axial shielding plate 6A extends from the circumferential upper end of the circumferential shielding plate 5 toward the breather chamber 2 along the axial direction of the sleeve 50 (in the direction of the axis O2). The axial shielding plate 6B extends from the circumferential lower end of the circumferential shielding plate 5 toward the breather chamber 2 along the axial direction of the sleeve 50 (in the direction of the axis O2). The axial shielding plate 6 </ b> A is disposed on the front extension line of the breather pipe 4. The axial shielding plate 6 </ b> B is disposed directly below the breather pipe 4.

  The circumferential shielding plate 5 and the axial shielding plates 6 </ b> A and 6 </ b> B may be formed integrally with the body portion 51, or are configured as separate members from the body portion 51 and assembled integrally with the body portion 51. It may be a thing.

<Clutch>
The clutch 200 is a connecting / disconnecting device for connecting / disconnecting power between a propeller shaft (not shown) and the drive pinion gear 10. In this embodiment, the clutch 200 is constituted by a hydraulic wet multi-plate clutch. The clutch 200 corresponds to a clutch case 210 that rotates integrally with the propeller shaft, an inner hub 220 that rotates integrally with the drive pinion gear 10, a plurality of outer clutch plates 231, a plurality of inner clutch plates 232, and hydraulic pressure. And a hydraulic device 240 that varies the frictional force between the outer clutch plate 231 and the inner clutch plate 232.

<Clutch-Clutch case>
The clutch case 210 includes a bottomed cylindrical clutch case main body 211 whose front side is closed, and a shaft portion 212 extending forward from the front bottom portion of the clutch case main body 211. The clutch case 210 is rotatably supported by the first case 110 via a radial bearing 251.

  A shaft spline 213 is formed substantially in the middle of the shaft portion 212. A hole spline 261 of a companion flange 260 is splined to the shaft spline 213 so that the shaft portion 212 and the companion flange 260 rotate together. The companion flange 260 is a short cylindrical body extending in the direction of the axis O1, and the rear end of the propeller shaft is bolted to the front end portion thereof.

  A male screw 214 is formed at the front end portion of the shaft portion 212. A nut 262 is screwed onto the male screw 214, and a companion flange 260 is fastened to the shaft portion 212.

<Clutch-inner hub>
The inner hub 220 is a cylindrical member, and a hole spline 221 is formed on the inner peripheral surface thereof. The hole spline 221 is splined to the shaft spline 13 d of the drive pinion gear 10.

<Clutch-outer clutch plate, inner clutch plate>
The outer clutch plate 231 is a ring plate-like member, and the outer peripheral edge portion thereof is spline-coupled with the inner peripheral surface of the clutch case main body 211. Therefore, the outer clutch plate 231 and the clutch case main body 211 rotate integrally.

  The inner clutch plate 232 is a ring plate-like member, and the inner peripheral edge thereof is spline-coupled to the outer peripheral surface of the inner hub 220. Therefore, the inner clutch plate 232 and the inner hub 220 rotate integrally.

  The outer clutch plates 231 and the inner clutch plates 232 are alternately stacked in the axial direction (front-rear direction). A ring-shaped pressing plate 233 that is movable in the axial direction is arranged on the front side of the alternately laminated body.

<Clutch-hydraulic device>
The hydraulic device 240 includes a ring-shaped piston 241 and a ring-shaped pump body 242 that slidably accommodates the piston 241 in the axial direction (front-rear direction), and a ring shape between the piston 241 and the pump body 242. The oil chamber 243 is formed. The oil chamber 243 is supplied with oil from the pump 270 and pressure-adjusted by a pressure adjustment valve (not shown) in accordance with a command from an ECU (Electronic Control Unit).

  The piston 241 abuts against the pressing plate 233 via the thrust bearing 244 and is biased to return to the initial position by a disc spring 245 that functions as a return spring (return spring). When the oil pressure in the oil chamber 243 increases, the piston 241 moves backward against the spring force of the disc spring 245, and the frictional force between the outer clutch plate 231 and the inner clutch plate 232 increases, and the propeller shaft Power is transmitted to the drive pinion gear 10.

  A pump 270 is disposed between the pump body 242 and the clutch case 210. The pump 270 is formed of, for example, a Trochoid (registered trademark) pump, and includes an outer rotor 271 that rotates integrally with the clutch case 210 and an inner rotor 272 that rotates integrally with the drive pinion gear 10.

  Since the clutch case 210 rotates integrally with the propeller shaft, the clutch case 210 rotates integrally with the front wheel. Further, the drive pinion gear 10 rotates integrally with the rear wheel. Therefore, since the rotational speeds of the front wheels and the rear wheels are equal in a normal traveling state, the outer rotor 271 and the inner rotor 272 rotate integrally, and the pump 270 does not generate hydraulic pressure. However, for example, when the front wheel idles, a difference in rotational speed occurs between the outer rotor 271 and the inner rotor 272, the pump 270 generates hydraulic pressure, and the hydraulic pressure is supplied to the oil chamber 243.

≪Operation and effect of final reduction gear≫
According to the final reduction gear device 1 of the first embodiment, the following operational effects are obtained.
The drive pinion gear 10 is configured to be rotatably supported by a rear taper roller bearing 40 on the rear side and a front taper roller bearing 30 on the front side, so that the front shaft portion 13 (back side shaft portion) is It becomes shorter than the prior art of the cantilever structure. Therefore, the drive pinion gear 10 and the case 100 can be reduced in size and weight.

When the vehicle moves forward and the ring gear 20 rotates in the direction of the arrow in FIG. 2 (clockwise), the lubricating oil lifted up by the ring gear 20 is scattered mainly in the forward direction. Therefore, although a large amount of lubricating oil does not enter the breather opening 3 opened in the forward direction, the splashed oil reflected on the inner wall of the case 100 may enter the breather opening 3. On the other hand, in this embodiment, the circumferential shielding plate 5 and the axial shielding plates 6A and 6B formed on the outer peripheral surface of the sleeve 50 shield the splash oil from the breather port 3. The circumferential shielding plate 5 mainly shields the splashing oil splashing rightward, the axial shielding plate 6A mainly shields the splashing oil splashing backward, and the axial shielding plate 6B mainly splashes upward. Shield from splashing oil. Thereby, intrusion of the lubricating oil into the breather port 3 is prevented. Particularly, since the circumferential shielding plate 5 is positioned so as to isolate the ring gear 20 and the breather port 3 in the direction of the axis O2, it is effective for shielding the splashed oil scattered from the ring gear 20.
Further, since the breather chamber 2 is also shielded from the right rear drive shaft by the sleeve 50, the splashed oil swept up by the rotation of the drive shaft does not reach the breather chamber 2.

  Further, when the vehicle moves backward and the ring gear 20 rotates counterclockwise in FIG. 2 and the splashed oil swept up by the ring gear 20 is mainly scattered backward, the axial shielding plate 6A shields this. By doing so, the penetration of the lubricating oil into the breather port 3 is prevented.

  According to the present embodiment, by providing the circumferential shielding plate 5 and the axial shielding plates 6A and 6B, it is possible to effectively prevent the lubricating oil from entering the breather port 3. Since the breather chamber can be formed by effectively utilizing the space from the housing portion of the ring gear 20 to the periphery of the rear surface of the sleeve 50, the lubricating oil around the housing portion of the drive pinion gear 10 located in front of the sleeve 50 can be obtained. Design flexibility of lubrication structure (lubrication space) is improved. Since the circumferential shielding plate 5 and the axial shielding plates 6A and 6B are formed on the sleeve 50, there is no need to assemble the shielding portion on the case 100 side. Further, it is not necessary to form an air flow path having a complicated labyrinth structure for preventing the lubricant from entering the case 100 side.

  In the present embodiment, the circumferential shielding plate 5 and the axial shielding plates 6A and 6B are formed as shielding portions. However, the circumferential shielding plate 5, the axial shielding plate 6A, and the axial shielding plate may be used depending on circumstances. Any one of 6B may be formed.

“Second Embodiment”
The second embodiment will be described with reference to FIGS. In addition, about the same component as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
In the second embodiment, the oil shielding rib 7 is formed on the inner wall surface of the third case 130 so as to surround the breather pipe 4.

  The position where the breather pipe 4 is attached to the third case 130 is the same as in the first embodiment. A circumferential shielding plate 5 is formed on the outer peripheral surface of the body portion 51 of the sleeve 50. The breather chamber 2 is formed to be surrounded by the circumferential shielding plate 5, the inner wall of the third case 130, and the outer peripheral surface of the body portion 51 of the sleeve 50. As can be seen from FIG. 6, the circumferential range of the circumferential shielding plate 5 of the present embodiment is generally the range on the rear side of the body portion 51 from slightly forward to the lower end of the body portion 51. . By extending the lower end of the circumferential shielding plate 5 downward until it is immersed in the lubricating oil, the disturbance of the oil surface due to the lifting of the ring gear 20 can be suppressed by the circumferential shielding plate 5. Therefore, the splash splashed upward from the oil reservoir 150 toward the breather port 3 can be reduced, and the axial shielding plate 6B of the first embodiment can be omitted. Also in this embodiment, the axial shielding plate 6A of the first embodiment may be formed.

  The oil shielding rib 7 protrudes forward from the inner wall of the third case 4 so as to surround the breather pipe 4 and has a rectangular tube shape with an open front end. The front end of the oil shielding rib 7 is located in front of the breather port 3.

≪Operation and effect of final reduction gear≫
The splashed oil splashed and scattered by the ring gear 20 is shielded by the circumferential shielding plate 5 and is also shielded by the oil shielding rib 7 formed so as to surround the breather pipe 4, thereby entering the breather port 3. It becomes difficult.

  According to the present embodiment, by providing the circumferential shielding plate 5 and the oil shielding rib 7, it is possible to effectively prevent the lubricating oil from entering the breather port 3. Also in the present embodiment, since the breather chamber can be formed by effectively using the space from the housing portion of the ring gear 20 to the periphery of the rear outer peripheral surface of the sleeve 50, the housing of the drive pinion gear 10 positioned at the front of the sleeve 50 is accommodated. The degree of freedom in designing the lubricating structure (lubricating space) of the lubricating oil around the part is improved.

  Note that the oil shielding rib 7 does not necessarily have a rectangular shape of four surfaces (upper surface, lower surface, right surface, and left surface). You may make it the shape which exhibits a U shape seeing O1 direction. Moreover, you may make it cylindrical shape.

≪Modification≫
As mentioned above, although two embodiment of this invention was described, this invention is not limited to this, For example, you may change as follows.

  In the two embodiments described above, the configuration in which the power transmission device is applied to the final reduction gear 1 is illustrated, but other configurations, for example, may be applied to the transfer device. The transfer device is a device that is mounted on an FF-based four-wheel drive vehicle, branches power from the engine toward the front drive shaft, which is the drive wheel, and inputs it to the front end of the propeller shaft that extends in the front-rear direction.

  In this case, the driven-side pinion gear fixed to the front end of the propeller shaft constitutes the second bevel gear, the drive-side ring gear that rotates about the axis extending in the vehicle width direction constitutes the first bevel gear, and the ring gear The fixed ring gear shaft constitutes a rotating body. The driven pinion gear includes a pinion gear (bevel gear body) that meshes with the ring gear, a front shaft portion formed on the front side (tooth surface side) of the pinion gear, and a rear shaft portion formed on the rear side (back side) of the pinion gear. It becomes the composition provided with.

  A sleeve is arranged coaxially with the ring gear shaft, one end portion of the sleeve holds the ring gear shaft rotatably via the first bearing, and the other end portion of the sleeve is fixed to the case of the transfer device. Moreover, the external fitting holding | maintenance part formed in the surrounding wall part of a sleeve becomes a structure which hold | maintains a front side axial part rotatably via a tooth surface side bearing.

1 Final reduction gear (power transmission device)
2 Breather chamber 3 Breather outlet 4 Breather pipe 5 Circumferential shielding plate (shielding part)
6 Axial shield (shield)
7 Shielding rib 10 Drive pinion gear (second bevel gear)
11 Pinion gear (bevel gear body)
12 Rear shaft (tooth surface side shaft)
20 Ring gear (first bevel gear)
40 Rear taper roller bearing (second bearing)
50 Sleeve 52 External fitting (one end)
53 Clamped part (other end part)
100 case 130 third case 300 differential gear 310 differential case (rotating body)
340 Right taper roller bearing (first bearing)

Claims (5)

A first bevel gear;
A second bevel gear having a bevel gear body meshing with the first bevel gear and a tooth surface side shaft portion formed on the tooth surface side of the bevel gear body;
A rotating body that rotates integrally with the first bevel gear;
A case in which the first bevel gear, the second bevel gear and the rotating body are accommodated, and lubricating oil is stored in a bottom portion;
A cylindrical sleeve having one end supporting the rotating body through a first bearing, the other end fixed to the case, and a peripheral wall supporting the tooth surface side shaft through a second bearing;
With
Inside the case is formed a breather chamber communicating with the outside through a breather port,
An oil shielding portion is formed on the outer peripheral surface of the sleeve, which is directed to the inner wall surface of the case and shields the lubricating oil that the first bevel gear lifts from the breather port,
The breather chamber is surrounded by an inner wall surface of the case, an outer peripheral surface of the sleeve, and the oil shielding portion.   2. The power transmission device according to claim 1, wherein the oil shielding portion includes a circumferential shielding plate extending in a radially outward direction along a circumferential direction of the sleeve.   The said oil shielding part is provided with the axial direction shielding plate extended in the said breather chamber side along the axial direction of the said sleeve from the circumferential direction edge part of the said circumferential direction shielding plate. Power transmission device. The breather port is a pipe port of a breather pipe attached to the case,
The power transmission device according to any one of claims 1 to 3, wherein an oil shielding rib is formed on an inner wall surface of the case so as to surround the breather pipe. The first bevel gear is a ring gear constituting a final reduction gear;
The power transmission device according to any one of claims 1 to 4, wherein the rotating body constitutes a differential device and is a differential case to which the ring gear is fixed.

Images