JP6079058B2 - Rolling bearing device for turbocharger - Google Patents

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. 4, 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 the annular clearance between the periphery of the main 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. is, the lubricating oil is a rolling bearing device for a turbocharger circulating flows into the bearing internal space from an oil passage provided on the periphery of the bearing housing The rolling bearing, said has a cylindrical cage which holds the rolling element disposed inside the bearing space, Oite at both ends or either end portion in the axial direction of the bearing housing, the rolling bearing And a disc-shaped seal member that is disposed between the discharge passage of the oil passage and closes a part of the opening of the bearing internal space, and the seal member includes an axially outer end surface of the outer ring and the The bearing housing has a fixed portion that is fixed to both or one of the inner peripheral surfaces of the end portion, and a disk portion that extends from the fixed portion toward the axis of the bearing, and the inner diameter of the seal member is It is set to be larger than the outer diameter of the cage.

  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, when the rotating shaft of the turbocharger rotates, the lubricating oil in the bearing inner space moves radially outward, and the outer diameter of the cage and the seal member As a result, the torque loss due to the agitation resistance of the lubricating oil in the rolling bearing can be reduced.

  The rolling bearing device for a turbocharger according to a second aspect is characterized in that the seal member is formed so as to be inclined outward in the axial direction from the outer diameter toward the inner diameter.

  According to the rolling bearing device for a turbocharger of the second aspect, since the seal member is inclined, the lubricating oil from the outer diameter side of the bearing housing is guided in the axial direction to the opposite side of the rolling bearing to the bearing inner space. Further restricts the inflow. Thereby, the torque loss by the stirring resistance of the lubricating oil in a rolling bearing can further be reduced.

  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.

It is sectional drawing which shows the turbocharger provided with the rolling bearing apparatus for turbochargers which concerns on one Embodiment of this invention. It is sectional drawing which expands and shows the rolling bearing apparatus for turbochargers of FIG. FIG. 3 is an enlarged view of a main part of FIG. 2. 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.

  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 axial cross section is fixed to one end portion of the bearing housing 10 to block a part of the axially outer opening 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. The disc portion 6b is formed so as to be inclined outwardly in the axial direction from the outer diameter toward the inner diameter. 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. The inner diameter A of the seal member 6 fitted in the bearing housing 10 is set to be equal to or larger than the outer diameter B of the cage 24 of the first rolling bearing 20.

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 2 is the oil passage 17a, the gap 18, and the oil passage 25. Then, the air flows into the bearing internal space 7 from the opening of the first rolling bearing 20. 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.

  Thus, in the turbocharger rolling bearing device 1, the lubricating oil from the oil passage 25 is restricted from flowing from the opening portion into the bearing internal space 7 by the seal member 6, and therefore the lubricating oil in the first rolling bearing 20. Torque loss due to the stirring resistance can be reduced.

  In the turbocharger rolling bearing device 1, the lubricating oil from the oil passage 25 is guided to the opposite side of the first rolling bearing 20 in the axial direction because the seal member 6 is inclined, and the bearing internal space 7. As a result, the torque loss due to the agitation resistance of the lubricating oil in the first rolling bearing 20 can be further reduced.

  Further, in the turbocharger rolling bearing device 1, when the rotary shaft 3 rotates, the lubricating oil in the bearing inner space 7 moves radially outward, and the gap between the outer diameter of the cage 24 and the seal member 6 is increased. 3 is discharged in the direction of arrow C shown in FIG. 3, 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 2 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 disc portion 6b of the seal member 6 is formed so as to be inclined so as to be outward in the axial direction from the outer diameter toward the inner diameter. You may apply to the structure which the side surface of the board part 6b contact | abuts to the axial direction outer end surface of the outer ring | wheel 22, and is orthogonal to the axis line 50. FIG.

  In the present embodiment, the seal member 6 is fitted to the inner peripheral surface of the one end portion of the bearing housing 10, but the present invention is not limited to this, for example, the inner peripheral surface of the one end portion of the bearing housing 10 and / or the outer ring 22. You may apply to the structure which adhere | attaches and fixes to an axial direction outer side end surface.

  In the present embodiment, 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 the bearing. You may apply to the structure fixed only to the other end part of the 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, 7, 8: bearing internal space, 10: bearing housing, 11, 12: housing part, 15: annular groove, 17: oil supply path, 17a: oil path, 18: clearance, 19: oil drainage path, 19a: oil drainage path, 20: first rolling bearing, 21: inner ring, 22: outer ring, 23: rolling element, 24: cage, 25, 26: oil path, 30 : Second rolling bearing, 31: inner ring, 32: outer ring, 33: rolling element, 34: cage, 40: spacer member, 50: axis, T: turbocharger

Claims (2)

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 annular gap between the periphery of the bearing housing and the inner peripheral surface of the main body case is filled with lubricating oil to form an oil film,
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 and circulates from an oil passage provided around the bearing housing into the bearing internal space,
The rolling bearing has a cylindrical cage that holds rolling elements arranged in the bearing internal space,
Oite at both ends or either end portion in the axial direction of the bearing housing, wherein arranged between the rolling bearing and the oil passage of the discharge port, a circle which closes the part of the opening of the bearing internal space It further includes a plate-like seal member,
The seal member includes a fixed portion that is fixed to either or both of the axially outer end surface of the outer ring and the end inner peripheral surface of the bearing housing, and a circle that extends from the fixed portion toward the bearing axis. Having a plate part,
The turbocharger rolling bearing device according to claim 1, wherein an inner diameter of the seal member is set to be equal to or larger than an outer diameter of the cage. 2. The rolling bearing device for a turbocharger according to claim 1, wherein the seal member is formed so as to be inclined outward in the axial direction from the outer diameter toward the inner diameter.

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