Rolling bearing lubrication structure

Abstract

To provide a rolling bearing lubrication structure for properly lubricating a rolling bearing even when flow of the lubricant flowing in an oil passage is reduced.SOLUTION: A rolling bearing lubrication structure 90 includes: an internal space 70a of a rolling bearing 70; an oil passage 85 formed between a main body case 50 and a bearing housing 60, communicated with the internal space 70a of the rolling bearing 70 and applied as a supply passage of lubricant 200; and an oil reservoir portion 66 disposed on a position adjacent to the rolling bearing 70 inside of the bearing housing 60, communicated with the internal space 70a, formed in a manner of including at least a part of an inner face 63 of the bearing housing 60, and reserving the lubricant 200.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a rolling bearing lubrication structure. [Background technology]

[0002] Patent Document 1 describes a rolling bearing device for a turbocharger. The rolling bearing device for a turbocharger is housed in a main body case of the turbocharger. The rolling bearing device for a turbocharger includes a cylindrical bearing housing and rolling bearings. A rotating shaft passes through the bearing housing. The rolling bearings are provided at both ends of the bearing housing. The rolling bearings support the rotating shaft so that it can rotate freely.

[0003] An oil passage that serves as a lubricating oil supply path is formed between the main case and the bearing housing. The oil passage communicates with the internal space of the rolling bearing. Lubricating oil is supplied to the oil passage from an oil feed pump via an oil supply passage formed in the main case. The rolling bearing is lubricated by the lubricating oil supplied to the internal space via the oil passage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-43920 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the flow rate of lubricating oil flowing through the oil passages decreases and it becomes difficult for the lubricating oil to be supplied to the rolling bearings, there is a risk that the rolling bearings will not be sufficiently lubricated. [Means for solving the problem]

[0006] A rolling bearing lubrication structure that solves the above-mentioned problems is a rolling bearing lubrication structure that lubricates the rolling bearing in a turbocharger that includes a cylindrical bearing housing, a rolling bearing device for a turbocharger that includes rolling bearings provided at both axial ends of the bearing housing and that rotatably support a rotating shaft that passes through the bearing housing, and a main body case that houses the rolling bearing device for the turbocharger, and includes: an internal space of the rolling bearing; an oil passage that is formed between the main body case and the bearing housing, that communicates with the internal space and serves as a supply path for lubricating oil to the internal space; and an oil reservoir portion that is provided at a position adjacent to the rolling bearing in the axial direction of the bearing housing, that communicates with the internal space, that is formed to include at least a part of the inner surface of the bearing housing, and that stores the lubricating oil.

[0007] According to the above configuration, while the turbocharger is running, lubricating oil is supplied to the oil reservoir via the oil passage and the internal space of the rolling bearing, and the lubricating oil is stored in the oil reservoir. Therefore, when vibrations generated during startup of the turbocharger are transmitted to the bearing housing, the lubricating oil stored in the oil reservoir flows into the internal space of the rolling bearing. Therefore, even if the flow rate of lubricating oil flowing through the oil passage decreases, the rolling bearing is properly lubricated.

[0008] In the above-described rolling bearing lubrication structure, the oil reservoir may be formed in the bearing housing. According to the above-described configuration, only the inner surface of the bearing housing needs to be machined to form the oil reservoir, which makes it easier to manufacture the rolling bearing lubrication structure.

[0009] In the above-described rolling bearing lubrication structure, the oil reservoir is formed in a circumferential portion of the bearing housing, the turbocharger is mounted on a mounting object with the oil reservoir facing vertically downward, and the inner surface has a first inner surface that forms the oil reservoir and a second inner surface that is adjacent to the first inner surface in the circumferential direction, and the second inner surface extends in the axial direction between the rolling bearings.

[0010] According to the above configuration, the lubricating oil that flows from the oil passage into the internal space of the rolling bearing flows between the rolling bearings. Because the second inner surface extends in the axial direction of the bearing housing, there are portions within the bearing housing where the lubricating oil flows smoothly between the rolling bearings. This allows for more optimal lubrication of the rolling bearings.

[0011] In the above-mentioned rolling bearing lubrication structure, the rolling bearing has an outer ring fixed to the bearing housing, an inner ring which forms the internal space together with the outer ring and is fixed to the rotating shaft, and rolling elements which are rollably sandwiched between the outer ring and the inner ring, and it is preferable that a portion of the inner surface which forms the oil reservoir has a portion which is continuous with the inner peripheral surface of the outer ring in the axial direction.

[0012] According to the above configuration, lubricating oil is more likely to flow from the oil reservoir into the internal space of the rolling bearing when the turbocharger is started. The above-mentioned rolling bearing lubrication structure comprises an oil drain passage formed in the bearing housing through which the lubricating oil is discharged, a supply passage formed in the main body case for supplying the lubricating oil to the oil passage, a discharge passage formed in the main body case and communicating with the oil drain passage, and an oil feed pump for returning the lubricating oil discharged from the discharge passage to the supply passage, wherein the bearing housing has a partition wall that partitions the oil drain passage, and the partition wall is positioned on the opposite side of the rolling bearing in the axial direction across the oil reservoir, and extends from the inner surface of the bearing housing towards the rotating shaft and forms part of the oil reservoir.

[0013] According to the above configuration, the lubricating oil that has lubricated the rolling bearing is discharged from the oil drain passage of the bearing housing to the discharge passage when sufficient lubricating oil is stored in the oil reservoir. The lubricating oil discharged from the discharge passage is returned to the supply passage by the oil feed pump. Since the lubricating oil that lubricates the rolling bearing is circulated, the cooling performance of the rolling bearing can also be improved. In addition, the partition wall forms part of the oil reservoir. Therefore, compared to when the partition wall and the oil reservoir are located at positions separated in the axial direction, the partition wall forms part of the oil reservoir, thereby suppressing the axial size of the bearing housing.

[0014] In the above-described rolling bearing lubrication structure, it is preferable that a surface of the partition wall positioned inside the oil reservoir extends in a radial direction of the bearing housing. With this configuration, the lubricating oil stored in the oil reservoir is more easily blocked than when the surface of the partition wall located inside the oil reservoir is inclined toward the inside of the oil drain passage, thereby making it possible to maintain the lubricating oil stored in the oil reservoir more easily. [Effects of the Invention]

[0015] According to this invention, even if the flow rate of lubricating oil flowing through the oil passage is reduced, the rolling bearing is suitably lubricated. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic diagram of a turbocharger. [Figure 2] 1 is a cross-sectional view showing an embodiment of a rolling bearing lubrication structure. [Figure 3] FIG. 10 is a cross-sectional view showing a modified example of the rolling bearing lubrication structure. [Figure 4] FIG. 10 is a cross-sectional view showing a modified example of the rolling bearing lubrication structure. [Figure 5] FIG. 10 is a cross-sectional view showing a modified example of the rolling bearing lubrication structure. [Figure 6] FIG. 10 is a cross-sectional view showing a modified example of the rolling bearing lubrication structure. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, a specific embodiment of the rolling bearing lubrication structure will be described with reference to FIGS. <Turbocharger> As shown in FIG. 1 , the turbocharger 100 includes a turbine wheel 10, a compressor impeller 20, a rotating shaft 30, a turbocharger rolling bearing device 40, a main body case 50, and an oil feed pump 110. The turbine wheel 10 is attached to a first end 31 of the rotating shaft 30. The compressor impeller 20 is attached to a second end 32 of the rotating shaft 30. The turbine wheel 10 is rotated by exhaust air from an internal combustion engine (not shown). The rotation of the turbine wheel 10 rotates the rotating shaft 30. The rotation of the rotating shaft 30 rotates the compressor impeller 20. The rotation of the compressor impeller 20 compresses air taken in from outside the turbocharger 100 and then supplies the compressed air to the internal combustion engine (not shown). That is, the turbocharger 100 compresses air using exhaust energy from the internal combustion engine (not shown) and then supercharges the compressed air into the internal combustion engine (not shown).

[0018] The turbocharger rolling bearing device 40 is housed in a main body case 50. The turbocharger rolling bearing device 40 is cylindrical. The turbocharger rolling bearing device 40 rotatably supports the rotating shaft 30. The axis m of the turbocharger rolling bearing device 40 and the axis of the rotating shaft 30 are coincident. In the following description, the direction in which the axis m of the turbocharger rolling bearing device 40 extends is referred to as the axial direction A. The direction perpendicular to the axis m of the turbocharger rolling bearing device 40 is referred to as the radial direction B. The direction in which a circle drawn around the axis m of the turbocharger rolling bearing device 40 extends is referred to as the circumferential direction C.

[0019] The main body case 50 has an insertion hole 51 through which the rotating shaft 30 is inserted. A part of the insertion hole 51 is an accommodation space S that accommodates the turbocharger rolling bearing device 40. The main body case 50 has an inner circumferential surface 52 and an axial end surface 53. The inner circumferential surface 52 is a substantially cylindrical surface extending in the circumferential direction C. The axial end surface 53 is an annular surface extending from the edge of the inner circumferential surface 52 in the axial direction A toward the inside in the radial direction B. The accommodation space S is a space surrounded by the inner circumferential surface 52 and the axial end surface 53. The main body case 50 is formed by a plurality of divided bodies, although not shown. The accommodation space S of the main body case 50 is formed by being surrounded by the plurality of divided bodies.

[0020] A supply path SR and a discharge path DR are formed in the main body case 50. The supply path SR is a path for supplying lubricating oil 200 to the turbocharger rolling bearing device 40. The supply path SR communicates between the outside of the main body case 50 and the accommodation space S of the main body case 50. The discharge path DR is a path for discharging the lubricating oil 200 to the outside of the main body case 50 after lubricating the turbocharger rolling bearing device 40. The discharge path DR communicates between the outside of the main body case 50 and the accommodation space S of the main body case 50. The supply path SR and the discharge path DR are located on opposite sides of the turbocharger rolling bearing device 40. The oil feed pump 110 supplies the lubricating oil 200 to the supply path SR. The oil feed pump 110 returns the lubricating oil 200 discharged from the discharge path DR to the supply path SR. The oil feed pump 110 circulates the lubricating oil 200 in the turbocharger 100. The supply passage SR and the discharge passage DR do not have to be located on opposite sides of the turbocharger rolling bearing device 40. The positional relationship between the supply passage SR and the discharge passage DR may be changed as appropriate.

[0021] <Rolling bearing device for turbochargers> As shown in Fig. 2, the turbocharger rolling bearing device 40 includes a cylindrical bearing housing 60, two rolling bearings 70, and a cylindrical sleeve 80. The rotating shaft 30 passes through the bearing housing 60. The rolling bearings 70 are provided at both ends of the bearing housing 60. The rolling bearings 70 support the rotating shaft 30 so that it can rotate freely. The axial direction of the bearing housing 60 is axial direction A. The radial direction of the bearing housing 60 is radial direction B. The circumferential direction of the bearing housing 60 is circumferential direction C.

[0022] <Bearing housing> The bearing housing 60 has an outer surface 61. The outer surface 61 is a cylindrical surface located on the outside of the bearing housing 60 in the radial direction B. The bearing housing 60 has an annular groove 62. The annular groove 62 is formed in the outer surface 61. A portion of the annular groove 62 faces the supply path SR in the inner circumferential surface 52 of the main body case 50.

[0023] The bearing housing 60 has an inner surface 63. The inner surface 63 is a surface located on the inside of the bearing housing 60 in the radial direction B. The bearing housing 60 has an accommodating portion 64 that accommodates the rolling bearing 70. The accommodating portion 64 is provided at both ends of the bearing housing 60 in the axial direction A.

[0024] The inner surface 63 has a first inner surface 64a that is continuous with both ends of the bearing housing 60 in the axial direction A, and a second inner surface 64b that extends from the first inner surface 64a in the radial direction B. The first inner surface 64a is a cylindrical surface. The second inner surface 64b is an annular surface that extends in the radial direction B. The housing portion 64 is formed by the first inner surface 64a and the second inner surface 64b.

[0025] An oil drain passage 60a is formed in the bearing housing 60. The oil drain passage 60a is formed between each of the accommodation portions 64 of the bearing housing 60 in the axial direction A. The oil drain passage 60a communicates between the inside and outside of the bearing housing 60. The bearing housing 60 has a partition wall 65 that partitions the oil drain passage 60a. The partition wall 65 has a cylindrical portion 65a that extends from the inner surface 63 toward the rotating shaft 30. In other words, the partition wall 65 extends from the inner surface 63 of the bearing housing 60 toward the rotating shaft 30. An outer peripheral surface 65b of the cylindrical portion 65a extends in the radial direction B of the bearing housing 60.

[0026] The bearing housing 60 has an oil reservoir 66. The oil reservoir 66 is provided inside the bearing housing 60. The oil reservoir 66 is formed in a portion of the bearing housing 60 in the circumferential direction C. The inner surface 63 of the bearing housing 60 has a first inner surface 601 and a second inner surface 602. The first inner surface 601 is a portion of the inner surface 63 that forms the oil reservoir 66. The second inner surface 602 is a surface that is adjacent to the first inner surface 601 in the circumferential direction C. The first inner surface 601 and the second inner surface 602 are continuous with a second accommodating inner surface 64b that forms the accommodating portion 64 in the axial direction A.

[0027] The first inner surface 601 is formed by an introduction surface 601a, an inclined surface 601b, and a bottom surface 601c. The introduction surface 601a extends in the axial direction A from a portion of the edge located on the inner peripheral side of the second accommodating inner surface 64b. The introduction surface 601a has an arc shape extending in the circumferential direction C. The inclined surface 601b is continuous with the introduction surface 601a. ​​The inclined surface 601b has an arc shape extending in the circumferential direction C. The inclined surface 601b extends from the introduction surface 601a toward the partition wall 65 in the axial direction A and outward in the radial direction B of the bearing housing 60. The bottom surface 601c connects the inclined surface 601b and a portion of the outer peripheral surface 65b of the cylindrical portion 65a. The bottom surface 601c has an arc shape extending in the circumferential direction C. The bottom surface 601c extends in the axial direction A of the bearing housing 60. The bottom surface 601c is perpendicular to the outer peripheral surface 65b.

[0028] The oil reservoir 66 is formed by the introduction surface 601a, the inclined surface 601b, the bottom surface 601c, and a part of the outer circumferential surface 65b. The oil reservoir 66 is formed in the bearing housing 60. The oil reservoir 66 is provided at a position adjacent to the rolling bearing 70 in the axial direction A of the bearing housing 60. The oil reservoir 66 is formed to include at least a first inner surface 601 that is a part of the inner surface 63 of the bearing housing 60. In other words, the first inner surface 601 is a surface that forms the oil reservoir 66.

[0029] The oil reservoir 66 is a portion inside the bearing housing 60 that includes at least a groove 66a having a depth in the radial direction B of the bearing housing 60. The groove 66a is formed by the inclined surface 601b, the bottom surface 601c, and a part of the outer peripheral surface 65b. The partition wall 65 forms a part of the oil reservoir 66. The outer peripheral surface 65b of the cylindrical portion 65a is the surface of the partition wall 65 that is located inside the oil reservoir 66. The partition wall 65 is also arranged on the opposite side of the oil reservoir 66 from the rolling bearing 70 in the axial direction A. The range in which the first inner surface 601 is provided in the circumferential direction C is the same as the range in the circumferential direction C where the part of the outer peripheral surface 65b that forms the oil reservoir 66 exists.

[0030] The second inner surface 602 extends in the axial direction A from a portion where the introduction surface 601a is not continuous at the edge located on the inner peripheral side of the second housing inner surface 64b. The second inner surface 602 has an arc shape extending in the circumferential direction C. The second inner surface 602 extends in the axial direction A between the rolling bearings 70.

[0031] <Rolling bearings> The rolling bearing 70 has an outer ring 71, an inner ring 72, a plurality of rolling elements 73, and a cage 74. The outer ring 71 is fixed to a first inner accommodating surface 64a of the accommodating portion 64. In other words, the outer ring 71 is fixed to the bearing housing 60. An inner circumferential surface 71a of the outer ring 71 is continuous with an introduction surface 601a of the bearing housing 60 in the axial direction A. The first inner surface 601, which is part of the inner surface 63 that forms the oil reservoir 66, has the introduction surface 601a, which is a portion that is continuous with the inner circumferential surface 71a of the outer ring 71 of the rolling bearing 70 in the axial direction A.

[0032] The inner ring 72 sandwiches the rolling element 73 together with the outer ring 71. The rolling element 73 is sandwiched between the outer ring 71 and the inner ring 72 so as to be able to roll. The rotating shaft 30 is inserted into the inner ring 72. The inner ring 72 is fixed to the rotating shaft 30. The inner ring 72 rotates integrally with the rotating shaft 30. An internal space 70a of the rolling bearing is formed between the outer ring 71 and the inner ring 72. The inner ring 72 forms the internal space 70a together with the outer ring 71. The internal space 70a is connected to both ends of the bearing housing 60. The internal space 70a is connected to the interior of the bearing housing 60. The internal space 70a is connected to the oil reservoir 66.

[0033] The cage 74 is an annular member that rotatably holds the rolling elements 73 in the internal space 70a of the rolling bearing 70. The cage 74 prevents contact between adjacent rolling elements 73 and prevents the rolling elements 73 from falling off the rolling bearing 70.

[0034] <Sleeve> The sleeve 80 is provided between the two rolling bearings 70. One end 81 of the sleeve 80 abuts against the inner ring 72 of one of the rolling bearings 70 in the axial direction A, and the other end 82 of the sleeve 80 abuts against the inner ring 72 of the other rolling bearing 70 in the axial direction A. The sleeve 80 is sandwiched between the inner rings 72 of the two rolling bearings 70. While sandwiched between the inner rings 72 of the two rolling bearings 70, the sleeve 80 is spaced from the inner surface 63 of the bearing housing 60.

[0035] The inner diameter of the sleeve 80 is the same as the inner diameter of the inner ring 72. The rotating shaft 30 is inserted into the sleeve 80. The sleeve 80 rotates integrally with the rotating shaft 30. The cylindrical portion 65a of the partition wall 65 does not abut against the sleeve 80. The sleeve 80 prevents the inner rings 72 from shifting in position toward the inside of the bearing housing 60.

[0036] <Method of housing the rolling bearing device for turbocharger in the main body case and the mounting position on the object to which the turbocharger is to be mounted> As shown in FIG. 1, the rolling bearing device 40 for a turbocharger is housed in the main body case 50 so that the drain passage DR of the main body case 50 communicates with the drain oil passage 60a of the bearing housing 60.

[0037] The supply passage SR is formed in the main body case 50 so as to be located above the vertical direction Vd when the turbocharger 100 is mounted on a vehicle. The discharge passage DR is formed in the main body case 50 so as to be located below the vertical direction Vd when the turbocharger 100 is mounted on a vehicle. The turbocharger 100 is mounted on a vehicle on which it is to be mounted so that the discharge passage DR is located below the vertical direction Vd and the supply passage SR is located above the vertical direction Vd. In other words, the turbocharger 100 is mounted on a vehicle on which it is to be mounted so that the oil reservoir 66 is located below the vertical direction Vd. Note that the supply passage SR may be formed in the main body case 50 so as to be located at a position other than above the vertical direction Vd when the turbocharger 100 is mounted on a vehicle.

[0038] <Oil road> As shown in FIG. 2 , the bearing housing 60 of the turbocharger rolling bearing device 40 is clearance-fitted into the main body case 50. Specifically, when the bearing housing 60 is surrounded by multiple segments (not shown) of the main body case 50, the bearing housing 60 is accommodated in the accommodation space S so as not to come into contact with the inner circumferential surface 52 and the shaft end face 53 of the main body case 50. Gaps are formed between the inner circumferential surface 52 of the main body case 50 and the outer surface 61 of the bearing housing 60, and between the shaft end face 53 of the main body case 50 and both ends of the bearing housing 60. These gaps are oil passages 85 formed between the main body case 50 and the bearing housing 60. The shaft end face 53 and the internal space 70a of the rolling bearing 70 face each other in the axial direction A. Therefore, the oil passage 85 communicates with the internal space 70a of the rolling bearing 70.

[0039] <Rolling bearing lubrication structure> A rolling bearing lubrication structure 90 for lubricating the rolling bearing 70 in the turbocharger 100 will be described.

[0040] The rolling bearing lubrication structure 90 includes a supply passage SR, an oil passage 85, an internal space 70a of the rolling bearing 70, an oil reservoir 66, an oil drain passage 60a, a discharge passage DR, and an oil feed pump 110. The rolling bearing lubrication structure 90 includes the oil passage 85 and the oil reservoir 66.

[0041] When the turbocharger 100 is driven, the oil feed pump 110 supplies the lubricating oil 200 to the supply passage SR. The supply passage SR supplies the lubricating oil 200 to the oil passage 85. The lubricating oil 200 supplied to the oil passage 85 flows into the internal space 70a of the rolling bearing 70. Therefore, the oil passage 85 serves as a supply path for the lubricating oil 200 to the internal space 70a. The lubricating oil 200 supplied to the oil passage 85 is supplied to the entire circumference of the bearing housing 60 in the circumferential direction C through the annular groove 62. An oil film 201 is formed by the lubricating oil 200 supplied between the inner circumferential surface 52 of the main body case 50 and the outer surface 61 of the bearing housing 60. The oil film 201 makes it difficult for vibrations of the bearing housing 60 to be transmitted to the main body case 50.

[0042] The lubricating oil 200 flows into the internal space 70a, thereby lubricating the rolling bearing 70. Specifically, the lubricating oil 200 lubricates the space between the rolling element 73 and the outer ring 71, and the space between the rolling element 73 and the inner ring 72. The lubricating oil 200 that flows into the internal space 70a of the rolling bearing 70 passes through the internal space 70a and then reaches the sleeve 80. The lubricating oil 200 that reaches the sleeve 80 is scattered toward the inner surface 63 of the bearing housing 60 by the centrifugal force of the rotating shaft 30. Some of the lubricating oil 200 that has scattered from the sleeve 80 adheres to the second inner surface 602. The lubricating oil 200 that has adhered to the second inner surface 602 flows along the second inner surface 602 between the rolling bearings 70.

[0043] The lubricating oil 200 that has flowed into the internal space 70a of the rolling bearing 70 flows along the outer ring 71 into the oil reservoir 66. A portion of the lubricating oil 200 that reaches the sleeve 80 splashes toward the oil reservoir 66. A portion of the lubricating oil 200 that runs along the second inner surface 602 flows toward the first inner surface 601 in the circumferential direction C, thereby flowing toward the oil reservoir 66. The lubricating oil 200 that has accumulated in the oil reservoir 66 is stored in the groove 66a of the oil reservoir 66. In other words, the oil reservoir 66 stores the lubricating oil 200. The lubricating oil 200 that cannot be stored in the groove 66a of the oil reservoir 66 passes over the partition wall 65 and is discharged from the oil drain path 60a into the discharge path DR. The lubricating oil 200 that has been discharged into the discharge path DR is returned to the supply path SR by the oil feed pump 110. When the turbocharger 100 stops, the oil feed pump 110 stops. The lubricating oil 200 is maintained in the groove 66a of the oil reservoir 66.

[0044] [Operation of this embodiment] The operation of this embodiment will be described. The discharge flow rate of the lubricating oil 200 by the oil feed pump 110 varies depending on the operating state of the vehicle on which the turbocharger 100 is mounted. When the turbocharger 100 is started, the discharge flow rate of the lubricating oil 200 by the oil feed pump 110 is smaller than when the turbocharger 100 is continuously driven. In other words, the flow rate of the lubricating oil 200 flowing through the oil passage 85 when the turbocharger 100 is started is smaller than when the turbocharger 100 is continuously driven. Furthermore, when the turbocharger 100 is used in a cold climate, the viscosity of the lubricating oil 200 increases, thereby reducing the flow rate of the lubricating oil 200 flowing through the oil passage 85. Therefore, when the turbocharger 100 is started and when the turbocharger 100 is used in a cold climate, the flow rate of the lubricating oil 200 flowing through the oil passage 85 is reduced.

[0045] According to the rolling bearing lubrication structure 90, while the turbocharger 100 is running, the lubricating oil 200 is supplied to the oil reservoir 66 via the oil passage 85 and the internal space 70a of the rolling bearing 70, and the lubricating oil 200 is therefore stored in the oil reservoir 66. Therefore, when vibrations generated when the turbocharger 100 is started are transmitted to the bearing housing 60, the lubricating oil 200 stored in the oil reservoir 66 flows into the internal space 70a of the rolling bearing 70. Therefore, even if the flow rate of the lubricating oil 200 flowing through the oil passage 85 decreases when the turbocharger 100 is started, the rolling bearing 70 is suitably lubricated.

[0046] [Effects of this embodiment] The effects of this embodiment will be described. (1) The bearing housing 60 has an oil reservoir 66 that stores the lubricating oil 200. Therefore, when vibrations generated when the turbocharger 100 starts are transmitted to the bearing housing 60, the lubricating oil 200 stored in the oil reservoir 66 flows into the internal space 70a of the rolling bearing 70. Therefore, even if the flow rate of the lubricating oil 200 flowing through the oil passage 85 decreases, the rolling bearing 70 is suitably lubricated.

[0047] (2) When a separate member is used to form part of the oil reservoir 66, in addition to machining the inner surface 63 of the bearing housing 60, machining of the bearing housing 60 is also required to attach the separate member. In this regard, in the present embodiment, the oil reservoir 66 is formed in the bearing housing 60. Therefore, it is only necessary to machine the inner surface 63 of the bearing housing 60 to form the oil reservoir 66. This makes it easier to manufacture the rolling bearing lubrication structure 90.

[0048] (3) The oil reservoir 66 is formed in a portion of the bearing housing 60 in the circumferential direction C. The turbocharger 100 is mounted on a vehicle with the oil reservoir 66 facing downward in the vertical direction Vd. The inner surface 63 of the bearing housing 60 has a first inner surface 601 and a second inner surface 602. The second inner surface 602 extends in the axial direction A between the rolling bearings 70. According to this embodiment, the lubricating oil 200 that flows from the oil passage 85 into the internal space 70a of the rolling bearings 70 flows between the rolling bearings 70. Because the second inner surface 602 extends in the axial direction A, there are portions within the bearing housing 60 through which the lubricating oil 200 flows smoothly between the rolling bearings 70. This allows the rolling bearings 70 to be more efficiently lubricated.

[0049] (4) The first inner surface 601 has an inlet surface 601a that is continuous with the inner circumferential surface 71a of the outer ring 71 of the rolling bearing 70 in the axial direction A. This makes it easier for the lubricating oil 200 to flow from the oil reservoir 66 into the internal space 70a of the rolling bearing 70 when the turbocharger 100 starts.

[0050] (5) The rolling bearing lubrication structure includes an oil drain passage 60a, a supply passage SR, a discharge passage DR, and an oil feed pump 110. The bearing housing 60 has a partition wall 65. The partition wall 65 is arranged on the opposite side of the rolling bearing 70 in the axial direction A, with an oil reservoir 66 between them. The partition wall 65 extends from the inner surface 63 of the bearing housing 60 toward the rotating shaft 30 and forms part of the oil reservoir 66.

[0051] According to this embodiment, the lubricating oil 200 that has lubricated the rolling bearing 70 is discharged from the oil drain passage 60a of the bearing housing 60 to the discharge passage DR, provided that a sufficient amount of lubricating oil 200 is stored in the oil reservoir 66. The lubricating oil 200 discharged from the discharge passage DR is returned to the supply passage SR by the oil feed pump 110. Circulating the lubricating oil 200 that lubricates the rolling bearing 70 also improves the cooling performance of the rolling bearing 70. The partition wall 65 also forms part of the oil reservoir 66. Therefore, compared to a case in which the partition wall 65 and the oil reservoir 66 are located at different positions in the axial direction A, the partition wall 65 forms part of the oil reservoir 66, thereby preventing the bearing housing 60 from becoming larger in the axial direction.

[0052] (6) The outer peripheral surface 65b of the partition wall 65 extends in the radial direction B. Compared to when the outer peripheral surface 65b of the partition wall 65 is inclined toward the inside of the oil drain passage 60a, the lubricating oil 200 stored in the oil reservoir 66 is more easily blocked. Therefore, the state in which the lubricating oil 200 is stored in the oil reservoir 66 can be more easily maintained.

[0053] [Example of change] The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0054] The oil reservoir 66 may be modified as follows, for example. 3, the first inner surface 601 does not include the inclined surface 601b and the bottom surface 601c, and is formed only by the introduction surface 601a. ​​The introduction surface 601a is modified so as to be connected to the outer peripheral surface 65b of the partition wall 65.

[0055] The oil reservoir 66 is a portion surrounded by the cage 74, the first inner surface 601, and a portion of the outer peripheral surface 65b of the cylindrical portion 65a. In other words, the oil reservoir 66 is formed to include at least a portion of the inner surface 63 of the bearing housing 60. When the turbocharger 100 is stopped, a small gap is formed between the cage 74 and a portion of the inner peripheral surface 71a of the outer ring 71 that is located below in the vertical direction Vd. This gap serves as a supply path for the lubricating oil 200 from the oil reservoir 66 to the internal space 70a of the rolling bearing 70 when the turbocharger 100 starts. Note that the small gap is preferably large enough to maintain the lubricating oil 200 stored in the oil reservoir 66 when the turbocharger 100 is stopped.

[0056] The oil reservoir 66 may be modified, for example, as follows. The configuration of this modified example is basically the same as the oil reservoir 66 shown in Fig. 3. Therefore, detailed description of the same configuration as the modified example will be omitted.

[0057] 4, the introduction surface 601a may be an inclined surface. The introduction surface 601a extends inward in the radial direction B of the bearing housing 60 from the position of the inner circumferential surface 71a of the outer ring 71 of the rolling bearing 70 toward the partition wall 65.

[0058] The oil reservoir 66 may be modified as follows, for example. As shown in FIG. 5 , the bearing housing 60 does not include the partition wall 65. An insertion hole 60b is formed in the bearing housing 60. A cylindrical partition member 95 is inserted into the insertion hole 60b. The partition member 95 is a member used in place of the partition wall 65. An oil drain passage 60a is formed in the partition member 95. The oil drain passage 60a penetrates the partition member 95 in its axial direction. The partition member 95 does not contact the sleeve 80 when inserted into the insertion hole 60b. An outer peripheral surface 95a of the partition member 95 forms a part of the oil reservoir 66 in place of the outer peripheral surface 65b of the partition wall 65. In other words, it is sufficient that the oil reservoir 66 is formed so as to include at least a part of the inner surface 63 of the bearing housing 60. The outer peripheral surface 95a of the partition member 95 preferably extends in the radial direction B, but may also be inclined with respect to the radial direction B.

[0059] The oil reservoir 66 may be modified as follows, for example. As shown in FIG. 6, the oil reservoir 66 may be provided on the inner surface 63 of the bearing housing 60 over the entire circumference in the circumferential direction C.

[0060] Although the outer peripheral surface 65b of the partition wall 65 extends in the radial direction B, it may be inclined with respect to the radial direction B, for example. Although the introduction surface 601a of the first inner surface 601 is continuous with the inner circumferential surface 71a of the outer ring 71 of the rolling bearing 70 in the axial direction A, this is not limited to this. For example, the introduction surface 601a may be located more inward in the radial direction B than the inner circumferential surface 71a of the outer ring 71 of the rolling bearing 70. In other words, a step may be formed between the introduction surface 601a and the inner circumferential surface 71a of the outer ring 71. When modified as in this modified example, the internal space 70a and the oil reservoir 66 are connected to each other.

[0061] The sleeve 80 may be omitted and the two rolling bearings 70 may share the inner ring 72 . The rolling bearing 70 may omit the outer ring 71. In this case, the rolling elements 73 are sandwiched between the first inner accommodating surface 64a of the bearing housing 60 and the inner ring 72. In other words, the rolling bearing 70 may be composed of a part of the bearing housing 60, the inner ring 72, and the rolling elements 73.

[0062] The rolling bearing 70 may have an outer ring 71, an inner ring 72, and a plurality of rolling elements 73, and may not have a cage 74. In this case, the oil reservoir 66 is formed in the bearing housing 60.

[0063] [Note] The technical ideas that can be understood from the embodiments and modified examples will be described. [1] A rolling bearing lubrication structure for lubricating the rolling bearing in a turbocharger comprising a cylindrical bearing housing, a rolling bearing device for a turbocharger provided at both axial ends of the bearing housing and rotatably supporting a rotating shaft passing through the bearing housing, and a main body case accommodating the rolling bearing device for the turbocharger, the rolling bearing lubrication structure comprising: an internal space of the rolling bearing; an oil passage formed between the main body case and the bearing housing, which communicates with the internal space and serves as a supply path for lubricating oil to the internal space; and an oil reservoir portion provided in a position adjacent to the rolling bearing in the axial direction of the bearing housing, which communicates with the internal space, is formed to include at least a part of the inner surface of the bearing housing, and which stores the lubricating oil.

[0064] [2] The rolling bearing lubrication structure according to [1], wherein the oil reservoir is formed in the bearing housing. [3] The oil reservoir is formed in a circumferential portion of the bearing housing, the turbocharger is mounted on a mounting object with the oil reservoir facing vertically downward, the inner surface has a first inner surface that forms the oil reservoir and a second inner surface that is adjacent to the first inner surface in the circumferential direction, and the second inner surface extends in the axial direction between the rolling bearings. [1] or [2] A rolling bearing lubrication structure described in

[0065] [4] The rolling bearing has an outer ring fixed to the bearing housing, an inner ring which forms the internal space together with the outer ring and is fixed to the rotating shaft, and rolling elements which are rotatably sandwiched between the outer ring and the inner ring, and a part of the inner surface which forms the oil reservoir has a portion which is continuous with the inner peripheral surface of the outer ring in the axial direction. A rolling bearing lubrication structure described in any one of [1] to [3].

[0066] [5] A rolling bearing lubrication structure according to any one of [1] to [4], comprising: an oil drain passage formed in the bearing housing through which the lubricating oil is discharged; a supply passage formed in the main case for supplying the lubricating oil to the oil passage; a discharge passage formed in the main case and communicating with the oil drain passage; and an oil feed pump for returning the lubricating oil discharged from the discharge passage to the supply passage, wherein the bearing housing has a partition wall that separates the oil drain passage, and the partition wall is arranged on the opposite side of the rolling bearing in the axial direction across the oil reservoir, and extends from the inner surface of the bearing housing towards the rotating shaft and forms part of the oil reservoir.

[0067] [6] A rolling bearing lubrication structure according to [5], wherein the surface of the partition wall located inside the oil reservoir extends in the radial direction of the bearing housing. [Explanation of symbols]

[0068] 30...rotating shaft, 40...rolling bearing device for turbocharger, 50...main body case, 60...bearing housing, 60a...oil drain passage, 63...inner surface, 65...compartment wall, 65b...outer surface, 66...oil reservoir, 70...rolling bearing, 71...outer ring, 71a...inner peripheral surface, 72...inner ring, 73...rolling element, 70a...internal space, 85...oil passage, 90...rolling bearing lubrication structure, 100...turbocharger, 110...oil feed pump, 200...lubricating oil, 601...first inner surface, 601a...introduction surface, 602...second inner surface, A...axial direction, B...radial direction, C...circumferential direction, Vd...vertical direction, SR...supply passage, DR...discharge passage.

Claims

1. A rolling bearing lubrication structure for lubricating the rolling bearing in a turbocharger, the rolling bearing device for a turbocharger including a cylindrical bearing housing and rolling bearings provided at both axial ends of the bearing housing and rotatably supporting a rotary shaft passing through the bearing housing, and a main body case accommodating the rolling bearing device for a turbocharger, an internal space of the rolling bearing; an oil passage formed between the main body case and the bearing housing, the oil passage communicating with the internal space and serving as a supply path for lubricating oil to the internal space; an oil reservoir portion that is provided at a position adjacent to the rolling bearing in the axial direction of the bearing housing, that is in communication with the internal space, that is formed to include at least a part of the inner surface of the bearing housing, and that stores the lubricating oil, The bearing housing is formed with an oil drain passage that connects the inside and outside of the bearing housing and drains the lubricating oil, the bearing housing has a partition wall that partitions the oil drain passage, The partition wall is positioned on the opposite side of the rolling bearing in the axial direction across the oil reservoir, extends from the inner surface of the bearing housing toward the rotating shaft, and forms part of the oil reservoir.

2. A rolling bearing lubrication structure for lubricating the rolling bearing in a turbocharger, the rolling bearing device for a turbocharger including a cylindrical bearing housing and rolling bearings provided at both axial ends of the bearing housing and rotatably supporting a rotary shaft passing through the bearing housing, and a main body case accommodating the rolling bearing device for a turbocharger, an internal space of the rolling bearing; an oil passage formed between the main body case and the bearing housing, the oil passage communicating with the internal space and serving as a supply path for lubricating oil to the internal space; an oil reservoir portion that is provided at a position adjacent to the rolling bearing in the axial direction of the bearing housing, that is in communication with the internal space, that is formed to include at least a part of the inner surface of the bearing housing, and that stores the lubricating oil, a hole communicating the inside and outside of the bearing housing is formed in the bearing housing on the opposite side of the rolling bearing with the oil reservoir in the axial direction of the bearing housing; A cylindrical partition member is inserted into the hole, The partition member forms an oil drain passage for discharging the lubricating oil, A rolling bearing lubrication structure, characterized in that the outer peripheral surface of the partition member forms a part of the oil reservoir.

3. 3. The rolling bearing lubrication structure according to claim 1, wherein the oil reservoir is formed in the bearing housing.

4. The oil reservoir is formed in a circumferential portion of the bearing housing, the turbocharger is mounted on a mounting object with the oil reservoir portion facing downward in a vertical direction, The inner surface is a first inner surface that forms the oil reservoir; The rotor has a second inner surface adjacent to the first inner surface in the circumferential direction, 3. The rolling bearing lubrication structure according to claim 1, wherein the second inner surface extends in the axial direction between the rolling bearings.

5. The rolling bearing is an outer ring fixed to the bearing housing; an inner ring that defines the internal space together with the outer ring and is fixed to the rotating shaft; a rolling element that is rollably sandwiched between the outer ring and the inner ring, 3. The rolling bearing lubrication structure according to claim 1, wherein a part of the inner surface forming the oil reservoir has a portion that is continuous with the inner circumferential surface of the outer ring in the axial direction.

6. A supply passage formed in the main body case for supplying the lubricating oil to the oil passage; a drain passage formed in the main body case and communicating with the drain oil passage; 3. The rolling bearing lubrication structure according to claim 1, further comprising: an oil feed pump that returns the lubricating oil discharged from the discharge passage to the supply passage.

7. 2. The rolling bearing lubrication structure according to claim 1, wherein the surface of the partition wall located inside the oil reservoir extends in the radial direction of the bearing housing.

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