JP2008101674A - Rolling bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent losing pre-load due to temperature rise of a rolling bearing device by impelling an outer ring of at least one rolling bearing axially inward by a bag shape elastic member communicating to a pressure supply means and including a sealed bag shape part. <P>SOLUTION: When axial pre-load is applied to a tapered roller bearing 9, the outer ring 42 receives a component of force on a tilted rolling contact surface of a tapered roller 43 and displaces in a radial direction, and the outer circumference surface 42b is pressed against an inner circumference surface 40a of a bearing housing 40 to support the pre-load. If the temperature of the tapered roller bearing 9 rises, light metal bearing housing 40 expands more greatly than a steel main rotary shaft 4 having the tapered roller bearing 9 attached thereto. However, since hydraulic pressure is applied axially inward on the outer ring from the bag shape elastic member 53, an inner circumference raceway surface 42a of the outer ring 42 does not separate from a rolling contact surface of the tapered roller 43. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a rolling bearing device, and more particularly to a rolling bearing device that is used with a preload such as a tapered roller bearing or an angular ball bearing.

In a rolling bearing device that is used with a preload, such as a tapered roller bearing or an angular ball bearing, an inner ring and an outer ring are fitted into a shaft and a bearing housing, respectively, and then the preload is adjusted. If the shaft and the bearing housing are made of the same material, the dimensional change due to temperature change is the same, there is no significant change in preload, and operation is performed with the preload set at the time of assembly.

For example, in a transmission for an automobile, a tapered roller bearing is adopted at its main point (for example, a final reduction gear portion). The tapered roller bearing has an advantage that it can be used with a large capacity while being compact, and also has an advantage of excellent durability against an impact load at the time of gear change or the like. However, the tapered roller bearing requires a preload for regulating the axial gap because the rolling surface of the tapered roller is inclined. By setting the axial clearance of the tapered roller bearing to be negative by preloading, the gear meshing accuracy is also improved.

By the way, in recent years, as a part of weight reduction, a transmission case is made of a light metal such as an Al alloy. Al has the highest linear expansion coefficient among the constituent materials (about 23.5 × 10 ⁻⁶ / ° C. at room temperature: hereinafter, the unit of linear expansion coefficient is abbreviated as ppm / ° C.), and steel constituting the rotating shaft (Fe-based) There is a considerable difference from the linear expansion coefficient of the material (about 12 ppm / ° C. at room temperature). Considering the possibility of usage environment of automobiles, the temperature environment to which the tapered roller bearings supporting the transmission and the rotating shaft are exposed is -40 ° C or more and 150 ° C or less at the maximum. The relative dimensional change range is also quite large. In this case, in a normal use environment other than a cold region, the temperature of the transmission is raised to a temperature range higher than room temperature, for example, 50 ° C. or higher and 80 ° C. or lower during traveling. When it is operated, the temperature rises from the time of installation, and due to the temperature increase during operation, the dimensional change of the bearing housing of the tapered roller bearing is larger than that of the rotating shaft, and the preload may be lost.

For example, as shown in FIG. 5, in the tapered roller bearing 109 in the conventional rolling bearing device, the outer ring 142 of the tapered roller bearing 109 has a material having a larger linear expansion coefficient than the constituent material of the main rotating shaft 104. The inner surface 140a of the bearing housing 140 is contacted. Specifically, the main rotating shaft 104 is made of steel (for example, low alloy steel for machine structure), and the bearing housing 140 is made of light metal (for example, die cast Al alloy).

As shown in FIG. 5, when a preload in the axial direction (arrow a direction) is applied to the tapered roller bearing 109, the outer ring 142 receives a component force on the inclined rolling surface of the tapered roller 143, and moves in the axial direction and radial direction. The preload in the radial direction is supported by pressing the outer peripheral surface 142b against the inner peripheral surface 140a of the bearing housing 140. However, when the bearing housing 140 is made of light metal as described above, as shown in FIG. 6, when the transmission is heated, the light metal bearing housing 140 is more than the main rotating shaft 104 to which the tapered roller bearing 109 is attached. Since it expands greatly, the inner circumferential raceway surface 142a of the outer ring 142 is separated from the rolling surface of the tapered roller 143 in the direction of arrow b. That is, there is a problem that the temperature change of the axial gap and the radial gap of the tapered roller bearing 109 in the preload state is large, and the preload is insufficient at the time of temperature rise, and noise due to rattling of the gear tends to occur.

For this reason, Patent Document 1 proposes a rolling bearing device including a preload mechanism including a plurality of pistons disposed in a bearing housing or a member provided in the bearing housing and abutted in the axial direction.
JP-A-57-33216 (page 16, FIG. 6)

When the rolling bearing device described in Patent Document 1 is used in an application in which the temperature change of the axial length of the shaft is smaller than the temperature change of the axial length of the bearing housing, the outer ring is pushed by the piston, so that the hydraulic pressure is lost. When the hydraulic pressure is applied again, the contact point between the piston and the outer ring may change, and if it is pushed in the axial direction by the hydraulic pressure as it is, the outer ring tends to tilt, and the inner raceway surface of the outer ring and the tapered roller come into contact with each other, The inner raceway surface of the outer ring and the tapered roller may be damaged.

An object of the present invention is to provide a rolling bearing device that prevents preload loss due to temperature rise during operation by urging the outer ring of the rolling bearing in the preloading direction using a bag-like elastic member. It is in.

Means for Solving the Problems and Effects of the Invention

The rolling bearing device according to claim 1 includes a housing having a first linear expansion coefficient, a shaft having a second linear expansion coefficient smaller than the first linear expansion coefficient, an inner ring fitted to the shaft, a first A rolling bearing having a third linear expansion coefficient smaller than that of the outer ring fitted into the housing, and a rolling element interposed between the inner ring and the outer ring to roll. The rolling bearing device includes two rolling bearing devices arranged such that a contact angle between the rolling element and the outer ring is increased from the inner side in the axial direction toward the outer side in the axial direction. The rolling bearing device communicates with the pressure supply means and is sealed. A bag-like elastic member having a bag-like portion, wherein the bag-like elastic member is brought into contact with the outer ring so as to urge the outer ring of at least one rolling bearing inward in the axial direction. . According to the rolling bearing device of the first aspect, the outer ring is attached in the preload application direction by injecting a liquid pressure medium (oil) from the pressure supply means (hydraulic pump) into the bag-like elastic member in contact with the outer ring. Thus, even if the bearing housing is thermally expanded due to a temperature rise, it is possible to prevent preload loss. Further, the use of the bag-like elastic member has an advantage that oil does not leak, a seal is unnecessary, and an extra pressure loss of the pressure supply means does not occur. Furthermore, since it is a bag-like elastic member, an impact can be absorbed when the bag-like elastic member is deformed with respect to an impact load or the like in the axial direction of the shaft. The contact angle is defined by the contact angle [nominal contact angle] described in Japanese Industrial Standards JISB 0104-1991 “Rolling Bearing Terms”.

The rolling bearing device according to claim 2 is characterized in that a concave portion recessed inward in the axial direction is formed in the outer ring, and the bag-like elastic member is fitted into the concave portion. According to the rolling bearing device of the second aspect, the radial gap and the axial gap between the bearing housing and the outer ring are small at a low temperature, but the radial gap and the axial gap between the bearing housing and the outer ring are increased at a high temperature. Since the bag-like elastic member extends in the axial direction and hardly shakes in the radial direction by making the oil pressure inside the elastic member the same as when the temperature is low, the outer ring is prevented from tilting and contacting the rolling element. be able to.

The problem that the dimensional change of the bearing housing is larger than that of the shaft due to the temperature rise during the operation of the rolling bearing and the preload is released is caused by the bag-like elastic member communicating with the pressure supply means and having a sealed bag-like portion. The problem was solved by urging the outer ring of at least one of the rolling bearings inward in the axial direction.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of an essential part showing an example of a transmission 1 in which a rolling bearing device according to Embodiment 1 of the present invention is arranged. The transmission 1 has a case 1M in which a gear box 7 is disposed. In the case 1M, an input shaft (rotation axis O2) 3 and a main rotation shaft (output shaft: rotation axis O1) 4 are arranged so as to penetrate the gear box 7, and the respective axes in the gear box 7 are arranged. Gears 30 and 31 arranged on the top mesh with each other. The rotation of the input shaft 3 is transmitted to the main rotating shaft 4 in both forward and reverse directions via gears 30 and 31. Both ends of the input shaft 3 are respectively supported by a cylindrical roller bearing 5 and a ball bearing 6 fixed inside the case 1M. On the other hand, both ends of the main rotating shaft 4 are supported by tapered roller bearings 8 and 9. Among these, the tapered roller bearing 8 on the one axial side is fixed to a bearing housing 20 integrated with the case 1M. On the other hand, the tapered roller bearing 9 on the other side in the axial direction is inserted into a bearing housing 40 integral with the case 1M, and is pre-biased in the outer ring 42 toward the one side in the axial direction. The bearing housing 40 is also integrated with the bearing housing 20 as a result of being integrated with the case 1M of the transmission 1.

In the transmission 1, the gears arranged in the gear box 7 are a plurality of input-side gears (reference numeral 31 side) arranged on the input shaft 3 and having the same number of teeth on the main rotating shaft 4. Output side gear (reference numeral 30 side), and the combination of meshes can be switched in accordance with the speed ratio to be obtained or the forward / reverse distinction (for example, in the case of a manual transmission vehicle, on the other hand). In the case of an automatic vehicle, the gears 30 and 31 may be divided into a planetary gear and a sun gear of a planetary gear mechanism).

The tapered roller bearing 8 includes a bearing housing 20 integral with the case 1M of the transmission 1, a main rotating shaft 4, an inner ring 14 fitted to the main rotating shaft 4, an outer ring 15 fitted to the bearing housing 20, The main part is composed of a plurality of tapered rollers 16 inserted so as to roll between the inner ring 14 and the outer ring 15. The tapered roller bearing 8 is disposed such that the contact angle between the tapered roller 16 and the outer ring 15 increases from the axially inner side toward the axially outer side.

In the tapered roller bearing 8, the outer peripheral surface of the outer ring 15 is in contact with the inner peripheral surface of the bearing housing 20 made of a material having a larger linear expansion coefficient than the constituent material of the main rotary shaft 4. Specifically, the main rotating shaft 4 is made of steel (for example, low alloy steel for machine structure), and the bearing housing 20 is made of light metal. The light metal is a metal containing either Al or Mg as a main component (content of 50% by mass or more), but Al or Al alloy is used from the viewpoint of workability and corrosion resistance. Specifically, an Al alloy for die casting is used as the Al alloy. In the first embodiment, the case 1M is also made of an Al alloy, and the bearing housing 20 is integrated with the inner surface of the case 1M. In the tapered roller bearing 8, the rolling elements (the tapered rollers 16) and the races (the outer ring 15 / the inner ring 14) are both made of steel (for example, bearing steel, case-hardened steel, carburized steel). Yes. The environmental temperature of the bearing in the automobile transmission 1 is in the range of −40 ° C. or higher and 150 ° C. or lower (normally reached temperature excluding cold regions and high-speed continuous operation is 50 ° C. or higher and 80 ° C. or lower). The linear expansion coefficient (first linear expansion coefficient) of Al which is a constituent main component is 23 to 24 ppm / ° C., and the linear expansion coefficient of Fe which is a main constituent constituent of the main rotary shaft 4 and the tapered roller bearing 8 (second linear expansion coefficient). (Expansion coefficient) is 12-13 ppm / ° C.

2 and 3 are enlarged cross-sectional views of a main part of the tapered roller bearing 9 in the rolling bearing device according to the first embodiment.

The tapered roller bearing 9 includes a bearing housing 40 made of a light metal (for example, an aluminum alloy for die casting) having a first linear expansion coefficient, and a steel having a second linear expansion coefficient smaller than the first linear expansion coefficient ( For example, a main rotating shaft 4 made of a low alloy steel for machine structure), an inner ring 41 fitted to the main rotating shaft 4, and a third coefficient smaller than the first linear expansion coefficient fitted to the bearing housing 40. From an outer ring 42 made of steel having a linear expansion coefficient (for example, bearing steel, case-hardened steel, carburized steel), and a plurality of tapered rollers 43 that are inserted between the inner ring 41 and the outer ring 42 and roll. Its main part is composed. The tapered roller bearing 9 is arranged so that the contact angle between the tapered roller 43 and the outer ring 42 increases from the axially inner side toward the axially outer side.

The outer ring 42 includes an inner peripheral raceway surface 42 a that contacts the rolling surface of the tapered roller 43, an outer peripheral surface 42 b that contacts the inner peripheral surface 40 a of the bearing housing 40, and a right end surface 42 c that faces the inner wall surface 40 b of the bearing housing 40. And. An annular recess 42d is formed in the right end surface 42c, and the annular bag-like portion 53a in the rubber-like bag-like elastic member 53 having a fourth linear expansion coefficient larger than the third linear expansion coefficient is formed in the recess 42d. Is fitted. Note that the recess 42d is not necessarily an essential component. That is, the present invention can also be realized by directly interposing the bag-shaped portion 53 a of the bag-shaped elastic member 53 between the right end surface 42 c of the outer ring 42 and the inner wall surface 40 b of the bearing housing 40. However, when an impact load or the like in the direction opposite to the preload application direction (see arrow c in FIG. 3) is applied to the main rotating shaft 4, the strength enough to prevent the bag-like portion 53a of the bag-like elastic member 53 from bursting. Required. The bag-like elastic member 53 is coupled to the open end of a hydraulic pipe 54 that communicates with the hydraulic pump 52 (see FIG. 1). The hydraulic pump 52, the bag-like elastic member 53, and the hydraulic pipe 54 constitute a pressure supply unit 50. When the oil pressure in the bag-like elastic member 53 rises and the bag-like portion 53a expands, the bag-like portion 53a presses the recess 42d of the outer ring 42. The material of the rubber used for the bag-like elastic member 53 is a rubber capable of achieving both mechanical strength and oil resistance in consideration of contact with the oil F, such as nitrile rubber (particularly hydrogenated nitrile rubber), acrylic rubber, Silicon rubber, fluorine rubber and the like are preferable.

The bearing housing 40 includes an inner circumferential surface 40a that is formed on the outer side in the axial direction and radially faces the outer circumferential surface 42b of the outer ring 42, an inner wall surface 40b, and a hole 40c that faces the concave portion 42d. The bearing housing 40 is also integrated with the bearing housing 20 as a result of being integrated with the inner surface of the Al alloy case 1M.

Further, the bearing housing 40 is a hole that forms part of the injection path of the oil F so as to penetrate the bearing housing 40 (the right side wall in FIG. 1) in order to inject the oil F into the bag-like elastic member 53. 40c is formed. A plurality of holes 40c may be formed at predetermined intervals in the circumferential direction. The bag-like elastic member 53 is communicated with the hydraulic pump 52 (see FIG. 1) through the hole 40c. The injection pressure (hydraulic pressure) of the oil F to the bag-like elastic member 53 by the hydraulic pump 52 becomes a preload applied to the outer ring 42, and the level of the preload can be adjusted according to the pumping pressure of the hydraulic pump 52. The bag-like elastic member 53, the hole 40 c, and the hydraulic pump 52 constitute a pressure supply means 50.

Since the bearing housing 40 is made of an Al alloy and the outer ring 42 is made of steel, when the temperature rises, the inner circumference of the bearing housing 40 is caused by a difference in linear expansion coefficient between the bearing housing 40 and the outer ring 42. The axial gap and the radial gap between the surface 40a and the outer peripheral surface 42b of the outer ring 42 are increased.

In the pressure supply means 50, an excessive preload of the outer ring 42 may occur due to the temperature history. Specifically, if the support position of the outer peripheral surface 42b of the outer ring 42 is moved in the diameter-expanding direction due to the temperature rise by the inner peripheral surface 40a of the bearing housing 40, the preload is insufficient as it is, and the axial gap and radial of the tapered roller bearing 9 are reduced. The gap will increase. Therefore, as described above, the outer ring 42 is displaced in the direction in which the axial gap and the radial gap are reduced, that is, in the direction in which the bag-like elastic member 53 is enlarged, by the injection of the oil F into the bag-like elastic member 53. However, when the temperature decreases in this state, the bearing housing 40 having a linear expansion coefficient smaller than that of the main rotating shaft 4 contracts, and the volume of the bag-like elastic member 53 filled with the oil F also decreases.

Therefore, in the pressure supply means 50, the pressure discharge means 55 branches off from the injection path between the hydraulic pump 52 and the bag-like elastic member 53. The pressure discharge means 55 is connected to a tank or a discharge container (not shown) for storing the oil F supplied to the hydraulic pump 52. When the oil F supplied to the bag-like elastic member 53 is the same as the lubricating oil used in the transmission 1, the oil F can be discharged into the transmission 1. As the pressure discharge means 55, for example, an opening / closing means such as an electromagnetic valve or a check valve, or a means for holding a differential pressure such as an orifice or a needle is used. In the case of a solenoid valve, a pressure sensor (not shown) for monitoring the internal pressure in the pressure supply means 50 (the internal pressure of the bag-like elastic member 53 and the hole 40c, the pressure of the hydraulic pump 52) is further provided, and the internal pressure is excessive. When the pressure rises, the solenoid valve is opened by the output of the pressure sensor to discharge the oil F and make the internal pressure appropriate. In the case of a check valve, it is set in advance so that it opens when the internal pressure in the pressure supply means 50 exceeds a certain pressure. In the case of an orifice or a needle, it is set so that an appropriate internal pressure can be obtained. Further, instead of the check valve, a stop valve constituted by an electromagnetic valve or the like is provided, and on the other hand, a pressure sensor is arranged in the bag-like elastic member 53, and the internal pressure of the bag-like elastic member 53 detected by the pressure sensor The occurrence of reverse thrust may be detected, and a stop valve may be operated to block outflow of oil F from the injection path. Furthermore, a method of changing the pressure of oil F fed by the hydraulic pump 52 by following the internal pressure of the bag-like elastic member 53 detected by the pressure sensor is also possible. In this case, when reverse thrust is generated, the pumping pressure of the oil F is increased to block outflow of the oil F from the injection path. Therefore, a check valve or a stop valve is not necessary.

Of course, the location of the pressure discharge means 55 can be provided on the injection path of the oil F connecting the hydraulic pump 52 and the bag-like elastic member 53, or the hydraulic pump 52 itself has a built-in check valve. If it is, you can divert it. However, if the elastic deformation allowance of the injection path of the oil F and the oil pumping space of the hydraulic pump 52 is large, the backflow of the oil F is allowed by the deformation allowance, and the effect of positioning the outer ring 42 may be impaired. There is also. Therefore, it can be said that the pressure discharge means 55 is desirably provided at a position as close as possible to the bag-like elastic member 53.

Next, operation | movement of the rolling bearing apparatus based on Example 1 comprised in this way is demonstrated.

In the state where the axial ring preload is applied to the outer ring 42 via the bag-like elastic member 53 by the hydraulic pressure from the hydraulic pump 52, the outer ring 42 is on the inclined rolling surface of the tapered roller 43 as shown in FIG. The radial preload is supported by pressing the outer peripheral surface 42b of the outer ring 42 against the inner peripheral surface 40a of the bearing housing 40, respectively.

The main rotating shaft 4 rotates in the forward direction during forward driving and in the reverse direction during backward driving. The direction in which the preload is applied from the bearing housing 40 to the outer ring 42 is made to coincide with the thrust direction of the gears 30 and 31 when rotating in the forward direction. As a result, the outer ring 42 receives the thrust from the gears 30 and 31 as a forward thrust that coincides with the preload application direction when the main rotating shaft 4 is rotated forward, while the outer ring 42 receives from the gears 30 and 31 when the main rotating shaft 4 is rotated reversely. This thrust is received as a reverse thrust opposite to the preload application direction. For this reason, when the main rotating shaft 4 rotates reversely, such as when the automobile is moving backward, the thrust of the gears 30 and 31 is applied in the opposite direction to the preload application direction. Then, the outer ring 42 is pushed back in the direction opposite to the preload application direction by the reverse direction thrust. In order for the outer ring 42 to move backward, the volume of the bag-like elastic member 53 must be reduced, and the oil F in the bag-like elastic member 53 needs to flow out from the hole 40c to the hydraulic pump 52 side. The oil F which is going to flow backward to the hydraulic pump 52 is stored in a tank or a discharge container (not shown) through the pressure discharge means 55 from the injection path.

If the temperature of the transmission 1 is kept relatively constant at a relatively low temperature, the position of the outer ring 42 in the preload application direction does not change much, and the level of the preload applied to the outer ring 42 by the hydraulic pressure from the hydraulic pump 52 is also substantially constant. Kept.

When the temperature of the transmission 1 rises, the linear expansion coefficient of the bearing housing 40 is larger than the linear expansion coefficient of the main rotating shaft 4, so that the inner peripheral surface 40 a of the bearing housing 40 is expanded and the outer diameter of the tapered roller bearing 9 is increased. It is going to separate from the outer peripheral surface 42b of the outer ring | wheel 42 which is a surface. That is, the support position of the outer peripheral surface 42b of the outer ring 42 by the inner peripheral surface 40a of the bearing housing 40 changes outward in the radial direction, and the reaction force to the outer ring 42 by the bearing housing 40 decreases. Then, the outer ring 42 moves to a position where the preload that is the hydraulic pressure by the hydraulic pump 52 and the reaction force from the bearing housing 40 are balanced. As a result, even if the support position of the outer peripheral surface 42b of the outer ring 42 is moved due to a temperature rise, the preload on the outer ring 42 is kept substantially constant. For this reason, the temperature change of the support position of the outer peripheral surface 42b of the outer ring 42 by the inner peripheral surface 40a of the bearing housing 40 due to the difference in linear expansion coefficient between the bearing housing 40 and the main rotary shaft 4 is absorbed. That is, even if the temperature change of the axial gap and the radial gap of the tapered roller bearing 9 in the preload state is large, the preload does not become insufficient when the temperature rises, and the inner circumferential raceway surface 42a of the outer ring 42 rolls the tapered roller 43. There is no separation from the surface, and noise caused by rattling of the gears 30 and 31 is also suppressed.

2, when an impact load or the like in the direction opposite to the preload application direction (see arrow c in FIG. 3) is applied to the main rotating shaft 4 via the inner ring 41 and the tapered roller 43. When the outer ring 42 moves in the axial direction against the hydraulic pressure by the hydraulic pump 52, an impact load or the like is buffered and suppressed. At this time, the oil F in the bag-like elastic member 53 flows out from the hole 40c to the hydraulic pump 52 side, and is stored in a tank or a discharge container (not shown) through the pressure discharge means 55 from the injection path. Further, even in the worst case where an excessive impact load exceeding the moving range of the outer ring 42 is applied, as shown in FIG. 3, the right end surface 42c of the outer ring 42 is formed on the inner wall surface 40b of the bearing housing 40 (case 1M). The impact load or the like is received by contact.

According to the first embodiment, the oil F is injected from the hydraulic pump 52 into the bag-like elastic member 53 in contact with the outer ring 42 to urge the outer ring 42 in the preload application direction, and the bearing housing 40 is increased due to a temperature rise. Even if thermal expansion occurs, preload loss can be prevented. Further, the use of the bag-like elastic member 53 has an advantage that the oil F does not leak, a seal is unnecessary, and an extra pressure loss of the pressure supply means 50 does not occur. Furthermore, since it is the bag-like elastic member 53, the bag-like elastic member 53 is deformed with respect to an impact load or the like in the axial direction of the shaft, so that an impact can be absorbed.

Further, the radial gap and the axial gap between the bearing housing 40 and the outer ring 42 are small at a low temperature, but the radial gap and the axial gap between the bearing housing 40 and the outer ring 42 are increased at a high temperature. By making the pressure of the oil F the same as that at low temperature, the bag-like elastic member 53 extends in the axial direction and hardly shakes in the radial direction, so that the outer ring 42 is prevented from inclining and contacting with the tapered rollers 43. Can do.

In the first embodiment, the pressure supply means 50 is provided only in the tapered roller bearing 9 on one side in the axial direction of the rolling bearing device. However, as shown in FIG. Supply means 50 can be provided. In this case, the hydraulic pump 52 and the pressure discharge means 55 may be provided in the pressure supply means 50 of the tapered roller bearing 8 and the pressure supply means 50 of the tapered roller bearing 9, respectively, or one may be used in common. , One can be common and the other can be separate.

Moreover, in the said Example 1, although the bag-shaped part 53a was formed in cyclic | annular form, the bag-shaped part 53a does not need to be cyclic | annular, for example, it may be circular arc shape and also the hole 40c is the circumferential direction predetermined space | interval. When a plurality of holes are formed, the same number as the holes 40c can be formed in a predetermined shape.

As mentioned above, although the Example of this invention was described, this is only an illustration and this invention is not limited to this, Based on the knowledge of those skilled in the art, unless it deviates from the meaning of a Claim Various changes are possible.

For example, in the embodiment, the description has been made by taking the rolling bearing device used for the transmission as an example, but the rolling bearing device used for other devices such as a gear unit for a drive distribution shaft to each wheel of a four-wheel drive vehicle is also described. It goes without saying that the invention can be similarly applied.

In each embodiment, the rolling bearing used in the rolling bearing device is a tapered roller bearing, but other rolling bearings that are used with a preload such as an angular ball bearing, a deep groove ball bearing, Needless to say, the present invention can be similarly applied.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an essential part cross-sectional view illustrating an example of a transmission in which a rolling bearing device according to a first embodiment of the present invention is disposed. FIG. 3 is a cross-sectional view of a main part of the tapered roller bearing in the first embodiment. FIG. 3 is a cross-sectional view of a main part of the tapered roller bearing in the first embodiment. The principal part sectional drawing which shows the modification of the transmission by which the rolling bearing apparatus which concerns on Example 1 of this invention was arrange | positioned. Sectional drawing of the principal part of the tapered roller bearing in the conventional rolling bearing apparatus. Sectional drawing of the principal part of the tapered roller bearing in the conventional rolling bearing apparatus.

Explanation of symbols

1 Transmission 3 Input shaft 4 Main rotating shaft 8, 9 Tapered roller bearing (rolling bearing)
40 Bearing housing (housing)
40a inner peripheral surface 40b inner wall surface 40c hole 41 inner ring 42 outer ring 42a inner peripheral raceway surface 42b outer peripheral surface 42c right end surface 42d recess 43 tapered roller (rolling element)
50 Pressure supply means 52 Hydraulic pump 53 Bag-like elastic member 53a Bag-like portion 54 Hydraulic pipe F Oil (liquid pressure medium)

Claims (2)

A housing having a first linear expansion coefficient, a shaft having a second linear expansion coefficient smaller than the first linear expansion coefficient, an inner ring fitted to the shaft, and a third smaller than the first linear expansion coefficient A rolling bearing provided with an outer ring having a linear expansion coefficient and fitted into the housing, and a rolling element that is inserted and rolled between the inner ring and the outer ring, and a contact between the rolling element and the outer ring. A rolling bearing device in which two corners are arranged so that the diameter increases from the inside in the axial direction toward the outside in the axial direction,
A bag-like elastic member that communicates with the pressure supply means and has a sealed bag-like portion;
The rolling bearing device according to claim 1, wherein the bag-like elastic member is in contact with the outer ring so as to urge the outer ring of at least one of the rolling bearings in an axially inward direction. The rolling bearing device according to claim 1, wherein the outer ring is formed with a recess recessed inward in the axial direction, and the bag-like elastic member is fitted into the recess.

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