JP2015124727A - Thrust bearing of turbocharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thrust bearing of a turbocharger which can suppress seizure in starting an engine while reducing friction at an operation of an engine.SOLUTION: A thrust bearing limits an axial movement of a rotating shaft by a turbine-side engagement part 201 in which a turbine-side thrust collar 401 and a thrust disc 30 are engaged with each other, and a compressor-side engagement part 202 in which a compressor-side thrust collar 402 and the thrust disc 30 are engaged with each other. Non-slide parts 303, 304 formed of recesses and slide parts 305, 306 having no recesses are alternately aligned at the thrust disc 30 in a circumferential direction, and a total area of the slide part 306 at the compressor-side engagement part 202 is larger than a total area of the slide part 305 at the turbine-side engagement part 201.

Description

  The present invention relates to a thrust bearing for a turbocharger that restricts axial movement of a rotating shaft that connects a turbine impeller and a compressor impeller.

  The turbocharger thrust bearing is composed of a thrust disk fixed to the housing and a thrust collar fixed to the rotating shaft, and the axial movement of the rotating shaft is limited by the engagement between the thrust disk and the thrust collar. doing. Oil is supplied to the engaging portion where the thrust disk and the thrust collar face each other by driving an oil pump.

  Patent Document 1 discloses a thrust bearing in which a thrust disk is disposed between a pair of thrust collars. In the thrust disk in the thrust bearing of this Patent Document 1, a plurality of depressions are provided at regular intervals in the circumferential direction on the surface facing the thrust collar.

  Thus, if a recess is provided on the surface facing the thrust collar in the thrust disk, the portion provided with the recess becomes a non-sliding part, and the sliding area between the thrust collar and the thrust disk becomes small, Friction can be reduced.

  Also, when the thrust collar rotates with the rotation of the rotating shaft, oil flows between the thrust disk and the thrust collar, and the oil is drawn from the non-sliding part to the sliding part where there is no depression, and the wide part Will flow into the narrow part. For this reason, the hydraulic pressure is increased at the portion where the sliding portion of the thrust disk and the thrust collar face each other, and a force for separating the thrust disk and the thrust collar acts. As a result, the thickness of the oil film on the sliding surface between the thrust disk and the thrust collar is secured, and the friction is further reduced by fluid lubrication.

JP 2011-127428 A

  By the way, when the turbine impeller and the compressor impeller are rotated and supercharging is performed, a pressure difference is generated between the upstream and the downstream of each impeller, and a force for pulling each impeller to the tip side acts. At this time, since the rotating shaft is pulled from both ends, the rotating shaft is not easily biased to one side.

  On the other hand, when the engine is started, since supercharging is not performed, the force that pulls the turbine impeller toward the tip side acts before the force that pulls the compressor impeller toward the tip side, and the rotating shaft is pulled toward the turbine housing side. It becomes like this. At the time of starting the engine, since the oil is not sufficiently supplied, the oil pressure of the oil existing between the thrust disk and the thrust collar is increased even if the depression is formed on the surface of the thrust disk as described above. I can't. Further, at this time, the non-sliding portion is formed by the depression and the sliding area is reduced, resulting in an increase in the surface pressure acting on the sliding surface. Therefore, there is a possibility that the oil film cannot be held and seizure occurs.

  Such a problem can occur in the same manner when a configuration is adopted in which a depression is provided in the thrust collar to reduce friction. In addition, when a thrust bearing in which a thrust collar is disposed between a pair of thrust disks adopts a configuration in which a recess is provided in the thrust disk or the thrust collar to reduce friction, the same problem as this problem occurs. Can occur.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a turbocharger thrust bearing capable of suppressing the occurrence of seizure during engine start-up while reducing friction during engine operation. There is to do.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A turbocharger thrust bearing for solving the above-mentioned problems is a turbine fixed to a thrust disk fixed to a housing, a rotating shaft connecting a turbine impeller and a compressor impeller, and disposed so as to sandwich the thrust disk. A turbine side engaging portion that engages the turbine side thrust collar and the thrust disc, and a compressor side engaging portion that engages the compressor side thrust collar and the thrust disc A thrust bearing of a turbocharger that restricts the axial movement of the rotary shaft by a recess formed on a surface of each engagement portion facing the other of at least one of the thrust disk and the thrust collar. Of the non-sliding part and the depression Non-sliding sliding parts are provided alternately in the circumferential direction, and the total area of the sliding parts in the compressor side engaging part is the total of the sliding parts in the turbine side engaging part. It is larger than the area.

  In the case of a thrust bearing in which a pair of thrust collars are disposed so as to sandwich the thrust disk, when the rotation shaft moves to the turbine housing side, the compressor-side thrust collar approaches the thrust disk. That is, in the case of a thrust bearing in which a pair of thrust collars are disposed so as to sandwich the thrust disk, seizure is likely to occur at the compressor side engaging portion at the time of engine start in which the rotating shaft is pulled to the turbine housing side.

  If the sliding area at each engaging portion is increased, the surface pressure acting on the sliding surface can be reduced by dispersing the load, and therefore the oil film can be easily held even when the engine is started. However, if the sliding area at each engagement portion is increased, the friction during engine operation increases.

  On the other hand, in the above configuration, the total area of the sliding portion in the compressor side engaging portion where seizure is likely to occur when the engine is started is selectively increased. Therefore, the friction reduction effect during engine operation obtained by reducing the sliding portion is less likely to be lost compared with the case where the total area of the sliding portion in the engaging portion on both the compressor side and the turbine side is increased.

  That is, according to the above configuration, it is possible to suppress the occurrence of seizure when starting the engine while reducing the friction during engine operation by reducing the sliding area at each engagement portion.

  Further, in the turbocharger thrust bearing, the number of sliding portions in the compressor side engaging portion is equal to the number of sliding portions in the turbine side engaging portion, and each sliding in the compressor side engaging portion The area of the part is larger than the area of each sliding part in the turbine side engaging part.

  In order to make the total area of the sliding part in the compressor side engaging part larger than the total area of the sliding part in the turbine side engaging part, each sliding part in the compressor side engaging part is configured as described above. It is sufficient to adopt a configuration in which the area of is larger than the area of each sliding part in the turbine side engaging part.

  According to such a configuration, even if the number of sliding portions in the compressor side engaging portion and the number of sliding portions in the turbine side engaging portion are equal, the total area of the sliding portions in the compressor side engaging portion is reduced. The total area of the sliding part in the turbine side engaging part can be made larger.

  In addition, the area of each sliding part in the compressor side engaging part is equal to the area of each sliding part in the turbine side engaging part, and the number of sliding parts in the compressor side engaging part is set to the sliding part in the turbine side engaging part. A configuration in which the number of moving parts is larger than the number of moving parts may be employed.

Even when such a configuration is adopted, the total area of the sliding portion in the compressor side engaging portion can be made larger than the total area of the sliding portion in the turbine side engaging portion.
As described above, when the engine is started, the oil pressure of the oil existing between the thrust disk and the thrust collar cannot be increased, and the non-sliding portion is formed by the depression to reduce the sliding area. Increases the surface pressure acting on the sliding surface. Therefore, there is a possibility that the oil film cannot be held and seizure occurs.

  A thrust bearing of a turbocharger for solving the above-mentioned problems is provided by a thrust collar fixed to a rotating shaft connecting a turbine impeller and a compressor impeller, a turbine fixed to a housing and disposed so as to sandwich the thrust collar. A turbine-side engaging portion that engages the turbine-side thrust disc and the thrust collar, and a compressor-side engaging portion that engages the compressor-side thrust disc and the thrust collar. A thrust bearing of a turbocharger that restricts the axial movement of the rotary shaft by a recess formed on a surface of each engagement portion facing the other of at least one of the thrust disk and the thrust collar. Of the non-sliding part and the depression Non-sliding sliding parts are provided alternately in the circumferential direction, and the total area of the sliding parts in the turbine side engaging part is the total of the sliding parts in the compressor side engaging part. It is larger than the area.

  In the case of a thrust bearing in which a pair of thrust disks are disposed so as to sandwich the thrust collar, when the rotating shaft moves to the turbine housing side, the thrust collar approaches the turbine side thrust disk. That is, in the case of a thrust bearing in which a pair of thrust disks are disposed so as to sandwich the thrust collar, seizure is likely to occur at the turbine side engaging portion at the time of engine start in which the rotating shaft is pulled to the turbine housing side.

  If the sliding area at each engaging portion is increased, the surface pressure acting on the sliding surface can be reduced by dispersing the load, and therefore the oil film can be easily held even when the engine is started. However, if the sliding area at each engagement portion is increased, the friction during engine operation increases.

  On the other hand, in the said structure, the total area of the sliding part in the turbine side engaging part which becomes easy to produce seizing at the time of engine starting is selectively enlarged. Therefore, the friction reduction effect during engine operation obtained by reducing the sliding portion is less likely to be lost compared with the case where the total area of the sliding portion in the engaging portion on both the compressor side and the turbine side is increased.

  That is, according to the above configuration, it is possible to suppress the occurrence of seizure when starting the engine while reducing the friction during engine operation by reducing the sliding area at each engagement portion.

  Further, in the turbocharger thrust bearing, the number of the sliding portions in the turbine side engaging portion is equal to the number of the sliding portions in the compressor side engaging portion. The area of the part is larger than the area of each sliding part in the compressor side engaging part.

  In order to make the total area of the sliding part in the turbine side engaging part larger than the total area of the sliding part in the compressor side engaging part, each sliding part in the turbine side engaging part is configured as described above. A configuration may be adopted in which the area is larger than the area of each sliding part in the compressor side engaging part.

  According to such a configuration, even if the number of sliding portions in the turbine side engaging portion and the number of sliding portions in the compressor side engaging portion are equal, the total area of the sliding portions in the turbine side engaging portion is reduced. The total area of the sliding portion in the compressor side engaging portion can be made larger.

  Further, the area of each sliding part in the turbine side engaging part and the area of each sliding part in the compressor side engaging part are made equal, and the number of sliding parts in the turbine side engaging part is set to the sliding part in the compressor side engaging part. A configuration in which the number of moving parts is larger than the number of moving parts may be employed.

  Even when such a configuration is adopted, the total area of the sliding portion in the turbine side engaging portion can be made larger than the total area of the sliding portion in the compressor side engaging portion.

(A) is sectional drawing of a turbocharger provided with the thrust bearing of 1st Embodiment. (B) is an enlarged view of the vicinity of the thrust bearing. The perspective view of the thrust disk which comprises the same thrust bearing. FIG. 3 is an end view of the thrust disk as viewed from the direction of arrow 3 in FIG. 2. Sectional drawing along line 4-4 in FIG. Sectional drawing which shows the 1st modification of the thrust bearing of 1st Embodiment. Sectional drawing which shows the 2nd modification of the thrust bearing of 1st Embodiment. Sectional drawing which shows the 3rd modification of the thrust bearing of 1st Embodiment. Sectional drawing which shows the cross-sectional structure of the thrust bearing vicinity of a turbocharger provided with the thrust bearing of 2nd Embodiment. Sectional drawing along line 9-9 in FIG. Sectional drawing which shows the 1st modification of the thrust bearing of 2nd Embodiment. Sectional drawing which shows the 2nd modification of the thrust bearing of 2nd Embodiment. Sectional drawing which shows the 3rd modification of the thrust bearing of 2nd Embodiment.

(First embodiment)
A turbocharger thrust bearing according to a first embodiment will be described below with reference to FIGS.

  As shown in FIG. 1A, in the turbocharger 10, a turbine housing 11 that houses a turbine impeller 110 and a compressor housing 12 that houses a compressor impeller 120 are assembled to a bearing housing 14. The bearing housing 14 is formed with an insertion hole 140 through which the rotary shaft 13 that connects the turbine impeller 110 and the compressor impeller 120 is inserted. The bearing housing 14 is provided with a thrust bearing 20 and a radial bearing 141 described later. Thus, the rotary shaft 13 is rotatably supported.

  A scroll passage 112 extending so as to surround the outer periphery of the turbine impeller 110 and a discharge passage 111 extending in the extending direction of the rotary shaft 13 from the vicinity of the tip of the turbine impeller 110 are formed in the turbine housing 11. The turbine housing 11 is disposed in the middle of the exhaust passage of the internal combustion engine, the upstream exhaust passage is connected to the scroll passage 112, and the downstream exhaust passage is connected to the discharge passage 111. As a result, the exhaust introduced into the scroll passage 112 from the upstream exhaust passage rotates the turbine impeller 110 and flows from the discharge passage 111 into the downstream discharge passage.

  In the compressor housing 12, a compressor passage 122 extending so as to surround the outer periphery of the compressor impeller 120 and an introduction passage 121 extending in the extending direction of the rotary shaft 13 from the vicinity of the tip of the compressor impeller 120 are formed. The compressor housing 12 is arranged in the middle of the intake passage of the internal combustion engine, the upstream intake passage is connected to the introduction passage 121, and the downstream intake passage is connected to the compressor passage 122. As a result, the intake air introduced from the upstream intake passage into the introduction passage 121 is sent to the compressor passage 122 as the compressor impeller 120 rotates, and is sent to the combustion chamber through the downstream intake passage.

  The radial bearing 141 that supports the rotating shaft 13 is a substantially cylindrical bearing disposed in the insertion hole 140 of the bearing housing 14, and restricts the radial movement of the rotating shaft 13. In FIG. 1, only the schematic shape of the radial bearing 141 is shown.

  As shown in FIG. 1A, the end portion of the bearing housing 14, the end portion closer to the compressor impeller 120 than the position where the radial bearing 141 is disposed, is substantially opposed to the base end of the compressor impeller 120. A disc-shaped retainer 142 is fitted. A disc-shaped thrust disk 30 is sandwiched between the retainer 142 and the bearing housing 14. The thrust disk 30 is fixed to the bearing housing 14 together with the retainer 142 by bolts 145.

  As shown in FIG. 1B, a thrust ring 40 is fixed to the rotary shaft 13 at a position corresponding to the thrust disk 30. A recess 41 corresponding to the thickness of the thrust disk 30 is provided over the entire circumference at the center of the outer peripheral surface of the thrust ring 40. Thereby, on the outer peripheral surface of the thrust ring 40, the turbine side thrust collar 401 positioned on the turbine impeller 110 side (right side in FIG. 1) with respect to the recess 41, and the compressor impeller 120 side (left side in FIG. 1) with respect to the recess 41. And a compressor-side thrust collar 402 located at the same position.

  As shown in FIG. 1B, the thrust disk 30 is sandwiched between the turbine-side thrust collar 401 and the compressor-side thrust collar 402. As a result, in the turbocharger 10, the first surface 301, which is the surface on the turbine impeller 110 side of the thrust disk 30, and the turbine-side thrust collar 401 face each other to form the turbine-side engagement portion 201. On the other hand, in the turbocharger 10, the second surface 302, which is the surface on the compressor impeller 120 side of the thrust disk 30, and the compressor-side thrust collar 402 face each other to form a compressor-side engagement portion 202.

  For this reason, when the rotating shaft 13 moves to the turbine housing 11 side (the right side in FIG. 1) in the insertion hole 140, the compressor-side thrust collar 402 of the thrust ring 40 fixed to the rotating shaft 13, the bearing housing 14 is engaged with the second surface 302 of the thrust disk 30 fixed to the disk 14. That is, in this case, the compressor-side engagement portion 202 restricts the movement of the rotary shaft 13 in the axial direction. On the other hand, when the rotary shaft 13 moves to the compressor housing 12 side (left side in FIG. 1) in the insertion hole 140, the turbine side thrust collar 401 of the thrust ring 40 fixed to the rotary shaft 13 and the bearing housing 14 is engaged with the first surface 301 of the thrust disk 30 fixed to the outer surface 14. That is, in this case, the turbine side engagement portion 201 restricts the movement of the rotating shaft 13 in the axial direction.

  That is, in the turbocharger 10, the thrust bearing 20 that restricts the axial movement of the rotary shaft 13 is configured by the thrust disk 30 and the thrust ring 40 including the pair of thrust collars 401 and 402.

Note that oil is supplied to the engaging portions 201 and 202 of the thrust bearing 20 and the radial bearing 141 by driving an oil pump.
Next, the configuration of the thrust disk 30 will be described with reference to FIG.

  As shown in FIG. 2, six recesses are provided in the central portion of the second surface 302 of the thrust disk 30 facing the compressor-side thrust collar 402 at regular intervals in the circumferential direction. A non-sliding portion 304 is formed. Thereby, on the second surface 302 of the thrust disk 30, as shown in FIG. 2, there are six non-sliding portions 304 formed by these depressions and six sliding portions 306 without any depressions. They are provided alternately in the circumferential direction. Note that the recess is tapered so as to gradually become deeper in one direction.

  Similarly, in the central portion of the first surface 301 facing the turbine-side thrust collar 401, six recesses are provided at regular intervals in the circumferential direction, and the non-sliding portion 303 is formed by these recesses. Is formed. That is, on the first surface 301 of the thrust disk 30, six non-sliding portions 303 formed by these recesses and six sliding portions 305 not provided with the recesses are alternately arranged in the circumferential direction. Is provided.

  The thrust disk 30 is formed with a bolt hole 310 that is a through hole for inserting the bolt 145. In the turbocharger 10, the retainer 142 and the thrust disk 30 are fixed by being fastened at a plurality of locations. Therefore, a plurality of bolt holes 310 are formed, but only one bolt hole 310 is illustrated in FIG. 2. Yes. Note that a plurality of fastening locations are not necessarily provided, and there may be only one fastening location as long as the retainer 142 and the thrust disk 30 can be fixed.

  Next, the configuration of the thrust disk 30 will be described in more detail with reference to FIG. FIG. 3 is an end view of the thrust disk 30 as viewed from the direction of the arrow 3 in FIG. In the following description, as shown in FIG. 3, the length of each non-sliding portion 304 on the second surface 302 is L1, and the length of each sliding portion 306 is L2. In addition, the length of each non-sliding portion 303 on the first surface 301 is L3, and the length of each sliding portion 305 is L4.

  As shown in FIG. 3, the length (L1 + L2) of the set of non-sliding portions 304 and sliding portions 306 formed on the second surface 302 and the set of non-sliding portions 306 formed on the first surface 301 The length (L3 + L4) of the sliding part 303 and the sliding part 305 is equal.

  The length L2 of each sliding portion 306 on the second surface 302 is longer than the length L4 of each sliding portion 305 on the first surface 301. Accordingly, the ratio λc of the length L2 of the sliding portion 306 to the length (L1 + L2) of the pair of non-sliding portions 304 and the sliding portions 306 on the second surface 302 is equal to one in the first surface 301. It is larger than the ratio λt of the length L4 of the sliding portion 305 to the length (L3 + L4) of the non-sliding portion 303 and the sliding portion 305 of the set.

  In order to reduce the friction, the smaller the ratios λt and λc occupied by the sliding portions 305 and 306, the more advantageous. Therefore, in this thrust disk 30, the ratio λt is set to about 0.1 and the ratio λc is set to 0.1. About 3

  Thus, by making the ratio λc larger than the ratio λt, in this thrust bearing 20, the area of each sliding portion 306 on the second surface 302 constituting the compressor-side engaging portion 202 is the turbine-side engaging portion 201. It is larger than the area of each sliding part 305 in the 1st surface 301 which comprises.

  As a result, in the thrust bearing 20, the total area of the sliding portion 306 in the compressor side engaging portion 202 is larger than the total area of the sliding portion 305 in the turbine side engaging portion 201.

  Next, the operation of the thrust bearing 20 of the turbocharger 10 according to this embodiment will be described with reference to FIGS. 4 is a cross-sectional view taken along line 4-4 in FIG.

  When the turbine impeller 110 and the compressor impeller 120 are rotated and supercharging is performed, a pressure difference is generated between the upstream and downstream sides of the respective impellers 110 and 120, and as shown by white arrows in FIG. , 120 is acted upon by a force for pulling each of them to the tip side.

  Further, when the rotating shaft 13 rotates, the thrust ring 40 fixed to the rotating shaft 13 also rotates as indicated by a solid arrow in FIG. At this time, the oil supplied to the turbine side engaging portion 201 and the compressor side engaging portion 202 also flows as indicated by the broken-line arrows as the thrust ring 40 rotates.

  As described above, in the thrust bearing 20, the non-sliding portion 303 is formed on the first surface 301 of the thrust disk 30, and the non-sliding portion 304 is formed on the second surface 302. Therefore, the sliding area between the thrust disk 30 and the thrust collars 401 and 402 of the thrust ring 40 is reduced. Therefore, the friction in the turbine side engaging part 201 and the compressor side engaging part 202 can be reduced.

  Further, as indicated by the broken line arrows, with the rotation of the thrust ring 40, in each of the engaging portions 201 and 202, the oil slides from the portion where the non-sliding portions 303 and 304 and the thrust collars 401 and 402 face each other. 305 and 306 and the thrust collars 401 and 402 are drawn into the facing part, and flow from a wide part to a narrow part. Therefore, the hydraulic pressure is increased at the portion where the sliding portions 305 and 306 and the thrust collars 401 and 402 face each other, and a force for separating the thrust disk 30 and the thrust collars 401 and 402 acts. As a result, the thickness of the oil film on the sliding surface between the thrust disk 30 and the thrust collars 401 and 402 is ensured, and the friction is further reduced by fluid lubrication.

  As shown in FIG. 4, the recesses forming the non-sliding portions 303 and 304 have a tapered shape that gradually becomes shallower toward the downstream side in the oil flow direction at this time. Becomes smooth. This is advantageous in reducing friction.

  By the way, when the engine is started, the turbine impeller 110 starts to rotate from a state where supercharging is not performed. Therefore, before the force that pulls the compressor impeller 120 toward the front end acts, the force that pulls the turbine impeller 110 toward the front end is increased. As a result, the rotary shaft 13 is pulled toward the turbine housing 11 side. At the time of starting the engine, since the oil is not sufficiently supplied to the respective engaging portions 201 and 202, even if the non-sliding portions 303 and 304 are formed on the thrust disk 30, the sliding portions 305 and 306 are provided. The hydraulic pressure cannot be increased at the portion where the thrust collars 401 and 402 face each other. Further, at this time, the non-sliding portions 303 and 304 are formed and the sliding area is reduced, which leads to an increase in the surface pressure acting on the sliding surface. Therefore, there is a possibility that the oil film cannot be held and seizure occurs. In the case of the thrust bearing 20 in which the thrust collars 401 and 402 are disposed so as to sandwich the thrust disk 30 as in this embodiment, when the rotary shaft 13 moves to the turbine housing 11 side, the compressor-side thrust collar 402 is moved to the thrust disk 30. Will approach. That is, in the case of the thrust bearing 20 in which the thrust collars 401 and 402 are disposed so as to sandwich the thrust disk 30, seizure is likely to occur in the compressor side engaging portion 202 when the engine is started.

  On the other hand, in the thrust bearing 20 of the present embodiment, the total area of the sliding portion 306 in the compressor side engaging portion 202 is made larger than the total area of the sliding portion 305 in the turbine side engaging portion 201 so that the compressor side The sliding area in the engaging portion 202 is increased. Therefore, the load acting on the sliding surface is dispersed, and the surface pressure acting on the sliding surface is reduced, so that the oil film can be easily held even when the engine is started.

  If the sliding areas of the sliding parts 305 and 306 are increased in both the turbine side engaging part 201 and the compressor side engaging part 202, the friction during engine operation obtained by reducing the sliding area is reduced. The reduction effect is impaired, and the friction during engine operation increases.

  On the other hand, in the thrust bearing 20 of the present embodiment, the total area of the sliding portion 306 in the compressor side engaging portion 202 where seizure is likely to occur when the engine is started is selectively increased. Therefore, the friction reduction during engine operation obtained by reducing the sliding area compared to the case where the total area of the sliding parts 305 and 306 in the engaging parts 201 and 202 on both the compressor side and the turbine side is increased. The effect is less likely to be impaired.

According to the first embodiment described above, the following effects can be obtained.
(1) By providing the non-sliding portion 303 in the turbine side engaging portion 201 and providing the non-sliding portion 304 in the compressor side engaging portion 202, the sliding area in each engaging portion 201, 202 is reduced. Therefore, friction can be reduced.

  (2) Along with the rotation of the thrust ring 40, the hydraulic pressure increases at the portion where the sliding portions 305 and 306 and the thrust collar 401 and 402 face each other, and the force that separates the thrust disk 30 and the thrust collar 401 and 402 acts. Will come to do. Therefore, the thickness of the oil film on the sliding surface between the thrust disk 30 and the thrust collars 401 and 402 can be secured, and friction can be reduced by fluid lubrication.

  (3) The total area of the sliding portion 306 in the compressor side engaging portion 202 that is likely to be seized when the engine is started is selectively increased. Therefore, the friction reduction during engine operation obtained by reducing the sliding area compared to the case where the total area of the sliding parts 305 and 306 in the engaging parts 201 and 202 on both the compressor side and the turbine side is increased. The effect is hard to be impaired.

  That is, according to the thrust bearing 20 of the present embodiment, the occurrence of seizure at the start of the engine is suppressed while reducing the friction during the engine operation by reducing the sliding area in each of the engaging portions 201 and 202. be able to.

In addition, the said 1st Embodiment is not limited to the structure demonstrated above, It can also implement with the following forms which changed this suitably.
-Although the structure which provides six hollows in the 1st surface 301 and the 2nd surface 302 of the thrust disc 30, respectively was illustrated, the number of the hollows provided in each surface 301,302 is not restricted to six. The number of depressions can be changed as appropriate.

  Although the example in which the ratio λt is set to about 0.1 and the ratio λc is set to about 0.3 is shown, the ratio λt and the ratio λc can be appropriately changed as long as the ratio λc is larger than the ratio λt It is. Since it is preferable to reduce the sliding portions 305 and 306 from the viewpoint of reducing friction, it is preferable to reduce the ratios λt and λc. However, if the sliding portions 305 and 306 are too small, it is difficult to hold the oil film. Thus, the load capacity of the thrust bearing 20 is reduced. Therefore, it is desirable that the ratios λt and λc be set to a size that can reduce friction as much as possible while securing a necessary load capacity based on the results of simulations through experiments and calculations. For example, the ratio λt is preferably 0.05 to 0.2, and the ratio λc is preferably 0.25 to 0.5.

  In the first embodiment, the non-sliding portion 303 and the sliding portion 305 are formed on the first surface 301 of the thrust disk 30, and the non-sliding portion 304 and the sliding portion 306 are formed on the second surface 302. It had been. However, if the non-sliding portion and the sliding portion are formed on at least one of the opposing surfaces of the engaging portions 201 and 202, the same effect as in the first embodiment can be obtained. it can.

  Therefore, as a first modification of the first embodiment, as shown in FIG. 5, a non-sliding portion 403 and a sliding portion 405 are formed in the turbine-side thrust collar 401, and non-sliding is performed on the compressor-side thrust collar 402. A configuration in which the portion 404 and the sliding portion 406 are formed may be employed. In this way, when the non-sliding portions 403 and 404 due to the depressions are formed in the thrust collars 401 and 402, as shown in FIG. 5, the depressions have a tapered shape that becomes deeper toward the front side in the rotation direction of the thrust ring 40. It is preferable to do.

  When the non-sliding portions 403 and 404 are formed in the thrust collars 401 and 402 in this way, as shown in FIG. 5, the length L12 of the sliding portion 406 in the compressor side engaging portion 202 is set to the turbine side. What is necessary is just to make it longer than length L14 of the sliding part 405 in the engaging part 201. FIG. By adopting such a configuration, the ratio λc of the length L12 of the sliding portion 406 to the length (L11 + L12) of the pair of non-sliding portions 404 and sliding portions 406 on the compressor side is set to one set on the turbine side. It becomes larger than the ratio λt of the length L14 of the sliding portion 405 to the length (L13 + L14) of the non-sliding portion 403 and the sliding portion 405. Thus, if the ratio λc is larger than the ratio λt, even in this thrust bearing 20, the area of each sliding portion 406 in the compressor-side thrust collar 402 constituting the compressor-side engaging portion 202 is the turbine-side engaging portion 201. It becomes larger than the area of each sliding part 405 in the turbine side thrust collar 401 which comprises.

  As a result, also in this thrust bearing 20, the total area of the sliding part 406 in the compressor side engaging part 202 can be made larger than the total area of the sliding part 405 in the turbine side engaging part 201. Effects similar to (1) to (3) in the embodiment can be obtained.

  As a second modification, as shown in FIG. 6, a non-sliding portion 303 and a sliding portion 305 are formed on the first surface 301 of the thrust disk 30, and the non-sliding portion is formed on the compressor-side thrust collar 402. A configuration in which 404 and the sliding portion 406 are formed may be employed.

  In this case, as shown in FIG. 6, the length L12 of the sliding portion 406 in the compressor side engaging portion 202 may be longer than the length L24 of the sliding portion 305 in the turbine side engaging portion 201. By adopting such a configuration, the ratio λc of the length L12 of the sliding portion 406 to the length (L11 + L12) of the pair of non-sliding portions 404 and sliding portions 406 on the compressor side is set to one set on the turbine side. It becomes larger than the ratio λt of the length L24 of the sliding portion 305 to the length (L23 + L24) of the non-sliding portion 303 and the sliding portion 305. Thus, if the ratio λc is made larger than the ratio λt, the area of each sliding portion 406 in the compressor side engaging portion 202 is equal to the area of each sliding portion 305 in the turbine side engaging portion 201 even in this thrust bearing 20. Bigger than.

  As a result, in this thrust bearing 20 as well, the total area of the sliding part 406 in the compressor side engaging part 202 can be made larger than the total area of the sliding part 305 in the turbine side engaging part 201. Effects similar to (1) to (3) in the embodiment can be obtained.

  Contrary to the second modified example, the non-sliding portion 304 and the sliding portion 306 are formed on the second surface 302 of the thrust disk 30, and the non-sliding portion 403 and the sliding portion are formed on the turbine-side thrust collar 401. A configuration that forms 405 can also be employed. Further, the thrust disk 30 shown in FIG. 4 and the thrust ring 40 shown in FIG. 5 are combined, and the sliding portions and the non-sliding portions are provided on both surfaces facing each other in the engaging portions 201 and 202. It can also be adopted.

  In the first embodiment, the sliding parts 305 in the turbine side engaging part 201 and the sliding parts 306 in the compressor side engaging part 202 have the same number. The number of parts and the number of sliding parts in the compressor side engaging part 202 are not necessarily the same. If the total area of the sliding part in the compressor side engaging part 202 is larger than the total area of the sliding part in the turbine side engaging part 201, the same effect as the first embodiment can be obtained.

  Therefore, as a third modification of the first embodiment, as shown in FIG. 7, the number of sliding portions 306 in the compressor side engaging portion 202 is made larger than the number of sliding portions 305 in the turbine side engaging portion 201. Many configurations can be adopted.

  For example, in the case of the third modified example shown in FIG. 7, the lengths (L21 + L22) of the pair of non-sliding portions 304 and sliding portions 306 in the compressor side engaging portion 202 are set in the turbine side engaging portion 201. The length of the pair of non-sliding portion 303 and sliding portion 305 (L23 + L24) is half. That is, in the thrust bearing 20, the number of non-sliding portions 304 in the compressor side engaging portion 202 is double the number of non-sliding portions 303 in the turbine side engaging portion 201, and the compressor side engaging portion 202. The number of sliding parts 306 in the turbine is doubled from the number of sliding parts 305 in the turbine side engaging part 201.

  In the thrust bearing 20, the length L22 of each sliding portion 306 in the compressor side engaging portion 202 is made equal to the length L24 of each sliding portion 305 in the turbine side engaging portion 201.

  According to such a configuration, the number of sliding portions in the entire compressor side engaging portion 202 is larger than the number of sliding portions in the entire turbine side engaging portion 201. Therefore, the total area of the sliding part 306 in the compressor side engaging part 202 can be made larger than the total area of the sliding part 305 in the turbine side engaging part 201.

Therefore, the same effect as (1) to (3) in the first embodiment can be obtained also by the third modified example.
In addition, the setting aspect of the length of the sliding part in each engaging part and a non-sliding part is not limited to the above setting aspects, The total area of the sliding part in the compressor side engaging part 202 is turbine side. Any setting mode can be used as long as it is larger than the total area of the sliding portions in the engaging portion 201.

  Moreover, the combination of the surface which forms a non-sliding part and a sliding part can be changed. For example, this technical idea can also be applied to the thrust bearing 20 in which the sliding portions and the non-sliding portions are formed in the thrust collars 401 and 402 as in the first modified example. That is, also in this case, the total area of the sliding parts in the compressor side engaging part 202 is changed in the turbine side engaging part 201 by making the number of sliding parts and non-sliding parts in the thrust collars 401 and 402 different. The total area of the sliding portion can be made larger. Similarly, as in the second modified example, a sliding portion and a non-sliding portion are formed on one thrust collar, and a sliding portion and a non-sliding portion are provided on the surface of the thrust disk 30 facing the other thrust collar. This technical idea can also be applied to the formed thrust bearing 20. Furthermore, this technical idea can also be applied to the thrust bearing 20 in which the sliding portions and the non-sliding portions are provided on both surfaces of the engaging portions 201 and 202 facing each other.

(Second Embodiment)
Next, a second embodiment of a turbocharger thrust bearing will be described with reference to FIGS.

  As shown in FIG. 8, the thrust bearing 50 of the second embodiment employs a configuration in which a thrust collar 71 is disposed between a pair of thrust disks 61 and 62. Since other configurations are the same as those in the first embodiment, the same reference numerals are used to omit redundant description, and the following description will focus on differences.

  As shown in FIG. 8, in the turbocharger 10 including the thrust bearing 50 of the present embodiment, a turbine side thrust disk 61, a spacer member 143, a compressor side thrust disk 62, and the like are interposed between the retainer 142 and the bearing housing 14. Is sandwiched. The spacer member 143 is sandwiched between the pair of thrust disks 61 and 62. The pair of thrust disks 61 and 62 and the spacer member 143 are fixed to the bearing housing 14 together with the retainer 142 by bolts 145.

  A thrust ring 70 is fixed to the rotary shaft 13 at a position corresponding to the pair of thrust disks 61 and 62. A thrust collar 71 is formed at the center of the outer peripheral surface of the thrust ring 70 over the entire circumference. The thrust collar 71 is sandwiched between the turbine side thrust disk 61 and the compressor side thrust disk 62.

  As a result, as shown in FIG. 9, in the turbocharger 10, the turbine side thrust disk 61 and the first surface 73 of the thrust collar 71 face each other to form a turbine side engaging portion 201. On the other hand, in the turbocharger 10, the compressor side thrust disk 62 and the second surface 72 of the thrust collar 71 face each other to form a compressor side engaging portion 202.

  For this reason, when the rotating shaft 13 moves to the turbine housing 11 side (the right side in FIGS. 8 and 9) in the insertion hole 140, the first surface 73 of the thrust collar 71 fixed to the rotating shaft 13, The turbine side thrust disk 61 fixed to the bearing housing 14 is engaged. That is, in this case, the turbine side engagement portion 201 restricts the movement of the rotating shaft 13 in the axial direction. On the other hand, when the rotary shaft 13 moves to the compressor housing 12 side (left side in FIGS. 8 and 9) within the insertion hole 140, the second surface 72 of the thrust collar 71 fixed to the rotary shaft 13, The compressor-side thrust disk 62 fixed to the bearing housing 14 is engaged. That is, in this case, the compressor-side engagement portion 202 restricts the movement of the rotary shaft 13 in the axial direction.

  That is, in the turbocharger 10, the thrust bearing 50 that restricts the axial movement of the rotary shaft 13 is configured by the pair of thrust disks 61 and 62 and the thrust ring 70 including the thrust collar 71.

Note that oil is supplied to the engaging portions 201 and 202 of the thrust bearing 50 by driving an oil pump.
As shown on the right side of FIG. 9, the portions facing the thrust collar 71 in the turbine side thrust disk 61 are provided with depressions at regular intervals in the circumferential direction as in the thrust disk 30 in the first embodiment. A non-sliding portion 603 is formed by the depression. Thus, the turbine-side thrust disk 61 is provided with non-sliding portions 603 formed by these recesses and sliding portions 605 not provided with the recesses arranged alternately in the circumferential direction.

  Further, as shown on the left side of FIG. 9, in the portion facing the thrust collar 71 in the compressor side thrust disk 62, depressions are provided at regular intervals in the circumferential direction as in the thrust disk 30 in the first embodiment. A non-sliding portion 604 is formed by these depressions. As a result, the compressor-side thrust disk 62 is provided with non-sliding portions 604 formed by these recesses and sliding portions 606 provided with no recesses alternately arranged in the circumferential direction.

  Each thrust disk 61, 62 is provided with an equal number of depressions. Therefore, the number of sliding parts 605 provided on the turbine side thrust disk 61 is equal to the number of sliding parts 606 provided on the compressor side thrust disk 62. Further, the shape of the recess in the thrust bearing 50 is also tapered so as to gradually become deeper in one direction.

  Here, the length of each non-sliding portion 604 in the compressor-side thrust disk 62 is L31, and the length of each sliding portion 606 is L32. In addition, the length of each non-sliding portion 603 in the turbine-side thrust disk 61 is L33, and the length of each sliding portion 605 is L34.

  As shown in FIG. 9, the set of non-sliding portions 604 and the length of the sliding portion 606 (L31 + L32) formed on the compressor-side thrust disk 62 and the set of non-sliding portions 606 formed on the turbine-side thrust disk 61. The length (L33 + L34) of the sliding part 603 and the sliding part 605 is equal.

  The length L34 of each sliding portion 605 in the turbine-side thrust disk 61 is longer than the length L32 of each sliding portion 606 in the compressor-side thrust disk 62. As a result, the ratio λt of the length L34 of the sliding portion 605 to the length (L33 + L34) of the pair of non-sliding portions 603 and the sliding portions 605 on the turbine side is a set of non-sliding portions on the compressor side. The ratio λc of the length L32 of the sliding portion 606 to the length (L31 + L32) of 604 and the sliding portion 606 is larger.

  In order to reduce the friction, the smaller the ratios λc and λt occupied by the sliding portions 605 and 606, the more advantageous. Therefore, in this thrust bearing 50, the ratio λc is set to about 0.1 and the ratio λt is set to 0. About 3

  Thus, by making the ratio λt larger than the ratio λc, in this thrust bearing 50, the area of each sliding portion 605 in the turbine-side thrust disk 61 constituting the turbine-side engaging portion 201 is the compressor-side engaging portion 202. It is larger than the area of each sliding part 606 in the compressor side thrust disk 62 which comprises.

  As a result, in the thrust bearing 50, the total area of the sliding part 605 in the turbine side engaging part 201 is larger than the total area of the sliding part 606 in the compressor side engaging part 202.

Next, the operation of the thrust bearing 50 according to this embodiment will be described.
As described above, in the turbocharger 10, when supercharging is performed, a force that pulls each impeller 110, 120 to the tip side acts.

  Further, when the rotating shaft 13 rotates, the thrust ring 70 fixed to the rotating shaft 13 also rotates as indicated by an arrow in FIG. At this time, the oil supplied to the turbine side engaging portion 201 and the compressor side engaging portion 202 also flows as the thrust ring 70 rotates.

  As described above, in this thrust bearing 50, the non-sliding portion 603 is formed on the turbine-side thrust disk 61 and the non-sliding portion 604 is formed on the compressor-side thrust disk 62. , 62 and the thrust collar 71 are reduced in sliding area. Therefore, the friction in the turbine side engaging part 201 and the compressor side engaging part 202 can be reduced.

  Further, as the thrust ring 70 rotates, the sliding portions 605 and 606 and the thrust collar 71 are moved from the portion where the non-sliding portions 603 and 604 and the thrust collar 71 face each other in the engaging portions 201 and 202. It is drawn into the opposite part and flows from a wide part to a narrow part. Therefore, the hydraulic pressure is increased at the portion where the sliding portions 605 and 606 and the thrust collar 71 are opposed to each other, and a force that separates the thrust disks 61 and 62 and the thrust collar 71 acts. As a result, the thickness of the oil film on the sliding surface between the thrust disks 61 and 62 and the thrust collar 71 is secured, and the friction is further reduced by fluid lubrication.

  In addition, as shown in FIG. 9, since the hollow which forms the non-sliding parts 603 and 604 becomes a taper shape which becomes shallow gradually toward the flow direction of the oil at this time, the flow of oil Becomes smooth. This is advantageous in reducing friction.

  By the way, when the engine is started, the turbine impeller 110 starts to rotate from a state where supercharging is not performed. Therefore, before the force that pulls the compressor impeller 120 toward the front end acts, the force that pulls the turbine impeller 110 toward the front end is increased. As a result, the rotary shaft 13 is pulled toward the turbine housing 11 side. At the time of starting the engine, since the oil is not sufficiently supplied to the engaging portions 201 and 202, even if the non-sliding portions 603 and 604 are formed on the thrust disks 61 and 62, the sliding portion 605 is used. , 606 and the thrust collar 71 are opposed to each other, the hydraulic pressure cannot be increased. Further, at this time, the non-sliding portions 603 and 604 are formed and the sliding area is reduced, which causes an increase in the surface pressure acting on the sliding surface. Therefore, there is a possibility that the oil film cannot be held and seizure occurs. In the case of the thrust bearing 50 in which the pair of thrust disks 61 and 62 are disposed so as to sandwich the thrust collar 71 as in the present embodiment, when the rotary shaft 13 moves to the turbine housing 11 side, the thrust collar 71 is moved to the turbine side thrust. The disk 61 is approached. That is, in the case of the thrust bearing 50 in which the pair of thrust disks 61 and 62 are disposed so as to sandwich the thrust collar 71, seizure is likely to occur in the turbine side engaging portion 201 when the engine is started.

  On the other hand, in the thrust bearing 50 of the present embodiment, the total area of the sliding portion 605 in the turbine side engaging portion 201 is made larger than the total area of the sliding portion 606 in the compressor side engaging portion 202 so that the turbine side The sliding area in the engaging portion 201 is increased. Therefore, the load acting on the sliding surface is dispersed, and the surface pressure acting on the sliding surface is reduced, so that the oil film can be easily held even when the engine is started.

  If the sliding area of the sliding parts 605 and 606 is increased in both the turbine side engaging part 201 and the compressor side engaging part 202, the friction during engine operation obtained by reducing the sliding area is reduced. The reduction effect is impaired, and the friction during engine operation increases.

  On the other hand, in the thrust bearing 50 of the present embodiment, the total area of the sliding portion 605 in the turbine side engaging portion 201 where seizure is likely to occur when the engine is started is selectively increased. Therefore, the friction reduction during engine operation obtained by reducing the sliding area compared to the case where the total area of the sliding parts 605 and 606 in the engaging parts 201 and 202 on both the compressor side and the turbine side is increased. The effect is less likely to be impaired.

According to the second embodiment described above, the following effects can be obtained.
(1) By providing the non-sliding portion 603 in the turbine side engaging portion 201 and providing the non-sliding portion 604 in the compressor side engaging portion 202, the sliding area in each engaging portion 201, 202 is reduced. Therefore, friction can be reduced.

  (2) With the rotation of the thrust ring 70, the hydraulic pressure increases at the portion where the sliding portions 605, 606 and the thrust collar 71 face each other, so that the force that separates the thrust disks 61, 62 and the thrust collar 71 acts. become. Therefore, the thickness of the oil film on the sliding surface between the thrust disks 61 and 62 and the thrust collar 71 can be secured, and friction can be reduced by fluid lubrication.

  (3) The total area of the sliding part 605 in the turbine side engaging part 201 where seizure is likely to occur when the engine is started is selectively increased. Therefore, the friction reduction during engine operation obtained by reducing the sliding area compared to the case where the total area of the sliding parts 605 and 606 in the engaging parts 201 and 202 on both the compressor side and the turbine side is increased. The effect is hard to be impaired.

  That is, according to the thrust bearing 50 of the present embodiment, the occurrence of seizure at the start of the engine is suppressed while reducing the friction during the engine operation by reducing the sliding area in each of the engaging portions 201 and 202. be able to.

In addition, the said 2nd Embodiment is not limited to the structure demonstrated above, It can also implement with the following forms which changed this suitably.
An example in which the ratio λc is set to about 0.1 and the ratio λt is set to about 0.3 is shown, but if the ratio λt is larger than the ratio λc, the sizes of the ratio λt and the ratio λc can be changed as appropriate. It is. Since it is preferable to reduce the sliding portions 605 and 606 from the viewpoint of reducing friction, it is preferable to reduce the ratios λt and λc. However, if the sliding portions 605 and 606 are too small, it is difficult to hold the oil film. Thus, the load capacity of the thrust bearing 50 is reduced. Therefore, it is desirable that the ratios λt and λc be set to a size that can reduce friction as much as possible while securing a necessary load capacity based on the results of simulations through experiments and calculations. For example, the ratio λc is preferably 0.05 to 0.2, and the ratio λt is preferably 0.25 to 0.5.

  In the second embodiment, the non-sliding portion 603 and the sliding portion 605 are formed on the turbine-side thrust disk 61, and the non-sliding portion 604 and the sliding portion 606 are formed on the compressor-side thrust disk 62. However, if the non-sliding portion and the sliding portion are formed on at least one of the mutually opposing surfaces of the engaging portions 201 and 202, the same effect as in the second embodiment can be obtained. it can.

  Therefore, as a first modification of the second embodiment, a non-sliding portion 703 and a sliding portion 705 are formed on the first surface 73 of the thrust collar 71 as shown in FIG. Alternatively, a configuration in which the non-sliding portion 704 and the sliding portion 706 are formed may be employed. When the non-sliding portions 703 and 704 are formed on the respective surfaces 73 and 72 of the thrust collar 71 in this way, the recess becomes deeper toward the front side in the rotation direction of the thrust collar 71 as shown in FIG. A tapered shape is preferred.

  When the non-sliding portions 703 and 704 are formed on the surfaces 73 and 72 of the thrust collar 71 as described above, the length L44 of the sliding portion 705 in the turbine side engaging portion 201 is set as shown in FIG. The length L42 of the sliding portion 706 in the compressor side engaging portion 202 may be made longer. By adopting such a configuration, the ratio λt of the length L44 of the sliding portion 705 to the length (L43 + L44) of the pair of non-sliding portions 703 and the sliding portions 705 on the turbine side is a set on the compressor side. It becomes larger than the ratio λc of the length L42 of the sliding portion 706 to the length (L41 + L42) of the non-sliding portion 704 and the sliding portion 706. Thus, if the ratio λt is made larger than the ratio λc, even in this thrust bearing 50, the area of each sliding portion 705 on the first surface 73 of the thrust collar 71 constituting the turbine side engaging portion 201 is the compressor side. It becomes larger than the area of each sliding part 706 in the 2nd surface 72 of the thrust collar 71 which comprises the engaging part 202. FIG.

  As a result, also in this thrust bearing 50, the total area of the sliding part 705 in the turbine side engaging part 201 can be made larger than the total area of the sliding part 706 in the compressor side engaging part 202, and the second embodiment described above. Effects similar to (1) to (3) in the embodiment can be obtained.

  As a second modification, as shown in FIG. 11, a non-sliding portion 603 and a sliding portion 605 are formed on the turbine-side thrust disk 61, and a non-sliding portion is formed on the second surface 72 of the thrust collar 71. A configuration in which 704 and the sliding portion 706 are formed may be employed.

  In this case, as shown in FIG. 11, the length L34 of the sliding portion 605 in the turbine side engaging portion 201 may be made longer than the length L42 of the sliding portion 706 in the compressor side engaging portion 202. By adopting such a configuration, the ratio λt of the length L34 of the sliding portion 605 to the length (L33 + L34) of the pair of non-sliding portions 603 and the sliding portions 605 on the turbine side is a set on the compressor side. It becomes larger than the ratio λc of the length L42 of the sliding portion 706 to the length (L41 + L42) of the non-sliding portion 704 and the sliding portion 706. Thus, if the ratio λt is larger than the ratio λc, also in this thrust bearing 50, the area of each sliding portion 605 in the turbine side engaging portion 201 is equal to the area of each sliding portion 706 in the compressor side engaging portion 202. Bigger than.

  As a result, also in this thrust bearing 50, the total area of the sliding part 605 in the turbine side engaging part 201 can be made larger than the total area of the sliding part 706 in the compressor side engaging part 202, and the second embodiment described above. Effects similar to (1) to (3) in the embodiment can be obtained.

  Contrary to the second modified example, the non-sliding portion 604 and the sliding portion 606 are formed on the compressor side thrust disk 62, and the non-sliding portion 703 and the sliding portion are formed on the first surface 73 of the thrust collar 71. A configuration for forming 705 may be employed. Further, the thrust disks 61 and 62 shown in FIG. 9 and the thrust ring 70 shown in FIG. 10 are combined, and a sliding portion and a non-sliding portion are provided on both surfaces facing each other in the engaging portions 201 and 202. A configuration can also be adopted.

  In the second embodiment, the sliding portion 605 in the turbine side engaging portion 201 and the sliding portion 606 in the compressor side engaging portion 202 are the same number, but sliding in the turbine side engaging portion 201 is performed. The number of parts and the number of sliding parts in the compressor side engaging part 202 are not necessarily the same. If the total area of the sliding part in the turbine side engaging part 201 is larger than the total area of the sliding part in the compressor side engaging part 202, the same effect as the second embodiment can be obtained.

  Therefore, as a third modification of the second embodiment, as shown in FIG. 12, the number of sliding portions 605 in the turbine side engaging portion 201 is set to be larger than the number of sliding portions 606 in the compressor side engaging portion 202. Many configurations can be adopted.

  For example, in the case of the third modified example shown in FIG. 12, the lengths (L51 + L52) of the pair of non-sliding portions 603 and sliding portions 605 in the turbine side engaging portion 201 are set in the compressor side engaging portion 202. One set of the non-sliding portion 604 and the sliding portion 606 is half the length (L31 + L32). That is, in the thrust bearing 50, the number of non-sliding portions 603 in the turbine side engaging portion 201 is double the number of non-sliding portions 604 in the compressor side engaging portion 202, and the turbine side engaging portion 201. The number of sliding portions 605 in the compressor is set to be twice the number of sliding portions 606 in the compressor side engaging portion 202.

  Further, in the thrust bearing 50, the length L52 of each sliding portion 605 in the turbine side engaging portion 201 is made equal to the length L32 of each sliding portion 606 in the compressor side engaging portion 202.

  According to such a configuration, the number of sliding portions in the entire turbine side engaging portion 201 is larger than the number of sliding portions in the entire compressor side engaging portion 202. Therefore, the total area of the sliding part 605 in the turbine side engaging part 201 can be made larger than the total area of the sliding part 606 in the compressor side engaging part 202.

Therefore, the same effect as (1) to (3) in the second embodiment can be obtained also by the third modified example.
In addition, the setting aspect of the length of the sliding part in each engaging part and the non-sliding part is not limited to the above setting aspects, The total area of the sliding part in the turbine side engaging part 201 is the compressor side. Any setting mode can be used as long as it is larger than the total area of the sliding portions in the engaging portion 202.

  Moreover, the combination of the surface which forms a non-sliding part and a sliding part can be changed. For example, this technical idea can also be applied to the thrust bearing 50 in which the sliding portions and the non-sliding portions are formed on the surfaces 73 and 72 of the thrust collar 71 as in the first modified example. That is, also in this case, the total area of the sliding parts in the turbine side engaging part 201 is made to be the compressor side engaging by making the number of sliding parts and non-sliding parts in the surfaces 73 and 72 of the thrust collar 71 different. The total area of the sliding part in the part 202 can be made larger. Similarly, as in the second modified example, the sliding portion and the non-sliding portion are formed on one thrust disk, and the sliding portion and the non-sliding portion are provided on the surface of the thrust collar 71 facing the other thrust disk. This technical idea can also be applied to the formed thrust bearing 50. Furthermore, this technical idea can also be applied to the thrust bearing 20 in which the sliding portions and the non-sliding portions are provided on both surfaces of the engaging portions 201 and 202 facing each other.

  In addition, as a thrust bearing of the turbocharger for solving the said subject, it is not limited to the structure shown to each said embodiment, It can also implement with the following forms which changed this suitably.

  In each of the above embodiments, the non-sliding portion in each of the engaging portions 201 and 202 is formed by providing a tapered recess. However, the shape of the recess is not limited to the tapered shape. For example, a recess having a rectangular cross-sectional shape may be provided. Also with this configuration, it is possible to reduce the friction by reducing the sliding area in each of the engaging portions 201 and 202. Further, a crater-like depression may be provided, and this configuration can also reduce the friction by reducing the sliding area in each of the engaging portions 201 and 202.

  DESCRIPTION OF SYMBOLS 10 ... Turbocharger, 11 ... Turbine housing, 110 ... Turbine impeller, 111 ... Discharge passage, 112 ... Scroll passage, 12 ... Compressor housing, 120 ... Compressor impeller, 121 ... Introduction passage, 122 ... Compressor passage, 13 ... Rotating shaft, DESCRIPTION OF SYMBOLS 14 ... Bearing housing, 140 ... Insertion hole, 141 ... Radial bearing, 142 ... Retainer, 143 ... Spacer member, 145 ... Bolt, 20 ... Thrust bearing, 201 ... Turbine side engaging part, 202 ... Compressor side engaging part, 30 ... Thrust disk 301 ... First surface 302 ... Second surface 303 ... Non-sliding part 304 ... Non-sliding part 305 ... Sliding part 306 ... Sliding part 310 ... Bolt hole, 40 ... thrust ring, 41 ... concave, 401 ... turbine side thrust collar, 402 ... compress Side thrust collar, 403 ... non-sliding part, 404 ... non-sliding part, 405 ... sliding part, 406 ... sliding part, 50 ... thrust bearing, 61 ... turbine side thrust disk, 62 ... compressor side thrust disk, 603 ... Non-sliding part, 604 ... Non-sliding part, 605 ... Sliding part, 606 ... Sliding part, 70 ... Thrust ring, 71 ... Thrust collar, 72 ... Second surface, 73 ... First surface, 703 ... non-sliding part, 704 ... non-sliding part, 705 ... sliding part, 706 ... sliding part.

Claims (6)

A thrust disk fixed to the housing;
A turbine-side thrust collar and a compressor-side thrust collar, which are fixed to a rotating shaft connecting the turbine impeller and the compressor impeller and disposed so as to sandwich the thrust disk;
The axial movement of the rotary shaft is limited by the turbine side engaging portion where the turbine side thrust collar and the thrust disk are engaged and the compressor side engaging portion where the compressor side thrust collar and the thrust disk are engaged. Is a turbocharger thrust bearing
A non-sliding portion formed by a recess and a sliding portion not provided with the recess are circumferentially provided on a surface of each engaging portion facing the other of at least one of the thrust disk and the thrust collar. It is provided side by side alternately,
A turbocharger thrust bearing in which a total area of the sliding portion in the compressor side engaging portion is larger than a total area of the sliding portion in the turbine side engaging portion. The number of sliding parts in the compressor side engaging part is equal to the number of sliding parts in the turbine side engaging part, and the area of each sliding part in the compressor side engaging part is the turbine side engaging part. The thrust bearing of the turbocharger according to claim 1, wherein the thrust bearing is larger than an area of each sliding portion. The area of each sliding part in the compressor side engaging part is equal to the area of each sliding part in the turbine side engaging part, and the number of sliding parts in the compressor side engaging part is equal to the turbine side engaging part. The turbocharger thrust bearing according to claim 1, wherein the thrust bearing is larger than the number of the sliding portions. A thrust collar fixed to a rotating shaft connecting the turbine impeller and the compressor impeller;
A turbine-side thrust disk and a compressor-side thrust disk fixed to the housing and disposed so as to sandwich the thrust collar;
The axial movement of the rotary shaft is limited by the turbine side engaging portion where the turbine side thrust disc and the thrust collar engage and the compressor side engaging portion where the compressor side thrust disc and the thrust collar engage. Is a turbocharger thrust bearing
A non-sliding portion formed by a recess and a sliding portion not provided with the recess are circumferentially provided on a surface of each engaging portion facing the other of at least one of the thrust disk and the thrust collar. It is provided side by side alternately,
A turbocharger thrust bearing in which a total area of the sliding portion in the turbine side engaging portion is larger than a total area of the sliding portion in the compressor side engaging portion. The number of sliding parts in the turbine side engaging part is equal to the number of sliding parts in the compressor side engaging part, and the area of each sliding part in the turbine side engaging part is the compressor side engaging part. The turbocharger thrust bearing according to claim 4, wherein the thrust bearing is larger than an area of each sliding portion. The area of each sliding part in the turbine side engaging part is equal to the area of each sliding part in the compressor side engaging part, and the number of sliding parts in the turbine side engaging part is the compressor side engaging part. The turbocharger thrust bearing according to claim 4, wherein the number of the sliding parts is greater than the number of the sliding parts.