JP2011149390A - Supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supercharger with high rotational stability. <P>SOLUTION: The super charger having bearings 62 and 63 rotatably supporting a turbine shaft 31 extending in a predetermined direction within a bearing housing 3 includes a bearing holding part 61 provided within the bearing housing 3 and formed with a hole part 71 for being inserted with the bearings 62 and 63, and a bearing retainer 64 having a bearing opposing part 86 formed at a position opposing to an end surface 82 of the bearing 63 in the axial direction on the outer side of the bearing holding part 61. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

 The present invention relates to a supercharger.

 Patent Document 1 discloses a supercharger that improves the performance of an internal combustion engine by supplying compressed air to the internal combustion engine using the kinetic energy of exhaust gas guided from the internal combustion engine. A turbine impeller and a compressor impeller, which are rotor blades, are installed inside the turbocharger. These impellers are integrally connected to both ends of a turbine shaft, which is a shaft member, and the turbine shaft is rotatably supported by a bearing housing of a supercharger via a predetermined bearing. The turbine impeller is rotated by the flow of the exhaust gas guided from the internal combustion engine, and the compressor impeller connected via the turbine shaft is rotated. The air introduced from the outside can be compressed by the rotation of the compressor impeller.

 Since the turbine impeller rotates at a high speed, the bearing that supports the turbine shaft is required to have durability that can withstand high-speed rotation and high rotational stability that can suppress vibration and the like that accompanies the rotation. . For example, a sliding bearing is used as the bearing. The plain bearing is a cylindrical member that is provided around the outer peripheral surface of the turbine shaft, and is installed inside a cylindrical bearing holding portion (so-called fitting ring) provided in the bearing housing, on the turbine side and the compressor side. Each is provided. A slight gap is formed on the inner and outer peripheral surfaces of the slide bearing, and the gap is filled with lubricating oil. Further, for example, C-ring-shaped regulating members are provided at both ends of the sliding bearing in the axial direction so that the sliding bearing does not move in the axial direction of the turbine shaft.

Japanese Patent No. 3170887 (page 3, FIG. 1)

However, the following problems exist in the above-described prior art.
A C-ring-shaped regulating member for regulating the movement of the plain bearing in the axial direction is provided inside the cylindrical bearing holding portion. For this reason, there is a problem that it is difficult to increase the distance between the pair of bearings. In particular, when the turbocharger is downsized, the length of the bearing housing and the turbine shaft in the axial direction is shortened. For this reason, the distance between the pair of bearings is narrowed, and there is a problem in that vibration suppressing performance and rotational stability are reduced.

 The present invention has been made in view of the above points, and an object thereof is to provide a supercharger having high rotational stability.

In order to solve the above problems, the present invention employs the following means.
The present invention relates to a turbocharger having a plurality of bearings in a bearing housing that rotatably support a turbine shaft extending in a predetermined axial direction, the bearing holding having a hole provided in the bearing housing and into which the bearing is inserted. And a bearing retainer provided with a bearing facing portion provided at a position facing the one end surface of the bearing in the axial direction outside the bearing holding portion.
In the present invention, the installation position of the bearing is displaced toward the end side of the hole portion in the bearing holding portion as compared with the conventional case.

 Moreover, this invention employ | adopts the structure that a bearing holding | suppressing is provided with the opposing surface which opposes a bearing holding part in an axial direction, and a bearing opposing part is an area | region which opposes a hole part in an axial direction among opposing surfaces.

 Further, according to the present invention, the bearing housing is provided with a second hole portion centered on the turbine shaft, and the bearing retainer is an annular member provided so as to surround the turbine shaft in the circumferential direction, and is fitted and held in the second hole portion. Is adopted.

 Moreover, this invention employ | adopts the structure that a bearing holding | maintenance is hold | maintained between a bearing holding | maintenance part and the thrust bearing which controls the movement in the axial direction of a turbine shaft.

 Further, the present invention employs a configuration in which the bearing retainer is an annular plate member that is provided so as to surround the turbine shaft in the circumferential direction, and is fixed to the bearing holding portion using a predetermined fastening member.

 Moreover, this invention employ | adopts the structure that a bearing holding | suppressing is provided with the discharge path which discharges | emits the lubricating oil used for lubrication of a turbine shaft and a bearing.

According to the present invention, the following effects can be obtained.
According to the present invention, the installation position of the bearing is displaced toward the end side of the hole in the bearing holding portion as compared with the conventional case. For this reason, the intervals between the plurality of bearings can be increased, the vibration suppressing performance can be improved, and high rotational stability can be obtained.

1 is a cross-sectional view showing an overall configuration of a supercharger 1. FIG. 2 is a cross-sectional view showing a configuration of a bearing structure of a turbine shaft 31. FIG. FIG. 6 is a schematic view showing a configuration of a bearing retainer 64. It is the schematic which shows the structure of 64 A of bearing holders. It is the schematic which shows the structure of the bearing holder 64B. 5 is a cross-sectional view showing a configuration of a second bearing retainer 95. FIG.

 Hereinafter, embodiments of the present invention will be described with reference to FIGS. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size. Moreover, the arrow F in each drawing shall show a front direction.

A configuration of the supercharger 1 according to the present embodiment will be described with reference to FIG.
FIG. 1 is a cross-sectional view showing the overall configuration of the supercharger 1.
The supercharger 1 compresses air introduced from the outside using kinetic energy of exhaust gas guided from an internal combustion engine (not shown), and supplies the compressed air to the internal combustion engine, thereby improving the performance of the internal combustion engine. It is to improve. The supercharger 1 has a turbine housing 2, a bearing housing 3, and a compressor housing 4.

 The turbine housing 2 is a member that constitutes the outer shell of the supercharger 1 and converts the kinetic energy of the exhaust gas guided from the internal combustion engine into a rotational driving force. The turbine housing 2 is provided with a turbine impeller 21, a turbine scroll passage 22, and an exhaust gas discharge port 23.

 The turbine impeller 21 is a rotor blade that is provided in a substantially central portion of the turbine housing 2 so as to be rotatable about a predetermined axis extending in the front-rear direction, and rotates in response to the flow of exhaust gas. The turbine scroll passage 22 is a passage that is formed in a substantially annular shape surrounding the turbine impeller 21 and into which exhaust gas from the internal combustion engine is introduced. The radially inner side of the turbine scroll passage 22 communicates with the installation space of the turbine impeller 21. The exhaust gas discharge port 23 is an exhaust port through which the exhaust gas after rotating the turbine impeller 21 is discharged from the turbine housing 2, and opens forward from the turbine impeller 21.

 The bearing housing 3 is a member constituting the outer shell of the supercharger 1 and rotatably supports the turbine impeller 21 and a compressor impeller 41 described later. The bearing housing 3 includes a turbine shaft 31, a thrust bearing structure 5, a radial bearing structure 6, an oil supply path 32, and an oil discharge path 33.

 The turbine shaft 31 is a rotating shaft extending in the front-rear direction, and integrally connects the turbine impeller 21 and the compressor impeller 41 to each other. The turbine shaft 31 is rotatably supported by the bearing housing 3. The thrust bearing structure 5 supports the turbine shaft 31 rotatably while holding the turbine shaft 31 in the axial direction. The radial bearing structure 6 supports the turbine shaft 31 so as to be rotatable while being held in the radial direction, and absorbs vibrations of the turbine shaft 31. Details of the thrust bearing structure 5 and the radial bearing structure 6 will be described later.

 The oil supply path 32 is a flow path for supplying lubricating oil to the thrust bearing structure 5 and the radial bearing structure 6 in order to smoothly rotate the turbine shaft 31. The oil supply passage 32 is provided on the upper side in the vertical direction of the turbine shaft 31. Lubricating oil is supplied to the oil supply passage 32 at a predetermined pressure. The oil drain passage 33 is a passage through which the lubricating oil after being supplied to the thrust bearing structure 5 and the radial bearing structure 6 is discharged. The oil drain passage 33 is provided on the lower side in the vertical direction of the turbine shaft 31.

 The compressor housing 4 is a member constituting the outer shell of the supercharger 1 and compresses air introduced from outside in the inside thereof. The compressor housing 4 includes a compressor impeller 41, an air introduction port 42, a diffuser flow path 43, and a compressor scroll flow path 44.

 The compressor impeller 41 is rotatably provided at a substantially central portion of the compressor housing 4 and is integrally connected to the rear end portion of the turbine shaft 31. The compressor impeller 41 is a rotor blade that sends air introduced from the rear side thereof radially outward by rotating. The air inlet 42 is an opening for introducing air outside the supercharger 1 into the compressor housing 4, and opens toward the rear of the compressor impeller 41.

 The diffuser flow path 43 is a flow path that is formed in a substantially annular shape surrounding the compressor impeller 41 and into which the air sent out by the rotation of the compressor impeller 41 is introduced. The air flow path gradually narrows from the air inlet 42 toward the diffuser flow path 43, and the compressor impeller 41 sends air to the diffuser flow path 43 so that the air is compressed. The compressor scroll passage 44 is a passage that is formed in a substantially annular shape surrounding the compressor impeller 41 and into which the air compressed in the diffuser passage 43 is introduced. The compressor scroll passage 44 is connected to an intake port of an internal combustion engine (not shown).

Next, the configuration of the thrust bearing structure 5 and the radial bearing structure 6 will be described in detail with reference to FIGS.
FIG. 2 is a cross-sectional view showing the configuration of the bearing structure of the turbine shaft 31. In FIG. 2, the central axis of the turbine shaft 31 is represented by a symbol L. 3A and 3B are schematic views showing the configuration of the bearing retainer 64, wherein FIG. 3A is a plan view and FIG. 3B is a cross-sectional view taken along line AA of FIG.
As shown in FIG. 2, the thrust bearing structure 5 includes a thrust bearing 51, a first thrust collar 52, and a second thrust collar 53.

 The thrust bearing 51 is a substantially disk-shaped member, and is provided in the bearing housing 3 with its central axis in a direction parallel to the front-rear direction. The thrust bearing 51 is integrally fixed to the bearing housing 3 using a fastening member (screw member) or the like. The thrust bearing 51 has a through-hole penetrating in the thickness direction at the center thereof, and the turbine shaft 31 is inserted through the through-hole in a non-contact manner. The thrust bearing 51 is formed with a bearing oil supply path (not shown) for supplying lubricating oil to sliding portions with the thrust collars 52 and 53, and this bearing oil supply path is an oil supply path of the bearing housing 3. 32.

 Each of the first thrust collar 52 and the second thrust collar 53 is a substantially disk-shaped member, and each has a through-hole penetrating the central portion in the thickness direction. The turbine shaft 31 is fitted in this through hole, and the thrust collars 52 and 53 are integrally fixed to the turbine shaft 31. Between the first thrust collar 52 and the second thrust collar 53, a substantially cylindrical spacer 54 provided so as to surround the turbine shaft 31 is disposed. By sandwiching the spacer 54, the distance between the first thrust collar 52 and the second thrust collar 53 is slightly wider than the thickness of the thrust bearing 51. Therefore, a predetermined gap is formed between the thrust bearing 51 and the thrust collars 52 and 53, and the lubricating oil is supplied into the gap so that the thrust collars 52 and 53 are smoothly moved with respect to the thrust bearing 51. It can be rotated.

 The radial bearing structure 6 includes a fitting ring (bearing holding portion) 61, a front bearing (bearing) 62, a rear bearing (bearing) 63, and a bearing retainer 64.

 The fitting wheel 61 is a substantially cylindrical member that is installed in the bearing housing 3 and is provided so as to surround the turbine shaft 31. The bearing housing 3 is formed with a fitting ring hole (second hole) 34 that extends in the front-rear direction and has a substantially circular shape when viewed from the front. The fitting wheel 61 is provided so as to be fitted in the fitting wheel hole 34 without any gap. Further, a stepped portion having an enlarged diameter is provided on the rear side of the fitting wheel hole portion 34, and at least a part of the fitting wheel 61 is engaged with the step portion of the fitting wheel hole portion 34. As a result, the forward movement of the fitting wheel 61 is restricted.

 The inner peripheral surface side of the fitting wheel 61 is a turbine shaft hole (hole) 71 through which the turbine shaft 31 is inserted. The inner diameter of the turbine shaft hole 71 is formed larger than the outer shape of the turbine shaft 31, and a substantially cylindrical cylindrical gap S is formed between the turbine shaft hole 71 and the turbine shaft 31. ing. Both the front end surface and the rear end surface of the fitting wheel 61 are formed in a planar shape perpendicular to the front-rear direction.

The fitting wheel 61 includes a fitting wheel oil supply path 72, a fitting wheel oil discharge path 73, a pin member 74, and a C ring 75.
The fitting wheel oil supply path 72 is a flow path for connecting the outer peripheral surface side and the inner peripheral surface side of the fitting wheel 61 to each other and supplying lubricating oil into the cylindrical gap S. The fitting wheel oil supply passage 72 on the outer peripheral surface side of the fitting wheel 61 communicates with the oil supply passage 32 of the bearing housing 3, and the fitting wheel oil supply passage 72 on the inner peripheral surface side faces the front bearing 62 and the rear bearing 63. Open.

 The fitting wheel oil discharge passage 73 is a flow path for allowing the outer peripheral surface side and the inner peripheral surface side of the fitting wheel 61 to communicate with each other and discharging the lubricating oil supplied into the cylindrical gap S to the oil discharge passage 33. is there. The pin member 74 is a member that extends in the radial direction of the fitting wheel 61 and that protrudes into the cylindrical gap S, and is installed corresponding to each of the front bearing 62 and the rear bearing 63. . In addition, a predetermined gap is formed between the tip of the pin member 74 on the cylindrical gap S side and the turbine shaft 31, and the protruding amount of the pin member 74 is the same even if the turbine shaft 31 is displaced in the radial direction. The amount is set so as not to touch. The C ring 75 is installed in a groove formed to extend around the central axis L at the front end of the turbine shaft hole 71.

 The front bearing 62 and the rear bearing 63 are so-called sliding bearings for rotatably supporting the turbine shaft 31 in the radial direction. The front bearing 62 and the rear bearing 63 are substantially cylindrical members provided surrounding the turbine shaft 31 and are disposed in the cylindrical gap S. Predetermined gaps are formed on the inner and outer peripheral surfaces of the front bearing 62 and the rear bearing 63 (that is, between the turbine shaft 31 and the turbine shaft hole 71). The front bearing 62 is provided on the front end side of the fitting wheel 61, and the rear bearing 63 is provided on the rear end side of the fitting wheel 61. The front bearing 62 is in contact with the C-ring 75, and its forward movement is restricted by the C-ring 75.

 The front bearing 62 is formed with an oil supply hole 77 penetrating in the radial direction. The oil supply hole 77 communicates with the fitting wheel oil supply path 72. The oil supply hole 77 is a hole for supplying the lubricating oil supplied from the fitting wheel oil supply path 72 to the inner peripheral surface side of the front bearing 62, that is, the outer peripheral surface of the turbine shaft 31. The front bearing 62 is formed with a notch 78. A projecting portion of the pin member 74 is disposed in the notch 78, and the pin member 74 restricts movement of the front bearing 62 to the rear side and restricts rotation around the central axis L. That is, the front bearing 62 is a so-called semi-float type plain bearing that does not rotate with the turbine shaft 31.

 The rear bearing 63 is formed with an oil supply hole 80 similar to the oil supply hole 77 of the front bearing 62. The rear bearing 63 is formed with a notch 81. A protruding portion of the pin member 74 is disposed in the notch 81, and the pin member 74 restricts the movement of the rear bearing 63 toward the front side and the rotation around the central axis L. That is, the rear bearing 63 is a semi-float type plain bearing. The rear bearing 63 is provided such that a rear end surface (one end surface) 82 thereof is in the same position as the rear end surface of the fitting wheel 61 in the front-rear direction.

 The bearing retainer 64 is an annular member that is provided so as to surround the turbine shaft 31 in the circumferential direction, and is provided to face the rear end surface 82 of the rear bearing 63, and restricts the rearward movement of the rear bearing 63. Is to do. As shown in FIG. 3, the bearing retainer 64 includes an annular flat plate portion 83 and an edge portion 84 that protrudes rearward from the outer peripheral end of the plate portion 83. The edge portion 84 is formed in a substantially cylindrical shape. As shown in FIG. 2, the bearing retainer 64 is formed in a size that can be fitted into the fitting wheel hole 34, and is disposed on the rear side of the fitting wheel 61 in the fitting wheel hole 34. The bearing retainer 64 is provided so that its central axis is parallel to the front-rear direction. The bearing retainer 64 is provided between the fitting wheel 61 and the thrust bearing 51 and is held by the fitting wheel 61 and the thrust bearing 51 in the front-rear direction. The thickness of the bearing retainer 64 in the front-rear direction (that is, the width of the edge portion 84 shown in FIG. 3) is formed to be somewhat narrower than the distance between the fitting wheel 61 and the thrust bearing 51. This is because the thrust bearing 51 and the bearing housing 3 are not intimately connected to each other and the lubricating oil is prevented from leaking from the joint portion between the thrust bearing 51 and the bearing housing 3.

 A surface desired on the front side of the bearing retainer 64 (that is, a surface facing the front side of the plate portion 83 shown in FIG. 3) is a facing surface 85 that faces the fitting wheel 61. The facing surface 85 is formed in a planar shape that is orthogonal to the front-rear direction and is in contact with the rear end surface of the fitting wheel 61. A radially inner region of the facing surface 85 is a bearing facing surface (bearing facing portion) 86 facing the cylindrical gap S and facing the rear end surface 82 of the rear bearing 63. Therefore, the bearing retainer 64 can restrict the rearward movement of the rear bearing 63, and the bearing retainer 64 and the pin member 74 cooperate to cause the rear bearing 63 to move to a predetermined position in the front-rear direction. Retained. Further, since the facing surface 85 of the bearing retainer 64 is in contact with the rear end surface of the fitting wheel 61, the rear bearing 63 is disposed at a position where the rear end surface 82 is flush with the rear end surface of the fitting wheel 61. Is done. Further, a through hole 87 that penetrates in the front-rear direction is formed in the center portion of the bearing retainer 64, and the turbine shaft 31 passes through the through hole 87 in a non-contact manner.

 As shown in FIG. 3, the bearing facing surface 86 is formed in an annular shape around the through hole 87. In order to prevent the bearing retainer 64 from rotating around the central axis L, a positioning member (such as a pin member) may be provided in the bearing housing 3 or the fitting wheel 61. Moreover, the structure by which the bearing holding | suppressing 64 is fixed to the bearing housing 3, the fitting ring 61 grade | etc., Using a predetermined fastening member etc. may be sufficient. Further, the edge portion 84 of the bearing retainer 64 may be a collar member independent of the plate portion 83, and the plate portion 83 may be held in the front-rear direction by the fitting wheel 61 and the collar member.

 Next, the operation and action of the supercharger 1 according to the present embodiment, particularly the radial bearing structure 6, will be described with reference to FIGS.

 Exhaust gas discharged from the internal combustion engine is introduced into the turbine scroll passage 22 of the turbine housing 2. The exhaust gas is introduced into the turbine impeller 21 while rotating around the turbine impeller 21 and flowing in the turbine scroll flow path 22. By introducing the exhaust gas, the turbine impeller 21 rotates. As the turbine impeller 21 rotates, the compressor impeller 41 connected via the turbine shaft 31 rotates. By the rotation of the compressor impeller 41, the air introduced from the air introduction port 42 is sent out to the diffuser flow path 43 and compressed. The compressed air is supplied to the internal combustion engine via the compressor scroll flow path 44, and the performance of the internal combustion engine such as output and fuel consumption is improved.

 The turbine impeller 21 and the compressor impeller 41 are supported by the turbine shaft 31. The turbine shaft 31 is rotatably supported by the thrust bearing structure 5 and the radial bearing structure 6 of the bearing housing 3. By introducing the exhaust gas, the turbine impeller 21 is urged toward the rear side, that is, the compressor impeller 41 side. However, the thrust bearing structure 5 holds the turbine shaft 31 in the front-rear direction, and the front and rear of the turbine impeller 21 and the compressor impeller 41. Movement in the direction is restricted. Further, since the lubricating oil is supplied from the oil supply passage 32 between the thrust bearing 51 and the thrust collars 52 and 53, the thrust bearing structure 5 can smoothly rotate the turbine shaft 31.

 The turbine shaft 31 is held in the radial direction by the radial bearing structure 6 and is rotatably supported. Lubricating oil is supplied into a cylindrical gap S provided surrounding the turbine shaft 31 via an oil supply passage 32 and a fitting wheel oil supply passage 72. Further, since the oil supply hole 77 is formed in the front bearing 62 and the oil supply hole 80 is formed in the rear bearing 63, the lubricating oil is also supplied to the gap between the turbine shaft 31 and the bearings 62 and 63. The Therefore, the clearance between the inner and outer peripheral surfaces of the bearings 62 and 63 is filled with lubricating oil, and the turbine shaft 31 can rotate smoothly.

 By filling the clearances on the inner and outer peripheral surfaces of the bearings 62 and 63 with the lubricating oil, the turbine shaft 31 is held in a floating state with respect to the fitting wheel 61. Further, since the lubricating oil is supplied into the cylindrical gap S at a predetermined pressure, the gaps on the inner and outer peripheral surfaces of the bearings 62 and 63 tend to be made uniform by the hydraulic pressure of the lubricating oil. Therefore, even if the turbine shaft 31 is displaced or vibrated in the radial direction, the turbine shaft 31 is positioned at the substantially central portion of the turbine shaft hole 71 in the fitting wheel 61 by the action of the lubricating oil filled in the cylindrical gap S. Retained. That is, even if the turbine shaft 31 is displaced or vibrated in the radial direction with rotation, the radial bearing structure 6 can suppress the displacement and vibration.

 In this embodiment, the rearward displacement of the rear bearing 63 is restricted by the bearing retainer 64. Since a part of the facing surface 85 in the bearing retainer 64 is a bearing facing surface 86, the rear bearing 63 is disposed at a position where the rear end surface 82 is flush with the rear end surface of the fitting wheel 61. This is because the installation position of the rear bearing 63 is larger than that of the conventional configuration in which a C ring similar to the C ring 75 that restricts the movement of the front bearing 62 is provided on the rear end face 82 side of the rear bearing 63. It is displaced to the rear end side. Therefore, the space | interval between the front side bearing 62 and the rear side bearing 63 can be expanded compared with the past, and the vibration suppression performance with respect to the vibration of the turbine shaft 31, rotation stability, etc. can be improved.

Therefore, according to the present embodiment, the following effects can be obtained.
According to the present embodiment, the installation position of the rear bearing 63 is displaced toward the rear end side of the turbine shaft hole 71 in the fitting wheel 61 as compared with the related art. Therefore, the space between the front bearing 62 and the rear bearing 63 can be widened, and there is an effect that vibration suppressing performance can be improved and high rotational stability can be obtained.

 As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

 For example, in the above embodiment, the front bearing 62 and the rear bearing 63 are semi-float type slide bearings, but are not limited thereto, and may be full float type slide bearings.

 Moreover, in the said embodiment, although the fitting ring 61 was comprised by the bearing housing 3 and another member, it is not limited to this, A part of bearing housing 3 becomes a bearing holding | maintenance part, A bearing housing 3 may be configured such that a turbine shaft hole 71 is formed.

Moreover, you may use the bearing holder | retainer 64A or 64B shown in FIG. 4 or FIG. 5 instead of the bearing holder | retainer 64 of the said embodiment.
4A and 4B are schematic views showing the configuration of the bearing retainer 64A, where FIG. 4A is a plan view and FIG. 4B is a cross-sectional view taken along line BB of FIG. 5A and 5B are schematic views showing the configuration of the bearing retainer 64B, where FIG. 5A is a plan view and FIG. 5B is a cross-sectional view taken along the line CC of FIG.

 The bearing retainer 64A shown in FIG. 4 includes a plurality of oil drain holes (oil drain passages) 89 that are holes penetrating in the thickness direction. The oil drain holes 89 are formed in the region of the bearing facing surface 86 and are arranged side by side in the circumferential direction. As the turbine shaft 31 rotates, the amount of metal powder, sludge, etc. in the lubricating oil in the cylindrical gap S increases. By forming the oil drain hole 89, the lubricating oil supplied into the cylindrical gap S can be quickly discharged toward the oil drain passage 33, and the smooth and safe rotation of the turbine shaft 31 is maintained. can do.

 The bearing retainer 64B shown in FIG. 5 includes an oil drain notch (oil drain passage) 90. The bearing retainer 64B can also quickly discharge the lubricating oil supplied into the cylindrical gap S through the oil drainage notch 90 toward the oil drainage passage 33, and smooth and safe rotation of the turbine shaft 31. Can be maintained. The bearing retainer 64B is preferably provided with a predetermined positioning member (pin member, fastening member) in order to prevent rotation around the central axis L shown in FIG.

Moreover, in the said embodiment, although the bearing holding | suppressing 64 is installed in the rear end surface 82 side of the rear side bearing 63, it is not limited to this, As shown in FIG. A second bearing retainer (bearing retainer) 95 may be provided.
FIG. 6 is a cross-sectional view showing the configuration of the second bearing retainer 95.

 As shown in FIG. 6, the second bearing retainer 95 is an annular plate member provided so as to surround the turbine shaft 31 in the circumferential direction, and the plate surface (opposing surface) abuts against the front end surface of the fitting wheel 61. Is provided. The second bearing retainer 95 is fixed to the fitting wheel 61 using a plurality of screw members (fastening members) 96. A radially inner portion of the plate surface of the second bearing retainer 95 is a bearing facing surface (bearing facing portion) provided to face the cylindrical gap S. Therefore, the front bearing 62 is in contact with the second bearing retainer 95 and is disposed at a position where the front end face is flush with the front end face of the fitting wheel 61. Therefore, when the second bearing retainer 95 is used, the front bearing 62 can be displaced to the front end side of the fitting wheel 61 as compared with the conventional case, and as a result, the distance between the front bearing 62 and the rear bearing 63 is increased. Can be expanded. In addition, a discharge path for discharging the lubricating oil supplied into the cylindrical gap S may be formed in the second bearing retainer 95. The bearing retainer 64 shown in the above embodiment may be an annular plate member like the second bearing retainer 95, and may be fixed to the fitting ring 61 using a fastening member such as a screw member.

DESCRIPTION OF SYMBOLS 1 ... Supercharger, 3 ... Bearing housing, 31 ... Turbine shaft, 34 ... Hole for fitting wheel (2nd hole), 51 ... Thrust bearing, 61 ... Fitting wheel (bearing holding part), 62 ... Front bearing ( Bearing), 63 ... rear side bearing (bearing), 64, 64A, 64B ... bearing holder, 71 ... turbine shaft hole (hole), 82 ... rear end face (one end face), 85 ... opposite face, 86 ... bearing Opposing surface (bearing facing portion), 89 ... oil drain hole (oil draining passage), 90 ... oil drain notch (oil draining passage), 95 ... second bearing press (bearing press), 96 ... screw member (fastening member) )

Claims (6)

A turbocharger having a plurality of bearings rotatably supporting a turbine shaft extending in a predetermined axial direction in a bearing housing,
A bearing holding portion provided in the bearing housing and provided with a hole into which the bearing is inserted;
A turbocharger comprising: a bearing retainer provided with a bearing facing portion provided at a position facing the one end surface of the bearing in the axial direction outside the bearing holding portion. The turbocharger according to claim 1, wherein
The bearing retainer includes a facing surface facing the bearing holding portion in the axial direction,
The bearing facing portion is a region of the facing surface that is opposed to the hole portion in the axial direction. In the supercharger according to claim 1 or 2,
The bearing housing includes a second hole centered on the turbine shaft,
The turbocharger is characterized in that the bearing retainer is an annular member that is provided so as to surround the turbine shaft in the circumferential direction, and is fitted and held in the second hole portion. In the supercharger as described in any one of Claim 1 to 3,
The turbocharger, wherein the bearing retainer is retained between the bearing retaining portion and a thrust bearing that restricts movement of the turbine shaft in the axial direction. In the supercharger according to claim 1 or 2,
The turbocharger is characterized in that the bearing retainer is an annular plate member provided so as to surround the turbine shaft in the circumferential direction, and is fixed to the bearing holding portion using a predetermined fastening member. In the supercharger as described in any one of Claim 1 to 5,
The supercharger according to claim 1, wherein the bearing retainer includes a discharge passage for discharging lubricating oil used for lubricating the turbine shaft and the bearing.

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