Vehicle power transmission mechanism

Abstract

The present invention addresses the problem of providing a power transmission mechanism for a vehicle capable of axially supporting a gear without increasing the number of components, the size in the axial direction, and positional variations. The flange ring is integrally provided with: a flange inner ring part which forms a flange surface in the bearing; and an abutting part which extends in the radial direction from the driven gear side end part of the flange inner ring part and abuts against the driven gear to limit the driven gear in the axial direction (the second axial direction). Therefore, the driven gear is limited in the axial direction (the second axial direction) by the flange ring, so that the driven gear is thrust-supported without increasing the number of parts, the size in the axial direction (the second axial direction), and the positional deviation. In addition, the assembling performance is also improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a power transmission mechanism for a vehicle provided with a rotating shaft, a gear, and a bearing. BACKGROUND

[0002] In a power transmission mechanism provided with a rotating shaft, a gear disposed with the same axis as the rotating shaft, and a bearing rotatably supporting the rotating shaft, in the case where a thrust load is generated on the rotating shaft, the bearing is required to have a support or load capacity not only in the radial direction but also in the axial direction. In order to improve the support or load capacity for the thrust load, a cylindrical roller bearing provided with a flange portion (flange ring) is known. For example, the cylindrical roller bearing described in Patent Document 1 is such a bearing. In this Patent Document 1, a technique is disclosed in which, for a cylindrical roller bearing having a flange portion on either one or both of the inner and outer rings on both sides or one side in the axial direction, the load capacity for the thrust load is improved.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2010-7678 SUMMARY In the power transmission mechanism as described above, in the case where the gear is adjacent to the cylindrical roller bearing (hereinafter, referred to as the bearing), the bearing is also required to have a support for the thrust load of the gear, that is, to axially restrict and support the gear (hereinafter, referred to as thrust support). In the past, the thrust support has been performed by inserting a dedicated spacer between the gear and the bearing. In the case where the bearing has a flange ring for the thrust support, it is necessary to assemble the flange ring of the bearing and the spacer adjacent to each other, and at the time of assembly, problems such as omission of the installation of the flange ring and poor assembly workability due to unstable posture of the flange ring are generated. Further, since the number of parts is large, the deviation in the size and position in the axial direction becomes large, and there are problems such as the necessity of considering the deviation in the design.

[0004] The present application has been achieved in view of the above-described circumstances, and an object thereof is to provide a power transmission mechanism for a vehicle capable of axially supporting a gear without increasing the number of parts, the deviation in the size and position in the axial direction.

[0005] The gist of the first application is a power transmission mechanism for a vehicle, (a) provided with: a rotating shaft; a gear disposed with the same axis as the rotating shaft; and a cylindrical roller bearing adjacent to the gear and rotatably supporting the rotating shaft, (b) an inner ring of the cylindrical roller bearing is configured to include a flange ring and a race ring in the axial direction from the gear side, (c) the flange ring integrally has: a flange inner ring portion forming a flange surface in the cylindrical roller bearing; and an abutment portion extending radially from the gear side end portion of the flange inner ring portion and abutting against the gear to axially restrict the gear.

[0006] Inventive Effects According to the first invention, the flange ring integrally has a flange inner ring portion that forms a flange surface in the cylindrical roller bearing, and an abutment portion that is provided extending radially from the gear side end portion of the flange inner ring portion, and that abuts against the gear to axially restrict the gear. Thus, the gear is restricted in the axial direction by the flange ring, so the gear is thrust supported without increasing the number of parts, the size in the axial direction, and the positional deviation. Also, the assembly is improved. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a diagram that explains the outline structure of a vehicle to which the present invention is applied.

[0008] Figure 2 is a sectional view that explains a vehicle power transmission mechanism to which the present invention is applied, showing the main parts in the same plane.

[0009] Figure 3 is a diagram that explains a related art example of a vehicle power transmission mechanism. DETAILED DESCRIPTION

[0010] Hereinafter, embodiments of the present invention will be explained in detail with reference to the drawings. Also, in the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of the parts, etc. are not necessarily accurately depicted.

[0011] EMBODIMENT Figure 1 is a skeleton diagram that explains the outline structure of a vehicle 10 that mounts a vehicle power transmission mechanism (hereinafter, referred to as a power transmission mechanism) 90 to which the present invention is applied. In the vehicle 10, a transfer 16 is provided on a power transmission path between an engine 12 and a pair of drive wheels 14. The engine 12 is a traveling power source, and is a well-known internal combustion engine. The vehicle 10 is, for example, a vehicle of a front engine rear drive (FR) system. The transfer 16 has a clutch K1, a bevel gear pair 24, a transmission 26, a final drive shaft 56, and a differential 58, which are housed in a case 70 that is a non-rotating member. Power from the engine 12 is transmitted sequentially via the clutch K1, the bevel gear pair 24, the transmission 26, the final drive shaft 56, and the differential 58, and is transmitted from the differential 58 to the drive wheels 14 via drive shafts 20. The clutch K1 is connected to the engine 12 via an input shaft 18, and is connected to one of the bevel gear pair 24 on the other side. The other side of the bevel gear pair 24 is connected to an intermediate shaft 28 that is an input shaft of the transmission 26.

[0012] The transmission 26 has a power transmission mechanism 90 arranged parallel to and horizontally of the intermediate shaft 28. The power transmission mechanism 90 has: the countershaft 52; the driven gear 34 arranged with the same axis as the countershaft 52; and a cylindrical roller bearing 92 to be described later, which is adjacent to the driven gear 34 and rotatably supports the countershaft 52.

[0013] The transmission 26 is a parallel two-shaft type transmission that forms a plurality of gears (shift stages) by reducing or increasing the rotation of the intermediate shaft 28 at a prescribed gear ratio γ (also referred to as a shift ratio) γ (= rotation speed of the intermediate shaft 28 / rotation speed of the countershaft 52). The intermediate shaft 28 is rotatably arranged with the first axis C1 as the center, and the countershaft 52 is rotatably arranged with the second axis C2 as the center. The first axis C1 direction and the second axis C2 direction are the same direction in which they extend horizontally. The countershaft 52 corresponds to the "rotating shaft" of the present application, and the driven gear 34 corresponds to the "gear" of the present application.

[0014] The transmission 26 has a plurality of gear pairs 30 that are always engaged. The gear pairs 30 include, in the first axis C1 direction, from the bevel gear pair 24 side (input side), in order, the reverse gear pair 30a, the second gear pair 30b, the first gear pair 30c, the fourth gear pair 30d, the fifth gear pair 30e, the sixth gear pair 30f, and the third gear pair 30g.

[0015] The gear pairs 30 have driving gears 32 (including 32a1 and 32a2, 32b, 32c, 32d, 32e, 32f, 32g) and driven gears 34 (including 34a, 34b, 34c, 34d, 34e, 34f, 34g) that are always engaged with the driving gears 32. The reverse gear pair 30a has two driving gears 32a1, 32a2 for reversing the driving direction. The driving gears 32 are arranged so as not to be relatively rotatable with respect to the intermediate shaft 28. The driven gears 34 are arranged so as to be relatively rotatable with respect to the countershaft 52 with the second axis C2 as the center.

[0016] In the second axis C2 direction, the transmission 26 has a plurality of shift mechanisms 36 between the reverse driven gear 34a, between the second driven gear 34b and the first driven gear 34c, between the fourth driven gear 34d and the fifth driven gear 34e, and between the sixth driven gear 34f and the third driven gear 34g, respectively. The shift mechanisms 36 are arranged so as not to be relatively rotatable with respect to the countershaft 52 and so as to be movable in the second axis C2 direction, respectively. The shift mechanisms 36 have shift engagement teeth 38 at positions opposite the driven gears 34 in the second axis C2 direction. The driven gears 34 have gear side engagement teeth 40 capable of engaging with the shift engagement teeth 38 at positions opposite the shift mechanisms 36 in the second axis C2 direction, respectively. The shift mechanisms 36 having the shift engagement teeth 38 and the driven gears 34 having the gear side engagement teeth 40 constitute engagement clutches, i.e., dog clutches 50.

[0017] The shift mechanism 60 has a shift fork 62, a shift barrel 64, and a shift actuator 66 that are respectively fitted to the switching mechanism 36. The shift barrel 64 has a shift groove 68 that respectively defines the moving position of the switching mechanism 36 in the 2nd axis C2 direction via the shift fork 62. The transmission 26 performs a shift by respectively moving the switching mechanism 36 to a prescribed position in the 2nd axis C2 direction according to the rotational position of the shift barrel 64, and respectively switching the disconnecting or connecting state of the dog clutch 50. For example, if the reverse driven gear 34a of the reverse gear Rev is connected to the pinion shaft 52 via the switching mechanism 36, the reverse gear Rev is formed in the transmission 26. The same applies to the 1st to 6th gears 1st to 6th.

[0018] The pinion shaft 52 and the final drive shaft 56 are connected by spline fitting (spline fitting portion 54), and the final drive shaft 56 and the differential 58 are connected by the engagement of the driving gear 56a and the driven gear 58a. The differential 58 is connected to the pair of drive wheels 14 via the pair of drive shafts 20.

[0019] Figure 3 is a diagram illustrating the structure of a power transmission mechanism 100 of a conventional example corresponding to the power transmission mechanism 90, and is a cross-sectional view in which the end portion around the side of the driven gear 34g in the power transmission mechanism 100 is shown in the same plane. A cylindrical roller bearing (hereinafter referred to as a bearing) 102 is provided between the housing 70 of the transfer case 16 and the pinion shaft 52, and rotatably supports the pinion shaft 52 on the 2nd axis C2. The bearing 102 has an outer ring 104, a roller (including a retainer) not shown, an inner ring 106, and the like. The inner ring 106 is configured to include a flange ring 106a and a race ring 106b from the side of the driven gear 34g in the 2nd axis C2 direction. A flange surface T is formed in the bearing 102 by the flange ring 106a, and the resistance of the bearing 102 to a thrust load is ensured. In the power transmission mechanism 100, the outer diameter B of the inner ring 106 (flange ring 106a, race ring 106b) is smaller than the inner diameter A of the driven gear 34g (B

[0020] In Figure 2In the assembly of the power transmission mechanism 100 shown, for example, the order of (1) press-fitting the outer ring 104 and the rollers into the housing 70, (2) mounting the gear thrust spacer 108 and the flange ring 106a and combining the countershaft 52 with the housing 70, and (3) assembling the track ring 106b is followed. That is, the flange ring 106a and the gear thrust spacer 108 need to be assembled adjacent to each other, and in the assembly, problems such as omission of the mounting of the flange ring 106a and instability of the posture of the flange ring 106a and poor workability of the assembly arise. Also, since the number of parts is large, the dimensional and positional deviations in the second axis C2 direction become large, and problems such as the need to take the deviations into account in the design arise.

[0021] Figure 2 is a view that explains the power transmission mechanism 90 to which the present application is applied, and corresponds to the view of Figure 3 . As with the prior example ( Figure 3 ), the bearing 92 is provided between the housing 70 of the transfer case 16 and the countershaft 52, and rotatably supports the countershaft 52 on the second axis C2. The bearing 92 has the outer ring 104 and rollers (same as the prior example) not shown, the inner ring 96, and the like. The inner ring 96 is configured to include the flange ring 98 and the track ring 106b (same as the prior example) in the second axis C2 direction from the driven gear 34g side. A flange face T is formed in the bearing 92 by the flange ring 98, and the resistance of the bearing 92 to the thrust load is ensured. The flange ring 98 is formed in a shape that integrates the flange ring 106a and the gear thrust spacer 108 in the prior example ( Figure 3 ), and integrally has: a flange inner ring portion 98a that is the same shape as the flange ring 106a of the prior example that forms the flange face T in the bearing 92; and an abutting portion 98b that is provided extending in the radial direction from the driven gear 34g side end portion of the flange inner ring portion 98a, and that abuts against the driven gear 34g to axially (in the second axis C2 direction) restrict the driven gear 34g. Also, the outer diameter B of the track ring 106b and the flange inner ring portion 98a is smaller than the inner diameter A of the driven gear 34g (B Figure 3The interference escape relief chamfer amount of the gear meshing portion of the fifth gear pair 30e (drive gear 32e and driven gear 34e) and the gear meshing portion of the sixth gear pair 30f (drive gear 32f and driven gear 34f) shown by the portion W enclosed by the double-dot chain line in FIG. 6 is set to a predetermined value, thereby further ensuring the strength. Also, the assembly is improved. The shape and size of the abutment portion 98b, including the outer diameter C of the abutment surface 98b1, are set to a preferred shape and size determined by design or experiment.

[0022] As described above, according to the present embodiment, the flange ring 98 integrally has the flange inner ring portion 98a that forms the flange surface T inside the bearing 92 and the abutment portion 98b that is provided extending radially from the driven gear 34g side end portion of the flange inner ring portion 98a and that abuts against the driven gear 34g to axially (in the direction of the second axis C2) restrict the driven gear 34g. Thus, the driven gear 34g is axially (in the direction of the second axis C2) restricted by the flange ring 98, so the driven gear 34g is thrust supported without increasing the number of parts, the size in the axial direction (in the direction of the second axis C2), and the positional deviation. Also, the assembly is improved.

[0023] Also, according to the present embodiment, the outer diameter B of the inner ring 98 is smaller than the inner diameter A of the driven gear 34g (B

[0024] The embodiments of the present application have been described in detail based on the drawings, but the present application can be implemented in various ways with various modifications and improvements added by those skilled in the art based on their knowledge.

[0025] Explanation of Symbols 34 (34g) - driven gear (gear), 52 - countershaft (rotating shaft), 90 - power transmission mechanism (vehicle power transmission mechanism), 92 - bearing (cylindrical roller bearing), 96 - inner ring, 98 - flange ring, 98a - flange inner ring portion, 98b - abutment portion, 98b1 - abutment surface, 106b - race ring, A - inner diameter, C - outer diameter, T - flange surface.

Claims

1. A power transmission mechanism for a vehicle, characterized in that, It comprises: a rotating shaft; a gear arranged with the rotating shaft at the same axis; and a cylindrical roller bearing adjacent to the gear and rotatably supporting the rotating shaft. The inner ring of the cylindrical roller bearing is configured to include a flange ring and a raceway ring axially from the gear side, wherein, The flange ring integrally comprises: an inner flange portion forming a flange surface within the cylindrical roller bearing; and an abutment portion extending radially from the gear-side end of the inner flange portion and abutting against the gear to axially restrict the gear.

2. The vehicle power transmission mechanism according to claim 1, characterized in that, The outer diameter of the track ring and the inner ring of the flange is smaller than the inner diameter of the gear, and the outer diameter of the contact surface of the contact portion that abuts against the gear is larger than the inner diameter of the gear.

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