Turbocharger

Patent metadata

Field	Value
Publication number	US-9790950-B2
Application number	US-201414548869-A
Country	US
Kind code	B2
Filing date	Nov 20, 2014
Priority date	Jun 29, 2012
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

A turbocharger includes: a bearing provided in a turbocharger body, and configured to rotatably support a turbine shaft in an insertion hole formed in the bearing; and an opposing portion which faces an end surface of the bearing in an axial direction of the turbine shaft. An end-surface guide portion is provided to any one of an opposing surface of the bearing which faces the opposing portion, and an opposing surface of the opposing portion which faces the bearing. The end-surface guide portion configured to make the insertion hole and an outer peripheral edge of the end surface of the bearing in radial directions of the turbine shaft communicate with each other extends forward in a rotational direction of the turbine shaft from a part of the end surface of the bearing which communicates with the insertion hole.

First claim

What is claimed is:

1. A turbocharger comprising:
a turbocharger body;
a turbine shaft rotatably housed in the turbocharger body with a turbine impeller provided to one end of the turbine shaft and a compressor impeller provided to an opposite end of the turbine shaft;
a bearing provided in the turbocharger body and configured to rotatably support the turbine shaft in an insertion hole formed in the bearing; and
an opposing portion facing an end surface of the bearing in an axial direction of the turbine shaft, wherein
an end-surface guide portion configured to make the insertion hole and an outer peripheral edge of the end surface of the bearing in radial directions of the turbine shaft communicate with each other is provided to any one of an opposing surface of the bearing which faces the opposing portion, and an opposing surface of the opposing portion which faces the bearing,
the end-surface guide portion extends forward in a rotational direction of the turbine shaft from a part of the end surface of the bearing which communicates with the insertion hole,
the end-surface guide portion forms a passage configured to discharge a foreign substance, together with lubricant, from the opposing surface provided with the end-surface guide portion to outside of the opposing surface in the radial directions,
wherein an oil droplet of the lubricant receives rotation force from the turbine shaft and follows the passage, and the motion of the oil droplet fulfills the following equation:

r
=

r
1

⁢

exp
⁡

[

(

θ
-

θ
1

)

2

2

]

where r denotes a distance of the oil droplet from an origin being a center of the bearing, θ denotes a phase angle of the oil droplet, r 1 denotes an initial distance of the oil droplet from the origin, and θ 1 denotes an initial phase angle of the oil droplet.

2. The turbocharger according to claim 1 , wherein the bearing is formed from a bush including a running surface configured to receive radial load of the turbine shaft with an oil film held between the running surface and the turbine shaft.

3. The turbocharger according to claim 2 , wherein
the running surface or an outer peripheral surface of the turbine shaft, which faces the running surface, is provided with an running-surface guide portion which is formed from a groove extending from one end to an opposite end in the axial direction of the turbine shaft,
one end of the running-surface guide portion in the axial direction of the turbine shaft communicates with the end-surface guide portion, and
the one end of the running-surface guide portion in the axial direction of the turbine shaft is located further forward in the rotational direction of the turbine shaft than the opposite end of the running-surface guide portion.

4. The turbocharger according to claim 3 , wherein
the running-surface guide portion forms a passage configured to discharge the foreign substance, together with the lubricant, from the running surface to the end-surface guide portion, and
a direction of extension of the running-surface guide portion is along the direction of the movement of the oil droplet of the lubricant receiving the rotational force of the turbine shaft.

5. The turbocharger according to claim 4 , wherein the bearing is formed from a semi-floating bearing whose movement in its rotational and axial directions is restricted by a pin provided to the turbocharger body.

6. The turbocharger according to claim 3 , wherein the bearing is formed from a semi-floating bearing whose movement in its rotational and axial directions is restricted by a pin provided to the turbocharger body.

7. The turbocharger according to claim 2 , wherein the bearing is formed from a semi-floating bearing whose movement in its rotational and axial directions is restricted by a pin provided to the turbocharger body.

8. A turbocharger comprising:
a turbocharger body;
a turbine shaft rotatably housed in the turbocharger body with a turbine impeller provided to one end of the turbine shaft and a compressor impeller provided to an opposite end of the turbine shaft;
a thrust collar configured to rotate integrally with the turbine shaft; and
a thrust bearing disposed facing the thrust collar in an axial direction of the turbine shaft, the turbine shaft inserted in an insertion hole formed in the thrust bearing, and the thrust bearing configured to receive thrust load of the turbine shaft via the thrust collar, wherein
an end-surface guide portion configured to make the insertion hole and an outer peripheral edge of the thrust collar in radial directions of the turbine shaft communicate with each other is provided to any one of an opposing surface of the thrust bearing which faces the thrust collar, and an opposing surface of the thrust collar which faces the thrust bearing,
the end-surface guide portion extends forward in a rotational direction of the turbine shaft from a part of an end surface of the thrust bearing which communicates with the insertion hole,
the end-surface guide portion forms a passage configured to discharge a foreign substance, together with lubricant, from the opposing surface provided with the end-surface guide portion to outside of the opposing surface in the radial directions,
wherein an oil droplet of the lubricant receives rotation force from the turbine shaft and follows the passage, and the motion of the oil droplet fulfills the following equation:

r
=

r
1

⁢

exp
⁡

[

(

θ
-

θ
1

)

2

2

]

where r denotes a distance of the oil droplet from an origin being a center of the bearing, θ denotes a phase angle of the oil droplet, r 1 denotes an initial distance of the oil droplet from the origin, and θ 1 denotes an initial phase angle of the oil droplet.

Assignees

• Ihi Corp

Inventors

• Uneura Yutaka
• Otani Tomomi
• Daito Yuichi

Classifications

• F05D2250/15

  spiral · CPC title

• F04D29/051 Primary

  Axial thrust balancing · CPC title

• F16C17/10

  for both radial and axial load · CPC title

• F05D2240/54

  Radial bearings · CPC title

• F16C17/107

  with at least one surface for radial load and at least one surface for axial load · CPC title