JP2013060977A - Lubrication structure of final reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubrication structure of a final reduction gear which has a simple structure and can effectively take in a lubricant stored at a bottom portion of a housing into a differential case.SOLUTION: In the final reduction gear 1 including a differential ring gear 2 coupled to an input shaft 25, a differential case 3 having a gear storage room 6 which stores a side gear 4 integrally rotating with a drive shaft 12 and a pinion gear 5 meshing with the side gear 4, and which integrally rotates with the differential ring gear 2, and the housing 58 which stores the differential case 3 and the differential ring gear 2, an inlet 34 for taking in the lubricant stored at the bottom portion of the housing 58 is formed at a side face of the differential ring gear 2, and a lubricant inflow path 33 which leads the lubricant flowing from the inlet 34 to the gear storage room 6 is formed inside the differential ring gear 2.

Description

  The present invention relates to a lubricating structure for a final reduction gear.

  The differential mechanism in the final reduction gear of the four-wheel vehicle has a meshing structure of a pinion gear and a side gear in the differential case. Since both the pinion gear and the side gear engage with each other while the through holes provided in the back or center of the gear are in sliding contact with each other, it is necessary to supply sufficient lubricating oil to the sliding contact portion.

  The differential case has a shape in which both ends in the axial direction are closed and an opening for incorporating the gear into the cylindrical surface is provided. The sliding contact is achieved by taking in the lubricating oil stored in the bottom of the housing that houses the differential case from the opening. There is something to supply to the site.

  Since the opening formed in the cylindrical surface of the differential case opens outward in the radial direction, it is difficult to take in a large amount of lubricating oil at the bottom of the housing while rotating. With respect to this problem, there are disclosed ones in which the periphery of the opening has a shape that makes it easy to take in lubricating oil (for example, see Patent Document 1) and those in which lubricating oil is taken in and attached to the opening (for example, see Patent Documents 2 to 5). ing.

  In Patent Document 1, a convex portion for supporting a pinion shaft formed on the outer periphery of the differential case with respect to an opening for inflow of lubricating oil is located on the reverse direction side, and a side surface on the forward direction side of this convex portion is A structure formed at an acute angle with respect to the outer peripheral surface of the differential case is described, and according to the structure, it is described that the lubricating oil scraped up by the acute angle side surface is positively introduced into the opening.

Patent Document 2 describes a technique in which an oil scooping member made of a metal plate is attached to a differential case, and lubricating oil that has been scooped up by the oil scrambling member flows into an oil introduction hole.
In Patent Document 3, a differential oil splash member made of a metal plate is attached to a differential case, the differential oil splash member strikes the oil surface of the lubricant stored in the housing, and the splashed lubricant oil is applied to the gear through the opening. The technology to supply is described.
Patent Document 4 describes a technique of providing an inward lubricating oil retaining lip at the edge of the opening of a differential case. According to this lubricating oil retaining lip, when the opening is directed upward, the inflow of lubricating oil that drops down is detected. It is described that the amount of lubricating oil in the differential case is secured by suppressing the outflow of the lubricating oil from the inside of the differential case when the opening is directed downward without being obstructed.
In Patent Document 5, a drop-off prevention plate for preventing the pinion shaft from falling off is provided, a space for introducing lubricating oil is formed between the drop-off prevention plate and the differential case, and this pin is provided on the outer peripheral side of the pinion shaft. A technique for supplying lubricating oil via a taxiway is described.

Japanese Patent No. 3915719 Japanese Utility Model Publication 4-52525 Japanese Utility Model Publication No. 4-19943 JP 2008-128265 A No. 7-44844

  However, all of the techniques of Patent Documents 1 to 5 have the problem that the lubricating oil inflow opening is formed on the outer periphery in the radial direction of the differential case, so that the captured lubricating oil is easily discharged from the opening again by centrifugal force. is there. Although Patent Document 4 describes a lubricating oil holding lip that suppresses the outflow of lubricating oil, the effect of suppressing the discharge of lubricating oil that has been vigorous by centrifugal force cannot be expected so much.

  In the techniques of Patent Documents 1 to 5, an opening for introducing lubricating oil is formed in the shell portion of the differential case. Here, in general, a diff case is integrally provided with a diff ring gear having a diameter larger than that of the shell portion, and the oil level of the lubricating oil stored in the bottom of the housing mainly immerses the teeth of the diff ring gear. It is set as a purpose, and the immersion depth of the shell portion is hardly considered. Therefore, in the structure in which the opening for inflow of the lubricating oil is formed in the differential case having a smaller diameter than that of the diff ring gear, in the lubricating oil stored in the bottom of the carrier, the lubricating oil attached to or around the opening is provided. The movement distance of the oil intake member becomes small, and it is not possible to expect a sufficient amount of lubricating oil.

  Further, in the technique of Patent Document 1, a convex part for supporting the pinion shaft is formed on the outer case of the differential case, and the side surface on the forward rotation direction side of the convex part is formed at an acute angle with respect to the outer peripheral surface of the differential case. There is a problem that the shape of the mold becomes complicated, leading to high cost of the mold and increasing the weight of the differential case.

  Further, the techniques of Patent Documents 2 to 5 have a problem in that the number of man-hours for assembling the differential case increases because bolts, rivets, and the like are used to attach the lubricant introduction member to the differential case.

  The present invention was devised to solve such a problem, and it is possible to lubricate the final reduction gear with a simple structure and capable of effectively taking the lubricating oil stored in the bottom of the housing into the differential case. The purpose is to provide a structure.

  In order to solve the above-mentioned problems, the present invention has a gear housing chamber that houses a diff ring gear connected to an input shaft, a side gear that rotates integrally with a drive shaft, and a pinion gear that meshes with the side gear, and is integrated with the diff ring gear. In the final reduction device comprising a differential case that rotates to the right and a housing that houses the differential case and the differential ring gear, an inflow port that takes in the lubricant stored in the bottom of the housing is formed on a side surface of the differential ring gear, A lubricating oil inflow passage for guiding the lubricating oil flowing in from the inflow port to the gear housing chamber is formed in the differential ring gear.

  According to the present invention, since the inlet is formed on the side surface of the diffring gear having a large diameter, it becomes possible to increase the arc-shaped moving distance of the inlet in the lubricating oil stored in the bottom of the housing. Compared to the conventional structure in which the opening for lubricating oil inflow is provided in the portion, it becomes easier to secure the inflow of lubricating oil.

  Further, according to the present invention, the lubricating oil inflow passage includes an annular space communicating with the gear housing chamber over 360 degrees around the axis of the diff ring gear, and an inflow hole passage communicating the annular space and the inflow port. It is characterized by becoming.

  According to the present invention, the lubricating oil can be effectively guided to the gear housing chamber through the annular space.

  Further, the present invention is characterized in that the lubricating oil inflow passage is formed of a flow passage that is formed in a local opening and communicates linearly with the communication port facing the gear storage chamber and the inflow port.

  According to the present invention, the lubricating oil flowing in from the inflow port can be effectively flowed to the gear housing chamber without being dispersed by the linear lubricating oil inflow passage. In addition, it is not necessary to form a relatively large cavity inside the diff ring gear, and it is easy to ensure the strength of the diff ring gear.

  Further, the present invention is characterized in that the communication port is located closer to the reverse rotation direction than the normal line of the diff ring gear passing through the inflow port.

  According to the present invention, the inertial force in the circumferential direction at the time of forward rotation works effectively, so that the lubricating oil in the lubricating oil inflow passage can flow smoothly toward the communication port.

  Further, the present invention is inserted and fixed to the inflow port so that a part thereof protrudes from a side surface of the diff ring gear, and a lubricating oil intake port is formed in the protruding portion toward the forward rotation direction of the def ring gear. And a lubricating oil intake member.

  According to the present invention, the lubricating oil stored at the bottom of the housing can be effectively taken into the lubricating oil inflow passage by the lubricating oil intake opening formed in the forward rotation direction.

  Further, the present invention is characterized in that the lubricating oil intake member is formed such that a lubricating oil discharge port formed at a downstream end thereof has a smaller opening area than the lubricating oil intake port.

  According to the present invention, the flow rate of the lubricating oil at the lubricating oil discharge port can be increased, and the backflow of the lubricating oil from the lubricating oil inflow path in the diff ring gear to the lubricating oil intake member can be suppressed.

  In the present invention, a rib for receiving the lubricating oil stored in the bottom of the housing and flowing a part thereof into the inflow port is formed near the reverse rotation direction of the inflow port on the side surface of the diff ring gear. It is characterized by being.

  According to the present invention, the lubricating oil stored at the bottom of the housing changes its direction due to the resistance from the rib, so that a part of the lubricating oil can flow into the inflow port.

  Further, the present invention is characterized in that the differential ring gear and the differential case are integrally formed by casting.

  According to the present invention, the lubricating oil inflow passage can be formed at the time of casting, so that a separate machining process is not required, and the manufacturing cost of the diff ring gear can be suppressed.

  According to the present invention, the lubricating oil stored at the bottom of the housing can be effectively taken into the differential case with a simple structure.

(A) is the block diagram which showed the final reduction gear typically, (b) is a schematic explanatory drawing which shows the positional relationship of the input shaft and output shaft in the final reduction gear device seen from the vehicle width direction. It is a sectional side view which shows 1st Embodiment of this invention. It is explanatory drawing which looked at the principal part of the lubricating structure in 1st Embodiment of this invention from the vehicle width direction. It is AA sectional drawing in FIG. It is a sectional side view which shows 2nd Embodiment of this invention. It is explanatory drawing which looked at the principal part of the lubrication structure in 2nd Embodiment of this invention from the vehicle width direction. It is a sectional side view which shows 3rd Embodiment of this invention. It is explanatory drawing which looked at the principal part of the lubricating structure in 3rd Embodiment of this invention from the vehicle width direction. It is an external appearance perspective view of a lubricating oil taking-in member.

  Hereinafter, the form which applied the lubrication structure concerning the present invention to the final reduction gear is explained. FIG. 1A is a configuration diagram schematically showing the final reduction gear. In this figure, the final reduction gear 1 rotates integrally with an input gear 24 formed on an input shaft 25 connected to the output shaft of the electric motor E, an idler driven gear 23 meshing with the input gear 24, and the idler driven gear 23, for example. An intermediate shaft 21, a differential ring gear 2 meshed with an idler drive gear 22 formed on the intermediate shaft 21 and supported coaxially with the drive shaft 12, and a differential gear formed integrally with the differential ring gear 2 It is configured.

  As shown in FIG. 1 (b), the above final reduction gear 1 has the input shaft 25, the intermediate shaft 21, and the differential gear arranged substantially horizontally in the housing 58 of the final reduction gear 1 as viewed from the vehicle width direction. Is done. Three embodiments of the present invention are shown below.

“First Embodiment”
In FIG. 2, the final reduction gear 1 includes an idler driven gear 23 that meshes with an input gear 24 of an input shaft 25, an intermediate shaft 21 that is formed integrally with the idler driven gear 23, and an idler drive gear 22 that is formed on the intermediate shaft 21. The differential ring 3 that meshes with the idler drive gear 22, the differential gear 3 that rotates integrally with the differential ring gear 2 and that rotates together with the drive shaft 12 and the pinion gear 5 that meshes with the side gear 4, and the differential case 3 and a housing 58 for housing the differential ring gear 2.
Note that FIG. 2 is generally shown as a cross-sectional view along the line AA in FIG.

  The differential case 3 is formed in a substantially spherical shell-shaped shell portion 7 that constitutes the gear housing chamber 6 and rotates about the vehicle width direction as the rotation axis O, and is formed at both ends in the vehicle width direction of the shell portion 7 with the rotation axis O as the axis. And a pair of cylindrical bosses 8. A pinion shaft 9 is disposed in the gear storage chamber 6 along a plane orthogonal to the rotation axis O. Both ends of the pinion shaft 9 are inserted into a shaft attachment hole 10 formed in the shell portion 7, and the pinion shaft 9 and the shell portion 7 are integrated by a fixing pin 11 in one shaft attachment hole 10.

  Near the both ends of the pinion shaft 9, pinion gears 5 are rotatably attached to the pinion shaft 9. A drive shaft 12 is inserted into each boss portion 8, and in the gear storage chamber 6, a side gear attached to the end portion of the drive shaft 12 so as to rotate integrally with the drive shaft 12 and slide along the rotational axis O by spline coupling. 4 meshes with the pinion gear 5. A thrust washer 13 is interposed between the back surface of the side gear 4 and the inner surface of the gear storage chamber 6. A spiral groove 14 is formed on the inner peripheral surface of the boss portion 8 to guide the lubricating oil on the surface of the drive shaft 12 toward the gear storage chamber 6 when the drive shaft 12 rotates in the forward rotation direction.

  The differential case 3 is rotatably supported on the housing 58 by a bearing 15 at each boss portion 8.

  A seal member 17 is interposed between the insertion hole of the drive shaft 12 in the housing 58 and the drive shaft 12. Between the seal member 17 and the bearing 15, the housing 58 is formed with an oil passage space 18 that is a space having a diameter larger than the diameter of the insertion hole of the drive shaft 12 to which the seal member 17 is attached. A part of the lubricating oil falling along the inner wall of the housing 58 is supplied to the gear housing chamber 6 of the differential case 3 through the spiral groove 14 via the oil passage space 18.

  A differential ring gear 2 that rotates integrally with the differential case 3 and rotates about the rotational axis O is provided near the rotational axis O direction of the shell portion 7 of the differential case 3. In this embodiment, the differential ring gear 2 is formed by integral molding with the differential case 3, extends along a plane orthogonal to the rotation axis O, and teeth are formed on the outer peripheral portion.

  An intermediate shaft 21 is arranged in parallel with the rotation axis O at a position substantially horizontal to the diff ring gear 2. The intermediate shaft 21 is formed of a cylindrical shaft member having both ends open, and an idler drive gear 22 and an idler driven gear 23 are provided on the outer periphery. The idler drive gear 22 meshes with the differential ring gear 2, and the idler driven gear 23 meshes with the input gear 24 of the input shaft 25. The intermediate shaft 21 is supported by bearings 26 and 27 at both ends, and the input shaft 25 is supported by bearings 30 and 31. Oil passage spaces 28, 29, and 32 are formed between the bearings 26, 27, and 31 and the inner surface of the housing 58, respectively.

  As described above, a part of the lubricating oil adhering to the inner wall of the housing 58 enters the gear housing chamber 6 of the differential case 3 through the spiral groove 14 through the oil passage space 18, and meshes between the side gear 4 and the pinion gear 5. Supplied to the unit 19. However, since this structure uses the inner wall of the housing 58 as a flow path for the lubricating oil, depending on the shape of the inner wall of the housing 58, the lubricating oil cannot be effectively guided to the oil passage space 18, In order to solve the problem, the shape of the inner wall of the housing 58 must be complicated.

  On the other hand, in the lubrication structure according to the present invention, the inlet 34 for taking in the lubricating oil stored in the bottom of the housing 58 is formed on the side surface of the diffring gear 2, and flows into the diffring gear 2 from the inlet 34. A lubricating oil inflow passage 33 is formed to guide the lubricating oil to the gear housing chamber 6. The lubricating oil inflow passage 33 of the present embodiment communicates the annular space 35 communicating with the gear housing chamber 6 over 360 degrees around the axis of the diffring gear 2 (ie, the rotation axis O), and the annular space 35 and the inlet 34. It consists of an inflow channel 36 that is locally drilled. The annular space 35 communicates with the gear housing chamber 6 so as to face the meshing portion 19 between the side gear 4 and the pinion gear 5.

  The height of the oil level H of the lubricating oil stored at the bottom of the housing 58 is generally located near the lower end of the shell portion 7 and is a height at which the lower teeth of the diff ring gear 2 are sufficiently immersed. The diff ring gear 2 has a larger diameter than the shell portion 7, and the inflow port 34 is located in the vicinity of the root of the teeth of the large diameter diff ring gear 2. Accordingly, the moving distance of the inflow port 34 in the lubricating oil stored in the bottom of the housing 58 is large, and the amount of lubricating oil inflow is ensured as compared with the conventional structure in which an opening for lubricating oil inflow is provided in the shell. It becomes easy to do.

  The number and diameter of the inlets 34 (inflow holes 36) are appropriately determined according to the amount of lubricating oil. When a plurality of inflow ports 34 are formed, they are provided at equal intervals in the circumferential direction of the diff ring gear 2. FIG. 3 shows a case where six inflow ports 34 are formed. The inflow hole path 36 is formed so that its hole axis is substantially parallel to the rotation axis O.

  The inflow port 34 has a part that protrudes from the side surface of the diff ring gear 2, and a lubricant oil intake port 37 a is formed in the protruding portion in the forward rotation direction of the diff ring gear 2. The member 37 is inserted and fixed. As shown in FIGS. 4 and 9, the lubricating oil intake member 37 is formed with an annular flange 37 b, and the lubricating oil intake member 37 is connected to the inflow port in such a manner that the flange 37 b is applied to the side surface of the diffring gear 2. 34 is inserted. The lubricating oil intake member 37 is inserted into the inflow port 34 in a manner such as press fitting, and is inserted and fixed in the inflow hole 36.

  In this embodiment, the outer peripheral edge of the side surface of the diff ring gear 2 is slightly protruded in the direction of the rotation axis O as shown in FIG. 2, so that the diff ring gear 2 is radially outward from the position of the inlet 34. In this position, the differential ring gear 2 is formed with an annular step surface 20 rising along the direction of the rotation axis O as shown in FIG. As shown in FIG. 9, a positioning wall 37e is formed on a part of the flange 37b of the lubricating oil intake member 37, and the positioning wall 37e abuts on the step surface 20 as shown in FIG. The oil intake member 37 is positioned and inserted and fixed to the inflow port 34 so that the lubricating oil intake port 37a opens in the forward rotation direction of the diff ring gear 2.

  Further, as shown in FIG. 4, an inclined surface 37c is formed inside the lubricating oil intake member 37, and the flow path in the lubricating oil intake member 37 is narrowed on the downstream side by the inclined surface 37c and formed at the downstream end. The opening area of the lubricating oil discharge port 37d is formed smaller than the opening area of the lubricating oil intake port 37a. The lubricant discharge port 37d is formed to open toward the rotation axis O (FIG. 2) and faces the annular space 35 (FIG. 2). The above lubricating oil intake member 37 is made of, for example, a resin molded product, a steel product, or the like.

  The lubricating oil inflow passage 33 can be easily formed by molding the diff ring gear 2 by casting. In the present embodiment, the differential ring gear 2 and the differential case 3 are integrally formed by casting. 2. Description of the Related Art Conventionally, as a structure of a differential case and a differential ring gear, a structure in which a differential ring gear made of a steel material that has been subjected to a carburizing process or the like is fastened and fixed to the flange by bolts with respect to a cast differential case formed with an annular flange. Carbon steel is often used as the diff ring gear from the viewpoint of tooth strength, etc. However, the formation of the lubricating oil inflow passage 33, particularly the annular space 35, in this carbon steel is costly because the machining process is increased accordingly. Easy to connect to high.

  On the other hand, by integrally molding the differential ring gear 2 and the differential case 3 by casting, the annular space 35 can be formed at the time of casting, so that a separate machining process is not required and the cost can be suppressed. As cast iron, for example, spheroidal graphite cast iron whose fatigue strength is improved by heat treatment can be used to secure the strength of the diff ring gear 2 even when a large cavity such as the annular space 35 is formed. Therefore, for example, by ensuring that the annular space 35 is formed up to the vicinity of the root of the tooth, it is possible to ensure both the volume in the annular space 35 and the strength of the diff ring gear 2. As a heat treatment method for spheroidal graphite cast iron, for example, those described in Japanese Patent Publication No. 61-19698 and Japanese Patent No. 3723706 can be suitably used.

"Action"
When the differential ring gear 2 and the differential case 3 are integrally rotated in the forward rotation direction via the intermediate shaft 21 by the rotational input from the electric motor E, a part of the lubricating oil stored in the bottom portion of the housing 58 is directed in the forward rotation direction. It is effectively taken into the lubricating oil intake port 37a of the lubricating oil intake member 37 formed with the opening. Since the lubricating oil intake member 37 is formed such that the opening area of the lubricating oil discharge port 37d is smaller than the opening area of the lubricating oil intake port 37a, the flow rate of the lubricating oil at the lubricating oil discharge port 37d is increased, The lubricating oil is discharged from the lubricating oil discharge port 37d with momentum in the annular space 35. Therefore, the backflow of the lubricating oil from the annular space 35 side to the lubricating oil discharge port 37d is also suppressed. The lubricating oil discharged to the annular space 35 mainly flows through the inner wall of the annular space 35 to the gear housing chamber 6 and is supplied to the meshing portion 19 between the side gear 4 and the pinion gear 5.

  As described above, the inlet 34 for taking in the lubricating oil stored in the bottom of the housing 58 is formed on the side surface of the diffring gear 2, and the lubricating oil flowing in from the inlet 34 is placed inside the diffring gear 2 in the gear storage chamber. If the lubricating oil inflow passage 33 leading to 6 is formed, the inflow port 34 is formed on the side surface of the diffring gear 2 having a large diameter, so that the moving distance of the inflow port 34 in the lubricating oil stored at the bottom of the housing 58 is increased. As a result, it becomes easier to secure the inflow amount of the lubricating oil as compared with the conventional structure in which the opening portion for inflowing the lubricating oil is provided in the shell portion. Thereby, if the amount of lubricating oil to the gear storage chamber 6 via the spiral groove 14 is insufficient, the shortage can be supplemented with the lubricating oil via the lubricating oil inflow passage 33.

  Further, the lubricating oil inflow path 33 communicates with the gear housing chamber 6 over 360 degrees around the axis (rotation axis O) of the diff ring gear 2, and the inflow hole path 36 communicates with the annular space 35 and the inlet 34. The lubricating oil can be effectively guided to the gear housing chamber 6 through the annular space 35.

  Further, the lubricating oil is inserted and fixed to the inlet 34 so that a part thereof protrudes from the side surface of the diffring gear 2, and the lubricating oil intake port 37 a is formed in the protruding portion in the forward rotation direction. If it is set as the structure provided with the taking-in member 37, the lubricating oil stored in the bottom part of the housing 58 will be effectively taken in into the lubricating oil inflow path 33 by the lubricating oil taking-in opening 37a formed in the forward rotation direction. Can do. And in this lubricating oil intake member 37, by forming the opening area of the lubricating oil discharge port 37d formed at the downstream end smaller than the opening area of the lubricating oil intake port 37a, the lubricating oil discharge port 37d The flow rate of the lubricating oil can be increased, and the backflow of the lubricating oil from the lubricating oil inflow path 33 in the diff ring gear 2 to the lubricating oil intake member 37 can be suppressed.

“Second Embodiment”
5 and 6 are drawings according to the second embodiment, and the same components as those in the first embodiment are denoted by the same reference numerals and detailed description thereof is omitted. In addition, FIG. 5 is shown as a cross-sectional view generally along the line AA in FIG.
In the second embodiment, the lubricating oil inflow path 33 is formed of a flow path that linearly connects the communication port 38 and the inflow port 34 that are locally opened and face the gear storage chamber 6. That is, in the first embodiment, an annular space 35 communicating with the gear storage chamber 6 and 360 degrees around the rotation axis O is interposed in the flow path from the inlet 34 to the gear storage chamber 6. Whereas the linear inflow hole path 36 is formed only between the annular space 35, the lubricating oil inflow path 33 of the second embodiment is a communication port 38 that faces the gear storage chamber 6 from the inflow port 34. In general, it is formed as one linear flow path.

  The lubricating oil inflow path 33 is the same as the inflow hole path 36 in the first embodiment, that is, the inflow hole path 36 formed to have a hole axis parallel to the rotation axis O in the vicinity of the root of the teeth of the diffring gear 2; The inflow hole path 36 and the communication port 38 are connected to each other and a lower channel 39 having a relatively large channel cross-sectional area. The flow passage sectional area of the inflow hole passage 36 is smaller than that of the lower flow passage 39.

  The number and diameter of the inlets 34 (inflow holes 36) are appropriately determined according to the amount of lubricating oil. When a plurality of inflow ports 34 are formed, they are provided at equal intervals in the circumferential direction of the diff ring gear 2. FIG. 6 shows a case where a pair of inflow ports 34 are formed at positions that face 180 degrees across the rotation axis O. The direction of the lower flow path 39 when viewed from the direction of the rotation axis O may be formed along the radial direction of the diffring gear 2, for example, and the inflow port 34 and the communication port 38 may be positioned on the same normal line. As shown in FIG. 3, the communication port 38 is positioned closer to the reverse rotation direction than the normal line N of the diffring gear 2 passing through the inflow port 34, so that the inertial force in the circumferential direction during forward rotation is effectively increased. Thus, the lubricating oil in the lower flow path 39 flows smoothly in the radially inward direction, and the lubricating oil is supplied from the communication port 38 to the gear housing chamber 6 (FIG. 5). As viewed from the direction of the rotation axis O, the lower flow path 39 is formed so as to be gradually separated from the normal line N as it goes downstream.

  Next, in the present embodiment, a rib 40 that receives the lubricating oil stored in the bottom of the housing 58 and flows a part thereof into the inflow port 34 is formed near the reverse rotation direction of the inflow port 34 on the side surface of the differential ring gear 2. Has been. The rib 40 is formed along the radial direction of the diff ring gear 2, and the radially outer end is continuous with the annular step surface 20. As can be seen from FIG. 6, the inflow port 34 is generally located in the vicinity of the corner portion between the rib 40 and the step surface 20.

  The lubricating oil inflow passage 33 of this embodiment can also be easily formed by molding the diff ring gear 2 by casting. In this embodiment, the diff ring gear 2 and the differential case 3 are integrally formed by casting.

"Action"
When the diff ring gear 2 and the differential case 3 are integrally rotated in the forward rotation direction via the intermediate shaft 21 by the rotation input from the electric motor E, the lubricating oil stored in the bottom portion of the housing 58 is subjected to the resistance by the wall surface of the rib 40. A part of which effectively flows into the inflow port 34 located on the forward rotation direction side of the rib 40. Particularly in the case of this embodiment, when the lubricating oil stored in the bottom of the housing 58 hits the wall surface of the rib 40, the lubricating oil flows along the rib 40 and collects at the corners of the rib 40 and the step surface 20. Lubricating oil flows more effectively into the inlet 34 located at the corner. The lubricating oil that has flowed into the lubricating oil inflow path 33 from the inflow port 34 flows through the lower flow path 39 to the gear housing chamber 6 from the communication port 38 and is supplied to the meshing portion 19 between the side gear 4 and the pinion gear 5.

  As described above, the lubricating oil inflow path 33 according to the second embodiment in which the lubricating oil inflow path 33 is configured by a flow path that is formed in a local opening and communicates linearly with the communication port 38 that faces the gear storage chamber 6 and the inflow port 34. According to the structure, the lubricating oil flowing in from the inflow port 34 can be effectively flowed to the gear housing chamber 6 without being dispersed by the linear lubricating oil inflow passage 33. In addition, since a relatively large cavity such as the annular space 35 of the first embodiment is not formed inside the diff ring gear 2, it is easy to ensure the strength of the diff ring gear 2.

  Further, if the rib 40 that receives the lubricating oil stored in the bottom of the housing 58 and flows a part thereof into the inflow port 34 is formed near the reverse rotation direction of the inflow port 34 on the side surface of the diffring gear 2, the lubricating oil is formed. Can effectively flow into the inlet 34.

“Third Embodiment”
7 and 8 are drawings according to the third embodiment. The same components as those in the first embodiment or the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In addition, FIG. 7 is shown as a cross-sectional view along the line AA in FIG.
3rd Embodiment is a form which replaced with formation of the rib 40 with respect to 2nd Embodiment, and attached the lubricating oil intake member 37 to the inflow port 34 by the attachment aspect similar to 1st Embodiment. Other configurations are the same as those of the second embodiment.

"Action"
When the differential ring gear 2 and the differential case 3 are integrally rotated in the forward rotation direction via the intermediate shaft 21 by the rotational input from the electric motor E, a part of the lubricating oil stored in the bottom portion of the housing 58 is directed in the forward rotation direction. It is effectively taken into the lubricating oil intake port 37a of the lubricating oil intake member 37 formed with the opening. Since the lubricating oil intake member 37 is formed such that the opening area of the lubricating oil discharge port 37d is smaller than the opening area of the lubricating oil intake port 37a, the flow rate of the lubricating oil at the lubricating oil discharge port 37d is increased, The lubricating oil is discharged from the lubricating oil outlet 37d with momentum in the lower flow path 39. Therefore, the backflow of the lubricating oil from the lower flow path 39 side to the lubricating oil discharge port 37d is also suppressed. The lubricating oil discharged to the lower flow path 39 flows from the communication port 38 to the gear housing chamber 6 and is supplied to the meshing portion 19 between the side gear 4 and the pinion gear 5.

The preferred embodiment of the present invention has been described above. In 1st Embodiment, it is good also as a structure which forms the rib 40 in 2nd Embodiment instead of the lubricating oil taking-in member 37. FIG.
Further, the lower flow path 39 in the second embodiment and the third embodiment is not limited to being formed in a straight line when viewed from the direction of the rotation axis O as shown in FIG. 6 and FIG. It is also possible to form a gentle arc-shaped channel that is convex in the radial direction.
Further, the input shaft 25 is not limited to that connected to the electric motor E, and may be connected to a transmission or the like.

DESCRIPTION OF SYMBOLS 1 Final reduction gear 2 Differential ring gear 3 Differential case 4 Side gear 5 Pinion gear 6 Gear storage chamber 12 Drive shaft 21 Intermediate shaft 22 Idler drive gear 23 Idler driven gear 25 Input shaft 33 Lubricating oil inflow path 34 Inlet port 35 Annular space 36 Inflow hole path 37 Lubrication Oil intake member 38 Communication port 39 Lower flow path 40 Rib 58 Housing

Claims (8)

A differential ring gear connected to the input shaft;
A differential case that has a side housing that rotates integrally with the drive shaft and a pinion gear that meshes with the side gear, and that rotates integrally with the differential ring gear;
A housing for housing the differential case and the differential ring gear;
In the final reduction gear equipped with
An inlet for taking in lubricating oil stored in the bottom of the housing is formed on a side surface of the diff ring gear,
A lubricating structure for a final reduction gear, wherein a lubricating oil inflow passage for guiding lubricating oil flowing in from the inflow port to the gear housing chamber is formed inside the differential ring gear.   The lubricating oil inflow path includes an annular space communicating with the gear housing chamber over 360 degrees around the axis of the diff ring gear, and an inflow hole path communicating with the annular space and the inlet. The lubricating structure of the final reduction gear according to claim 1.   2. The final deceleration according to claim 1, wherein the lubricating oil inflow path includes a flow path that is locally formed to communicate with the communication port that faces the gear storage chamber and the inflow port. Lubrication structure of the device.   The lubrication structure for a final reduction gear according to claim 3, wherein the communication port is located closer to a reverse rotation direction than a normal line of the diff ring gear passing through the inflow port.   Lubricating oil intake member that is inserted and fixed to the inflow port so that a part thereof protrudes from the side surface of the diff ring gear, and a lubricating oil intake port is formed in the protruding portion in the forward rotation direction of the diff ring gear The lubricating structure of the final reduction gear according to any one of claims 1 to 4, wherein the lubricating structure is provided.   The end of the lubricating oil intake member according to claim 5, wherein an opening area of a lubricating oil discharge port formed at a downstream end of the lubricating oil intake member is smaller than that of the lubricating oil intake port. Reduction gear lubrication structure.   A rib is formed on the side surface of the diff ring gear near the reverse rotation direction of the inlet to receive the lubricating oil stored in the bottom of the housing and allow a part thereof to flow into the inlet. The lubricating structure of the final reduction gear device according to any one of claims 1 to 4.   The lubricating structure for a final reduction gear according to any one of claims 1 to 7, wherein the differential ring gear and the differential case are integrally formed by casting.

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