CN114198307A

CN114198307A - Vacuum pump

Info

Publication number: CN114198307A
Application number: CN202110727117.XA
Authority: CN
Inventors: 石井俊裕; 高崎雄佑; 小田信祯; 对马雅范; 江波户昭裕; 矢泽浩史
Original assignee: Mikuni Corp
Current assignee: Mikuni Corp
Priority date: 2020-09-18
Filing date: 2021-06-29
Publication date: 2022-03-18
Also published as: JP7479258B2; JP2022050841A

Abstract

Provided is a vacuum pump which can prevent an oil supply pipe from remaining on the engine side when the vacuum pump is detached from an engine. A vacuum pump (1) is provided with: an oil supply pipe (2) having an inlet (12) for lubricating oil formed at one end (10) and an outlet (20) for lubricating oil formed at the other end (18); a rotor (4) including a shaft portion (28), the shaft portion (28) being formed with a recess (26) into which the other end portion (18) of the oil supply pipe (2) can be inserted; a coupling (6) that engages with the shaft (28); and a bushing (8) that presses the coupling (6), is fitted to the inner circumferential surface (30) of the recess (26), and is configured to restrict the other end (18) of the oil supply pipe (2) from coming off the recess (26).

Description

Vacuum pump

Technical Field

The present disclosure relates to a vacuum pump for a vehicle.

Background

A vacuum pump for a vehicle may be mounted on an engine so that lubricating oil is supplied from the outside. The vacuum pump described in patent document 1 includes: a shaft portion of a rotor coupled to a camshaft of an engine; and an oil supply pipe having one end fitted in the recess of the shaft portion via an O-ring on the pump side and the other end fitted in the recess of the camshaft via an O-ring on the engine side.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2006-118424

Disclosure of Invention

Technical problem to be solved

However, in the technique described in patent document 1, when the vacuum pump attached to the engine is detached from the engine, there is a possibility that the oil supply pipe is pulled out from the shaft portion and is held by the camshaft. That is, there is a possibility that the oil supply pipe remains on the engine side. If the oil supply pipe remains on the engine side, the operability at the time of mounting the vacuum pump to the engine again (reassembly) is deteriorated.

The present disclosure has been made in view of the above-described problems, and an object thereof is to provide a vacuum pump that can suppress an oil supply pipe from remaining on an engine side when detached from the engine.

(II) technical scheme

(1) A vacuum pump according to at least one embodiment of the present disclosure includes: an oil supply pipe having an inlet for lubricating oil formed at one end portion and an outlet for lubricating oil formed at the other end portion; a rotor including a shaft portion formed with a recess into which the other end portion of the oil supply pipe is inserted; a coupling engaged with the shaft portion; and a bushing configured to press the coupling and fit into an inner circumferential surface of the recess, and to restrict the other end portion of the oil supply pipe from coming off the recess.

(2) In some embodiments, in the structure described in (1) above, the bushing may include: a coupling pressing portion that presses the coupling; and a cylindrical portion fitted to the inner peripheral surface.

(3) In some embodiments, in the structure described in the above (2), the cylindrical portion of the bush may include: a first part which is cylindrical, is connected with the coupling pressing part and is embedded in the inner circumferential surface; and a second portion connected to the first portion on the opposite side of the coupling pressing portion and extending toward the inside in the radial direction of the rotor as the second portion is separated from the first portion, wherein the bushing is configured to restrict the separation of the other end portion of the oil supply pipe from the recess portion by the second portion.

(4) In some embodiments, in the structure described in (3) above, the outer peripheral surface of the other end portion of the oil supply pipe may include a convex portion at a position deeper than the second portion in the concave portion, and a distance between an inner end of the second portion in the radial direction and the outer peripheral surface of the other end portion of the oil supply pipe may be smaller than a height of the convex portion in the radial direction from the outer peripheral surface.

(5) In some embodiments, in the structure described in (3) above, an elastic body may be further provided at a position deeper than the second portion of the recess, the elastic body may be held on an outer peripheral surface of the other end portion of the oil supply pipe, and a distance between an inner end of the second portion in the radial direction of the rotor and the outer peripheral surface of the other end portion of the oil supply pipe may be smaller than a size of the elastic body in the radial direction when the elastic body is in an uncompressed natural state.

(6) In some embodiments, in the structure described in (2) above, an annular member may be further provided at a position deeper than the bushing in the recess, the annular member having an outer diameter larger than an inner diameter of the cylindrical portion of the bushing, and the bushing may be configured to restrict detachment of the other end portion of the oil supply pipe from the recess via the annular member.

(7) In some embodiments, in the structure described in (6) above, an inner peripheral surface of the recess may include a step portion, and the annular member may be disposed between the bush and the step portion.

(8) In some embodiments, in the structure described in (6) or (7), an outer peripheral surface of the other end portion of the oil supply pipe may include a convex portion at a position deeper than the annular member in the concave portion, and a distance between an inner end of the annular member in a radial direction of the rotor and the outer peripheral surface of the other end portion of the oil supply pipe may be smaller than a height of the convex portion in the radial direction from the outer peripheral surface.

(9) In some embodiments, in the structure described in the above (6) or (7), an elastic body may be further provided at a position deeper than the annular member in the recess, the elastic body may be held on an outer peripheral surface of the other end portion of the oil supply pipe, and a distance between an inner end of the annular member in a radial direction of the rotor and the outer peripheral surface of the other end portion of the oil supply pipe may be smaller than a size of the elastic body in the radial direction when the elastic body is in an uncompressed natural state.

(III) advantageous effects

According to the vacuum pump of the present disclosure, when detached from the engine, the oil feed pipe can be suppressed from remaining on the engine side.

Drawings

Fig. 1 is a sectional view showing the structure of a vacuum pump according to a first embodiment of the present disclosure.

Fig. 2 is a perspective view of a vacuum pump according to a first embodiment of the present disclosure.

Fig. 3 is a diagram showing the structure of a bush and a fuel supply pipe according to a first embodiment of the present disclosure, and is an enlarged sectional view of a part of fig. 1.

Fig. 4 is a sectional view showing the structure of a fuel supply pipe according to a modification of the first embodiment of the present disclosure.

Fig. 5 is a sectional view showing the structure of a vacuum pump according to a second embodiment of the present disclosure.

Fig. 6 is a sectional view showing the structure of a fuel supply pipe according to a modification of the second embodiment of the present disclosure.

Description of the reference numerals

1-a vacuum pump; 2-oil supply pipe; 4-a rotor; 6-a coupler; 8-a bushing; 10-one end of the oil supply pipe; 12-an inlet; 18-the other end of the oil supply pipe; 20-an outlet; 26-a recess; 28-a shaft portion; 30-inner peripheral surface of the recess; 35-a second cylindrical portion (convex portion); 37-the outer peripheral surface of the second cylindrical portion (the outer peripheral surface of the convex portion); 45-a barrel section; 47-a coupler pressing part; 49-a first part of the barrel; 56-a second part of the barrel; 58-an inboard end of the second portion; 60-an elastomer; 62-a ring-shaped member; 64-step of inner peripheral surface; 66-the inboard end of the annular member; 70-an elastomer; o-axis of rotation.

Detailed Description

An embodiment of the present disclosure is described below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the members described as the embodiments or shown in the drawings do not limit the scope of the present invention, and are merely illustrative examples.

For example, expressions indicating relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "central", "concentric", or "coaxial" do not only indicate an arrangement in a strict sense, but also indicate a state in which the elements are relatively displaced by an angle or distance to the extent that the same function can be obtained, or a tolerance is provided.

For example, expressions such as "identical", "equal", and "homogeneous" indicating that objects are in an equal state do not only indicate states that are strictly equal but also indicate states that are different in tolerance or degree of obtaining the same function.

For example, the expression indicating the shape such as a square shape or a cylindrical shape does not only indicate the shape such as a square shape or a cylindrical shape in a strict geometrical sense, but also indicates a shape including a concave and convex portion, a chamfered portion, and the like within a range in which the same effect can be obtained.

On the other hand, the expression "present", "having", "provided", "including", or "having" one constituent element is not an exclusive expression that excludes the presence of other constituent elements.

A vacuum pump according to an embodiment of the present disclosure is a pump for making a negative pressure in a negative pressure chamber of a brake booster (Mastervac) of a vehicle such as an automobile, for example. Such a vacuum pump rotates a rotor of the vacuum pump by, for example, a driving force of an engine. In addition, such a vacuum pump is supplied with lubricating oil from an engine through an oil supply pipe of the vacuum pump, for example, in order to smoothly rotate a rotor of the vacuum pump.

(first embodiment)

The structure of the vacuum pump 1 according to the first embodiment of the present disclosure will be described. Fig. 1 is a sectional view showing the structure of a vacuum pump 1 according to a first embodiment of the present disclosure. Fig. 1 shows a state in which a vacuum pump 1 is mounted on an engine 100. As shown in fig. 1, a vacuum pump 1 includes: oil supply pipe 2, rotor 4, coupling 6, and bushing 8.

Hereinafter, the direction in which the rotation axis O of the rotor 4 of the vacuum pump 1 extends is simply referred to as the "axial direction", the circumferential direction of the rotor 4 is simply referred to as the "circumferential direction", and the radial direction of the rotor 4 is simply referred to as the "radial direction".

The oil supply pipe 2 is cylindrical and has an oil supply passage 7 formed therein through which the lubricating oil flows. An inlet 12 of the oil supply passage 7 through which the lubricating oil flows is formed at one end 10 of the oil supply pipe 2. One end portion 10 of the oil supply pipe 2 is inserted into an outlet portion 106 forming an outlet of a flow path 104, the flow path 104 being formed inside a camshaft 102 of the engine 100 and through which lubricating oil flows. That is, the oil supply passage 7 of the oil supply pipe 2 communicates with the flow path 104 of the camshaft 102.

In the embodiment illustrated in fig. 1, the one end portion 10 of the oil supply pipe 2 holds an O-ring 16 on the outer circumferential surface 14 in order to prevent leakage of the lubricating oil. More specifically, an annular groove 17 is formed in the outer peripheral surface 14 of the one end portion 10 of the oil supply pipe 2, and an O-ring 16 is fitted in the groove 17.

On the other hand, an outlet 20 of the oil supply passage 7 through which the lubricating oil flows is formed at the other end portion 18 of the oil supply pipe 2. The lubricant oil passing through the outlet 20 is supplied into a pump chamber of the vacuum pump 1, not shown, through a lubricant oil flow path 25 formed inside the rotor 4.

In the embodiment illustrated in fig. 1, the other end 18 of the oil supply pipe 2 holds an O-ring 24 to prevent leakage of the lubricating oil. More specifically, the other end portion 18 of the oil supply pipe 2 includes: a first cylindrical portion 33, and a second cylindrical portion 35 configured to have a wall thickness greater than that of the first cylindrical portion 33. The second cylindrical portion 35 projects radially outward beyond the outer peripheral surface 37a of the first cylindrical portion 33 by the difference in wall thickness. The second cylindrical portion 35 of the oil supply pipe 2 is closer to the rotor 4 side in the axial direction than the first cylindrical portion 33. The outlet 20 is formed in the axial end surface of the second cylindrical portion 35 of the oil supply pipe 2 on the rotor 4 side. An annular groove 27 is formed in the outer peripheral surface 37b of the second cylindrical portion 35 of the oil supply pipe 2, and the O-ring 24 is fitted into the groove 27. The second cylindrical portion 35 of the oil supply pipe 2 is provided at an arbitrary position of the other end portion 18 in the axial direction. That is, the second cylindrical portion 35 of the fuel fill pipe 2 is not limited to the tip of the rotor 4 side constituting the fuel fill pipe 2.

The rotor 4 includes a shaft portion 28, and the shaft portion 28 is coupled to a camshaft 102 of an engine 100 that drives the rotor 4. In the embodiment illustrated in fig. 1, the shaft portion 28 is coupled to the camshaft 102 via the coupling 6, which will be described in detail later. Although fig. 1 shows the shaft portion 28 as a part of the rotor 4, the remaining part is not shown.

The shaft portion 28 is formed with a recess 26 into which the other end portion 18 of the fuel supply pipe 2 can be inserted. In the embodiment illustrated in fig. 1, the shaft portion 28 includes: a base 34 disposed in the casing 31 of the vacuum pump 1; and an engaging portion 38 protruding from one end 36 in the axial direction of the base portion 34. The open end 40 of the recess 26 of the shaft 28 is formed on the projection surface 42 of the engagement portion 38. The recess 26 of the shaft portion 28 extends axially from the open end 40 to the base 34 of the shaft portion 28.

In the embodiment illustrated in fig. 1, the inner circumferential surface 30 of the recess 26 of the shaft portion 28 includes: large diameter portion 46, small diameter portion 48, and inclined portion 50. The large diameter portion 46 and the small diameter portion 48 extend straight in the axial direction. The large diameter portion 46 forms the open end 40 of the recess 26 of the shaft portion 28. The small diameter portion 48 is formed at a position deeper than the large diameter portion 46 in the recess 26 of the shaft portion 28, and has a smaller diameter than the large diameter portion 46. The inclined portion 50 is located between the large diameter portion 46 and the small diameter portion 48, and is inclined so as to become smaller in diameter as it approaches the small diameter portion 48. According to such a configuration, since the recess 26 of the shaft portion 28 includes the large diameter portion 46, the inclined portion 50, and the small diameter portion 48 in this order from the position where the depth of the recess 26 of the shaft portion 28 is small, the oil supply pipe 2 can be easily inserted deep into the recess 26 of the shaft portion 28.

The coupling 6 is engaged with the shaft portion 28. In the embodiment illustrated in fig. 1, the coupling 6 has a cylindrical shape, and the engagement portion 38 of the shaft portion 28 is fitted into the engagement portion 38 of the shaft portion 28 so that the engagement portion 38 of the shaft portion 28 is positioned inside the coupling 6. The shaft portion 28 is coupled to a camshaft 102 of the engine 100 via the coupling 6. That is, the driving force for driving the rotor 4 can be transmitted from the camshaft 102 of the engine 100 to the shaft portion 28 of the rotor 4 via the coupling 6.

The bush 8 is configured to press the joint 6 and fit into the inner circumferential surface 30 of the recess 26 of the shaft portion 28, and to restrict the other end portion 18 of the oil supply pipe 2 from coming off the recess 26 of the shaft portion 28. Such a bush 8 may be formed of a metal material.

The operation and effect of the vacuum pump 1 according to the first embodiment of the present disclosure will be described. According to the embodiment illustrated in fig. 1, the bushing 8 is configured to press the coupling 6 engaged with the shaft portion 28. The bush 8 is configured to restrict the other end portion 18 of the fuel supply pipe 2 from coming off the recess 26 of the shaft portion 28. Therefore, when the vacuum pump 1 attached to the engine 100 is detached from the engine 100, the oil pipe 2 can be pulled out from the engine 100 together with the shaft portion 28. Therefore, when the vacuum pump 1 is detached from the engine 100, the oil feed pipe 2 can be suppressed from remaining on the engine 100 side.

An example of the structure of the bush 8 that regulates the detachment of the other end portion 18 of the oil supply pipe 2 from the recess 26 of the shaft portion 28 will be described. Fig. 2 is a perspective view of a vacuum pump 1 according to a first embodiment of the present disclosure. Fig. 3 is a diagram showing the structure of the bush 8 and the oil supply pipe 2 according to the first embodiment of the present disclosure, and is an enlarged sectional view of a part of fig. 1.

As shown in fig. 2 and 3, the bushing 8 includes: a coupling pressing portion 47 that presses the coupling 6; and a cylindrical portion 45 having a cylindrical shape, which is connected to the coupling pressing portion 47 and is fitted to the inner circumferential surface 30 of the recess 26 of the shaft portion 28. In the embodiment illustrated in fig. 2, a part 47a of the coupling pressing portion 47 is located radially outward of the engaging portion 38 and functions as a stopper of the coupling 6 having a cylindrical shape.

According to such a structure, when the vacuum pump 1 is detached from the engine 100, the oil feed pipe 2 can be suppressed from remaining on the engine 100 side with such a simple structure that the bush 8 includes the coupling pressing portion 47 and the cylindrical portion 45.

In the manner illustrated in fig. 3, the cylindrical portion 45 of the bush 8 comprises: a first cylindrical portion 49 connected to the coupling pressing portion 47 and fitted to the inner circumferential surface 30 of the recess 26 of the shaft portion 28; and a second portion 56 connected to the opposite side of the coupling pressing portion 47 of the first portion 49 and extending toward the radially inner side of the rotor 4 as being distant from the first portion 49. The first portion 49 is fitted to the large diameter portion 46. In other words, the first portion 49 does not extend to the inclined portion 50. The second portion 56 is a portion (so-called chisel portion) formed by pressing and deforming an end portion of the bushing 8 on the rotor 4 side in the axial direction of the cylindrical portion 45 before the second portion 56 is formed. The pressurization may be performed while the bushing 8 is fitted to the inner circumferential surface 30 of the recess 26 of the shaft portion 28, or may be performed before the bushing 8 is fitted to the inner circumferential surface 30 of the recess 26 of the shaft portion 28.

In the embodiment illustrated in fig. 3, the second cylindrical portion 35 (convex portion) of the oil supply pipe 2 is provided at a position deeper than the concave portion 26 of the shaft portion 28 than the second portion 56. Further, a distance d1 between the inner end 58 of the second portion 56 in the radial direction and the outer peripheral surface 37a of the first cylindrical portion 33 of the other end portion 18 of the fuel supply pipe 2 is smaller than a length h (height of the radially protruding portion from the outer peripheral surface) from the outer peripheral surface 37a of the first cylindrical portion 33 in the radial direction to the outer peripheral surface 37b of the second cylindrical portion 35. That is, when the vacuum pump 1 is pulled out from the engine 100, the second cylindrical portion 35 of the oil supply pipe 2 is caught or abutted on the second portion 56 of the liner 8. In this way, the bushing 8 is configured such that the second portion 56 is caught or brought into contact with the second cylindrical portion 35 of the fuel filler pipe 2, and the second portion 56 restricts the other end portion 18 of the fuel filler pipe 2 from coming out of the recess 26 of the shaft portion 28. That is, the bush 8 functions as a stopper of the fuel supply pipe 2.

According to such a configuration, when the vacuum pump 1 attached to the engine 100 is detached from the engine 100, the second cylindrical portion 35 (convex portion) of the oil feed pipe 2 can be engaged with (caught on or abutted against) the second portion 56 of the bush 8, and the oil feed pipe 2 can be pulled out together with the shaft portion 28. Therefore, when the vacuum pump 1 is detached from the engine 100, the oil feed pipe 2 can be suppressed from remaining on the engine 100 side.

In the embodiment illustrated in fig. 3, the second portion 56 of the bushing 8 is engaged with the second cylindrical portion 35 of the fuel supply pipe 2, thereby restricting the other end portion 18 of the fuel supply pipe 2 from coming out of the recess 26 of the shaft portion 28.

For example, as shown in fig. 4, the oil supply pipe 2 further includes an elastic body 60 at a position deeper than the second portion 56 of the recess 26 of the shaft portion 28, and the elastic body 60 is held on the outer peripheral surface 37a of the first cylindrical portion 33 of the other end portion 18 of the oil supply pipe 2. The elastic body 60 is, for example, an O-ring configured in an annular shape, and is fitted to the outer peripheral surface 37a of the first cylindrical portion 33 of the oil supply pipe 2. More specifically, an annular groove 61 is formed in the outer peripheral surface 37a of the first cylindrical portion 33 of the oil supply pipe 2, and the elastic body 60 is fitted in the groove 61. Further, a distance d1 between the inner end 58 of the second portion 56 of the bushing 8 in the radial direction of the rotor 4 and the outer peripheral surface 37a of the first cylindrical portion 33 of the oil supply pipe 2 is smaller than a dimension x1 of the elastic body 60 in the radial direction when the elastic body 60 is in an uncompressed natural state.

According to such a configuration, when the vacuum pump 1 is detached from the engine 100, the elastic body 60 held on the outer peripheral surface 37a of the first cylindrical portion 33 of the other end portion 18 of the oil supply pipe 2 can be engaged with the second portion 56 of the bush 8, and the oil supply pipe 2 can be pulled out together with the shaft portion 28. Therefore, when the vacuum pump 1 is detached from the engine 100, the oil feed pipe 2 can be suppressed from remaining on the engine 100 side.

(second embodiment)

A vacuum pump 1 according to a second embodiment of the present disclosure will be explained. The second embodiment differs from the first embodiment in that: the bushing 8 is configured to restrict the separation of the other end portion 18 of the oil supply pipe 2 from the recess 26 of the shaft portion 28 of the rotor 4 not through the second portion 56 but through an annular member 62 provided separately from the bushing 8, and the other configuration is the same as that described in the first embodiment. In the second embodiment, the same members as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

Fig. 5 is a sectional view showing the structure of a vacuum pump 1 according to a second embodiment of the present disclosure. As shown in fig. 5, the vacuum pump 1 is configured such that: the cylindrical portion 45 of the bush 8 includes the first portion 49 described in the first embodiment, but does not include the second portion 56 (chisel edge portion). The vacuum pump 1 further includes an annular member 62 at a position deeper than the bushing 8 in the recess 26 of the shaft portion 28, and the annular member 62 has an outer diameter r2 larger than an inner diameter r1 of the first portion 49 of the cylindrical portion 45 of the bushing 8.

In the embodiment illustrated in fig. 5, the annular member 62 is configured to be annular and extend in the entire circumferential direction. Such an annular member 62 is, for example, a washer. Further, the present disclosure is not limited to the ring member 62 extending in the entire circumferential direction (being ring-shaped). For example, the annular member 62 may have a C-shape at an axial angle.

In the embodiment illustrated in fig. 5, the inner circumferential surface 30 of the recess 26 of the shaft portion 28 includes a step portion 64 connecting the large diameter portion 46 and the inclined portion 50. The step portion 64 has a surface orthogonal to the axial direction. The annular member 62 is disposed between the bush 8 and the step portion 64. More specifically, the ring member 62 is sandwiched between the first portion 49 of the bush 8 and the step portion 64. With this configuration, the annular member 62 can be prevented from moving toward the engine 100 in the axial direction. In the embodiment illustrated in fig. 5, the stepped portion 64 has a surface perpendicular to the axial direction, but may have a surface inclined with respect to a cross section perpendicular to the axial direction as long as the annular member 62 can be disposed between the liner 8.

In the embodiment illustrated in fig. 5, the second cylindrical portion 35 (convex portion) of the oil supply pipe 2 is provided at a position deeper than the concave portion 26 of the shaft portion 28 than the annular member 62. Further, the distance d2 between the inner end 66 of the annular member 62 in the radial direction and the outer peripheral surface 37a of the first cylindrical portion 33 of the fuel filler pipe 2 is smaller than the length h (height of the radially protruding portion from the outer peripheral surface) from the outer peripheral surface 37a of the first cylindrical portion 33 in the radial direction to the outer peripheral surface 37b of the second cylindrical portion 35. That is, when the vacuum pump 1 is pulled out from the engine 100, the second cylindrical portion 35 of the oil feed pipe 2 is caught or abutted on the annular member 62. In this way, the bush 8 is configured to engage with the second cylindrical portion 35 of the fuel supply pipe 2 via the annular member 62, and to restrict the other end portion 18 of the fuel supply pipe 2 from coming out of the recess 26 of the shaft portion 28. That is, the bush 8 functions as a stopper of the fuel supply pipe 2 via the annular member 62 (washer).

According to such a configuration, when the vacuum pump 1 attached to the engine 100 is detached from the engine 100, the second cylindrical portion 35 of the oil feed pipe 2 can be engaged with the bush 8 via the annular member 62, and the oil feed pipe 2 can be pulled out together with the shaft portion 28. Therefore, when the vacuum pump 1 is detached from the engine 100, the oil feed pipe 2 can be suppressed from remaining on the engine 100 side.

In the embodiment illustrated in fig. 5, the bush 8 is engaged with the second cylindrical portion 35 of the fuel supply pipe 2 via the annular member 62, and the other end portion 18 of the fuel supply pipe 2 is restricted from being detached from the recess 26 of the shaft portion 28.

For example, as shown in fig. 6, the oil supply pipe 2 further includes an elastic body 70 at a position deeper than the annular member 62 in the recess 26 of the shaft portion 28, and the elastic body 70 is held on the outer peripheral surface 37a of the first cylindrical portion 33 of the other end portion 18 of the oil supply pipe 2. The elastic body 70 is, for example, an O-ring configured in an annular shape, and is fitted to the outer peripheral surface 37a of the first cylindrical portion 33 of the oil supply pipe 2. More specifically, an annular groove 71 is formed in the outer peripheral surface 37a of the first cylindrical portion 33 of the oil supply pipe 2, and the elastic body 70 is fitted in the groove 71. Further, a distance d2 between the inner end 66 of the annular member 62 in the radial direction and the outer peripheral surface 37a of the first cylindrical portion 33 of the oil supply pipe 2 is smaller than a dimension x2 of the elastic body 70 in the radial direction when the elastic body 70 is in an uncompressed natural state.

According to such a configuration, when the vacuum pump 1 attached to the engine 100 is detached from the engine 100, the elastic body 70 held on the outer peripheral surface 37a of the first cylindrical portion 33 of the other end portion 18 of the oil feed pipe 2 can be engaged with the annular member 62, and the oil feed pipe 2 can be pulled out together with the shaft portion 28. Therefore, when the vacuum pump 1 is detached from the engine 100, the oil feed pipe 2 can be suppressed from remaining on the engine 100 side.

The vacuum pumps according to the first and second embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

Claims

1. A vacuum pump is provided with:

an oil supply pipe having an inlet for lubricating oil formed at one end portion thereof and an outlet for the lubricating oil formed at the other end portion thereof;

a rotor including a shaft portion formed with a recess into which the other end portion of the oil supply pipe is inserted;

a coupling engaged with the shaft portion; and

and a bushing configured to press the coupling and fit into an inner circumferential surface of the recess, and to restrict the other end portion of the oil supply pipe from coming off the recess.

2. A vacuum pump according to claim 1,

the bushing includes:

a coupling pressing portion that presses the coupling; and

and a cylindrical portion fitted to the inner peripheral surface.

3. A vacuum pump according to claim 2,

the cylindrical portion of the bushing includes:

a first portion which is cylindrical, connected to the coupling pressing portion, and fitted to the inner peripheral surface; and

a second portion connected to the first portion on the opposite side of the coupling pressing portion and extending toward the inside in the radial direction of the rotor as being separated from the first portion,

the bushing is configured to restrict the other end portion of the oil supply pipe from coming off the recess portion by the second portion.

4. A vacuum pump according to claim 3,

an outer peripheral surface of the other end portion of the oil supply pipe includes a convex portion at a position deeper than the second portion of the concave portion,

a distance between an inner end of the second portion in the radial direction and the outer peripheral surface of the other end portion of the oil supply pipe is smaller than a height of the convex portion in the radial direction from the outer peripheral surface.

5. A vacuum pump according to claim 3,

an elastic body that is held on an outer peripheral surface of the other end portion of the oil supply pipe is further provided at a position deeper than the second portion in the recess,

a distance between an inner end of the second portion in the radial direction of the rotor and the outer peripheral surface of the other end portion of the oil supply pipe is smaller than a size of the elastic body in the radial direction when the elastic body is in an uncompressed natural state.

6. A vacuum pump according to claim 2,

further comprising an annular member having an outer diameter larger than an inner diameter of the cylindrical portion of the bush at a position deeper than the bush in the recessed portion,

the bushing is configured to restrict the other end portion of the oil supply pipe from coming off the recess portion via the annular member.

7. A vacuum pump according to claim 6,

the inner peripheral surface of the recess includes a step portion,

the annular member is disposed between the bushing and the step portion.

8. A vacuum pump according to claim 6 or 7,

an outer peripheral surface of the other end portion of the oil supply pipe includes a convex portion at a position deeper than the annular member than the concave portion,

a distance between an inner end of the annular member in the radial direction of the rotor and the outer peripheral surface of the other end portion of the oil supply pipe is smaller than a height of the convex portion in the radial direction from the outer peripheral surface.

9. A vacuum pump according to claim 6 or 7,

an elastic body that is held on an outer peripheral surface of the other end portion of the oil supply pipe is further provided at a position deeper than the annular member in the recessed portion,

a distance between an inner end of the annular member in a radial direction of the rotor and the outer peripheral surface of the other end portion of the oil supply pipe is smaller than a size of the elastic body in the radial direction when the elastic body is in an uncompressed natural state.