JP6379828B2 - Power transmission device - Google Patents

Description

  The present invention relates to a power transmission device that transmits engine power to wheels, and more particularly to a power transmission device including a transfer case that houses a transfer mechanism.

  A power transmission device mounted on a vehicle such as an automobile includes a breather chamber in a case that accommodates a transmission mechanism, a transfer mechanism, or the like, and when the pressure inside the case rises, the pressure inside the case is increased via the breather chamber. I try to escape outside.

  As a conventional power transmission device of this type, as described in Patent Document 1, a breather chamber is formed in the upper portion of the transfer case, and an air inlet portion that communicates the internal space of the transfer case with the lower portion of the breather chamber is provided. In addition, there has been known one provided with an air outlet for communicating the upper part of the breather chamber with the outside of the transfer case.

  In the conventional power transmission device described in Patent Document 1, when the pressure inside the transfer case becomes higher than the atmospheric pressure, the air inside the transfer case sequentially passes through the air inlet, the breather chamber, and the air outlet. By flowing out to the outside of the transfer case, the pressure inside the transfer case is maintained at atmospheric pressure.

  Moreover, the conventional power transmission device described in Patent Document 1 stores lubricating oil that lubricates the transfer mechanism inside the transfer case, and the oil level of the lubricating oil is sufficient to lubricate the transfer mechanism. It is set to height.

JP 10-138774 A

  However, since the conventional power transmission device described in Patent Document 1 has a large amount of lubricating oil stored below the transfer mechanism in the transfer case, the amount of lubricating oil scooped up by the transfer mechanism increases. For this reason, there is a possibility that the lubricating oil scraped up by the transfer mechanism enters the breather chamber through the air inlet portion and leaks to the outside through the air outlet portion.

  Further, in the conventional power transmission device, there is a possibility that a drive loss of the transfer mechanism occurs due to the transfer mechanism stirring the lubricating oil.

  The present invention has been made to solve the above-described problems, and prevents the lubricating oil from leaking out of the breather chamber while ensuring a sufficient amount of lubricating oil in the transfer case. Another object of the present invention is to provide a power transmission device that can reduce drive loss due to the transfer mechanism stirring the lubricating oil.

A first aspect of the present invention for solving the above problem includes a transmission case attached to an engine and a transfer case attached to the transmission case, and the transmission case is input from the engine. A speed change mechanism for shifting power and an output member for outputting the power changed by the speed change mechanism to one of the front wheels or the rear wheels are housed, and the transfer case is provided on the outer peripheral portion of the output member. A drive gear that rotates integrally with the member, a driven gear that meshes with the drive gear and that rotates in a driven manner, and rotates integrally with the driven gear on the same axis as the driven gear, and transmits power to the other of the front wheel or the rear wheel. accommodating the transfer mechanism having a bevel gear, and the upper portion of the transfer case, among the transfer case In the power transmission device in which a breather chamber communicating with the outside is formed, the transfer case is disposed at a bottom portion of the transfer case and is disposed at an upper portion of the oil reservoir chamber. A transfer mechanism chamber that houses the transfer mechanism and communicates with the breather chamber, and has a partition wall defining the interior of the transfer case below the transfer mechanism, the partition wall including the bevel gear and the follower A first partition wall portion extending along an outer peripheral edge of a large-diameter gear of the bevel gear or the driven gear so as to cover a lower portion of the gear; and extending downward from the first partition wall portion to the drive gear. A second partition wall portion extending along the outer peripheral edge of the drive gear so as to cover the lower portion of the drive gear, and the second partition wall portion, Serial is constituted a transfer mechanism chamber and the oil reservoir chamber from the one provided a lubricating oil communicating holes communicating.

As a second aspect of the present invention, one end of the first partition wall is connected to the bottom of the transfer case on the bevel gear side, and the other end of the first partition wall is connected to the bevel gear and the It is arranged between the drive gear or the driven gear and the drive gear, one end of the second partition wall is connected to the other end of the first partition wall, and the second partition wall It is preferable that the other end is connected to the bottom of the transfer case on the drive gear side .

As a third aspect of the present invention, the transfer case includes a first case in which the drive gear, the driven gear, and the bevel gear are arranged and coupled to the transmission case, and the first case includes the transmission case; And a second case that is connected from the opposite side and closes the transfer mechanism chamber between the first case and the lubricating oil communication hole in the axial direction of the output member with respect to the drive gear. Preferably, the breather chamber has a breather inlet opening that opens in the upper wall of the second case so as to communicate with the transfer mechanism chamber.

  As a fourth aspect of the present invention, it is preferable that the oil sump chamber is formed by the first case and the second case.

  As a fifth aspect of the present invention, the breather chamber has a breather outlet portion that opens to the first case so as to communicate with the outside of the transfer case, and straddles the first case and the second case. It is preferable to be formed as follows.

  As described above, according to the first aspect, the partition wall having the lubricating oil communication hole is provided below the transfer mechanism, so that the oil level of the lubricating oil in the transfer mechanism chamber is maintained and the transfer mechanism is improved. A sufficient amount of lubricating oil for lubricating the transfer mechanism can be secured by the oil reservoir chamber while being lubricated.

  In addition, since the partition wall is provided inside the transfer case, only the lubricating oil in the transfer mechanism chamber is lifted up by the transfer mechanism, and the lubricating oil in the oil sump chamber is not picked up. The amount of is reduced.

  Therefore, since the amount of the lubricating oil that the transfer mechanism scrapes is reduced, it is possible to prevent the lubricating oil in the transfer mechanism chamber from being scooped up by the transfer mechanism and leaking out of the transfer case through the breather chamber. In addition, since the amount of lubricating oil that the transfer mechanism scrapes is reduced, it is possible to reduce drive loss due to the transfer mechanism stirring the lubricating oil.

  As a result, while ensuring a sufficient amount of lubricating oil in the transfer case, the lubricating oil is prevented from leaking out of the breather chamber, and driving loss due to the transfer mechanism stirring the lubricating oil is reduced. be able to.

  According to the second aspect described above, the lower part of the bevel gear is covered with the first partition wall and the lower part of the drive gear is covered with the second partition wall, so that it exists between the partition wall and the bevel gear and the drive gear. The amount of lubricating oil to be reduced can be effectively reduced.

  In addition, since the lubricating oil communication hole is provided in the second partition wall, the lubricating oil in the oil reservoir chamber is directed toward the transfer mechanism chamber through the lubricating oil communication hole by the drive gear having a smaller diameter than the bevel gear and a small lubricating oil scooping action. It is scraped up. Therefore, the rotation of the bevel gear, which has a larger diameter than the drive gear and has a large lubricating oil scavenging action, prevents the oil in the oil reservoir chamber from being violently scooped up toward the transfer mechanism chamber. Inflow to the breather chamber can be prevented.

  According to the third aspect, the lubricating oil communication hole is formed at a position close to the second case side in the first case in the axial direction of the drive shaft with respect to the drive gear, so that the oil is retained by the drive gear. It is possible to suppress the lubricating oil in the chamber from being scraped up toward the transfer mechanism chamber through the lubricating oil communication hole.

  For this reason, the drive loss by a drive gear stirring lubricating oil can be reduced.

  According to the fourth aspect, since the oil reservoir chamber is formed by the first case and the second case, the oil reservoir chamber is formed rather than forming the oil reservoir chamber in one of the first case or the second case. And a sufficient amount of lubricating oil can be stored in the oil reservoir chamber.

  According to the fifth aspect, the breather chamber is formed so as to straddle the first case and the second case, so that the breather chamber is formed in one of the first case and the second case. The chamber volume can be increased. By expanding the volume of the breather chamber, when the air inside the transfer case flows out of the transfer case through the breather chamber, the speed of the air flowing out can be reduced. For this reason, the particulate lubricating oil inside the transfer case is prevented from leaking to the outside of the transfer case. In addition, by providing the breather inlet portion in the first case and providing the breather outlet portion in the second case, the distance from the breather inlet portion to the breather outlet portion can be increased, so that the lubricating oil flows into the breather inlet portion. Even if it exists, it can prevent that this lubricating oil leaks out from a breather exit part.

FIG. 1 is a plan view showing a schematic configuration of a vehicle equipped with a power transmission device according to an embodiment of the present invention. FIG. 2 is a plan view of the power transmission device according to the embodiment of the present invention. FIG. 3 is an exploded perspective view in which a part of the power transmission device according to the embodiment of the present invention is disassembled. FIG. 4 is a side view of the first case of the transfer case of the power transmission device according to the embodiment of the present invention as viewed from the second case side. FIG. 5 is a cross-sectional view showing a II cross section of FIG. FIG. 6 is a cross-sectional view showing a II-II cross section of FIG. FIG. 7 is a cross-sectional view showing a cross section taken along the line III-III of FIG. 4, and is a view showing a state of the lubricating oil in the transfer case when the vehicle is traveling on a flat road at a constant speed in a straight line. FIG. 8 is a cross-sectional view showing a cross section taken along the line III-III in FIG. 4, and is a view showing a state of the lubricating oil in the transfer case when the vehicle is traveling on a flat road in a left turn. FIG. 9 is a cross-sectional view showing the IV-IV cross section of FIG. 4 and showing the structure of the breather chamber above the transfer case.

  Hereinafter, a power transmission device 10 according to an embodiment in which a power transmission device according to the present invention is applied to a vehicle 1 will be described with reference to FIGS.

  First, the configuration will be described. As shown in FIG. 1, the vehicle 1 includes an engine 2, a power transmission device 10, left and right front wheels 8L and 8R, and left and right rear wheels 9L and 9R.

  The vehicle 1 is based on a so-called FF (Front engine Front drive) vehicle in which the left and right front wheels 8L and 8R and the left and right rear wheels 9L and 9R are always driven by the power output from the engine 2 disposed at the front of the vehicle. It consists of a full-time four-wheel drive vehicle.

  The vehicle 1 is a full-time four-wheel drive vehicle comprising a so-called RR (Rear engine Rear drive) vehicle base that constantly drives the left and right rear wheels and the left and right front wheels by power output from an engine disposed at the rear of the vehicle. It may be.

  Here, in this embodiment, the front / rear, left / right, and up / down directions are indicated by arrows in the drawing so as to coincide with the front / rear direction, the left / right direction, and the up / down direction seen from the driver seated in the driver's seat of the vehicle 1. ing.

  The engine 2 is a four-cycle engine that performs a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke while a piston (not shown) reciprocates two cylinders. It is placed. The piston is connected to a connecting rod and a crankshaft (not shown), and the power of the engine 2 is output from the crankshaft to the transmission 3 of the power transmission device 10.

  The power transmission device 10 includes a transmission 3, a front differential 4, a transfer 5, left and right front drive shafts 6L and 6R, left and right rear drive shafts 7L and 7R, a propeller shaft 11, and a rear differential 12. It consists of

  The transmission 3 includes a speed change mechanism 31, an input shaft 32, a counter shaft 33, a counter gear 34, a reverse shaft 35, and a transmission case 36 that accommodates these components.

  The speed change mechanism 31 includes a plurality of gears incorporated in the input shaft 32, the counter shaft 33, and the reverse shaft 35. The input shaft 32, the counter shaft 33, and the reverse shaft 35 are rotatably supported by the transmission case 36.

  The speed change mechanism 31 changes the power of the engine 2 input to the input shaft 32 and outputs it to the front differential 4 via the counter gear 34 incorporated in the counter shaft 33.

  As shown in FIGS. 1 to 3, the transmission case 36 includes a first case 41 fastened to the left side of the engine 2 in the vehicle width direction and a second case fastened to the left side of the first case 41 in the vehicle width direction. 42.

  The second case 42 accommodates the speed change mechanism 31, the input shaft 32, the counter shaft 33, the counter gear 34, and the reverse shaft 35.

  The first case 41 has a side wall 41a that protrudes rearward in the vehicle front-rear direction, and the front differential 4 is accommodated inside the side wall 41a. A part of the front drive shaft 6R as a power transmission shaft is accommodated in the side wall 41a and is rotatably supported by the first case 41.

  The second case 42 has a side wall 42a protruding rearward in the vehicle front-rear direction, and a part of the front drive shaft 6L as a power transmission shaft is accommodated in the side wall 42a and rotated to the second case 42. It is supported freely.

  As shown in FIG. 1, the front differential 4 has a differential mechanism 45 and a final gear 46 that meshes with the counter gear 34 and transmits power from the transmission mechanism 31 to the differential mechanism 45.

  The differential mechanism 45 includes a differential case 45a that is rotatably supported inside the side wall 41a of the first case 41, and a differential mechanism portion 45b that is accommodated in the differential case 45a.

  The left and right front drive shafts 6L and 6R are connected to the differential mechanism portion 45b, and the differential mechanism portion 45b provides power while allowing a rotational difference between the left and right front drive shafts 6L and 6R. To communicate.

  As shown in FIGS. 1 and 3 to 8, the transfer 5 includes a transfer mechanism 51 and a transfer case 52. The transfer 5 converts the power input from the front drive shaft 6 </ b> R in a direction orthogonal to the front drive shaft 6 </ b> R and increases the speed to transmit to the propeller shaft 11.

  The transfer mechanism 51 includes a drive gear 61, a driven gear 64, a bevel gear 63, and a rotating shaft 62. The drive gear 61 is provided on the outer periphery of the front drive shaft 6R and rotates integrally with the front drive shaft 6R. The front drive shaft 6R constitutes a drive shaft as an output member in the present invention.

  The driven gear 64 is fixed to the rotating shaft 62 on the right side of the bevel gear 63, meshes with the drive gear 61 shown in FIG. 1, and is driven to rotate to transmit power to the bevel gear 63. The bevel gear 63 is fixed to the rotating shaft 62 and rotates integrally with the driven gear 64 to transmit power to the left and right rear wheels 9L and 9R. In the present embodiment, the bevel gear 63 is composed of a hypoid gear. The bevel gear 63 is formed with a larger diameter than the drive gear 61. The rotating shaft 62 is disposed in parallel with the front drive shaft 6R.

  Furthermore, the transfer mechanism 51 includes a transfer pinion 65 that converts power in a direction orthogonal to the rotation shaft 62 and transmits the power at an increased speed, and a transfer pinion shaft 66 as a rotation shaft that rotates together with the transfer pinion 65. ing.

  Each of these members constituting the transfer mechanism 51 is housed inside the transfer case 52 and is rotatably supported by the transfer case 52.

  The bevel gear 63 is disposed closer to the transmission case 36 than the drive gear 61 and the driven gear 64. As shown in FIGS. 1 and 2, the rear end portion of the transfer pinion shaft 66 in the vehicle front-rear direction is connected to the front end portion of the propeller shaft 11, and the transfer pinion shaft 66 rotates together with the propeller shaft 11.

  When the vehicle 1 moves forward, as indicated by an arrow R2 in FIG. 4, the front drive shaft 6R rotates clockwise toward the paper surface. When the front drive shaft 6R rotates in the clockwise direction, the rotating shaft 62 and the bevel gear 63 rotate in the counterclockwise direction indicated by the arrow R1 via the drive gear 61 and the driven gear 64.

  When the bevel gear 63 rotates in the counterclockwise direction, the transfer pinion 65 rotates in the clockwise direction indicated by the arrow R3 when viewed from the lower side toward the paper surface of FIG. 5 and the propeller shaft 11 is similarly rotated. Rotate clockwise through the transfer pinion shaft 66 as indicated by the arrow R3. As a result, the power input to the front drive shaft 6R is converted to a right angle and transmitted to the propeller shaft 11.

  As shown in FIGS. 2 and 4, the transfer case 52 includes a first case 71 fastened to the side wall 41 a of the first case 41 of the transmission case 36, a second case 72 fastened to the first case 71, have.

  In the first case 71, a drive gear 61, a driven gear 64, and a bevel gear 63 are arranged. As shown in FIG. 4, the lubricating oil is stored inside the transfer case 52 so as to be at the oil level position OL1.

  The transfer case 52 includes a plurality of fastening bolts 73 that fasten the second case 72 to the first case 71 and a plurality of fastening bolts 74 that fasten the first case 71 to the first case 41.

  As shown in FIGS. 3, 4, 7, and 8, a partition wall 90 is provided below the transfer mechanism 51 inside the transfer case 52. The partition wall 90 is disposed inside the transfer case 52 at the bottom portion of the transfer case 52 and stores an oil reservoir chamber 93 that stores lubricating oil, and a transfer chamber that is disposed above the oil reservoir chamber 93 and accommodates the transfer mechanism 51. It is divided into a mechanism chamber 95.

  The second case 72 is connected to the first case 71 from the opposite side to the transmission case 36, and closes the transfer mechanism chamber 95 with the first case 71.

  The oil reservoir chamber 93 is formed of a first case 71 and a second case 72 as shown in FIGS. 6 to 8.

  The partition wall 90 includes a first partition wall portion 91 and a second partition wall portion 92. The first partition wall portion 91 extends along the outer peripheral edge of the bevel gear 63 so as to cover the lower portion of the bevel gear 63. The second partition wall portion 92 extends along the outer peripheral edge of the drive gear 61 so as to cover the lower portion of the drive gear 61.

  As shown in FIG. 4, one end 91 a of the first partition wall 91 is connected to the bottom 52 a of the transfer case 52 on the bevel gear 63 side. The other end 91 b of the first partition wall 91 is disposed between the bevel gear 63 and the driven gear 64.

  One end 92 a of the second partition wall 92 is connected to the other end 91 b of the first partition wall 91. The other end 92 b of the second partition wall 92 is connected to the bottom 52 b on the drive gear 61 side of the transfer case 52.

  A lubricating oil communication hole 94 is formed in the second partition wall portion 92, and the lubricating oil communication hole 94 communicates the transfer mechanism chamber 95 and the oil reservoir chamber 93. As shown in FIGS. 6 to 8, the lubricating oil communication hole 94 is formed at a position close to the second case 72 side in the first case 71 in the axial direction of the front drive shaft 6 </ b> R with respect to the drive gear 61. .

  The lubricating oil stirred under the drive gear 61 flows into the oil reservoir chamber 93 from the lubricating oil communication hole 94 along the inner wall of the transfer case 52. The lubricating oil that has flowed into the oil reservoir chamber 93 flows along the lower surfaces of the first partition wall portion 91 and the second partition wall portion 92, and again flows out of the oil reservoir chamber 93 from the upper portion of the lubricating oil communication hole 94. .

  As shown in FIGS. 3, 4, and 7 to 9, a breather chamber 100 is formed in the upper portion of the transfer case 52.

  The breather chamber 100 has a breather inlet 101 and a breather outlet 102. The breather inlet portion 101 opens in the upper wall of the second case 72 so as to communicate with the transfer mechanism chamber 95 that is the inside of the transfer case 52. The breather outlet 102 opens in the first case 71 so as to communicate with the outside of the transfer case 52. Therefore, the breather chamber 100 communicates with the inside and the outside of the transfer case 52.

  As shown in FIG. 9, the breather chamber 100 is formed so as to straddle the first case 71 and the second case 72. Specifically, the breather chamber 100 extends from the breather inlet portion 101 that opens to the second case 72 to the first case 71, then turns back to the second case 72 side and extends to the second case 72 again, and then It extends to the breather outlet portion 102 that is folded back to the side of the first case 71 and opens to the first case 71.

  The effect of the power transmission device 10 of this embodiment is demonstrated. As shown in FIG. 4, when the vehicle 1 moves forward, the drive gear 61 rotates in the clockwise direction indicated by the arrow R2, and the bevel gear 63 rotates in the counterclockwise direction indicated by the arrow R1. At this time, the lubricating oil in the transfer mechanism chamber 95 lubricates the drive gear 61, the bevel gear 63, and the like. The lubricating oil in the transfer mechanism chamber 95 is agitated by the drive gear 61, the bevel gear 63, and the like.

  When the pressure inside the transfer case 52 becomes higher than the atmospheric pressure, the air inside the transfer case 52 passes through the breather inlet portion 101, the breather chamber 100, and the breather outlet portion 102 sequentially to the outside of the transfer case 52. As a result, the pressure inside the transfer case 52 decreases to atmospheric pressure. As a result, the pressure inside the transfer case 52 is maintained at atmospheric pressure.

  According to the power transmission device 10 of the present embodiment, the transfer case 52 is disposed at the bottom of the transfer case 52 and stores an oil reservoir chamber 93 for storing lubricating oil, and is disposed at the top of the oil reservoir chamber 93 for transfer. A transfer mechanism chamber 95 that houses the mechanism 51 and communicates with the breather chamber 100, and a partition wall 90 that defines the interior of the transfer case 52 are provided below the transfer mechanism 51. Further, the partition wall 90 has a lubricating oil communication hole 94 that allows the transfer mechanism chamber 95 and the oil reservoir chamber 93 to communicate with each other.

  Thus, the partition wall 90 having the lubricating oil communication hole 94 is provided below the transfer mechanism 51, so that the oil level of the lubricating oil in the transfer mechanism chamber 95 is maintained and the transfer mechanism 51 is lubricated well, A sufficient amount of lubricating oil for lubricating the transfer mechanism 51 can be secured by the pool chamber 93.

  Further, since the partition wall 90 is provided inside the transfer case 52, only the lubricating oil in the transfer mechanism chamber 95 is scraped up by the transfer mechanism 51, and the lubricating oil in the oil reservoir chamber 93 is not scraped up. The amount of lubricating oil 51 is scraped off is reduced.

  Accordingly, since the amount of the lubricating oil that the transfer mechanism 51 scrapes is reduced, the lubricating oil in the transfer mechanism chamber 95 is prevented from being scraped up by the transfer mechanism 51 and leaking out of the transfer case 52 through the breather chamber 100. be able to. Further, since the amount of lubricating oil that the transfer mechanism 51 scoops up is reduced, it is possible to reduce drive loss due to the transfer mechanism 51 stirring the lubricating oil.

  As a result, while ensuring a sufficient amount of lubricating oil in the transfer case 52, the lubricating oil is prevented from leaking outside from the breather chamber 100, and the driving loss due to the transfer mechanism 51 stirring the lubricating oil. Can be reduced.

  Further, since the lubricating oil moves back and forth between the transfer mechanism chamber 95 and the oil reservoir chamber 93 through the lubricating oil communication hole 94 provided in the partition wall 90, the lubricating oil in the oil reservoir chamber 93 is changed when the traveling state of the vehicle 1 changes. Abrupt flow into the transfer mechanism chamber 95 is suppressed. For this reason, even when the running state of the vehicle 1 changes, the lubricating oil is prevented from leaking to the outside from the breather chamber 100, and driving loss due to the transfer mechanism 51 stirring the lubricating oil is reduced. .

  Also, since the partition wall 90 is provided inside the transfer case 52, the amount of lubricating oil that the transfer mechanism 51 scoops up is reduced, so that the temperature of the lubricating oil rises when the lubricating oil is stirred by the transfer mechanism 51. Is suppressed.

  Further, by providing the lubricating oil communication hole 94 in the partition wall 90, the lubricating oil in the oil reservoir chamber 93 and the lubricating oil in the transfer mechanism chamber 95 heated by stirring by the transfer mechanism 51 are connected to the lubricating oil communication hole. 94, the temperature of the lubricating oil is prevented from rising.

  For this reason, since the temperature rise of lubricating oil is suppressed, it is prevented that lubricating oil deteriorates by temperature rise.

  Further, according to the power transmission device 10 of the present embodiment, the partition wall 90 includes the first partition wall portion 91 extending along the outer peripheral edge of the bevel gear 63 so as to cover the lower portion of the bevel gear 63, and the lower portion of the drive gear 61. The second partition wall 92 extends along the outer peripheral edge of the drive gear 61 so as to cover it, and a lubricating oil communication hole 94 is formed in the second partition wall 92. One end 91a of the first partition wall 91 is connected to the bottom 52a of the transfer case 52 on the bevel gear 63 side, and the other end 91b of the first partition wall 91 is disposed between the bevel gear 63 and the driven gear. The One end 92 a of the second partition wall 92 is connected to the other end 91 b of the first partition 91, and the other end 92 b of the second partition 92 is on the drive gear 61 side of the transfer case 52. Is connected to the bottom 52b. A lubricating oil communication hole 94 is formed in the second partition wall portion 92.

  As a result, the lower part of the bevel gear 63 is covered by the first partition wall part 91 and the lower part of the drive gear 61 is covered by the second partition wall part 92, thereby existing between the partition wall 90 and the bevel gear 63 and the drive gear 61. The amount of lubricating oil to be reduced can be effectively reduced.

  Further, since the lubricating oil communication hole 94 is provided in the second partition wall portion 92, the lubricating oil in the oil reservoir chamber 93 is caused to flow into the lubricating oil communication hole 94 by the drive gear 61 having a smaller diameter than the bevel gear 63 and having a small action of scavenging the lubricating oil. Through the transfer mechanism chamber 95. For this reason, it is possible to prevent the lubricating oil in the oil reservoir chamber 93 from being violently scooped up toward the transfer mechanism chamber 95 by the rotation of the bevel gear 63 having a larger diameter than the drive gear 61 and having a large effect of scavenging the lubricating oil. It is possible to prevent 95 lubricating oil from flowing into the breather chamber 100.

  Further, according to the power transmission device 10 of the present embodiment, the transfer case 52 includes the first case 71 and the second case 72. The first case 71 is connected to the transmission case 36, and a drive gear 61, a driven gear 64, and a bevel gear 63 are disposed. The second case 72 is connected to the first case 71 from the side opposite to the transmission case 36, and closes the transfer mechanism chamber 95 with the first case 71.

  The lubricating oil communication hole 94 is formed at a position close to the second case 72 side in the first case 71 in the axial direction of the front drive shaft 6 </ b> R with respect to the drive gear 61. The breather chamber 100 has a breather inlet 101 that opens to the upper wall of the second case 72 so as to communicate with the transfer mechanism chamber 95.

  Accordingly, the lubricating oil communication hole 94 is formed at a position close to the second case side in the first case in the axial direction of the front drive shaft 6 </ b> R with respect to the drive gear 61. Can be prevented from being scraped up toward the transfer mechanism chamber 95 through the lubricating oil communication hole 94. For this reason, the drive loss by the drive gear 61 stirring the lubricating oil can be reduced.

  Further, according to the power transmission device 10 of the present embodiment, the oil sump chamber 93 is formed by the first case 71 and the second case 72. As a result, the volume of the oil reservoir chamber 93 can be expanded rather than forming the oil reservoir chamber 93 in one of the first case 71 or the second case 72, and a sufficient amount of lubricating oil is stored in the oil reservoir chamber 93. be able to.

  Further, according to the power transmission device 10 of the present embodiment, the breather chamber 100 has the breather outlet portion 102 that opens to the first case 71 so as to communicate with the outside of the transfer case 52. It is formed so as to straddle the case 72.

  Thereby, the volume of the breather chamber 100 can be increased as compared with the case where the breather chamber 100 is formed in one of the first case 71 and the second case 72. By expanding the volume of the breather chamber 100, when the air inside the transfer case 52 flows out of the transfer case 52 through the breather chamber 100, the speed of the air flowing out can be reduced. For this reason, the particulate lubricating oil inside the transfer case 52 is prevented from leaking outside the transfer case 52.

  Further, by providing the breather inlet portion 101 in the first case 71 and providing the breather outlet portion 102 in the second case 72, the distance from the breather inlet portion 101 to the breather outlet portion 102 can be increased. Even when the lubricating oil flows, the lubricating oil can be prevented from leaking from the breather outlet portion 102.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

  2 ... Engine, 6R ... Front drive shaft (output member, drive shaft), 8R, 8L ... Front wheel, 9R, 9L ... Rear wheel, 10 ... Power transmission device, 31 ... Transmission mechanism, 36 ... Transmission case, 51 ... Transfer mechanism , 52 ... transfer case, 52a ... bottom (bottom of the transfer case on the bevel gear side), 52b ... bottom (bottom of the transfer case on the drive gear side), 61 ... drive gear, 63 ... bevel gear, 64 ... driven gear, 71 ... 1 case, 72 ... 2nd case, 90 ... partition wall, 91 ... 1st partition wall part, 91a ... one end part, 91b ... other end part, 92 ... 2nd partition wall part, 92a ... one end part, 92b ... other end , 93 ... Oil reservoir chamber, 94 ... Lubricating oil communication hole, 95 ... Transfer mechanism chamber, 100 ... Breather chamber, 101 ... Breather inlet, 102 ... Brea Outlet portion

Claims (5)

A transmission case attached to the engine;
A transfer case attached to the transmission case,
The transmission case houses a speed change mechanism that changes the power input from the engine, and an output member that outputs the power changed by the speed change mechanism to one of the front wheels or the rear wheels,
The transfer case is provided on the outer periphery of the output member and rotates integrally with the output member, a driven gear that meshes with the drive gear and driven and rotated, and is coaxial with the driven gear and integrated with the driven gear. Containing a transfer mechanism that rotates and has a bevel gear that transmits power to the other of the front wheel or the rear wheel ;
In the power transmission device in which a breather chamber communicating with the inside and the outside of the transfer case is formed in the upper part of the transfer case,
The transfer case is disposed at the bottom of the transfer case to store a lubricating oil, and the transfer mechanism chamber is disposed at an upper portion of the oil reservoir to accommodate the transfer mechanism and communicate with the breather chamber. And a partition wall that divides the interior of the transfer case into the lower part of the transfer mechanism,
The partition wall includes a first partition wall portion extending along an outer peripheral edge of a large-diameter gear of the bevel gear or the driven gear so as to cover a lower portion of the bevel gear and the driven gear, and the first partition wall portion. A second partition wall extending along the outer peripheral edge of the drive gear so as to extend downward and cover the lower portion of the drive gear,
A power transmission device, wherein the second partition wall is provided with a lubricating oil communication hole for communicating the transfer mechanism chamber and the oil reservoir chamber . One end of the first partition wall is connected to the bottom of the transfer case on the bevel gear side, and the other end of the first partition wall is the bevel gear and the drive gear or the driven gear and the drive gear. Placed between and
One end of the second partition wall is connected to the other end of the first partition wall, and the other end of the second partition wall is connected to the bottom of the transfer case on the drive gear side. the power transmission device according to claim 1, characterized in that the. The transfer case is
A first case in which the drive gear, the driven gear and the bevel gear are arranged and coupled to the transmission case;
The second case is connected to the first case from the opposite side of the transmission case, and includes a second case that closes the transfer mechanism chamber with the first case,
The lubricating oil communication hole is formed at a position close to the second case side in the first case in the axial direction of the output member with respect to the drive gear;
The power transmission device according to claim 2, wherein the breather chamber has a breather inlet portion that opens in an upper wall of the second case so as to communicate with the transfer mechanism chamber.   The power transmission device according to claim 3, wherein the oil reservoir chamber is formed by the first case and the second case.   The breather chamber has a breather outlet that opens to the first case so as to communicate with the outside of the transfer case, and is formed so as to straddle the first case and the second case. The power transmission device according to claim 3 or 4.

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