JP2017002802A - Bearing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently lubricate the inside of a bearing by using lubricants from oil feed holes while simplifying a housing, in a bearing unit which supports a turbine shaft by a rolling bearing.SOLUTION: In an oil feed passage 3 which introduces lubricants into a rolling bearing 2 which rotatably supports a turbine shaft 100 to a housing 1 from the outside of the housing 1 which penetrates the turbine shaft 100, there are employed oil feed holes 19 which oppose rolling faces of rolling bodies 10 in the bearing in a radial direction. With this constitution, it becomes unnecessary to form a protrusion for processing the oil-feed holes at the housing 1, the lubricants from the oil feed holes 19 are directly supplied to the rolling bodies 10 from a radial direction, abut on a cage 11, and are hardly dispersed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bearing unit used for supporting a turbine shaft of a supercharger for supercharging air to an engine.

  Since the turbocharger rotates the turbine shaft with the force of the exhaust gas to supercharge the air, a response delay occurs until the actual supercharging starts with respect to the time when the accelerator is depressed. This delay is generally called a turbo lag. The turbo lag is preferably shortened in order to give the driver a feeling of strangeness. In high-performance oriented engines, a turbine shaft is supported by a rolling bearing unit that is more responsive than a plain bearing.

  In order to support a high-speed rotating turbine shaft under high temperature conditions, lubrication that also serves as cooling of the rolling bearing is important. Conventionally, there is a bearing unit including a housing through which the turbine shaft is inserted, a rolling bearing that rotatably supports the turbine shaft with respect to the housing, and an oil supply passage that guides lubricating oil from the outside of the housing to the inside of the bearing of the rolling bearing. ing. The oil supply path communicates with a flow path of a lubricating oil circulation system provided outside the housing. Lubrication of the bearing is achieved by processing an oil supply hole portion serving as an outlet portion of the oil supply passage in the housing and performing oil jet lubrication in which the lubricating oil is blown directly into the bearing from the oil supply hole portion (Patent Document) 1).

JP 2011-220240 A

  However, the rolling elements and the cage rotate at a high speed inside the bearing, and when the lubricating oil blown out from the oil supply hole hits the cage, it becomes difficult to be diffused and supplied to the inside of the bearing and also becomes rotational resistance. Therefore, the position and angle of the oil supply hole are finely limited. When processing the oil supply hole in the housing as in Patent Document 1, the housing is formed with an annular protrusion protruding in the radial direction to the vicinity of the inner diameter of the cage, and the oil supply hole is provided in the annular protrusion. Therefore, the structure of the housing becomes complicated and processing becomes difficult.

  In view of the above-mentioned background, the problem to be solved by the present invention is to efficiently lubricate the inside of a bearing with lubricating oil from an oil supply hole while simplifying a housing in a bearing unit that supports a turbine shaft by a rolling bearing. It is to be.

  To achieve the above object, the present invention includes a housing through which a turbine shaft is inserted, a rolling bearing that rotatably supports the turbine shaft with respect to the housing, and lubrication from the outside of the housing into the bearing of the rolling bearing. The rolling bearing has an inner raceway surface, an outer raceway surface, a plurality of rolling elements interposed between the raceway surfaces, and a cage for holding the rolling elements. In the bearing unit in which the oil supply path has an oil supply hole facing the inside of the bearing, the oil supply hole is open at a position facing the rolling element in the radial direction. .

  According to the above configuration, since the oil supply hole is opened at a position facing the rolling element in the radial direction, it is unnecessary to form a protrusion in the housing for processing the oil supply hole to the vicinity of the inner diameter of the cage. Thus, it is possible to simplify the inner periphery of the housing. In addition, if an oil supply hole that opens at a position facing the rolling element in the radial direction is adopted, the lubricating oil from the oil supply hole is directly applied to the vicinity of the rolling element and the raceway surface on which the rolling surface is in rolling contact. Therefore, it is difficult to diffuse by hitting the cage, and the inside of the bearing can be efficiently lubricated. Here, “outer raceway surface” refers to a radially outer raceway surface, and “inner raceway surface” refers to a radially inner raceway surface.

For example, as a more specific means, the rolling bearing is an angular ball bearing that receives an axial load only on one side, and the oil supply hole portion extends from the outer raceway surface to the other side opposite in the axial direction. It is mentioned that it opens only in the position from which it remove | deviated.
In a ball bearing suitable for high-speed rotation, the entire surface of a rolling element made of balls becomes a rolling surface. Therefore, if the oil supply hole is opened at a position facing the ball in a radial direction, the lubricating oil can be directly supplied from the oil supply hole to the rolling surface. In the case of an angular contact ball bearing that receives an axial load only on one side, the width of the raceway surface can be reduced on the other side opposite to the one in the axial direction. For this reason, it is possible to set the opening area of the oil supply hole at the position facing the rolling element in the radial direction and the position deviating from the outer raceway surface to the other side. Also, if the oil supply hole is open only at a position that is off the other side of the outer raceway surface, the rolling surface will not be strongly pressed against the hole edge of the oil supply hole when an axial load is applied. Therefore, damage to the rolling surface and the oil supply hole can be avoided.

Another more specific means is that the rolling bearing has an outer ring fitted into the housing, and the oil supply hole is formed in the outer ring.
The outer ring is a bearing component having at least a part of the outer raceway surface, and the oil supply hole portion can be arranged on the inner periphery. When the oil supply hole portion is formed in the outer ring, an outlet portion on the housing side of the oil supply passage can be formed at a housing portion that receives the outer ring in the radial direction and communicated with the oil supply hole portion.

Preferably, the outer ring is formed so as to extend over the entire outer circumference of the outer ring at a position facing the outlet portion on the housing side of the oil supply passage in the radial direction, and to intersect the oil supply hole part in the circumferential direction. It is good to have a groove.
Even if the outlet on the housing side of the oil supply passage and the oil supply hole on the outer ring side are displaced in the circumferential direction, the lubricating oil from the outlet is guided to the oil supply hole through the groove. For this reason, when such a groove part is employ | adopted, when an outer ring | wheel is fitted to a housing, the phase shift of the circumferential direction between these fitting partners can be permitted.

As still another more specific means, it further comprises a fixed ring that fits into the housing, the rolling bearing has an outer ring that fits into the housing, and the fixed ring is on the other side of the side surface of the outer ring. And a concave surface recessed in the axial direction from the end surface across the inner and outer peripheries of the fixed ring, and the oil supply hole portion is formed by the concave surface and the side surface of the outer ring. Is mentioned.
As described above, in the case of an angular ball bearing that receives only one axial load, the outer ring width can be shortened on the other side, and the other side surface of the outer ring can be brought closer to the outer raceway surface. If it does so, the side surface of the outer ring | wheel will be formed in the position which opposes a rolling surface in radial direction, and the arrangement | positioning space of the fixed ring | wheel with the end surface which abuts on the other side here can be obtained. If there is a concave surface that is recessed in the axial direction from the end surface of the fixed ring to the inner and outer periphery of the fixed ring, the oil supply hole can be formed by the concave surface and the side surface of the outer ring. Therefore, this specific means is suitable when it is desired to avoid drilling the outer ring.

Preferably, the fixed ring has a first outer peripheral end portion having a small-diameter gradient toward the end surface, and the outer ring has a second outer peripheral end portion having a small-diameter gradient toward the side surface. And the groove-shaped part formed by the said 1st outer peripheral end part and the said 2nd outer peripheral end part is good to continue over the perimeter in the position which opposes the outlet part by the side of the housing of the said oil supply path in radial direction.
When the end surface of the fixed ring and the side surface of the outer ring are brought into contact with each other, a first outer peripheral end portion having a small diameter gradient toward the end surface and a second outer peripheral end portion having a small diameter gradient toward the side surface extend over the entire circumference. A continuous groove-like portion is formed. Even if the oil supply hole portion formed by the concave surface of the fixed ring and the side surface of the outer ring and the outlet portion on the housing side of the oil supply passage are displaced in the circumferential direction, the lubricating oil from the outlet portion passes through the groove-like portion. Guided to the oiling hole. For this reason, when a 1st outer periphery end part and a 2nd outer periphery end part are employ | adopted, when fitting a fixed ring to a housing, the phase shift of the circumferential direction between these fitting partners can be permitted.

Still another more specific means is that the outer raceway surface and the oil supply hole are formed in the housing.
This eliminates the need for the outer ring, reduces the number of parts, and simplifies the assembly of the bearing unit.

  According to the present invention, in the bearing unit that supports the turbine shaft of the supercharger by the rolling bearing, the inside of the bearing is efficiently lubricated with the lubricating oil from the oil supply hole while simplifying the housing. Can do.

Sectional drawing which shows the rolling bearing vicinity of the bearing unit which concerns on 1st Embodiment of this invention integrated in the supercharger Sectional drawing which shows the whole bearing unit of FIG. Sectional drawing which shows the rolling bearing vicinity of the bearing unit which concerns on 2nd Embodiment of this invention Sectional drawing which shows the bearing unit which concerns on 3rd Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
The bearing unit of the first embodiment shown in FIGS. 1 and 2 includes a housing 1 through which the turbine shaft 100 is inserted, a pair of rolling bearings 2 that rotatably support the turbine shaft 100 with respect to the housing 1, An oil supply path 3 that guides lubricating oil from the outside to the inside of the bearing of the rolling bearing 2 and a spacer 4 are provided, and are arranged inside the supercharger casing 110. Hereinafter, the direction along the central axis of the rolling bearing 2 is referred to as “axial direction”, the direction perpendicular to the axial direction is referred to as “radial direction”, and the circumferential direction is centered on the central axis of the rolling bearing 2. Is called “circumferential direction”. The center axis of the rolling bearing 2 corresponds to the center axis of the turbine shaft 100.

  The supercharger casing 110 includes an intermediate casing portion 111 that holds the housing 1, a turbine casing portion 112 that houses the turbine impeller 101, and a compressor casing portion 113 that houses the compressor impeller 102. The turbine shaft 100 is integrated with a turbine impeller 101 and a compressor impeller 102 and serves as a rotating shaft of the impellers 101 and 102.

  Exhaust gas discharged from the engine of the vehicle is taken into the turbine casing portion 112. Air is taken into the compressor casing 113. The turbine impeller 101 is rotated by exhaust gas introduced into the turbine casing portion 112. The turbine shaft 100 is rotated by the rotational force transmitted from the turbine impeller 101. The compressor impeller 102 that rotates integrally with the turbine shaft 100 compresses the air introduced into the compressor casing portion 113. The compressed air exits from the compressor casing 113 and is supplied to the engine cylinder.

  The intermediate casing portion 111 is provided with a lubricating oil circulation system that circulates engine oil as lubricating oil. The lubricating oil circulation system includes a supply channel 114 that guides the lubricating oil from the outside of the supercharger casing 110 to the outer periphery of the housing 1, and a recovery that discharges the lubricating oil flowing out of the housing 1 to the outside of the supercharger casing 110. And a flow path 115.

  A circumferential groove portion 5 that communicates with the outlet portion 116 of the supply flow path 114 is formed on the outer periphery of the housing 1. The outer circumferential surface of the groove wall of the circumferential groove portion 5 is fitted to the inner circumference of the intermediate casing portion 111. The circumferential groove 5 intersects the inlet 6 on the housing 1 side of the oil supply passage 3 in the circumferential direction. The inlet portion 6 and the outlet portion 7 on the housing 1 side of the oil supply passage 3 communicating with the inlet portion 6 are formed in series by simple drilling that penetrates between the inner and outer periphery of the housing 1 in the radial direction.

  The rolling bearing 2 includes an inner ring 8, an outer ring 9, a plurality of rolling elements 10, and a cage 11 that holds these rolling elements 10. An inner raceway surface 12 is formed on the outer periphery of the inner ring 8. An outer raceway surface 13 is formed on the inner periphery of the outer ring 9. The rolling element 10 is interposed between the inner raceway surface 12 and the outer raceway surface 13 and is in rolling contact with these raceway surfaces 12 and 13. The cage 11 has a pocket portion 14 that accommodates the rolling elements 10, and maintains a predetermined circumferential interval between the rolling elements 10.

  The inner periphery of the housing 1 has a fitting surface 15 that receives the outer ring 9 in the radial direction, a shoulder 17 that receives one side 16 of the outer ring 9 in the axial direction, and a cylindrical shape that extends from the inner diameter of the shoulder 17 in the axial direction. The part 18 is formed concentrically. The fitting surface 15 and the shoulder portion 17 are respectively formed on both sides in the axial direction of the housing 1. The inner diameter of the cylindrical portion 18 is set to be larger than the outer diameter of the cage 11.

  The oil supply passage 3 has an oil supply hole portion 19 that faces the inside of the rolling bearing 2. The oil supply hole 19 is formed in the outer ring 9. Note that the inside of the rolling bearing 2 refers to the rotation and revolution space of the rolling element 10 that is in rolling contact with the inner raceway surface 12 and the outer raceway surface 13.

  The spacer 4 is a hollow part into which the turbine shaft 100 can be inserted, and is an annular part that receives the inner rings 8, 8 of the pair of rolling bearings 2, 2 in the axial direction and determines the axial distance between the inner rings 8, 8. It has become.

  The rolling bearing 2 is a non-separable type in which a plurality of rolling elements 10 held by a cage 11 are arranged between the inner ring 8 and the outer ring 9 so that the inner ring 8 and the outer ring 9 cannot be separated. For this reason, the rolling bearing 2 is integrated with the housing 1 by fitting the outer ring 9 to the fitting surface 15 of the housing 1. The rolling bearings 2 are provided at both ends of the housing 1 and rotatably support the turbine shaft 100 at both ends.

  In addition, the rolling bearing 2 is a ball bearing that is more excellent in high-speed rotation than a roller bearing. The entire surface of the rolling element 10 made of balls is a rolling surface.

  The rolling bearing 2 is an angular ball bearing that receives an axial load on only one side. For this reason, a rolling bearing 2 that receives only the load Fr facing right in the drawing in the axial direction and a rolling bearing 2 that receives only the load Fl facing left in the drawing are attached to the housing 1.

  The outer ring 9 is a shoulder outer ring whose shoulder height on the other side of the raceway surface 13 is lower than that on one side of the outer raceway surface 13. For this reason, the width of the outer raceway surface 13 is less distributed in the region on the other side with respect to the rolling element 10, and is kept to the extent that a non-separable shape can be realized.

  Further, the outer ring 9 is continuous over the entire outer circumference of the outer ring 9 at a position facing the outlet 7 on the housing 1 side of the oil supply passage 3 in the radial direction, and intersects the oil supply hole 19 in the circumferential direction. It has the groove part 20 formed. When the outer ring 9 is fitted to the fitting surface 15 of the housing 1, when one side surface 16 of the outer ring 9 abuts against the shoulder portion 17 of the housing 1 in the axial direction, the groove portion 20 faces the outlet portion 7 in the radial direction. To do.

  Lubricating oil that has flowed out from the outlet portion 116 of the supply flow path 114 enters the circumferential groove portion 5 of the housing 1 or the inlet portion 6 on the housing 1 side of the oil supply passage 3 and further flows out from the outlet portion 7 on the housing 1 side of the oil supply passage 3. Then, it enters the groove 20 or the oil supply hole 19 of the outer ring 9 and flows out from the oil supply hole 19 into the bearing of the rolling bearing 2. Thus, the lubricating oil supplied to the inside of the bearing flows out from the oil drain hole 21 formed in the housing 1 or the inner peripheral end of the housing 1 to the outside of the housing 1 and reaches the recovery flow path 115.

  The oil supply hole 19 opens at a position facing the rolling surface of the rolling element 10 in the radial direction. For this reason, the lubricating oil that has flowed out from the oil supply hole portion 19 is easily supplied directly to the rolling surface of the rolling element 10 and the vicinity of the raceway surfaces 12 and 13, and is difficult to diffuse by hitting the cage 11 (particularly the annular portion).

  The oil supply hole 19 is opened only at a position where the shoulder height of the outer raceway surface 13 is lowered. For this reason, when the rolling bearing 2 on the left side in the figure receives one load Fr, or when the rolling bearing 2 on the right side in the figure receives one load Fl, the rolling element 10 has a shoulder height of the outer raceway surface 13. Since it is pressed to the side where the height is increased, a situation in which it is strongly pressed against the hole edge of the oil supply hole portion 19 adjacent in the axial direction does not occur.

  The oil supply hole 19 is opened only in a region facing the rolling element 10 in the radial direction. This is to prevent the lubricating oil from the oil supply hole 19 from spreading on the annular portion of the cage 11 and diffusing to the outside of the bearing.

  The oil supply holes 19 are formed in a series by simple hole processing that penetrates between the inner and outer circumferences of the outer ring 9 in the radial direction.

  Further, the oil supply holes 19 are formed at a plurality of locations in the circumferential direction in an equal arrangement. As long as the number of the oil supply holes 19 and the like, the arrangement interval in the circumferential direction, the opening cross-sectional area, and the like satisfy the fact that the lubricating oil can be directly supplied to the rolling element 10 from the radial direction, the required lubrication and cooling are performed. What is necessary is just to determine suitably according to performance.

  According to the first embodiment as described above, the oil supply hole 19 opens at a position facing the rolling element 10 in the radial direction, so the oil supply hole is processed in the housing 1 to the vicinity of the inner diameter of the cage 11. For this reason, it becomes unnecessary to form a protrusion for this purpose, and simplification can be achieved on the inner periphery of the housing 1. Simplifying the structure of the housing 1 in this way is advantageous for reducing processing costs, material costs, and the like. For example, in the first embodiment, the housing 1 does not need to have an inner diameter change between the left and right shoulders 17 and 17 in the figure, and can be a simple cylindrical portion 18.

  Moreover, according to 1st Embodiment, since the oil supply hole part 19 is opened in the position facing the rolling element 10 in radial direction, the lubricating oil from the oil supply hole part 19 is the rolling element 10 and track surface 12,13. Before reaching the surface of the rolling element 10 and the raceway surfaces 12 and 13, it is difficult to diffuse by hitting the cage 11. For this reason, 1st Embodiment can lubricate the bearing inside of the rolling bearing 2 efficiently. Increasing the lubrication efficiency makes it possible to reduce the amount of lubricating oil supplied to the inside of the bearing, and consequently to reduce the amount of hard foreign matter contained in the lubricating oil entering the inside of the bearing. It will also extend the service life. In addition, since the rolling surface of the rolling element 10 and the oil supply hole 19 are opposed to each other in the radial direction, the rolling contact portion can be particularly efficiently lubricated.

  Further, according to the first embodiment, the rolling bearing 2 is an angular ball bearing that receives an axial load on only one side, and the oil supply hole 19 is only at a position where the shoulder height of the outer raceway surface 13 is lowered. Since it is open, the rolling element 10 is not strongly pressed against the hole edge of the oil supply hole 12 when the axial load Fr or Fl is applied. For this reason, in the first embodiment, the lubricating oil can be directly supplied to the rolling elements 10 from the oil supply holes 19, and damage to the rolling elements 10 and the oil supply holes 19 can be avoided.

  In addition, according to the first embodiment, the rolling bearing 2 has the outer ring 9 that fits into the housing 1, and the oil supply hole portion 19 is formed in the outer ring 9, so that the housing 1 that receives the outer ring 9 in the radial direction is provided. An outlet portion 7 on the housing 1 side of the oil supply passage 3 can be formed on the inner peripheral side and communicated with the oil supply hole portion 19.

  Moreover, according to 1st Embodiment, it continues over the outer periphery perimeter of the outer ring | wheel 9 in the position facing the exit part 7 by the side of the housing 1 of the oil supply path 3, and cross | intersects the oil supply hole part 19 and the circumferential direction. Since the outer ring 9 has the groove part 20 formed to do so, even if the outlet part 7 on the housing 1 side and the oil supply hole part 19 on the outer ring 9 side are displaced in the circumferential direction, the lubricating oil from the outlet part 7 is not The oil supply hole 19 is guided through the groove 20. For this reason, the first embodiment can allow a circumferential phase shift between the outer ring 9 and the housing 1 when the outer ring 9 is fitted to the housing 1.

  A second embodiment will be described with reference to FIG. Hereinafter, only differences from the first embodiment will be described.

  As shown in FIG. 3, the second embodiment further includes a fixed ring 30 that fits into the housing 1. The fixed ring 30 has an end surface 33 that abuts the other side surface 32 of the outer ring 31 from the other side, a concave surface 34 that is recessed from the end surface 33 in the axial direction across the inner and outer periphery of the fixed ring 30, and a small diameter toward the end surface 33. And a first outer peripheral end portion 35 having a gentle gradient.

  The outer ring 31 has a second outer peripheral end portion 36 having a small diameter gradient toward the side surface 32. As compared with the first embodiment, the outer ring 31 has the outer ring width dimension packed on the other side.

  When the outer ring 31 is fitted to the fitting surface 15 until it abuts against the shoulder portion 17 of the housing 1, the side surface 32 of the outer ring 31 is disposed at a position facing the rolling element 10 in the radial direction. Further, when the fixed ring 30 is fitted to the fitting surface 15 of the housing 1 and the end surface 33 of the fixed ring 30 abuts against the side surface 32 of the outer ring 31, an oil supply hole 37 is formed by the concave surface 34 and the side surface 32. The outer peripheral end portion 35 and the second outer peripheral end portion 36 form a groove-like portion 38 that extends over the entire circumference at a position facing the outlet portion 7 on the housing 1 side of the oil supply passage in the radial direction. The groove-shaped portion 38 has a joint of the end surface 33 and the side surface 32 at the groove bottom, and intersects the oil supply hole portion 37 in the circumferential direction.

  As described above, according to the second embodiment, since the oil supply hole portion 37 is formed by the concave surface 34 of the fixed ring 30 and the side surface 32 of the outer ring 31, drilling of the outer ring 31 can be avoided.

  Moreover, according to 2nd Embodiment, since it has the groove-shaped part 38 connected over the perimeter in the position facing the exit part 7 by the side of the housing 1 of an oil supply path in the radial direction, the exit part 7 and the oil supply hole part 37 are provided. Even if they are shifted in the circumferential direction, the lubricating oil from the outlet portion 7 is guided to the oil supply hole portion 37 through the groove-shaped portion 38. For this reason, the second embodiment can allow a circumferential phase shift between the fixed ring 30 and the housing 1 when the fixed ring 30 is fitted to the housing 1.

A third embodiment will be described with reference to FIG.
An outer raceway surface 41 and an oil supply hole 42 are formed in the housing 40 of the third embodiment.

  The oil supply holes 42 are formed in a series by simple hole processing that penetrates between the inner and outer periphery of the housing 40 in the radial direction. That is, the oil supply path of the third embodiment is composed of the oil supply holes 42 and is further simplified as compared with the first embodiment.

  The rolling bearing 43 is configured by using an outer raceway surface 41 formed in the housing 40 and does not have an outer ring attached to the housing 40. For this reason, 3rd Embodiment can reduce a number of parts compared with 1st Embodiment, and can simplify the assembly of a bearing unit.

  Further, in the third embodiment, in order to further reduce the number of parts, the spacer is omitted, the inner ring 44 of the rolling bearing 43 that receives only one load Fr, and the inner ring 44 of the rolling bearing 43 that receives only one load Fl. Are arranged so as to face each other in the axial direction on the opposite side surfaces.

  Each embodiment disclosed this time should be considered as illustrative in all points and not restrictive. Accordingly, the scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1,40 Housing 2,43 Rolling bearing 3 Oil supply path 7 Outlet part 8 of the oil supply path on the housing side 8,44 Inner ring 9,31 Outer ring 10 Rolling element 11 Retainer 12 Inner raceway surface 13,41 Outer raceway surface 14 Pocket part 18 Cylindrical portions 19 and 42 Oil supply hole portion 20 Groove portion 30 Fixed ring 32 Other side surface 33 of outer ring End surface 34 Concave surface 35 First outer peripheral end portion 36 Second outer peripheral end portion 37 Oil supply hole portion 38 Groove portion 100 Turbine shaft Fr, Fl load

Claims (7)

A housing through which the turbine shaft is inserted, a rolling bearing that rotatably supports the turbine shaft with respect to the housing, and an oil supply path that guides lubricating oil from the outside of the housing to the inside of the bearing of the rolling bearing,
The rolling bearing has an inner raceway surface, an outer raceway surface, a plurality of rolling elements interposed between the raceway surfaces, and a cage that holds these rolling elements,
In the bearing unit in which the oil supply passage has an oil supply hole facing the inside of the bearing,
The bearing unit, wherein the oil supply hole is opened at a position facing the rolling element in a radial direction. The rolling bearing is an angular ball bearing that receives an axial load on only one side,
The bearing unit according to claim 1, wherein the oil supply hole is opened only at a position where a shoulder height of the outer raceway surface is lowered. The rolling bearing has an outer ring that fits into the housing;
The bearing unit according to claim 1, wherein the oil supply hole is formed in the outer ring.   A groove portion formed so that the outer ring is continuous over the entire outer periphery of the outer ring at a position facing the outlet portion on the housing side of the oil supply passage in the radial direction and intersects the oil supply hole portion in the circumferential direction. The bearing unit according to claim 3. Further comprising a fixed ring fitted to the housing,
The rolling bearing has an outer ring that fits into the housing;
The fixed ring has an end surface that abuts against the side surface of the outer ring from the other side, and a concave surface that is recessed in the axial direction from the end surface between the inner and outer periphery of the fixed ring;
The bearing unit according to claim 2, wherein the oil supply hole is formed by the concave surface and a side surface of the outer ring. The fixed ring has a first outer peripheral end portion having a small-diameter gradient toward the end surface;
The outer ring has a second outer peripheral end portion having a small-diameter gradient toward the side surface;
6. The groove-shaped portion formed by the first outer peripheral end portion and the second outer peripheral end portion is continuous over the entire circumference at a position facing the outlet portion on the housing side of the oil supply passage in the radial direction. Bearing unit.   The bearing unit according to claim 1, wherein the outer raceway surface and the oil supply hole are formed in the housing.

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