JP2014043919A - Rolling bearing device for turbocharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing device for a turbocharger that is capable of reducing torque loss caused by agitation resistance of a lubricating oil in a rolling bearing.SOLUTION: A rolling bearing device for a turbocharger comprises a disc-like seal member 6 that is disposed at one end in an axial direction of a bearing housing 10 to seal an opening 7a of an interior space 7 of a bearing. The seal member 6 comprises: a fixed portion 6a that is fixed to an axially outer end surface of an outer ring 22 and to an inner peripheral surface of an end of the bearing housing 10; and a disc portion 6b that extends from the fixed portion 6a toward an axis 50 of the bearing and is formed to overlap with an axially outer surface of an inner ring 21 in a radial direction. The disc portion 6b comprises: grooves 6d that are formed in opposite positions relative to an axial direction on an inner diameter side end of the opening 7a so as to allow an exterior space 9 of the housing located in the periphery of the bearing housing 10 to communicate with the interior space 7 of the bearing; and discharge holes 6c that are formed in opposite positions relative to the axial direction on an outer diameter side end of the opening 7a so as to allow the exterior space 9 of the housing to communicate with the interior space 7 of the bearing.

Description

  The present invention relates to a rolling bearing device for a turbocharger.

  A turbocharger is a device that rotates a turbine by exhaust gas from an engine, drives a compressor by the rotation, and compresses air for intake to the engine. The rotating shaft of such a turbocharger is rotatably supported by a rolling bearing. However, since the rotational speed is very large (for example, 200,000 revolutions per minute), it is necessary to lubricate the rolling bearing with lubricating oil. In view of this, there is a bearing device in which an oil supply hole is provided in a bearing housing that holds a rolling bearing, lubricating oil is poured therein, and oil is supplied to the rolling bearing. (For example, see Patent Document 1)

In such a turbocharger rolling bearing device, as shown in FIG. 7, at both ends of the bearing housing 110, a first rolling bearing 120 on the turbine side that rotatably supports the rotating shaft 103 of the turbocharger, and A second rolling bearing 130 on the compressor side is provided.
Further, the bearing housing 110 is formed with a jet oil supply hole (nozzle hole) 109 for injecting lubricating oil toward the first rolling bearing 120 at a portion located in the vicinity of the first rolling bearing 120 in the bearing space. Has been. Then, the first rolling bearing 120 is lubricated by the lubricating oil ejected from the jet oil supply hole 109, and seizure is prevented.

JP 2009-264526 A

  By the way, the conventional turbocharger rolling bearing device described above has a structure in which the lubricating oil is directly ejected from the jet oil supply hole 109 of the bearing housing 110 toward the first rolling bearing 120. It is assumed that the amount of lubricating oil ejected from the jet oil supply hole 109 toward the first rolling bearing 120 becomes excessive in the state of being in the rotational region. In this case, torque loss due to the agitation resistance of the lubricating oil in the first rolling bearing 120 may increase.

  In view of the above problems, an object of the present invention is to provide a turbocharger rolling bearing device capable of reducing torque loss due to agitation resistance of lubricating oil in the rolling bearing.

  In order to solve the above problems, a rolling bearing device for a turbocharger according to claim 1 of the present invention is a pair of rolling bearings that are arranged apart from each other in the axial direction and rotatably support the rotating shaft of the turbocharger. A cylindrical bearing housing in which outer rings of the pair of bearings are fitted to inner peripheral surfaces of both end portions in the axial direction, and the bearing housing is mounted in a main body case of the turbocharger, and the bearing housing An oil film is formed by filling an annular gap between the periphery of the body case and the inner peripheral surface of the main body case with lubricating oil, and an annular bearing inner space is formed between the inner and outer rings of the rolling bearing, Lubricating oil is a rolling bearing device for a turbocharger that circulates by flowing from the periphery of the bearing housing into the bearing internal space, A disc-shaped seal member that is disposed at both end portions or one of the end portions in the direction and closes the opening of the bearing internal space, and the seal member includes an axially outer end surface of the outer ring and the bearing housing. A fixed portion that is fixed to both or one of the inner peripheral surfaces of the end portion of the inner ring, and a circle that extends from the fixed portion toward the axis of the bearing and that overlaps the axially outer end surface of the inner ring in the radial direction. The disk portion is formed at a position facing the inner diameter side end portion of the opening portion in the axial direction, and communicates the housing outer space and the bearing inner space around the bearing housing. An inflow portion and a discharge hole formed in a position facing the outer diameter side end portion of the opening in the axial direction and communicating the housing outer space and the bearing inner space are provided.

  According to the rolling bearing device for a turbocharger of the first aspect, the lubricating oil around the bearing housing is restricted from flowing from the opening into the bearing internal space by the seal member fixed to the end portion in the axial direction. Further, according to this turbocharger rolling bearing device, the lubricating oil that has flowed into the bearing internal space from the inflow portion moves radially outward and is discharged from the discharge hole as the rotating shaft of the turbocharger rotates. Therefore, torque loss due to the stirring resistance of the lubricating oil in the rolling bearing can be reduced.

  The rolling bearing device for a turbocharger according to claim 2 is characterized in that the discharge hole is formed so that a circumscribed circle diameter is set to be equal to or larger than an inner diameter of the outer ring.

  According to the turbocharger rolling bearing device of the second aspect, when the rotating shaft of the turbocharger rotates, the lubricating oil in the inner space of the bearing moves radially outward to face the outermost diameter end of the opening. Since it is discharged from the discharge hole formed in this manner, it can be discharged smoothly, and torque loss due to the stirring resistance of the lubricating oil in the rolling bearing can be reduced.

  In the turbocharger rolling bearing device according to claim 3, the inflow portion is formed of a groove or a hole-shaped inflow hole opened on an inner diameter side of the disk portion, and a circumscribed circle diameter of the groove or the inflow hole is determined by the inner ring. It is characterized by being set larger than the outer diameter.

  According to the rolling bearing device for a turbocharger of the third aspect, since the lubricating oil flows into the bearing inner space from the groove or inflow hole formed at the innermost end of the opening, the inner ring side where the lubricating oil tends to be insufficient is appropriately Lubricated. Further, according to this turbocharger rolling bearing device, the amount of lubricating oil flowing into the bearing internal space can be adjusted by the size of the groove or the inflow hole.

  The rolling bearing device for a turbocharger according to claim 4, wherein the inflow portion is formed from the inner diameter end of the disc portion over the entire circumference in a band shape, and the inner diameter of the disc portion excluding the inflow portion is It is characterized by being set larger than the outer diameter of the inner ring.

  According to the rolling bearing device for a turbocharger of the fourth aspect, since the lubricating oil flows into the bearing inner space from the inflow portion formed at the innermost end of the opening, the inner ring side where the lubricating oil tends to be insufficient is properly lubricated. The In addition, according to this turbocharger rolling bearing device, the amount of lubricating oil flowing into the bearing internal space can be adjusted by the size of the inflow portion. Further, according to this turbocharger rolling bearing device, the belt-like inflow portion is formed over the entire circumference of the disc portion, and therefore lubrication is performed with good balance in the circumferential direction.

  The rolling bearing device for a turbocharger according to a fifth aspect is characterized in that the inflow portion and the discharge hole are provided at different positions in the circumferential direction.

  According to the rolling bearing device for a turbocharger of the fifth aspect, the lubricating oil that has flowed into the bearing internal space is discharged immediately after being lubricated without being immediately discharged, so that the inside of the bearing is properly lubricated.

  ADVANTAGE OF THE INVENTION According to this invention, the rolling bearing apparatus for turbochargers which can reduce the torque loss by the stirring resistance of the lubricating oil in a rolling bearing can be provided.

1st Embodiment: It is sectional drawing which shows the turbocharger provided with the rolling bearing apparatus for turbochargers which concerns on one Embodiment of this invention. 1st Embodiment: It is sectional drawing which expands and shows the rolling bearing apparatus for turbochargers of FIG. 1st Embodiment: It is the principal part enlarged view of FIG. 1st Embodiment: It is the arrow line view which looked at the sealing member of FIG. 2nd Embodiment: It is a principal part expanded sectional view of the turbocharger provided with the rolling bearing device for turbochargers which concerns on one Embodiment of this invention. 2nd Embodiment: It is the arrow line view which looked at the sealing member of FIG. 5 from the direction of arrow Y1. It is sectional drawing which shows the conventional rolling bearing device for turbochargers.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a turbocharger rolling bearing device according to the present invention will be described below with reference to the drawings.

<First Embodiment>
FIG. 1 is a cross-sectional view illustrating a turbocharger T including a turbocharger rolling bearing device 1 according to an embodiment of the present invention. The turbocharger T rotates the turbine wheel 4 fixed to one end portion (the right side in FIG. 1) of the rotating shaft 3 by the exhaust gas flowing through the exhaust passage 4a.

  The rotation of the rotating shaft 3 is transmitted to the compressor impeller 5 fixed to the other end portion (left side in FIG. 1) of the rotating shaft 3, and the compressor impeller 5 rotates in the intake passage 5a. As a result, the air sucked from the upstream opening of the intake passage 5a is compressed, and the compressed air together with fuel such as gasoline or light oil is sent into a cylinder chamber of an engine (not shown).

  The rotating shaft 3 of the turbocharger T rotates at a high speed of several tens of thousands to several ten thousand rotations / minute, and the rotation speed frequently changes according to the rotation state of the engine. Therefore, the rotating shaft 3 is supported by the turbocharger rolling bearing device 1 with a small rotational resistance with respect to the main body case 2 of the turbocharger T in order to reduce the rotation loss. Specifically, the main body case 2 is formed with a bearing housing assembly 2a, and the turbocharger rolling bearing device 1 is assembled to the inner peripheral surface of the bearing housing assembly 2a. The turbocharger rolling bearing device 1 rotatably supports an axial intermediate portion of the rotary shaft 3 between the turbine wheel 4 and the compressor impeller 5.

  FIG. 2 is an enlarged cross-sectional view of the turbocharger rolling bearing device 1 of FIG. The turbocharger rolling bearing device 1 includes a pair of a first rolling bearing 20 and a second rolling bearing 30 that are arranged apart from each other in the axial direction and rotatably support the rotating shaft 3, and each rolling bearing 20, 30. And a spacer member 40 disposed between the pair of rolling bearings 20 and 30.

  The bearing housing 10 is formed in a cylindrical shape. A housing portion 11 into which the first rolling bearing 20 on the turbine side is fitted is formed on the inner peripheral surface of one end portion, and the compressor side is formed on the inner peripheral surface of the other end portion. A housing part 12 into which the second rolling bearing 30 is fitted is formed.

The first rolling bearing 20 is disposed so as to be able to roll while being held by a cage 24 in an inner ring 21, an outer ring 22, and a bearing inner space 7 that is an annular space between the inner ring 21 and the outer ring 22. A plurality of rolling elements (balls in the figure) 23 are provided.
Further, the second rolling bearing 30 is formed in the bearing inner space 8 which is an inner ring 31 formed in the same shape and size as the first rolling bearing 20, an outer ring 32, and an annular space between the inner ring 31 and the outer ring 32. And a plurality of rolling elements 33 arranged so as to be able to roll while being held by the holder.
The first and second rolling bearings 20 and 30 are configured such that the outer rings 22 and 32 are the housing portions 11 and 12 of the bearing housing 10 in a state where the spacer member 40 is disposed between the inner rings 21 and 31. It is inserted and fixed to.

  A disc-shaped seal member 6 having an approximately L-shaped cross section in the axial direction is fixed to one end of the bearing housing 10 to close the axially outer opening 7 a of the bearing internal space 7. The seal member 6 is fitted to the inner peripheral surface of one end portion of the bearing housing 10 and is in contact with the outer end surface of the outer ring 22 in the axial direction. The seal member 6 faces the axial line 50 from the axially inner end portion of the fixed portion 6a. And a disc portion 6b extending. As a material of the seal member 6, for example, SPCC of a cold-rolled steel sheet that has been rust-proofed is used.

  As shown in FIG. 1, the main body case 2 is formed with an oil supply passage 17 that guides lubricating oil fed by an oil feed pump (not shown) and an oil discharge passage 19 that discharges the lubricating oil. The oil supply passage 17 has an upstream end opened to the outer peripheral surface of the main body case 2, and a downstream end branched into two branches, and each oil passage 17 a is opened to the inner peripheral surface of the main body case 2. The oil drain passage 19 is formed so as to penetrate the central portion in the axial direction of the bearing housing assembly portion 2a.

  As shown in FIGS. 1 and 2, an annular gap 18 is formed between the inner peripheral surface of the main body case 2 and the outer peripheral surface of the bearing housing 10, and the lubricating oil supplied to the oil supply passage 17 is , It is fed into the gap 18. The gap 18 is formed by a loose fit between the main body case 2 and the bearing housing 10. Thus, by filling the gap 18 with lubricating oil, an oil film (oil film) is formed over the entire circumference between the inner peripheral surface of the main body case 2 and the outer peripheral surface of the bearing housing 10, and the vibration of the bearing housing 10. Is difficult to be transmitted to the main body case 2. In this way, an oil film damper that attenuates vibration based on the rotation of the rotating shaft 3 is formed by the lubricating oil filled in the gap 18.

  On both axial sides of the outer peripheral surface of the bearing housing 10, annular grooves 15 are formed over the entire circumference in the circumferential direction so as to correspond to the openings of the oil passages 17a. Further, an oil drain passage 19 a for discharging the lubricating oil is formed in the axial center portion of the outer peripheral surface of the bearing housing 10 so as to correspond to the opening of the oil drain passage 19 of the main body case 2.

  An oil passage 25 that supplies lubricating oil to the first rolling bearing 20 is formed in the radial direction of the end surface of the one end portion of the bearing housing 10. An oil passage 26 that supplies lubricating oil to the second rolling bearing 30 is formed in the radial direction of the end surface of the other end portion of the bearing housing 10.

  FIG. 3 is an enlarged view of a main part of FIG. FIG. 4 is an arrow view of the seal member 6 of FIG. As shown in FIGS. 3 and 4, the disc portion 6 b of the seal member 6 is formed so that its inner diameter A is set smaller than the outer diameter B of the inner ring 23 and overlaps the axially outer end face of the inner ring 23 in the radial direction. The As a result, the seal member 6 closes the opening 7 a of the bearing internal space 7.

  The disc portion 6b includes a groove 6d that is an inflow portion for taking the lubricating oil from the housing outer space 9 around the bearing housing 10 into the bearing inner space 7, and the lubricating oil from the bearing inner space 7 to the housing outer space 9. And a discharge hole 6c.

  The grooves 6d are radially opposed to the inner diameter side end of the opening 7a in the radial direction, and are equally divided into eight pieces having the same shape in the circumferential direction. The inner diameter side of 6b is opened and formed in a semicircular groove, and the housing outer space 9 and the bearing inner space 7 are communicated with each other. The groove 6d is formed such that its circumscribed circle diameter C is set larger than the outer diameter B of the inner ring.

  The eight discharge holes 6c are axially opposed to the outer diameter side end of the opening 7a in the radial direction, and are equally divided into eight in the circumferential direction. The housing outer space 9 and the bearing inner space 7 communicate with each other. The discharge hole 6c is formed such that its circumscribed circle diameter E is set to be equal to or larger than the inner diameter D of the outer ring.

  The groove 6d and the discharge hole 6c are provided at different positions in the circumferential direction. As a result, in the turbocharger rolling bearing device 1, the lubricating oil that has flowed into the bearing internal space 7 is discharged immediately after being lubricated without being immediately discharged, so that the inside of the bearing is properly lubricated.

  According to the turbocharger rolling bearing device 1 according to the present embodiment, when the turbocharger T is operated, the lubricating oil supplied to the oil supply passage 17 of the main body case 1 is the oil passage 17a, the gap 18, and the oil passage 25. After passing through, it flows into the bearing internal space 7 from the groove 6d of the seal member 6. The first rolling bearing 20 is lubricated and cooled by the flowing lubricating oil. The lubricating oil is discharged through the oil discharge passage 19 a and the oil discharge passage 19. Then, the discharged lubricating oil is fed by an oil feeding pump and circulated.

  Thereby, in the turbocharger rolling bearing device 1, the lubricating oil from the oil passage 25 is restricted from flowing into the bearing internal space 7 from the opening 7 a by the seal member 6, so that lubrication in the first rolling bearing 20 is performed. Torque loss due to oil agitation resistance can be reduced.

  Further, in the turbocharger rolling bearing device 1, since the lubricating oil flows into the bearing inner space 7 from the groove 6d formed at the innermost end of the opening 7a, the inner ring 21 side where the lubricating oil tends to be insufficient is appropriately lubricated. The

  Further, in this turbocharger rolling bearing device 1, the amount of lubricating oil flowing into the bearing internal space 7 can be adjusted by the arrangement and size of the grooves 6d.

  Further, in the turbocharger rolling bearing device 1, when the rotary shaft 3 rotates, the lubricating oil in the bearing inner space 7 moves outward in the radial direction, and is formed to face the outermost diameter end of the opening 7 a. Since it is discharged from the discharge hole 6c of the seal member 6 in the direction of the arrow F shown in FIG. 3, it can be discharged smoothly and torque loss due to the agitation resistance of the lubricating oil in the rolling bearing can be reduced.

  Here, in the turbocharger rolling bearing device 1, when the rotary shaft 3 rotates at a high speed and the first and second rolling bearings 20 and 30 rotate at a high speed, the bearing needs to be cooled. The bearings 24 and 34 entrain the lubricating oil and flow into the bearing internal spaces 7 and 8 to properly lubricate the bearings.

  In the turbocharger rolling bearing device 1, when the turbocharger T is operated, the lubricating oil supplied to the oil supply passage 17 of the main body case 1 passes through the oil passage 17 a, the gap 18, and the oil passage 26, and then Similarly to the first rolling bearing 20, it flows into the bearing internal space 8 from the opening of the second rolling bearing 30. The second rolling bearing 30 is lubricated and cooled by the flowing lubricating oil. The lubricating oil is discharged through the oil discharge passage 19 a and the oil discharge passage 19. Then, the discharged lubricating oil is fed by an oil feeding pump and circulated.

In addition, this invention is not limited to this embodiment, In the range which does not deviate from the summary of this invention, it can implement with a various form.
In the present embodiment, the groove 6d is formed in a semicircular groove with the inner diameter side of the disk portion 6b opened in the radial cross section. However, the present invention is not limited to this, for example, the inner diameter of the disk portion 6b. The shape of the grooves and the holes may be a circle, a square, or the like.

  Further, in the present embodiment, the grooves 6d and the discharge holes 6c are equally distributed at eight places in the circumferential direction, but the present invention is not limited to this, and for example, there may be two places and four places. What is necessary is just to determine suitably with the environmental conditions etc. of the bearing apparatus 1.

Second Embodiment
In the turbocharger rolling bearing device 1 according to the first embodiment, the inflow portion of the seal member 6 that takes the lubricating oil into the bearing internal space 7 is formed by the groove 6d. It is embodiment of the structure formed over a perimeter. In the second embodiment, the description of the same configuration as that of the first embodiment is omitted for the sake of brevity.

  FIG. 5 is an enlarged cross-sectional view of a main part of a turbocharger T including the turbocharger rolling bearing device 1 according to an embodiment of the present invention. FIG. 6 is an arrow view of the seal member 6 of FIG. 5 as viewed from the direction of the arrow Y1. As shown in FIGS. 5 and 6, the disc portion 6 b of the seal member 6 is formed such that the inner diameter C <b> 1 is set larger than the outer diameter B of the inner ring 23. As a result, the seal member 6 closes the opening 7 a of the bearing internal space 7.

  In the turbocharger rolling bearing device 1, an inflow portion 6 d 1 is formed in a belt shape between the inner diameter C <b> 1 of the disc portion 6 b and the outer diameter B of the inner ring 23 over the entire circumference. Thus, in the turbocharger rolling bearing device 1, the inflow portion 6 d 1 forms an annular gap between the seal member 6 and the inner ring 23 to communicate the housing outer space 9 and the bearing inner space 7. The lubricating oil in the external space 9 is taken into the bearing internal space 7.

  According to the rolling bearing device for turbocharger 1 according to the present embodiment, in addition to the operational effects of the first embodiment, the inflow portion 6d1 is formed over the entire circumference of the opening portion 7a, so that lubrication is performed with a good balance in the circumferential direction. Is done.

  In the first and second embodiments, the seal member 6 is fitted to the inner peripheral surface of the one end portion of the bearing housing 10. However, the present invention is not limited to this. For example, the inner peripheral surface of the one end portion of the bearing housing 10 or / Further, the present invention may be applied to a configuration in which the outer ring 22 is bonded and fixed to the outer end surface in the axial direction.

  In the first and second embodiments, the seal member 6 is fixed to one end portion of the bearing housing 10. However, the present invention is not limited to this. For example, the seal member 6 is also fixed to the other end portion of the bearing housing 10. Or you may apply to the structure fixed only to the other end part of the bearing housing 10. FIG.

1: rolling bearing device for turbocharger, 2: body case, 2a: bearing housing assembly, 3: rotating shaft, 4: turbine wheel, 4a: exhaust passage, 5: compressor impeller, 5a: intake passage, 6 : Seal member, 6a: fixed part, 6b: disk part, 6c: groove (inflow part), 6d: discharge hole, 6d1: inflow part, 7, 8: bearing internal space, 7a: opening, 9: outside of housing Space, 10: bearing housing, 11, 12: housing portion, 15: annular groove, 17: oil supply passage, 17a: oil passage, 18: gap, 19, 19a: oil discharge passage, 20: first rolling bearing, 21 : Inner ring, 22: outer ring, 23: rolling element, 24: cage, 25, 26: oil passage, 30: second rolling bearing, 31: inner ring, 32: outer ring, 33: rolling element, 34: holding 40: spacer member, 50: axis, A: inner diameter of seal member, B: outer diameter of inner ring, C: circumscribed circle diameter of groove, C1: inner diameter of seal member, D: inner diameter of outer ring, E: discharge hole Circumscribed circle diameter, T: turbocharger

Claims (5)

A pair of rolling bearings arranged axially apart from each other and rotatably supporting the rotating shaft of the turbocharger;
Each of the outer rings of the pair of bearings includes a cylindrical bearing housing fitted to the inner peripheral surfaces of both end portions in the axial direction,
The bearing housing is mounted in a body case of the turbocharger;
An oil film is formed by filling lubricating oil in an annular gap between the periphery of the bearing housing and the inner peripheral surface of the main body case,
In the rolling bearing, an annular bearing internal space is formed between the inner and outer rings,
The lubricating oil is a rolling bearing device for a turbocharger that flows into the bearing internal space from the periphery of the bearing housing and circulates,
A disc-shaped seal member that is disposed at either or both ends of the bearing housing in the axial direction and closes the opening of the bearing internal space;
The seal member is fixed to both or either one of the axially outer end surface of the outer ring and the inner peripheral surface of the end portion of the bearing housing, and extends from the fixed portion toward the bearing axis. A disk part formed to overlap the axially outer end face of the inner ring in the radial direction,
The disc portion is formed at a position facing the inner diameter side end of the opening in the axial direction, and an inflow portion communicating the housing outer space and the bearing inner space around the bearing housing;
A rolling bearing device for a turbocharger, comprising: a discharge hole formed at a position facing an outer diameter side end of the opening in the axial direction and communicating the housing outer space and the bearing inner space.   2. The rolling bearing device for a turbocharger according to claim 1, wherein the discharge hole is formed with a circumscribed circle diameter set to be equal to or larger than an inner diameter of the outer ring.   The inflow portion includes a groove or a hole-shaped inflow hole opened on an inner diameter side of the disk portion, and a circumscribed circle diameter of the groove or the inflow hole is set larger than an outer diameter of the inner ring. The rolling bearing device for turbochargers according to claim 1 or 2.   The inflow portion is formed from the inner diameter end of the disc portion over the entire circumference in a band shape, and the inner diameter of the disc portion excluding the inflow portion is set larger than the outer diameter of the inner ring. A rolling bearing device for a turbocharger according to claim 1 or 2.   The rolling bearing device for a turbocharger according to claim 3, wherein the inflow portion and the discharge hole are provided at different positions in the circumferential direction.

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