WO2015181601A1

WO2015181601A1 - Manual transmission

Info

Publication number: WO2015181601A1
Application number: PCT/IB2015/000707
Authority: WO
Inventors: Hiroshi Ishiyama
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2014-05-29
Filing date: 2015-05-20
Publication date: 2015-12-03
Also published as: JP6131911B2; CN106461059B; CN106461059A; DE112015002532T5; KR20160145708A; DE112015002532B4; JP2015224750A; KR101834977B1

Abstract

A manual transmission (10) includes a shaft (21) that has an axial oil passage (61) that extends in an axial direction of the shaft (21), and a radial oil passage (62) that is communicated with the axial oil passage (61) and extends in a radial direction of the shaft (21); an inner race (37) that is provided on an outer periphery of the shaft (21) and includes an oil passage (72) that is communicated with the radial oil passage (62) and extends in the radial direction of the shaft (21); a rolling element (36) that is provided on an outer periphery of the inner race (37); and a cylindrical pin (81) that is provided along the radial oil passage (62) and the oil passage (72), on an inner peripheral side of the radial oil passage (62) and the oil passage (72).

Description

MANUAL TRANSMISSION

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The invention typically relates to a manual transmission, and more particularly, relates to a manual transmission provided with a mechanism for supplying lubricating oil to a bearing that supports an idler gear. 2. Description of Related Art

[0002] As a related manual transmission, Japanese Patent Application Publication No. 2010-236589 (JP 2010-236589 A), for example, describes a manual transmission that aims to further shorten the axial dimension. The manual transmission described in JP 2010-236589 A has an input shaft, a first counter shaft, a second counter shaft, and a plurality of gears provided so as to be idly rotatable on these shafts via a bearing such as a needle bearing.

[0003] In addition, Japanese Patent Application Publication No. 2009-63152 (JP 2009-63152 A) and Japanese Patent Application Publication No. 2012-154444 (JP 2012-154444 A) also describe various manual transmissions.

[0004] In the manual transmission described in JP 2010-236589 A, as means for supplying lubricating oil to the bearing, an axial oil passage that extends in the axial direction and a radial oil passage that extends in the radial direction are formed in the shaft, and an oil hole that passes through in the radial direction is formed in an inner race of the bearing. Lubricating oil introduced from one end surface of the shaft passes through the axial oil passage and the radial oil passage of the shaft in this order, and is supplied to a rolling element (a roller in the case of a needle bearing) of the bearing through the oil hole in the inner race.

[0005] However, with this kind of lubricating oil supply mechanism, some of the lubricating oil that heads from the radial oil passage toward the oil hole leaks through a gap between the shaft and the inner race, so the utilization efficiency of the lubricating oil decreases. One conceivable way to prevent the lubricating oil from leaking out is to provide a seal member such as an O-ring between the shaft and the inner race, but doing so would end up increasing both the number of parts and the manufacturing cost of the manual transmission.

[0006] Also, with a manual transmission in which an inner race of the bearing is provided on an outer periphery of the shaft, if relative rotation occurs between the shaft and the inner race, the radial oil passage of the shaft will end up being circumferentially offset from the oil passage of the inner race. As a result, the supply of lubricating oil to the rolling element of the bearing may be impeded, so a rotation stopper to prevent the inner race from rotating with respect to the shaft must be provided. On one hand, machining to grind down a portion of the inner race can be performed in order to provide this inner race rotation stopper. However, in this case, in order to prevent the strength of the machined portion from decreasing, the thickness of the inner race must be made thicker, so the radial dimension may become larger by the amount that the thickness of the inner race is increased.

SUMMARY OF THE INVENTION

[0007] In view of the foregoing problem, the invention provides a manual transmission that is able to both improve the utilization efficiency of lubricating oil and prevent relative rotation of the inner race, with a simple structure, by solving the problem described above.

[0008] A first aspect of the invention relates to a manual transmission that includes a shaft, an inner race, a rolling element, and a first cylindrical member. The shaft has a first oil passage that extends in an axial direction of the shaft, and a second oil passage that is communicated with the first oil passage and extends in a radial direction of the shaft. The inner race is provided on an outer periphery of the shaft. Also, the inner race includes a third oil passage that is communicated with the second oil passage and extends in the radial direction of the shaft. The rolling element is provided on an outer periphery of the inner race. The first cylindrical member is provided along the second oil passage and the third oil passage, on an inner peripheral side of the second oil passage and the third oil passage.

[0009] According to the manual transmission structured in this way, by providing the first cylindrical member along the second oil passage and the third oil passage, on the inner periphery of the second oil passage and the third oil passage, lubricating oil is able to be inhibited from leaking out between the shaft and the inner race, while the first cylindrical member is also able to be used as a rotation stopper of the inner race. As a result, the utilization efficiency of lubricating oil is able to be improved, and relative rotation of the inner race is able to be prevented, all with a simple structure.

[0010] Here, in the manual transmission described above, the first cylindrical member may have a C-shaped or an O-shaped sectional shape. According to this kind of first cylindrical member, the outer peripheral surface of the first cylindrical member is able to closely contact the inside walls of the second oil passage and the third oil passage when the first cylindrical member is installed into the shaft.

[0011] Also, in the manual transmission described above, the first cylindrical member may be engaged with the second oil passage and the third oil passage. According to the manual transmission structured in this way, by having the first cylindrical member closely contact the inside walls of the second oil passage and the third oil passage, lubricating oil is able to be more effectively inhibited from leaking out between the shaft and the inner race.

[0012] Here, the manual transmission described above may also include an idler gear that is provided on an outer periphery of the rolling element. This idler gear may be configured to be rotatably supported. Also, the inner race may be relatively rotatably provided with respect to the rolling element.

[0013] According to the manual transmission structured in this way, relative rotation between idler gear, and the shaft and the inner race, is possible via the rolling element, so the idler gear is able to idly rotate with respect to the shaft.

[0014] Also, in the manual transmission described above, the shaft may have a fourth oil passage that is communicated with the first oil passage and extends in the radial direction of the shaft in a position apart from the second oil passage in the axial direction of the shaft. The second oil passage and the fourth oil passage may have equal opening areas.

[0015] According to the manual transmission structured in this way, machining the shaft when forming the second oil passage and the fourth oil passage is able to be easier due to the second oil passage and the fourth oil passage having equal opening areas, i.e., having the same opening shape.

[0016] Also, in the manual transmission described above, the fourth oil passage may be arranged farther to a downstream side, in a lubricating oil flow direction, in the first oil passage than the second oil passage.

[0017] According to the manual transmission structured in this way, when the first cylindrical member is provided in the second oil passage and a cylindrical member is not provided in the fourth oil passage, the passage area of lubricating oil in the fourth oil passage is larger than the passage area of lubricating oil in the second oil passage. As a result, an insufficiency in the amount of lubricating oil that flows to the downstream side due to the oil passages being arranged on the upstream and downstream sides, in the lubricating oil flow direction, in the first oil passage is able to be inhibited.

[0018] Further, in the manual transmission described above, the manual transmission may include a second cylindrical member. The second cylindrical member may be provided on an inner peripheral side of the fourth oil passage. Also, an opening area of the second cylindrical member may be larger than an opening area of the first cylindrical member. Here, the second cylindrical member may have a C-shaped or an Oshaped sectional shape.

[0019] According to the manual transmission structured in this way, by providing the second cylindrical member that is thinner than the first cylindrical member in the fourth oil passage, the opening area of the second cylindrical member is able to be larger than the opening area of the first cylindrical member. As a result, the passage area of lubricating oil in the fourth oil passage is able to be larger than the passage area of lubricating oil in the second oil passage. Consequently, an insufficiency in the amount of lubricating oil that flows to the downstream side due to the oil passages being arranged on the upstream and downstream sides, in the lubricating oil flow direction, in the first oil passage is able to be inhibited.

[0020] As described above, according to a structure such as that of the manual transmission of the aspect of the invention, it is possible to both improve the utilization efficiency of lubricating oil, and prevent relative rotation of the inner race, with a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:

FIG. 1 is a sectional view of a manual transmission according to a first example embodiment of the invention;

FIG. 2 is an enlarged sectional view of an area encircled by the alternate long and two short dashes line II in FIG. 1 ;

FIG. 3 is a perspective view of a cylindrical pin before being assembled to the manual transmission in FIG. 1 ;

FIG. 4 is a sectional view of the manual transmission taken along line IV - IV in FIG.

2;

FIG. 5 is a perspective view of a modified example of the cylindrical pin in FIG. 3; and

FIG. 6 is a sectional view of a manual transmission according to a second example embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0022] Example embodiments of the invention will now be described with reference to the accompanying drawings. In the drawings referred to below, like or corresponding members will be denoted by like reference characters.

[0023] First, a first example embodiment of the invention will be described. FIG. 1 is a sectional view of a manual transmission according to this first example embodiment of the invention. Referring to FIG. 1, the manual transmission 10 of this example embodiment is a vehicular manual transmission that selectively decelerates or accelerates rotation generated by a power source and outputs the resultant rotation to driving wheels, and reverses the generated rotation and outputs this reversed rotation to the driving wheels.

[0024] First, in describing the overall structure of the manual transmission 10, the manual transmission 10 includes a shaft 21, a bearing 35, a bearing 45, a bearing 55, an idler gear 31, an idler gear 41, and an idler gear 51. The shaft 21, the bearings 35, 45, and 55, and the idler gears 31 , 41, and 51 are all provided centered on a virtual central axis 101 shown in the drawing.

[0025] The shaft 21 extends in a shaft shape along the central axis 101. The shaft 21 is rotatably supported centered on the central axis 101. The shaft 21 is supported by a bearing 26, on one end 21p side in the axial direction of the central axis 101.

[0026] The bearing 35, the bearing 45, and the bearing 55 are provided on an outer periphery of the shaft 21. The bearing 35, the bearing 45, and the bearing 55 are lined up in the axial direction of the shaft 21. The bearing 35 is arranged on the side closest to the one end 21p of the shaft 21, the bearing 55 is arranged on the side farthest from the one end 21p of the shaft 21, and the bearing 45 is arranged between the bearing 35 and the bearing 55.

[0027] The idler gear 31, the idler gear 41, and the idler gear 51 are arranged on the outer peripheries of the bearing 35, the bearing 45, and the bearing 55, respectively. The idler gear 31, the idler gear 41, and the idler gear 51 are rotatably supported centered on the central axis 101, by the bearing 35, the bearing 45, and the bearing 55, respectively. The idler gears 31, 41, and 51 are provided on the shaft 21, in a manner idly rotatable with respect to the shaft 21. The idler gears 31, 41, and 51 are power transmitting gears for specific gear speeds, and idly rotate with respect to the shaft 21 when the corresponding gear speed is not selected. [0028] In this example embodiment, needle bearings are used for the bearings 35, 45, and 55.

[0029] The bearing 35 is formed by an inner race 37 and a rolling element 36. The inner race 37 is provided on the outer periphery of the shaft 21. The inner race 37 is prevented from rotating with respect to the shaft 21, by a cylindrical pin 81 (also referred to as a "first cylindrical member") that will be described later. The rolling element 36 is provided on the outer periphery of the inner race 37. The rolling element 36 is provided between the inner race 37 and the idler gear 31 in the radial direction. The inner race 37 is relatively rotatably provided with respect to the rolling element 36. The rolling element 36 is formed from a plurality of rollers arranged in the circumferential direction.

[0030] The bearing 45 is formed by an inner race 47, and a rolling element (roller) 46. The inner race 47 is provided on the outer periphery of the shaft 21.

[0031] The inner race 47 is prevented from rotating by a spherical ball bearing 42. More specifically, a groove 44 and a groove 43 are formed in the shaft 21 and the inner race 47, respectively. The groove 44 and the groove 43 are provided recessed from an outer peripheral surface of the shaft 21 and an inner peripheral surface of the inner race 47, respectively, in positions facing one another in the radial direction. The ball bearing 42 is housed in the groove 44, and a portion of the ball bearing 42 that protrudes from the groove 44 is retained in the groove 43, thus preventing the inner race 47 from rotating with respect to the shaft 21.

[0032] A cylindrical pin, similar to the rotation stopping mechanism of the inner race 37, may also be provided instead of the ball bearing 42, as the rotation stopping mechanism of the inner race 47.

[0033] The rolling element 46 is provided in the same manner as the rolling element 36 described above. The bearing 55 is formed by a rolling element (a roller) 56. In the bearing 55, an inner race is not provided. Instead, the rolling element 56 is provided directly on the outer periphery of the shaft 21.

[0034] The bearings that rotatably support the idler gears 31, 41, and 51 are not limited to needle bearings. Ball bearings or the like may also be used as the rolling elements to match the type of bearing.

[0035] The shaft 21 has a small diameter portion 22 within which a radial oil passage 62 as a second oil passage (this radial oil passage 62 may also be referred to as a "second oil passage") is formed, and on which the inner race 37 and the rolling element 36 that serves as a first rolling element are provided, and a large diameter portion 23 that has a larger diameter than the small diameter portion 22, and within which a radial oil passage 64 that serves as a fourth oil passage is formed. The manual transmission 10 includes the idler gear 31 as a first idler gear, the rolling element 56 as a second rolling element, the idler gear 51 as a second idler gear, an inner race 27 as a first abutting member, and the inner race 47 as a second abutting member. The idler gear 31 is provided on the outer periphery of the rolling element 36 and is rotatably supported. The rolling element 56 is provided on the outer periphery of the large diameter portion 23. The idler gear 51 is provided on the outer periphery of the rolling element 56, and is rotatably supported. The inner race 27 is fixed to the outer periphery of the shaft 21 and arranged across a gap from the idler gear 31 by abutting against the inner race 37 in the axial direction. The inner race 47 is fixed to the outer periphery of the shaft 21 and arranged across a gap from the idler gear 51 by abutting against the large diameter portion 23 in the axial direction.

[0036] In describing the structure above in more detail, the shaft 21 has a shape that widens in a stepped manner from the one end 21p side toward the other end side. The shaft 21 has the small diameter portion 22 and the large diameter portion 23 as constituent portions. The small diameter portion 22 has a diameter Dl . The small diameter portion 22 is arranged at the one end 21p of the shaft 21. The large diameter portion 23 has a diameter D2 that is larger than the diameter Dl. The large diameter portion 23 is arranged apart from the one end 21p of the shaft 21. A shoulder portion 24 having a step is provided on an end portion on the one end 21p side of the large diameter portion 23.

[0037] The inner race 37 of the bearing 35 is provided on the outer periphery of the small diameter portion 22. The inner race 27 (the first abutting member) of the bearing 26 is provided abutting against the inner race 37 in the axial direction of the shaft 21, on the outer periphery of the small diameter portion 22. The inner race 27 is positioned so as to create a gap in the axial direction between the inner race 27 and the idler gear 31, by abutting against the inner race 37 in the axial direction of the shaft 21.

[0038] The rolling element 56 of the bearing 55 is provided on the outer periphery of the large diameter portion 23. The inner race 47 (the second abutting member) of the bearing 45 abuts against the shoulder portion 24 of the large diameter portion 23 in the axial direction of the shaft 21. The inner race 47 is positioned so as to create a gap in the axial direction between the inner race 47 and the idler gear 51, by abutting against the shoulder portion 24 of the large diameter portion 23 in the axial direction of the shaft 21.

[0039] One conceivable way to position the inner race 27 in the axial direction of the shaft 21 is to provide a shoulder portion on the small diameter portion 22. However, if a shoulder portion is provided on the thin small diameter portion 22, the one end 21p side of the shaft 21 provided with the shoulder portion must have an even smaller diameter, which would make it difficult to sufficiently ensure the rigidity of the shaft 21. Therefore, by providing the inner race 37 as a constituent part of the bearing 35, and using this inner race 37 as the positioning means of the inner race 27, the inner race 27 is able to be prevented from contacting the idler gear 31 that idly rotates with respect to the shaft 21. Meanwhile, the shoulder portion 24 is able to be provided on the thick large diameter portion 23, so the inner race 47 is able to be prevented from contacting the idler gear 51 that idly rotates with respect to the shaft 21, by having the inner race 47 abut against the shoulder portion 24. For this reason, an inner race is not provided as a constituent part of the bearing 55 in this example embodiment.

[0040] The manual transmission 10 in this example embodiment is provided with a mechanism for supplying lubricating oil to the bearings 35, 45, and 55 that support the idler gears 31, 41, and 51. Continuing on, this lubricating oil supply mechanism will be described.

[0041] FIG. 2 is an enlarged sectional view of the area encircled by the alternate long and two short dashes line II in FIG. 1. Referring to FIGS. 1 and 2, an axial oil passage 61 (also referred to as a "first oil passage"), a radial oil passage 62, a radial oil passage 63, and a radial oil passage 64, are formed in the shaft 21.

[0042] The axial oil passage 61 extends in the axial direction of the shaft 21. The axial oil passage 61 opens to an end surface on the one end 21p side of the shaft 21, and extends linearly along the central axis 101. A guide member 28 for guiding lubricating oil to the axial oil passage 61 is provided on an open end of the axial oil passage 61. Lubricating oil led to the axial oil passage 61 by the guide member 28 flows from the one end 21p side of the shaft 21 toward the other end side, as shown by arrow 102 in FIG. 1.

[0043] The radial oil passages 62, 63, and 64 are communicated with the axial oil passage 61, and extend in the radial direction of the shaft 21. The radial oil passages 62, 63, and 64 extend in the radial direction from the axial oil passage 61 and pass through the shaft 21. The radial oil passage 62, the radial oil passage 63, and the radial oil passage 64 are formed from holes having the same opening area. The radial oil passages 62, 63, and 64 have an inside diameter dl . This inside diameter dl is φ 3 mm, for example.

[0044] The radial oil passage 62, the radial oil passage 63, and the radial oil passage 64 are provided in positions offset from each other in the axial direction of the shaft 21. The radial oil passage 62 is arranged on the side farthest upstream, in the lubricating oil flow direction, in the axial oil passage 61. The radial oil passage 63 is arranged farther on the downstream side, in the lubricating oil flow direction, in the axial oil passage 61 than the radial oil passage 62, and the radial oil passage 64 is arranged even farther on the downstream side, in the lubricating oil flow direction, in the axial oil passage 61 than the radial oil passage 63. The radial oil passage 62, the radial oil passage 63, and the radial oil passage 64 are provided in positions corresponding to the bearing 35, the bearing 45, and the bearing 55, respectively, in the axial direction of the shaft 21.

[0045] An oil hole 72 (also referred to as a "third oil passage") and an oil hole 73 are formed in the inner race 37 and the inner race 47, respectively. The oil hole 72 and the oil hole 73 are provided passing through the inner race 37 and the inner race 47, respectively, in the radial direction. The oil hole 72 and the oil hole 73 are communicated with the radial oil passage 62 and the radial oil passage 63 (also referred to as a "fourth oil passage"), respectively. The oil hole 72 passes through the inner race 37 from a position communicated with the radial oil passage 62, and reaches the space where the rolling element 36 is arranged. The oil hole 73 passes through the inner race 47 from a position communicated with the radial oil passage 63, and reaches the space where the rolling element 46 is arranged.

[0046] The oil hole 72 and the oil hole 73 are formed from holes having the same opening area. The oil hole 72 and the oil hole 73 have the same inside diameters, i.e., the inside diameter dl , as the radial oil passage 62 and the radial oil passage 63.

[0047] FIG. 3 is a perspective view of a cylindrical pin before being assembled to the manual transmission in FIG. 1. FIG. 4 is a sectional view of the manual transmission taken along line IV - IV in FIG. 2.

[0048] Referring to FIGS. 1 to 4, the manual transmission 10 of this example embodiment also has a cylindrical pin 81. This cylindrical pin 81 is provided extending in a cylindrical manner along the radial oil passage 62 and the oil hole 72, on the inner peripheral sides of the radial oil passage 62 and the oil hole 72. The cylindrical pin 81 has a circular cylindrical shape and therein forms a passage for the lubricating oil. The cylindrical pin 81 has an inside diameter d2 that is smaller than the inside diameter dl. The inside diameter d2 is φ 2 mm, for example.

[0049] The cylindrical pin 81 is formed from a metal plate, for example. The cylindrical pin 81 has a C-shaped sectional shape when not installed in the radial oil passage 62 and the oil hole 72. The cylindrical pin 81 has a shape that is curved in the circumferential direction, and has an end portion 82 and an end portion 83, one on each end, that face each other across a cutout 84.

[0050] The cylindrical pin 81 is engaged with the radial oil passage 62 and the oil hole 72. In this example embodiment, the cylindrical pin 81 is inserted through the radial oil passage 62 and the oil hole 72 in a state elastically deformed such that the end portion 82 and the end portion 83 approach one another. The outer peripheral surface of the cylindrical pin 81 closely contacts the inner walls of the radial oil passage 62 and the oil hole 72 by the elastic force of the cylindrical pin 81 trying to return to its original shape.

[0051] As shown in FIG. 4, the end portion 82 and the end portion 83 preferably abut against each other when the cylindrical pin 81 is mounted in the radial oil passage 62 and the 72, but there may also be a gap between the end portion 82 and the end portion 83. The term "cylindrical" in the invention is not limited to meaning only a shape that is completely connected in the circumferential direction.

[0052] The cylindrical pin 81 extends continuous between the radial oil passage 62 and the oil hole 72 that are communicated together. The cylindrical pin 81 is preferably provided so as not to protrude from an inner peripheral surface 21b of the shaft 21 where the radial oil passage 62 opens (see FIG. 2). This kind of structure makes it possible to prevent the flow of lubricating oil in the axial oil passage 61 from being impeded by the cylindrical pin 81. The cylindrical pin 81 is preferably provided so as not to protrude from an outer peripheral surface 37a of the inner race 37 where the oil hole 72 opens (see FIG. 2). This kind of structure makes it possible to prevent the cylindrical pin 81 from interfering with the rolling element 36 that rolls on the outer periphery of the inner race 37.

[0053] Here, a modified example of the cylindrical pin in the first example embodiment will be described. FIG. 5 is a perspective view of a modified example of the cylindrical pin 81 shown in FIG. 3. Referring to FIG. 5, in this modified example, the cylindrical pin 81 has an O-shaped sectional shape when the cylindrical pin 81 is not installed in the radial oil passage 62 and the oil hole 72. The outside diameter of the cylindrical pin 81 is set slightly larger than the inside diameter dl of the radial oil passage 62 and the oil hole 72. The outer peripheral surface of the cylindrical pin 81 closely contacts the inside walls of the radial oil passage 62 and the oil hole 72 by the cylindrical pin 81 being press-fit into the radial oil passage 62 and the oil hole 72.

[0054] Referring to FIGS. 1 and 2, lubricating oil that is picked up by a ring gear, not shown, and accumulates in a tray-shaped separator, also not shown, is guided by the guide member 28 and introduced into the axial oil passage 61. The lubricating oil that flows through the axial oil passage 61 flows into the radial oil passage 62, the radial oil passage 63, and the radial oil passage 64, and is supplied to the bearing 35, the bearing 45, and the bearing 55, in this order.

[0055] In this example embodiment, the cylindrical pin 81 is provided in the radial oil passage 62 and the oil hole 72, so the lubricating oil that has flowed in from the axial oil passage 61 passes through this cylindrical pin 81. Therefore, the cylindrical pin 81 functions as a seal member between the shaft 21 and the inner race 37, inhibiting lubricating oil heading toward the rolling element 36 from leaking out of the gap between the outer peripheral surface 21a of the shaft 21 and an inner peripheral surface 37b of the inner race 37.

[0056] The cylindrical pin 81 also functions as a rotation stopper for the inner race 37 with respect to the shaft 21, restricting relative rotation between the shaft 21 and the inner race 37. This obviates the need for the ball bearing 42 as a rotation stopper such as that provided in the inner race 47, which in turn contributes to a more compact structure in the radial direction. Also, machining of a groove for installing the ball bearing 42 is not necessary, so the manufacturing cost is able to be reduced.

[0057] When the radial oil passage 62, the radial oil passage 63, and the radial oil passage 64 are provided in this order, in the lubricating oil flow direction, in the axial oil passage 61 to which lubricating oil is supplied from one direction, there is a tendency for the amount of lubricating oil that flows into the radial oil passages to decrease from the upstream side toward the downstream side, in the lubricating oil flow direction, in the axial oil passage 61. On the other hand, in this example embodiment, the radial oil passage 62, the radial oil passage 63, and the radial oil passage 64 all have the same diameter, but the passage area of the radial oil passage 62 that is arranged farther on the upstream side, in the lubricating oil flow direction, in the axial oil passage 61 than the radial oil passage 63 and the radial oil passage 64 is reduced by the cylindrical pin 81 that serves as the orifice. This kind of structure makes it possible to inhibit the amount of lubricating oil that flows to the downstream side from becoming insufficient, while avoiding complicated machining by using a uniform drill diameter when machining the radial oil passages 62, 63, and 64.

[0058] For reasons already described, in this example embodiment, the inner race 37 is provided in the bearing 35 in order to position the inner race 27 on the upstream side, in the lubricating oil flow direction, of the axial oil passage 61, but an inner race is not provided with respect to the rolling element 56, in the bearing 55, on the downstream side, in the lubricating oil flow direction, of the axial oil passage 61. With this kind of structure, the position where the cylindrical pin 81 is necessary is on the upstream side, in the lubricating oil flow direction, of the axial oil passage 61, so the aforementioned effect of inhibiting the amount of lubricating oil that flows to the downstream side from becoming insufficient is able to be advantageously achieved.

[0059] To summarize the structure of the manual transmission 10 of the first example embodiment of the invention described above, the manual transmission 10 of this example embodiment includes the shaft 21 within which are formed the axial oil passage

61 as a first oil passage that extends in the axial direction, and the radial oil passage 62 as a second oil passage that is communicated with the axial oil passage 61 and extends in the radial direction, the inner race 37 that is provided on the outer periphery of the shaft 21 and has the oil hole 72 as a third oil passage that is communicated with the radial oil passage

62 and extends in the radial direction, the rolling element 36 as a rolling element that is provided on the outer periphery of the inner race 37, and the cylindrical pin 81 as a cylindrical member that is provided along the radial oil passage 62 and the oil hole 72, on the inner peripheral sides of the radial oil passage 62 and the oil hole 72.

[0060] According to the manual transmission 10 of the first example embodiment of the invention that is structured in this way, the utilization efficiency of lubricating oil is able to be improved, and relative rotation of the inner race is able to be prevented, all with a simple structure.

[0061] Next, a second example embodiment of the invention will be described. FIG. 6 is a sectional view of a manual transmission according to the second example embodiment of the invention. The manual transmission of this example embodiment has basically the same structure as the manual transmission 10 of the first example embodiment. Hereinafter, descriptions of redundant structure will not be repeated.

[0062] Referring to FIG. 6, the manual transmission of this example embodiment has a cylindrical pin (also referred to as a "second cylindrical member") 86, in addition to the cylindrical pin 81. The cylindrical pin 86 is provided extending in a cylindrical manner along the radial oil passage 63 and the oil hole 73. The cylindrical pin 86 is provided in the same manner as the cylindrical pin 81 that is provided in the radial oil passage 62 and the oil hole 72.

[0063] The cylindrical pin 86 is provided so as to restrict relative rotation between the inner race 47 and the shaft 21. In this example embodiment, the ball bearing 42 as a rotation stopper is not provided on the inner race 47.

[0064] The cylindrical pin 81 has an inside diameter d3 that is smaller than the inside diameter dl . The cylindrical pin 86 has an inside diameter d4 that is smaller than the inside diameter dl, and larger than the inside diameter d3 of the cylindrical pin 81. The inside diameter dl is φ 3 mm, for example. The inside diameter d3 is φ 1.5 mm, for example, and the inside diameter d4 is φ 2 mm, for example.

[0065] According to this kind of structure, the passage area of the radial oil passage 63 that is arranged farther on the upstream side, in the lubricating oil flow direction, in the axial oil passage 61 than the radial oil passage 64 is reduced by the cylindrical pin 86, and the passage area of the radial oil passage 62 that is arranged farther on the upstream side, in the lubricating oil flow direction, in the axial oil passage 61 than the radial oil passage 63 is further reduced by the cylindrical pin 81. Therefore, the amount of lubricating oil that flows to the downstream side is able to be effectively inhibited from being insufficient.

[0066] According to the manual transmission of this second example embodiment of the invention that is structured in this way, the effect described in the first example embodiment is similarly able to be achieved.

[0067] The example embodiments disclosed herein are in all respects merely examples and should in no way be construed as limiting. The scope of the invention is indicated not by the foregoing description but by the scope of the claims for patent, and is intended to include all modifications that are within the scope and meanings equivalent to the scope of the claims for patent. Also, the invention mainly applies to a manual transmission for a vehicle.

Claims

CLAIMS:

1. A manual transmission comprising:

a shaft that has a first oil passage extending in an axial direction of the shaft, and a second oil passage being communicated with the first oil passage and extending in a radial direction of the shaft;

an inner race that is provided on an outer periphery of the shaft, the inner race including a third oil passage that is communicated with the second oil passage and extends in the radial direction of the shaft;

a rolling element that is provided on an outer periphery of the inner race; and a first cylindrical member that is provided along the second oil passage and the third oil passage, on an inner peripheral side of the second oil passage and the third oil passage.

2. The manual transmission according to claim 1, wherein

the first cylindrical member has a C-shaped sectional shape.

3. The manual transmission according to claim 1, wherein

the first cylindrical member has an O-shaped sectional shape.

4. The manual transmission according to any one of claims 1 through 3, wherein the first cylindrical member is engaged with the second oil passage and the third oil passage.

5. The manual transmission according to any one of claims 1 through 4, further comprising:

an idler gear that is provided on an outer periphery of the rolling element, the idler gear being configured to be rotatably supported,

wherein the inner race is relatively rotatably provided with respect to the rolling element.

6. The manual transmission according to any one of claims 1 through 5, wherein the shaft has a fourth oil passage that is communicated with the first oil passage and extends in the radial direction of the shaft in a position apart from the second oil passage in the axial direction of the shaft; and

the second oil passage and the fourth oil passage have equal opening areas.

7. The manual transmission according to claim 6, wherein

the fourth oil passage is arranged farther to a downstream side, in a lubricating oil flow direction, in the first oil passage than the second oil passage.

8. The manual transmission according to claim 7, further comprising:

a second cylindrical member that is provided on an inner peripheral side of the fourth oil passage, an opening area of the second cylindrical member being larger than an opening area of the first cylindrical member.

9. The manual transmission according to claim 8, wherein

the second cylindrical member has a C-shaped sectional shape.

10. The manual transmission according to claim 8, wherein

the second cylindrical member has an O-shaped sectional shape.