Gearbox device

Abstract

A transmission device comprising a planetary gear mechanism (P) having a plurality of planetary gears (33) each meshing with a sun gear (31) and a ring gear (32), a plurality of support shafts (34) each rotatably extending through and supporting the plurality of planetary gears (33), and a carrier (35) supporting the plurality of support shafts (34), wherein a gear element (10) adjacent to the carrier (35) is connected to the carrier (35) for integrated rotation therewith, wherein each of the support shafts (34) has an oil hole (h1) extending in the axial direction of the support shaft (34), an outlet hole (h2) whose inner end communicates with the oil hole (h1) and whose outer end (h2o) opens onto an outer peripheral surface of the support shaft (34), and an engagement part (K) provided at one end portion (34a) of the support shaft (34), the other end portion (34b) of the support shaft (34) being fixed to the carrier (35), and an engagement part (S) provided on the gear element (10), the engagement part (K) engaging with the engagement part (S) to be able to position the support shaft (34) at a position where the outer end (h2o) of the outlet hole (h2) faces outward in the radial direction of the carrier (35), characterized in that the oil hole (h1) extends through the bearing shaft (34) in the axial direction, and an open end portion (h1e) of the oil hole (h1) on the gear element (10) side is blocked by mutual engagement between the engaging part (K) and the part to be engaged (S).

Description

TECHNICAL FIELDThe present invention relates to a transmission device comprising a planetary gear mechanism having a plurality of planet gears respectively meshed with a sun gear and an ring gear, a plurality of support shafts respectively rotatably extending through and supporting the plurality of planet gears, and a carrier supporting the plurality of support shafts, wherein a transmission member adjacent to the carrier is connected to the carrier for integral rotation therewith.BACKGROUND ARTConventionally, the structure of the above planetary gear mechanism is known (for example, JP 2009-197 821 A) in which a support shaft of a planetary gear is provided with an oil hole extending in the axial direction and an outlet hole communicating with the oil hole via its inner end and opening on an outer circumferential surface of the support shaft via its outer end, and opposite end parts of the support shaft are fixed to a carrier in a state in which the outlet hole faces outward in the radial direction of the carrier. In the structure disclosed in JP 2009-197 821 A, when the carrier rotates, lubricating oil that has been supplied to the oil hole via the outer end of the bearing shaft is smoothly discharged from the outlet hole due to the centrifugal force, and the area around the bearing shaft, for example, a bearing, etc., can be efficiently lubricated.RELATED ART DOCUMENTSUS 9447 863 B2 shows a transmission device according to the preamble of claims 1 and 4. Similar transmission devices are shown in JP H04-126 055 U, KR 10 1 262 130 B1, U.S. Pat. No. 4,756,212 A and U.S. Pat. No. 8 251 862 B2.SUMMARY OF THE INVENTIONPROBLEMS TO BE SOLVED BY THE INVENTIONHowever, in the planetary gear mechanism of JP 2009-197 821 A above, in one assembling step, it is necessary to fix the support shaft to the carrier while performing positioning so that the outlet hole faces outward in the radial direction of the carrier, and this positioning step is complicated. Further, in order to support the support shaft, it is necessary to fix both opposite end parts of the support shaft to the bracket, and therefore the number of fixing steps increases accordingly.The present invention has been proposed in the light of the above, and its object is to provide a transmission device that can solve the above problems of the conventional structure.MEANS FOR SOLVING THE PROBLEMSIn order to achieve the above object, there is provided a transmission device according to claims 1 and 4.The transmission device includes a planetary gear mechanism including a plurality of planet gears respectively meshed with a sun gear and an ring gear, a plurality of support shafts respectively rotatably extending through and supporting the plurality of planet gears, and a carrier supporting the plurality of support shafts, wherein a transmission member adjacent to the carrier is connected to the carrier for integral rotation therewith, characterized in that each of the support shafts has an oil hole extending in an axial direction of the support shaft, an exhaust hole having an inner end communicating with the oil hole and an outer end opening to an outer circumferential surface of the support shaft, and an engaging part provided at one end portion of the support shaft, the other end portion of the support shaft being fixed to the carrier, and an engaging part is provided on the gear member, the engaging part being engaged with the engaging part so as to be able to position the support shaft at a position where the outer end of the outlet hole faces outward in the radial direction of the carrier.Further, according to claims 1 and 5, the oil hole extends through the support shaft in the axial direction, and an open end portion of the oil hole on the gear member side is blocked by mutual engagement between the engagement part and the to-be-engaged part.Further, according to claims 2 and 6, the carrier and the gear element are formed of separate components and integrally connected to each other, wherein the carrier and the gear element abut against each other at a periphery of the engaging part and the to-be-engaged part, and a support surface between the carrier and the gear element has, in a cross section including a rotational axis of the carrier, a bent portion at the outer side of the support shaft in the radial direction.Further, according to claims 3 and 4, the to-be-engaged part is formed of an annular step part provided on a side of the gear member opposite to the carrier and coaxial with the gear member, and the engaging part has such a shape that the carrier can be positioned coaxially with the gear member via the support shaft due to the engagement between the engaging part and the step part.EFFECTS OF THE INVENTIONBy simply engaging the engaging part provided to an end portion of the support shaft supporting the planetary gear with the to-be-engaged part provided to the gear member, it becomes possible to easily and correctly position the support shaft at a position where the outlet hole of the support shaft faces outward in the radial direction of the carrier. Moreover, by merely fixing the other end portion of the support shaft to the bracket in the positioned state, by using the gear member, it becomes possible to easily hold the support shaft and prevent the rotation thereof. The number of steps for positioning and fixing the support shaft is thereby reduced, which contributes to improvement of ease of assembly of the apparatus and cost reduction.Further, according to claims 1 and 5, even when the oil hole is a through hole in the axial direction, by utilizing the engagement between the engagement part and the to-be-engaged part, it becomes possible to easily block the open end portion of the oil hole on the transmission member side, thereby making it possible to increase the amount of lubricating oil flowing from the oil hole to the outlet hole side, and it becomes possible to efficiently lubricate a part to be lubricated in the area around the support shaft. Moreover, because the oil hole is a through hole in the axial direction, manufacturing of the oil hole becomes easier compared to a case where the oil hole is a blind hole.Moreover, particularly according to claims 2 and 6, because the support surface between the carrier and the gear member, which are separate components, has a bent portion and extends as a labyrinth, the amount of lubricating oil that tries to leak along the support surface to the open end of the oil hole by centrifugal force can be reduced. The amount of lubricating oil flowing from the oil hole to the discharge hole can be further increased thereby.Further, particularly according to claims 3 and 4, it is possible to perform the alignment of the carrier and the gear member with each other by utilizing the engagement between the engagement part and the to-be-engaged part (i.e., positioning means for the support shaft provided with the discharge hole). Therefore, it is not necessary to provide a special aligning means between the carrier and the gear member, which serves exclusively for the carrier and the gear member, thus contributing to simplification of the structure of the apparatus and further cost reduction.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a longitudinal sectional view of a transmission device including a differential device and a reduction gear mechanism relating to a first embodiment of the present invention (first embodiment). FIG. 2 is a sectional view taken along line A 2-A 2 in FIG. 1 (first embodiment). FIG. 3 is a sectional view taken along line A 3-A 3 in FIG. 1 (first embodiment). FIG. 4 is a sectional view taken along line A 4-A 4 in FIG. 1 (first embodiment). FIG. 5 is an enlarged sectional view of a part shown by the arrow A 5 in FIG. 5 (first embodiment). FIG. 6 is a perspective view of a support shaft alone (first embodiment). FIG. 7 is an enlarged sectional view (view corresponding to FIG. 5 ) of an essential part of a transmission device related to a second embodiment of the present invention (second embodiment). FIG. 8 is a longitudinal sectional view (view corresponding to FIG. 1 ) of a transmission device related to a third embodiment of the present invention (third embodiment). FIG. 9 is a sectional view (view corresponding to FIG. 3 taken along line A 9-A 9 in FIG. 8 (third embodiment). FIG. 10 is an enlarged sectional view of a part shown by arrow A 10 in FIG. 8 and an enlarged sectional view (view corresponding to FIG. 5 ) taken along line A 10-A 10 in FIG. 9 (third embodiment).EXPLANATION OF REFERENCE NUMERALS AND SYMBOLSP: Planetary gear mechanism h1: Oil hole h1e: Oil hole open end portion h2: Exhaust hole h2o: Exhaust hole outer end K: Cut-out surface (engaging part) L: Rotation axis L': Axis of support shaft S: Step part (to-be-engaged part) 10: Differential case (gear member) 31: Sun gear 32: Ring gear 33: Planetary gear 34: Support shaft 34a, 34b: One end portion and other end portion of support shaft 35: Carrier 200: Support surface 200a: Bent portion of support surfaceMODES FOR CARRYING OUT THE INVENTIONEmbodiments of the present invention will be explained with reference to the drawings.FIRST EMBODIMENTFirst, referring to FIGS. 1 to 6, a first embodiment of the present invention will be explained. In FIG. 1, a differential device D is connected to an engine or electric motor (not shown) mounted on an automobile as a drive source via a planetary gear mechanism P functioning as a reduction mechanism. The differential device D transmits rotational force transmitted from the motor to a differential case 10 of the differential device D via the planetary gear mechanism P by distributing it between first and second output shafts 21 and 22 connected to a pair of left and right axles, which are not shown, so as to drive the two axles while allowing differential rotation between the two axles.The differential device D is accommodated and supported together with the planetary gear mechanism P in a transmission case 10 disposed next to the engine, for example, in a front part of the vehicle body. A conventionally known transmission mechanism (not shown) including a power connection / disconnection device, a speed change device, etc. is disposed between the motor and the planetary gear mechanism P. Specific examples of the planetary gear mechanism P and the differential device D will now be explained sequentially.The planetary gear mechanism P includes a sun gear 31 relatively rotatable about the same axis with respect to the differential case 10 of the differential device D, a large-diameter ring gear 32 concentrically surrounding the sun gear 31 and fixed to an inner wall of the transmission case 1, a plurality of (for example, four) planetary gears 33 disposed between the sun gear 31 and the ring gear 32 and meshed with the sun gear 31 and the ring gear 32, a plurality of support shafts 34 rotatably extending through and supporting the plurality of planetary gears 33 via a bearing B 1 (for example, a needle bearing), and a carrier 35 receiving the plurality of planetary gears 33 and supporting opposite end parts of the plurality of support shafts 34. The carrier 35 is connected to the differential case 10 so as to be able to rotate integrally on the same axis L. The plurality of support shafts 34 are arranged at equal intervals on the same circumference c whose center is on the rotation axis L of the carrier 35.The sun gear 31 can be rotationally driven by the motor via the transmission system. A rotational force input to the sun gear 31 is transmitted to the differential case 10 while its rotational speed is sequentially reduced via the planetary gear 33, the support shaft 34, and the carrier 35.The carrier 35 includes, for example, a carrier main body 35B having the same diameter as and coaxial with the differential case 10, and a disk-shaped cover 35C connected to the outer end of the carrier main body 35B. The carrier main body 35B has a main body base portion 35B that is formed in a circular ring plate shape and is adjacent to and fixed to the differential case 10, and a plurality of, for example, four main body arm portions 35Ba that integrally project with the main body base portion 35B with gaps therebetween in the circumferential direction and extend outward in the axial direction (that is, the side opposite to the differential case 10).As clearly shown in FIG. 3, each of the main body arm portions 35Ba is fan-shaped when viewed on a projection plane orthogonal to the rotation axis L of the carrier 35. therefore, spaces opening to the outside and having a fan shape on the projection plane are formed between the main body arm portions 35Ba adjacent to each other with gaps therebetween in the circumferential direction of the carrier 35, and the planetary gear 33 is arranged together with the support shaft 34 in each of the spaces. The lid 35C is detachably connected to the end of each of the main body arm portions 35Ba by a bolt 34.As means for connecting the lid 35C, other suitable connecting means other than a bolt (for example, caulking, welding, etc.) may also be employed. When the structure allows the carrier 35 to be machined and assembled or the planetary gear 33 and the support shaft 34 to be attached to the carrier 35, the cover 35C may be formed integrally with the carrier main body 35B, for example.In the present embodiment, each of the support shafts 34 is formed into a hollow cylindrical shape whose opposite ends are open, and an inner circumferential surface of the support shaft 34 functions as an oil hole h 1 extending through the inner space of the support shaft 34 in the axial direction. Further, at least one discharge hole h 2 is provided in a circumferential wall of an intermediate part of the support shaft 34 (more specifically, a circumferential wall portion disposed on the outermost side in the radial direction of the carrier 35), the inner end of the discharge hole h 2 directly communicates with the oil hole h 1, and an outer end h 2 oof the discharge hole h 2 opens toward an outer circumferential side of the circumferential wall.One end portion 34 a(right end part in FIG. 1 ) on the differential case 10 side of each of the support shafts 34 is inserted and supported in a through hole 34Bh of the carrier main body 35B (specifically, the main body base portion 35B), whereas the other end portion 34 b(left end part thereof) is inserted and supported in a through hole 35Ch of the cover 35C. Among the opposite end parts 34 aand 34 bof the support shaft 34, specifically, only the other end portion 34 bis connected to the bracket 35. For example, in the present embodiment, a caulking portion 35Cf around the lid 35C locked to the other end portion 34B connects the other end portion 34 bto the lid 35C.As a means for connecting the other end portion 34 bto the lid 35C, another suitable connecting means such as caulking (for example, welding means, a snap ring that is snapped on the outer periphery of the other end portion 34 band engages with an inner surface of the lid 35C, a retaining pin that crosses the other end portion 34 band is inserted into the lid 35C, etc.) may also be used.Positioning means I is provided between the one end portion 34 aof each of the support shafts 34 and the differential case 10, the positioning means I positioning the support shaft 34 at a specific rotational position at which the outer end h 2 oof the outlet hole h 2 faces outward in the radial direction of the carrier 35. The structure of the positioning means I will be described later.Now, a specific example of the differential apparatus D will be explained. The differential device D in the present embodiment includes the differential case 10 and a differential gear mechanism 11 accommodated in the transmission case 10.One end part (the right end part in FIG. 1 ) in the axial direction of the differential case 10 is rotatably supported on the transmission case. On the other hand, in the other end part (the left end part in FIG. 1 ) of the differential case 10, the sun gear 31 and / or the carrier 35 and / or the first output shaft 31 is rotatably supported on the transmission case 1, although not illustrated. A connected body of the differential case 11 and the carrier 35 which rotate as a unit is thereby rotatably supported on the transmission case 1.A through hole 1 a(a through hole on the first output shaft 21 side is not illustrated) is formed in the transmission case 1, and the first and second output shafts 21, 22 are inserted into the through hole 1 a, respectively. An annular seal member 13 is disposed between the inner periphery of each of the through holes 1a and the outer periphery of each of the output shafts 21 and 22.An oil pan (not shown) is provided at a bottom part of the transmission case 1, the oil pan facing an inside of the case and storing lubricating oil. Lubricating oil in the oil pan is stirred and sprayed in the transmission case 1 by the rotation of the differential case 10, etc., whereby movable parts in the transmission case 1, for example, each movable part of the planetary gear mechanism P or the differential gear mechanism 11 can be lubricated.The differential gear mechanism 11 includes a plurality of (in the present embodiment, two) pinion gears 14 accommodated in the transmission case 10, a pinion shaft 15 accommodated in the differential case 10 and rotatably supporting the pinion gear 14, and first and second side gears 16 and 16' accommodated in the differential case 10 and respectively meshed with the pinion gears 14 from the left and right sides.Each pinion gear 14 is supported on the differential case 10 via the pinion shaft 15. Each pinion gear 14 can thereby rotate about the axis of the pinion shaft 15 with respect to the differential case 10, and can rotate about the rotation axis L of the differential case 10 along with the rotation of the differential case 10.The pinion shaft 15 is disposed in the differential case 10 so as to be orthogonal to the rotational axis L of the differential case 10. Opposite end portions of the pinion shaft 15 are inserted through and supported by the differential case 10 (a tube portion 10Aa of the first case half body 10A, as described later), and are fixed by appropriate fastening means (a retaining pin 25 in the present embodiment).The first and second side gears 16 and 16' include integral, for example, cylindrical shaft portions 16j and 16j' into which inner end parts of the first and second output shafts 21 and 22 are longitudinally inserted in a toothed manner, respectively, annular tooth portions 16g and 16g' located at a position spaced outwardly in the radial direction from the shaft portions 16j and 16j' and having a tooth surface meshed with the pinion gear 14, and intermediate wall portions 16m and 16m' formed into a flat ring plate shape extending outwardly in the radial direction from the inner end parts of the shaft portions 16j and 16j' to inner circumferential end parts of the tooth portions 16g and 16g'.The differential case 10 is formed so as to be divided into at least two case members, for example, first and second case half bodies 10A and 10B. Among them, the first case half body 10A includes a disc-shaped first side wall portion 10As that is adjacent to and fixed to the carrier 35 and whose inside is opposite to a rear side of the first side wheel 16, a short cylindrical tube portion 10Aa integrally connected to an end part of the outer periphery of the first side wall portion 10As and extends toward the second case half body 10B side, and a first boss portion 10Ab that extends cylindrically outward in the axial direction from a central part of an outside of the first side wall portion 10As.The sun gear 31 is rotatably supported on the outer periphery of the first boss portion 10Ab via a bearing B 3. The first output shaft 21 is rotatably inserted and supported in the inner periphery of the first boss portion 10Ab, and the shaft portion 16 jof the first side gear 16 is inserted in the inner periphery of the first boss portion 10Ab directly or with play.An outer surface of the first side wall portion 10As opposed to the bracket 35 is a bracket receiving surface 17 that is flat and abuts against and supports an end surface of the bracket main body 35B (specifically, an outer end surface of the main body base portion 35B) in a surface contact state. A thrust bearing is disposed between opposed surfaces of the carrier receiving surface 17 and the sun gear 31, as required.On the other hand, the second half body 10B includes a second side wall portion 10Bs formed in a thick disc shape to block an open end of the first half body 10A and having an inner side opposite to a rear side of the second side gear 16', and a second boss portion 10B cylindrically extending outward in the axial direction from a central part of an outer side of the second side wall portion 10Bs. The shaft portion 16j' of the second side gear 16' is rotatably inserted and supported in the inner periphery of the second boss portion 10B.An inner side of an outer circumferential end part of the second side wall portion 10Aa abuts against an end surface of the tube portion 10Aa of the first half case body 10A. The second half body 10B is detachably connected to the first half body 10A by connecting means such as a bolt 19. As the connecting means, other suitable connecting means may also be used as the bolt 19, such as caulking, bonding, or welding, for example.The rear surfaces of the tooth portions 16g and 16g' of the first and second side gears 16 and 16' are rotatably supported directly or via a thrust washer on the first and second side wall portions 10As and 10Bs. A rear side of a tooth portion of the pinion gear 14 is also supported on a corresponding inner surface of the tube portion 10Aa of the first half body 10A directly or via a thrust washer.Helical grooves g and g' are formed in one of the mating surfaces between the boss portion 10Ab of the first half housing body 10A and the first output shaft 21 (for example, an inner circumferential surface of the boss portion 10Ab), and one of the mating surfaces between the boss portion 10B of the second half housing body 10B and the shaft portion 16j' of the second side gear 16' (for example, an inner circumferential surface of the boss portion 10B). The helical grooves g and g' may produce a screw-pumping action along with the relative rotation between the mating surfaces, and may suck the lubricating oil sprayed in the transmission case 1 to the inside of the differential case 10.An annular positioning groove 18 concentric with the differential case 10 is formed at a position of the carrier receiving surface 17 of the first case half body 10A corresponding to the bearing shaft 34, and a part (the outer end) of the one end portion 34 aof the bearing shaft 34 is received by the positioning groove 18. An inner surface 18 sin the outer circumferential end side of the positioning groove 18 and the carrier receiving surface 17 contiguous thereto form an annular positioning step part S. This step part S is a constituent element on the differential case 10 side of the positioning means I, and is an example of the to-be-engaged part of the present invention.A component on the support shaft 34 side of the positioning means I is formed in a specific shape formed on the one end portion 34 aof the support shaft 34 protruding to the outside of the carrier main body 35B, for example, a cut-out surface K. The cut-out surface K is an example of the engagement part of the present invention.The cut-out surface K is formed so as to lack a substantially semicircular part from the outer end of the one end portion 34 aof the support shaft 34, and to engage with the step part S. According to this engagement, it is possible to position the support shaft 34 inserted into the through holes 35Bh and 35Ch at a certain rotational position around the own axis L' (that is, a rotational position at which the outer end h 2 oof the outlet hole h 2 faces outward in the radial direction of the carrier 35).In order to position the support shaft 34, the cut-out surface K has a first engagement surface Ka formed as a flat surface orthogonal to the axis L' of the support shaft 34 and extending semi-arc-shaped about the axis L', and a pair of second engagement surfaces Kb and Kc each formed as an arc surface whose center is on the longitudinal axis L of the bracket 35 disposed with a gap therebetween in the circumferential direction of the bracket 35 and extending in the axial direction.In a state where the cut-out surface K and the step part S are engaged, an end surface of the one end portion 34 aof the support shaft 34 is engaged with a bottom surface of the positioning groove 18, the first engagement surface Ka of the cut-out surface K is in contact with the carrier receiving surface 17, and the second engagement surfaces Kb and Kc of the cut-out surface K are in contact with the inner surface 18 sin the outer circumferential side of the positioning groove 18. Due to this contact, an open end surface of the one end portion 34 aof the support shaft 34 (that is, an open end portion h 1 con the differential case 10 side of the oil hole h 1) is blocked by the first case half body 10A as a blocking wall. The other end portion 34 bof the bearing shaft 34 opens into the transmission case 1, and lubricant oil scattered in the transmission case 1 can directly enter the oil hole h 1 via the opening.In this way, even when the oil hole h 1 of the support shaft 34 is a through hole in the axial direction, it is possible to use the engagement between the cut-out surface K and the step part S to easily and correctly block the open end portion h 1 cof the oil hole h 1 on the differential case 10 side. By doing so, it becomes possible to increase the amount of lubricating oil flowing from the oil hole h 1 to the outlet hole h 2 side, and it becomes possible to efficiently lubricate a part to be lubricated in the area around the bearing shaft 34 (for example, the bearing B 1 on the inner periphery of the planetary gear 33). Moreover, because the oil hole h 1 is a through hole in the axial direction, the machining of the oil hole h 1, that is, the support shaft 34, is facilitated as compared with a case where the oil hole h 1 is a blind hole.Further, according to the engagement of the pair of second engagement surfaces Kb and Kc, and particularly the step part S, the support shaft 34 can be positioned with respect to the carrier 35 in a certain rotational position in which the outer end h 2 oof the outlet hole h 2 faces outward in the radial direction of the carrier 35, and it also becomes possible to concentrically align the carrier 35 with the first housing half body 10A via the plurality of support shafts 34 arranged on the same circumference c concentrically with the carrier 35. That is, the positioning means I for positioning the support shaft 34 at a certain rotational position with respect to the carrier 35 is also used as a means for aligning the carrier 35 with the differential case 10, an only aligning means used therefor becomes unnecessary, and the structure of the transmission device including the planetary gear mechanism P and the differential device D can be simplified, thereby reducing the cost.Thus, mutually opposing surfaces of the bracket 35 and the first case half body 10A subjected to this alignment are integrally joined to each other by a weld w over the entire circumference. The carrier 35 is thereby connected and united with the first housing half body 10A. The welding work may be performed in a state in which the carrier 35 and the first half body case 10A are concentrically opposed and supported to each other, for example, by laser welding an outer circumferential part of a support surface 200 by a laser welding gun directed outward in the radial direction.The operation of the first embodiment will now be explained. With respect to the differential apparatus D of the present embodiment, in a situation where the differential case 10 receives the rotational force from the motor via the planetary gear mechanism P, when the pinion gear 14 does not rotate around the pinion shaft 15 but rotates the rotational axis L of the differential case 10 together with the differential case 10, the left and right side gears 16 and 16' are rotated at the same speed via the pinion gear 14 from the differential case 10, and the driving forces of the side gears 16 and 16' are similarly transmitted to the left and right first and second output shafts 21 and 22. When a rotational speed difference occurs between the first and second output shafts 21 and 22 due to turning of the automobile, the pinion gear 14 revolves around the rotational axis L of the differential case 10 while it rotates, thereby transmitting the rotational force from the pinion gear 14 to the left and right side gears 16 and 16', while permitting differential rotation. The above is similar to the operation of a conventionally known differential device.As for a method of assembling the carrier 35 and the differential case 10 of the present embodiment, for example, a first assembling method in which, in a state in which the carrier 35 and the differential case 10 are provisionally aligned by a frame, the support shaft 34 supporting the planetary gear 33 is positioned and permanently fixed to the carrier 35 with the engagement between the cut-out surface K and the step part S, and then the carrier 35 and the differential case 10 are permanently connected to each other, and a second assembling method in which the support shaft 34 supporting the planetary gear 33 is provisionally preliminarily assembled to the carrier in a state in which it is detached from the differential case 10, and then positioning and permanently fixing the support shaft 34 to the carrier, may be considered, and the aligning and permanently connecting the carrier 35 to the differential case 35 are performed to make the differential case 10 face and abut against the carrier 35 while the cut-out surface K and the step member S are engaged with each other.While in the first assembling method, the carrier 35 and the first case half body 10A are supported by a frame (not shown) so as to be concentrically adjacent to each other, the planetary gear 33 is disposed in the carrier 35, the support shaft 34 is inserted through a center hole of the planetary gear 33 via the bearing B 1, and the opposite end parts 34 aand 34 bof the support shaft 34 are inserted into the through holes 35Bh and 35Ch of the carrier 35. The engagement of the cut-out surface K with the step part S provides positioning of the support shaft 34 at a certain rotational position, and the thus positioned other end portion 34 bof the support shaft 34 is joined to the bracket 35 (the lid 35C) by caulking. Subsequently, the rack is removed, and in this process, since the first half body case 10A is aligned with the bracket 35 due to the interference between the cut-out surface K and the step part S, the aligned state can be maintained without the rack, and in this state, an outer peripheral part of the support surface 200 between the bracket 35 and the first half body case 10A is welded by the welding w, thereby concentrically connecting the bracket 35 to the first half body case 10A as a unit.On the other hand, in the second assembling method, the planetary gear 33 is disposed in the carrier 35 separated from the first housing main body 10A, the support shaft 34 is inserted through the center hole of the planetary gear 33 via the bearing B 1, the opposite end parts 34 aand 34 bof the support shaft 34 are inserted into the through holes 34Bh and 35Ch of the carrier 35, and in this process, the support shaft 34 is provisionally positioned by utilizing the orientation of the cut-out surface K. In this state, the first half body case 10A is brought up to and approached to the carrier 35, and in this process, the engagement of the cut-out surface K with the step part S enables permanent positioning of the support shaft 34 at a certain rotational position, thereby performing alignment of the carrier 35 with the first half body case 10A. Subsequently, the other end portion 34 bof the support shaft 34 is joined by caulking, and an outer circumferential part of the support surface 200 between the bracket 35 and the first half housing body 10A is welded with the weld w, thereby concentrically joining the bracket 35 to the first half housing body 10A as a unit.After the carrier 35 is integrally joined to the first half case body 10A by the first or second assembling method, the first and second half case bodies 10A and 10B are joined together in a state where the side gears 16 and 16', the pinion gear 14, and the pinion shaft 35 are interposed therebetween, thereby completing the assembling of the differential device D. Subsequently, an assembly of the differential device D and the carrier 35 is mounted on the transmission case 1. The attachment of the sun gear 31 may be performed before or after the connection of the carrier 35 to the first half body case 10A.In the assembly process of the first embodiment described above, the simple engagement of the cut-out surface K (the engagement part) of the one end portion 34 aof the support shaft 34 with the step part S (to-be-engaged part) of the first case half body 10A as a gear member enables the support shaft 34 to be easily and easily positioned at a certain rotational position in which the outlet hole h 2 faces outward in the radial direction of the carrier 35. Moreover, merely fixing the other end portion 34 bof the support shaft 34 to the bracket (specifically, connecting to the cover 35C by caulking) in the positioned state allows the support shaft 34 to be easily held and prevented from rotating by utilizing the first half case body 10A. The number of steps for positioning and fixing the support shaft 34 is thereby reduced, ease of assembly of the transmission device is improved, and cost can be reduced. Moreover, compared with a case where the to-be-engaged part is provided on the side of the carrier 35, the structure of the carrier 35 can be simplified and is advantageous in terms of strength.SECOND EMBODIMENTA second embodiment of the present invention will now be explained with reference to Fig. 7.In the first embodiment, the annular step part S (to-be-engaged part) of the first half housing body 10A as a gear member is formed from the inner surface 18 sin the outer circumferential side of the annular positioning groove 18 recessed in the carrier receiving surface 17 of the first half housing body 10A and the carrier receiving surface 17 continuous to the annular step part S. In contrast, in the second embodiment, an annular protrusion 118 concentric with the differential case 10 is formed on the carrier receiving surface 17 of the first case half body 10A, and the annular step part S (to-be-engaged part) is formed by a side surface 118 sin the inner periphery and an end surface of the protrusion 118.In a state where the cut surface K and the step part S of the second embodiment are engaged, one end surface of the one end portion 34 aof the support shaft 34 is in contact with the carrier receiving surface 17, the first engagement surface Ka of the cut surface K is in contact with one end surface of the protrusion 118, and the second engagement surfaces Kb and Kc of the cut surface K are in contact with the inner surface 118 sin the inner peripheral side of the protrusion 118. Due to this contact, an open end surface of the one end portion 34 aof the support shaft 34 (that is, the open end portion h 1 con the differential case 10 side of the oil hole h 1) is blocked by the first case half body 10A as a wall.The arrangement of the second embodiment is otherwise basically the same as that of the first embodiment; components such as those of the corresponding components of the first embodiment are denoted by the same reference numerals and symbols, and further detailed explanation is omitted. According to the second embodiment, the same operational effects as those of the first embodiment can also be basically obtained.THIRD EMBODIMENTA third embodiment of the present invention will now be explained with reference to Figs. 8 to 10.In the first embodiment, the support surface 200 (that is, the carrier receiving surface 17 and the end surface of the carrier main body 35B) between the carrier 35 and the first half housing body 10A is made as a flat surface having no recesses or protrusions, more outward in the radial direction than the positioning groove 18 recessed in the carrier receiving surface 17, to form the annular step part S (part to be engaged) on the first half housing body 10A as a gear member. On the other hand, in the third embodiment, the support surface 200 has a concave-convex engaging part concentrically surrounding the positioning groove 18 more outward in the radial direction than the annular positioning groove 18 (to-be-engaged part).That is, in the third embodiment, an annular protrusion portion 17 tis formed on the carrier receiving surface 17 farther outward in the radial direction than the positioning groove 18, while an annular recess part 35Bi into which the protrusion portion 17 tis inserted is formed in an end surface of the carrier main body 35B. Because the protrusion portion 17 tand the recess part 35Bbiare assembled concentrically and interlockingly, the carrier 35 and the first half body case 10A are aligned with each other. In the third embodiment, the inner circumferential surface of the protrusion portion 17 tis in contact with an outer circumferential surface of the one end portion 34 aof the support shaft 34, but may be slightly separated from the outer circumferential surface.According to the third embodiment, also in the same manner as in the first and second embodiments, the carrier 35 and the first housing main body 10A are supported against each other on the circumferential side of the engagement part between the cut-out surface K and the step part S, but the support surface 200 is formed in the third embodiment, in particular, as a surface shape having an L-shaped bent portion 200 ain cross section (for example, FIG. 7 ) including the rotation axis L of the carrier 35 on the outer side of the bearing shaft 34 in the radial direction of the carrier 35, Thus, by bypassing the outlet hole h2), the sealing effect of the labyrinth of the support surface 200 can be reduced. Therefore, the amount of lubricating oil flowing from the oil hole h 1 to the outlet hole h 2 side can be further increased.In the first embodiment, the outer peripheral part of the support surface 200 between the bracket 35 and the first half housing body 10A is welded over the entire circumference by the weld w, but in the third embodiment, the outer peripheral part of the support surface 200 between the bracket 35 and the first half housing body 10A is welded only for a part of the circumferential direction (that is, a region corresponding to the main body arm portion 35Ba of the bracket 35) by the weld w. This is because, in a certain area where the weld w is omitted (that is, an area farther outward in the radial direction of the carrier 35 than the bearing shaft 34) due to the labyrinth sealing effect of the support surface 200 bent in a labyrinth shape, leakage of the lubricating oil from the open end portion h 1 eof the oil hole h 1 can be avoided, and even if the weld w is omitted, no particular inconveniences occur due to the leakage of the lubricating oil.For the mounting of the carrier 35 and the differential case 10 in the third embodiment, a third mounting method somewhat similar to the first mounting method described in the first embodiment is used. In the third assembling method, the carrier 35 and the differential case 10 are permanently joined in a state of being aligned due to the concentric fit between the protrusion portion 17 tand the recess part 35Bbi(that is, without provisional alignment by a rack), and after permanent joining, the planetary gear 33 and the support shaft 34 are positioned and permanently fixed to the carrier 35. Therefore, no temporary aligning stage or aligning means exclusively used therefor is required, which reduces the cost.In the third mounting method, the carrier 35 and the first half body 10A are first approached to each other in a state where they are aligned because the protrusion portion 17 tand the recess part 35Bbiare concentrically assembled, and in this state, an outer peripheral part of the support surface 200 between the carrier 35 and the first housing half body 10A is welded by a weld w in a part of the range in the circumferential direction of the outer peripheral part, thereby concentrically connecting the carrier 35 to the first housing half body 10A as a unit. Subsequently, the planetary gear 33 is inserted into the carrier 35, the support shaft 34 is inserted through the center hole of the planetary gear 33 via the bearing B 1, and the opposite end parts 34 aand 34 bof the support shaft 34 are inserted into the through holes 35Bh and 35Ch of the carrier 35. The engagement of the cut-out surface K and the step part S provides positioning of the support shaft 34 at a certain rotational position, and is joined to the bracket 35 (specifically, the lid 35C) by caulking after positioning of the other end portion 34 bof the support shaft 34. The subsequent mounting of the differential device D is the same as in the first embodiment.The arrangement of the third embodiment is otherwise basically the same as that of the first embodiment; components such as those for the corresponding components of the first embodiment are denoted by the same reference numerals and symbols, and further detailed explanation is omitted. According to the third embodiment, in addition to the specific operation effects of the third embodiment, basically the same operation effects as those of the first embodiment can be obtained.In the first and second embodiments, the positioning means I for positioning the support shaft 34 at a certain rotational position is also used as means for aligning the carrier 35 with the differential case 10, and in the third embodiment, on the support surface 200 between the carrier 35 and the differential case 10, the annular protrusion portion 17 tand the recess part 35Bbi concentrically assembled for the purpose of the labyrinth sealing effect are also used as means for aligning the carrier 35 with the differential case 10.On the other hand, as a fourth embodiment of the present invention, which is not shown, the alignment of the carrier 35 with the differential case 10 is performed by only aligning means used therefor, and an outer peripheral part of the support surface 200 between the carrier 35 and the differential case 10 can be welded over the entire periphery. The only alignment means used may be provided, for example, on one or the other of the support surface 200 between the carrier 35 and the differential case 10, and is formed of an annular protrusion part and a recess part concentrically assembled more inward in the radial direction of the carrier 35 than the support shaft 34.This fourth embodiment can basically achieve the same operational effects as those of the third embodiment. Moreover, because the aligning means (i.e., the annular protrusion part and the recess part of the support surface 200) is disposed more inward in the radial direction of the carrier 35 than the support shaft 34, a labyrinth sealing effect cannot be expected due to the aligning means (17t, 35Bbi) located more outward in the radial direction than the support shaft 34 as in the third embodiment.Above, embodiments of the present invention are explained, but the present invention is not limited to the above embodiments and can be modified in various ways as long as the modifications do not deviate from its spirit and scope.For example, in the embodiments, the differential case 10 of the differential device D that allows a rotational speed difference between the left and right axles is illustrated as a transmission member, but in the present invention, a differential case of the center differential that allows a rotational speed difference between front and rear wheels may also be the transmission member.In the above-described embodiments, the carrier 35 (specifically, the carrier main body 35B) is integrally joined to the differential case 10 (specifically, the first case half body 10A) as the gear member by means of the welding w, but in the present invention, the carrier 35 may be integrally joined to the differential case 10 by various types of joining means other than welding (for example, bolting, caulking, bonding, etc.), or the carrier 35 may be integrally formed with at least a part of the differential case 10.In the above embodiments, a flat differential is illustrated in which the differential device D including the differential case 10 as the gear member is a gear differential device having a pair of side gears 16 and 16' and a plurality of pinion gears 14 capable of meshing with the two side gears and rotating and revolving, and the side gears 16 and 16' and the differential case side wall portions 10As and 10Bs are flattened in the axial direction, but in the present invention, the gear member may also be a differential case of various gear differential device types other than the flat differential (for example, a gear differential device having a spherical split or integrated differential case). Alternatively, the gear member may be a differential case of various different types of differential device from the gear differential device (for example, various types of differential device including a planetary gear mechanism and / or a rolling ball gear mechanism in which a rolling ball and a cycloid or trochoidal wave-shaped transmission groove in which the rolling ball rolls are provided between opposing surfaces of two members).Further, in the above, as the transmission member connected to the carrier 35, the differential case 10 of the differential device D is illustrated and power is transmitted from the carrier 35 to the differential case 10 side (transmission member), but in the present invention, the transmission member may be an input member or an output member connected to the carrier among various types of power transmission devices other than a differential device. The power transmission device includes, for example, a reduction device of various types (for example, one formed of a gear train having a plurality of spur gears, one formed of a planetary gear mechanism, one formed of a rolling ball gear mechanism, etc.), and a speed increasing device having the same structure as that of the reduction device.

Claims

A transmission device comprising a planetary gear mechanism (P) having a plurality of planet gears (33) respectively meshed with a sun gear (31) and an ring gear (32), a plurality of support shafts (34) respectively rotatably extending through and supporting the plurality of planet gears (33), and a carrier (35) supporting the plurality of support shafts (34), wherein a transmission member (10) adjacent to the carrier (35) is connected to the carrier (35) for integral rotation therewith, each of the support shafts (34) having an oil hole (h1) extending in the axial direction of the support shaft (34), an exhaust hole (h2), An inner end thereof communicates with the oil hole (h1) and an outer end (h2o) thereof opens to an outer circumferential surface of the support shaft (34), and an engaging part (K) provided at one end portion (34a) of the support shaft (34), the other end portion (34b) of the support shaft (34) being fixed to the bracket (35), and an engageable part (S) provided at the gear member (10), the engaging part (K) being engaged with the engageable part (S) so as to be able to position the support shaft (34) at a position where the outer end (h2o) of the outlet hole (h2) faces outward in the radial direction of the bracket (35), characterized in that, that the oil hole (h1) extends through the support shaft (34) in the axial direction, and an open end portion (h1e) of the oil hole (h1) on the gear member (10) side is blocked by mutual engagement between the engagement part (K) and the to-be-engaged part (S).The transmission device according to claim 1, wherein the carrier (35) and the transmission member (10) are formed of separate components and integrally connected to each other, the carrier (35) and the transmission member (10) abut against each other at a periphery of the engagement part (K) and the to-be-engaged part (S), and a support surface (200) between the carrier (35) and the transmission member (10), in a cross section including a rotation axis (L) of the carrier (35), has a bent portion (200a) on the outer side of the support shaft (34) in the radial direction.The transmission device according to claim 1 or 2, wherein the to-be-engaged part (S) is formed of an annular step part provided on a side of the transmission member (10) opposite to the carrier (35) and coaxial with the transmission member (10), and the engagement part (K) has a shape such that, due to the engagement between the engagement part (K) and the step part (S), the carrier (35) can be positioned coaxially with the transmission member (10) via the support shaft (34).A transmission device comprising a planetary gear mechanism (P) having a plurality of planet gears (33) respectively meshed with a sun gear (31) and an ring gear (32), a plurality of support shafts (34) respectively rotatably extending through and supporting the plurality of planet gears (33), and a carrier (35) supporting the plurality of support shafts (34), wherein a transmission member (10) adjacent to the carrier (35) is connected to the carrier (35) for integral rotation therewith, each of the support shafts (34) having an oil hole (h1) extending in the axial direction of the support shaft (34), an exhaust hole (h2), An inner end thereof communicates with the oil hole (h1) and an outer end (h2o) thereof opens to an outer circumferential surface of the support shaft (34), and an engaging part (K) provided at one end portion (34a) of the support shaft (34), the other end portion (34b) of the support shaft (34) being fixed to the bracket (35), and an engageable part (S) provided at the gear member (10), the engaging part (K) being engaged with the engageable part (S) so as to be able to position the support shaft (34) at a position where the outer end (h2o) of the outlet hole (h2) faces outward in the radial direction of the bracket (35), characterized in that, the to-be-engaged part (S) is formed of an annular step part provided on a side of the gear member (10) opposite to the carrier (35) and coaxial with the gear member (10), and the engaging part (K) has a shape such that, due to the engagement between the engaging part (K) and the step part (S), the carrier (35) can be positioned coaxially with the gear member (10) via the support shaft (34).The transmission device according to claim 4, wherein the oil hole (h1) extends through the support shaft (34) in the axial direction, and an open end portion (h1e) of the oil hole (h1) on the transmission member (10) side is blocked by mutual engagement between the engagement part (K) and the to-be-engaged part (S).The transmission device according to claim 4 or 5, wherein the carrier (35) and the transmission member (10) are formed of separate components and integrally connected to each other, wherein the carrier (35) and the transmission member (10) abut against each other at a periphery of the engagement part (K) and the to-be-engaged part (S), and a support surface (200) between the carrier (35) and the transmission member (10), in a cross section including a rotation axis (L) of the carrier (35), has a bent portion (200a) on the outer side of the support shaft (34) in the radial direction.

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