JP4453478B2 - Bearing device for constant mesh transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize the attitude of a bearing when a gear is not used to prevent abnormal noise from occurring and prevent fretting and peeling from occurring when the gear is used. <P>SOLUTION: This bearing device for a constant-mesh transmission comprises a roller bearing (needle-like roller bearing 5) interposed between a shaft (countershaft 2) and the gear (driven gear 4). The roller bearing comprises an outer ring 6, an inner ring 7, and a plurality of rollers (needle-like rollers 8) rollingly interposed between both rings 6 and 7. The outer ring 6 comprises an annular flange part 62 elastically press-fitted to the inner peripheral surface of the gear in a curved state in which its axial center side has a clearance from the inner peripheral surface of the gear, and in the press-fitted state, extending to the approximately center of a roll diameter in the radial inner direction. The inner ring 7 comprises an annular flange part 72 elastically press-fitted to the outer peripheral surface of a shaft in a curved state in which its axial center side has a clearance from the outer peripheral surface of the shaft, and in the press-fitted state, extending to the approximately center of the roll diameter on the axial end side in the radial outer direction. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a bearing device for a constant meshing transmission equipped with a radial roller bearing, and in particular, for a gear inner that is interposed between a shaft and a gear in a constant meshing transmission to support the gear. The present invention relates to a suitable constant meshing transmission bearing device.

  The constant-mesh type transmission is such that the drive gear at each speed stage on the main shaft and the driven gear at each speed stage on the counter shaft are always meshed, and between the drive gears at each speed stage and between the driven gears at each speed stage. A gear dog clutch for shifting is interposed between the main shaft and the drive gear on the main shaft or the counter shaft and the driven gear on the counter shaft to shift and transmit the power of the in-vehicle engine. . The continuously meshing transmission that performs power transmission as described above is used in vehicles such as trucks and buses where fuel efficiency is important because of its superior fuel efficiency compared to general automatic transmissions. (See Patent Document 1). In such a constantly meshing transmission, radial type roller bearings are used for gear inners inside the gears of the respective shift stages. In such a roller bearing, when the gear is not used, it is in an almost no-load state in which only the weight of the gear is loaded, and thus acts to rotate the gear and the shaft relative to each other. However, in such a relative rotation state, since a sufficient load is not applied to the roller bearing, the posture of the roller bearing is not stable, and an inconvenience that abnormal noise (cool noise) is generated from the gear occurs. Probability is high.

Also, in the always-mesh transmission, the gear and the shaft rotate synchronously when the gear is used, so that the roller bearing does not rotate at all relative to the shaft or the gear at all or only slightly relative rotation. As a result of using the roller bearing roller, the shaft and gear contact or vibrate at the same location, fretting occurs at the roller arrangement pitch, or due to the inclination of the gear, There is a high possibility that inconveniences such as peeling occur at both ends of the roller.
No. 2003-042183

  Accordingly, the problem to be solved by the present invention is that it is possible to prevent the generation of abnormal noise from the gear by stabilizing the posture of the roller bearing when the gear is not used, and fretting is performed when the gear is used. It is possible to prevent the occurrence of peeling and peeling.

That by the present invention always-on mesh type transmission bearing apparatus is a constant mesh type transmission bearing apparatus is interposed a radial type roller bearing between the shaft and the gear, the roller bearing outer ring The outer ring is elastically press-fitted into the inner peripheral surface of the gear in a curved state with a gap between the inner ring and the inner peripheral surface of the gear. And an annular flange portion extending radially outward along the end surface of the gear in the press-fitted state in the press-fitted state, and the inner ring has a gap between the axial center and the outer peripheral surface of the shaft. An inner ring body that is elastically press-fitted into the outer peripheral surface of the shaft in a curved state, and two annular flange portions that extend radially outward from each of both axial ends in the press-fitted state to substantially the center of the roller diameter. It is characterized by being.

According to the above-mentioned constantly meshing transmission bearing device, the roller bearing is preloaded from the gear and the shaft because the outer ring and the inner ring of the roller bearing are elastically pressed into the gear and the shaft, respectively. As a result, the original rotation of the roller bearing when the gear is not in use (the roller bearing can be rotated at a rotational speed approximately half the rotational speed of the gear) and the bearing posture is stabilized. As a result, the generation of abnormal noise (cool noise) from the gear is eliminated or reduced. Furthermore, when the gear is used, vibrations of the gear and the like are absorbed by the damper action of the outer ring and the inner ring that are elastically press-fitted into the gear and the shaft, and fretting caused by the vibration can be prevented. The rigidity of the roller bearing is increased, and peeling is prevented from occurring, so that the gear can be prevented from coming off due to wear of the roller due to the progress of peeling. In addition, the axially central side of the outer ring main body is elastically press-fitted into the inner peripheral surface of the gear in a curved state with a gap between the inner peripheral surface of the gear, and the axially central side of the inner ring main body is connected to the outer peripheral surface of the shaft. Since it is elastically press-fitted into the outer peripheral surface of the shaft in a curved state with a gap between them, preload is not excessive and early bearing damage can be prevented. Furthermore, the provision of the outer ring and the inner ring eliminates the need for heat-treating the inner peripheral surface of the gear and the outer peripheral surface of the shaft with high hardness, thereby reducing the manufacturing cost.

In particular, in the bearing device for a constant mesh type transmission of the present invention, since the annular flange of the outer ring extends to the end face radially outwardly along the gear, positionable roller bearing and that Do.

  According to the present invention, when the gear is not in use, it is possible to stabilize the bearing posture to prevent the generation of abnormal noise from the gear, and during the use rotation of the gear, the occurrence of fretting and peeling, etc. Can be prevented.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A constant mesh transmission bearing device (hereinafter referred to as a bearing device) according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

( Reference form )
A bearing device according to a reference embodiment will be described with reference to FIGS. 1 to 3.

  FIG. 1 is a cross-sectional view schematically showing a main part of a constantly meshing transmission, FIG. 2 is an enlarged view showing a needle roller bearing, a part of a counter shaft, and a driven gear in FIG. FIG. 3 is a cross-sectional view of the needle roller bearing in a free state before being incorporated into a constantly meshing transmission.

  In these drawings, 1 is a main shaft, 2 is a counter shaft, 3 is a drive gear at an arbitrary speed on the main shaft 1, 4 is a driven gear at an arbitrary speed on the counter shaft 2, and 5 is a radial type. Needle roller bearings. The driving gear 3 and the driven gear 4 shown on the left side in the figure have an arbitrary gear train of the m-th shift stage, and the driving gear 3 and the driven gear 4 shown on the right side in the figure show the next one gear of the n-th speed stage. Configure the column.

  The drive gear 3 and the driven gear 4 in the m-th gear stage gear train and the drive gear 3 and the driven gear 4 in the n-th gear stage gear train are always meshed.

  In the drawing, for convenience of explanation, only two arbitrary gear stages are shown. In the form of the gear stage, each drive gear 3 on the main shaft 1 side is integrated with the main shaft 1, and each driven gear 4 on the counter shaft 2 side can be rotated with respect to the counter shaft 2 by a needle roller bearing 5. However, the configuration of this shift stage train is merely an example. For example, in the case of 6-speed, six drive gears are arranged on the main shaft, and six driven gears are arranged on the counter shaft. The drive gear and the driven gear corresponding to each speed stage are always meshed with each other.

In the reference embodiment shown in the drawings, each drive gear 3 is formed integrally with the main shaft 1, and each driven gear 4 is disposed on the counter shaft 2 via a needle roller bearing 5 so as to be relatively rotatable. Although not shown in the drawings, in the reference embodiment , a drive gear may be disposed on the main shaft 1 via a needle roller bearing so as to be relatively rotatable, and a driven gear may be integrally formed on the counter shaft 2. There are various combinations depending on the transmission mode.

  Between the driven gear 4 of the m-th shift stage, which is an arbitrary one of the shift shafts of the counter shaft 2, and the driven gear 4 of the n-th shift stage, which is the next shift stage, only an outline is illustrated by a virtual line. A gear dog clutch A for shifting is provided. The dog-tooth clutch is coupled to the countershaft 2 by a clutch hub, two dog teeth attached to each driven gear 4 and the clutch hub so as to be slidable to the left and right. It is composed of a sleeve which makes one (left side in the figure) driven gear 4 or the other (right side in the figure) driven gear 4 rotate integrally with the countershaft 2 by being engaged with and disengaged from the dog tooth of the destination. With such a dog-tooth clutch, the main shaft 1 is rotated by the drive gear 3 and the driven gear 4 of the m-th gear stage or by the drive gear 3 and the driven gear 4 of the n-th gear stage. Thus, the speed is reduced and transmitted to the countershaft 2.

In the constant mesh transmission of the reference embodiment having the above-described configuration, a needle roller bearing 5 is disposed between the counter shaft 2 and the driven gear 4.

  The needle roller bearing 5 includes an outer ring 6, an inner ring 7, a plurality of needle rollers 8 that are cylindrical rollers interposed between the wheels 6 and 7, and a holding unit that holds the needle rollers 8. And a container 9.

  The outer ring 6 includes an outer ring main body 61 and an annular flange portion 62 that extends radially inward on one axial end side of the outer ring main body 61.

  The outer ring body 61 has a curved shape in which the outer diameter do1 on both sides in the axial direction is larger than the inner diameter dg of the driven gear 4 and the outer diameter do2 on the center side in the axial direction is smaller than the inner diameter dg of the driven gear 4 in the free state. ing. The outer ring main body 61 is elastically press-fitted into the inner peripheral surface of the driven gear 4 in a curved state with a gap so between the driven gear 4 and the inner peripheral surface of the driven gear 4 with respect to the driven gear 4. .

  The annular flange portion 62 extends to substantially the center of the roller diameter with respect to each of the plurality of needle rollers 8 in the press-fitted state of the outer ring main body 61.

  The inner ring 7 includes an inner ring main body 71 and an annular flange portion 72 that extends radially outward from the other axial end of the inner ring main body 71.

  The inner ring main body 71 has a curved shape in which the inner diameter di1 on both axial sides is smaller than the outer diameter dc of the countershaft 2 and the inner diameter di2 on the axially central side is larger than the outer diameter dc of the countershaft 2 in a free state. ing. The inner ring main body 71 is elastically press-fitted into the outer peripheral surface of the countershaft 2 in a curved state with a gap si between the axially central side and the outer peripheral surface of the countershaft 2.

  The annular flange portion 72 extends to substantially the center of the diameter of each of the plurality of needle rollers 8 on the other axial end side in the above-described press-fitted state of the inner ring main body 71.

In the bearing device of the reference embodiment having the above configuration, the needle roller bearing 5 is such that the outer ring main body 61 and the inner ring main body 71 are elastically pressed into the driven gear 4 and the counter shaft 2 respectively. Preload is applied from the driven gear 4 and the counter shaft 2.

  Therefore, when the driven gear 4 is not used, the driven gear 4 and the countershaft 2 can rotate at a rotational speed almost half the rotational speed of the driven gear 4 in the same manner as a normal bearing, and the bearing posture is As a result of stabilization, no abnormal noise (cooking) is generated. Further, when the driven gear 4 is used, the outer ring main body 61 and the inner ring main body 71 are elastically pressed into the driven gear 4 and the countershaft 2, respectively, so that they act like a damper. The vibration of the driven gear 4 is absorbed and the occurrence of fretting caused by the vibration can be prevented, and the rigidity of the needle roller bearing 5 itself is increased by the press-fitting, and the occurrence of gear slippage due to the wear of the roller due to the progress of peeling is generated. Can be prevented.

And, according to the bearing device of the reference form , the outer ring 6 and the inner ring 7 are prevented from coming off in the axial direction with the annular flange portions 62 and 72, respectively, so that they can be prevented from being separated. become able to.

Note that the needle roller bearing 5 may be disposed in a gear stage in which a roller bearing is disposed between the main shaft 1 and the drive gear 3 .

( Embodiment )
The embodiment will be described with reference to FIG.

FIG. 4 is a diagram corresponding to FIG. In FIG. 4, parts corresponding to those in FIG. In FIG. 4, 1 is a main shaft, 2 is a counter shaft, 3 is a drive gear at an arbitrary speed on the main shaft, 4 is a driven gear at an arbitrary speed on the counter shaft, and 5 is a needle roller bearing. is there. The needle roller bearing 5 includes an outer ring 6, an inner ring 7, and a plurality of needle rollers 8 interposed between the wheels 6 and 7 so as to be able to roll. However, the needle roller bearing 5 of the embodiment is a full roller type roller bearing that does not include a cage for holding the needle roller 8.

  The outer ring 6 includes an outer ring main body 61 and an annular flange portion 63 on one axial end side of the outer ring main body 61.

  The outer ring body 61 has a curved shape in which the outer diameter do1 on both sides in the axial direction is larger than the inner diameter dg of the driven gear 4 and the outer diameter do2 on the center side in the axial direction is smaller than the inner diameter dg of the driven gear 4 in the free state. ing. The outer ring main body 61 is elastically press-fitted into the inner peripheral surface of the driven gear 4 with a gap so between the driven gear 4 and the inner peripheral surface of the driven gear 4 on the center side in the axial direction.

  The annular flange portion 63 extends radially outward along the end surface 4 a of the driven gear 4 in the above-described press-fitted state of the outer ring main body 61.

  The inner ring 7 includes an inner ring main body 71 and two annular flange portions 73a and 73b on both axial ends of the inner ring main body 71.

  The inner ring main body 71 has a curved shape in which the inner diameter di1 on both axial sides is smaller than the outer diameter dc of the countershaft 2 and the inner diameter di2 on the axially central side is larger than the outer diameter dc of the countershaft 2 in a free state. ing. The inner ring main body 71 is elastically press-fitted into the outer peripheral surface of the countershaft 2 with a gap si between the axially central side and the outer peripheral surface of the countershaft 2.

  The two annular flange portions 73a and 73b extend radially outward from both ends in the axial direction in the press-fitted state of the inner ring main body 71.

  The two annular flange portions 73a and 73b, that is, the annular flange portion 73b on the other end side in the axial direction and the annular flange portion 73a on the one end side in the axial direction are respectively pressed into the counter shaft 2 by the needle roller bearing 5. In the state, it extends radially outward to substantially the center of the roller diameter for each of the plurality of needle rollers 8. Note that the annular flange 73b on the other axial end side is radially outward beyond the approximate center of the roller diameter for each of the plurality of needle rollers 8 when the needle roller bearing 5 is in the press-fit state to the counter shaft 2. The structure extended in this may be sufficient.

Or more at the bearing device of the embodiment having the configuration, by needle bearing 5 and the outer ring main body 61 and the inner ring main body 71 is press-fitted into a resiliently driven gear 4 and the counter shaft 2, respectively, Preload is applied from the driven gear 4 and the counter shaft 2.

  Therefore, when the driven gear 4 is not used, the driven gear 4 and the countershaft 2 can rotate at a rotational speed almost half the rotational speed of the driven gear 4 in the same manner as a normal bearing, and the bearing posture is As a result of stabilization, no abnormal noise (cooking) is generated. Further, when the driven gear 4 is used, the outer ring main body 61 and the inner ring main body 71 are elastically pressed into the driven gear 4 and the countershaft 2, respectively, so that they act like a damper. The vibration of the driven gear 4 is absorbed and the occurrence of fretting caused by the vibration can be prevented, and the rigidity of the needle roller bearing 5 itself is increased by the above press-fitting, and the occurrence of gear slippage due to the wear of the roller due to the progress of peeling is prevented. Will be able to.

According to the bearing device of the embodiment , since the annular flange portion 63 extends radially outward along the end surface of the driven gear 4, particularly in the press-fitted state of the outer ring main body 61 into the driven gear 4, the needle The tapered roller bearing 5 can be positioned and arranged with respect to the driven gear 4.

In the gear stage in which the roller bearing is disposed between the main shaft 1 and the drive gear 3, the needle roller bearing 5 may be disposed, and such an arrangement is also included in the embodiment . .

Sectional drawing which shows schematically the principal part of the constant meshing type transmission with which the bearing apparatus which concerns on a reference form is integrated The figure which expands and shows the needle roller bearing which is the principal part of FIG. 1, a driven gear, and a countershaft. Sectional view in the free state of the needle roller bearing used in FIG. Is an enlarged view showing a needle roller bearing and the driven gear and the counter shaft is a main part of the constant mesh type transmission bearing apparatus according to an embodiment of the present invention, corresponding to FIG. 2

Explanation of symbols

1 ... Main shaft 2 ... Counter shaft (shaft)
3 ... Drive gear 4 ... Driven gear (gear)
5 ... Needle roller bearings (radial roller bearings)
6 ... Outer ring 61 ... Outer ring main body 62 ... Annular flange part 7 ... Inner ring 71 ... Inner ring main body 72 ... Annular flange part 8 ... Needle roller (roller)
9 ... Retainer

Claims (1)

  A bearing device for a constant-mesh transmission in which a radial type roller bearing is interposed between a shaft and a gear, wherein the roller bearing includes a plurality of rollers that are rotatably provided between an outer ring, an inner ring, and both wheels. The outer ring includes an outer ring body that is elastically press-fitted into the inner peripheral surface of the gear in a curved state with a gap between the axial center and the gear inner peripheral surface, and a gear on one end in the axial direction in this press-fitted state. The inner ring is elastically press-fitted into the outer peripheral surface of the shaft in a curved state with a gap between the axial center of the inner ring and the outer peripheral surface of the shaft. A bearing device for a constantly meshing transmission, comprising: a main body; and two annular flange portions extending radially outward from each end in the axial direction to substantially the center of the roller diameter in this press-fitted state.

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