JPH1089488A - Fitting structure of lip seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a lip seal easily attachable in an insertional hole and also its close adhesion with an inner circumferential surface of the insertional hole so as not to be impeded. SOLUTION: A drive shaft 18 is projected to the outside via an insertional hole 41 formed in a front housing 12. A lip seal 50 is insertionally set up in this hole 41, sealing the drive shaft 18. An engaging piece 55 is extendedly installed from the lip seal 50, and it is engaged with an engaging part 43 in the hole 41 through both roughly irregular relations 43a and 55a, thereby regulating any movements in the axial direction of the lip seal 50. Then, on an innercircumferential surface 41a of the insertional hole 41, a sealing part 42 with which an outer circumferential surface 52b of the lip seal 50 comes into contact is made up to be diametrally larger than the engaging part 43. Therefore, when the lip seal 50 is inserted into the hole 41, the engaging piece 55 is made so as not to resiliently slide the sealing part 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lip seal mounting structure for sealing a drive shaft of a compressor applied to, for example, a vehicle air conditioning system.

[0002]

2. Description of the Related Art In a compressor of this type, a compression mechanism is housed in a housing. The drive shaft is rotatably supported by the housing and connected to a compression mechanism. The drive shaft protrudes outside through an insertion hole formed in the housing, and is operatively connected to an external drive source such as a vehicle engine through the protruding end. The compression mechanism is operated by driving the drive shaft by driving of an external drive source, and a cycle of suction, compression and discharge of the refrigerant gas is performed.

[0003] The lip seal is interposed between the inner peripheral surface of the insertion hole and the outer peripheral surface of the drive shaft to seal the drive shaft.
The lip seal comes into contact with a step formed in the back of the insertion hole, and also comes into contact with a circlip fitted on the entrance side of the insertion hole, in a drive shaft direction (hereinafter, referred to as an axial direction). Movement is regulated.

However, in order to assemble the circlip, it is necessary to take a procedure of once reducing the diameter of the circlip, inserting the circlip into the insertion hole and expanding the diameter again, and it is difficult to automate the assembling. Did not. Further, since the circlip is a small part, it is difficult to assemble the circlip, and it is difficult to detect the circlip even when the assembling is forgotten or the assembling is incomplete.

Here, in order to solve the above problem, for example, in Japanese Utility Model Laid-Open No. 4-77066,
A mounting structure has been proposed in which an engagement piece engageable with the inner peripheral surface of the insertion hole is extended from a lip seal. Therefore, only by inserting the lip seal into the insertion hole, for example, the engagement protrusion provided on the engagement piece is provided on the inner peripheral surface of the insertion hole by the elastic force of the engagement piece. The lip seal is immersed and engaged in the mating recess, and the movement of the lip seal in the axial direction is restricted.

[0006]

However, according to the above-mentioned prior art, in the inner peripheral surface of the insertion hole, the seal portion contacting the lip seal and the engaging portion engaged with the engaging piece have the same diameter. Is configured. Therefore, when the lip seal is inserted into the insertion hole, for example, in a configuration in which the engagement piece is passed through the seal portion, the engagement protrusion of the engagement piece is elastically slid on the seal portion, Depending on the material of the seal portion and the engagement piece, the seal portion may be damaged. As a result, the damaged part of the seal part hinders the close contact with the lip seal,
The hermeticity inside the housing was reduced. In addition, since the seal portion and the engagement portion have the same diameter, if the engagement pieces are not accurately engaged, the hermeticity is impaired.

SUMMARY OF THE INVENTION The present invention has been made in view of the problems existing in the prior art described above, and has as its object to be able to be easily inserted into an insertion hole and to be connected to the inner peripheral surface of the insertion hole. An object of the present invention is to provide a lip seal mounting structure that does not hinder close contact.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, the inner peripheral surface of the insertion hole is different from the seal portion in contact with the outer peripheral surface of the lip seal. An engagement portion having an inner diameter is formed, and an engagement piece extending from the lip seal is engaged with the engagement portion, thereby restricting movement of the lip seal in the axial direction. The mounting structure is as described above.

According to the second aspect of the present invention, the engaging portion and the engaging piece are provided outside the housing with respect to the lip seal. According to the third aspect of the present invention, the engaging portion and the engaging piece are engaged in an uneven relationship.

According to the fourth aspect of the present invention, the engaging piece has an engaging convex portion, and the engaging portion has an engaging concave portion into which the engaging convex portion is immersed. It is partially present in the circumferential direction of the engaging portion.

According to the fifth aspect of the present invention, the engaging portion and the engaging piece are provided on the outer side of the housing with respect to the lip seal, and the engaging portion has a leak for collecting oil leaking from the lip seal. An oil passage is opened, and the opening also serves as an engagement recess.

In the invention according to claim 6, the engaging piece is elastically engaged with the engaging portion. (Operation) In the first aspect of the present invention, the inner peripheral surface of the insertion hole is formed with a seal portion with which the outer peripheral surface of the lip seal contacts and an engaging portion with which the engaging piece of the lip seal engages. The seal portion and the engagement portion have different inner diameters. That is, for example, when the lip seal is inserted into the insertion hole, in a configuration in which the engagement piece passes through the inner space of the seal portion, the diameter of the seal portion is made larger than that of the engagement portion so that the engagement piece does not come into contact. Can be. Therefore, damage to the seal portion due to sliding with the engagement piece can be prevented, and the adhesion between the two can be enhanced.

According to the second aspect of the present invention, the engaging portion and the engaging piece are provided on the outer side of the housing with respect to the lip seal. Therefore, for example, even when the inside of the housing has a high temperature and a high pressure, the same temperature and pressure are not directly applied to the engagement portion and the engagement piece. As a result, deformation and deterioration of the engagement portion and the engagement piece can be prevented, and the engagement between the two does not become loose.

According to the third aspect of the present invention, the engaging piece and the engaging portion of the insertion hole are securely engaged in an uneven relationship, and the movement of the lip seal in the axial direction is reliably restricted. According to the fourth aspect of the present invention, the engagement projections of the engagement pieces are recessed into the engagement recesses of the engagement portion, so that the two are engaged with each other, and the movement of the lip seal in the axial direction is restricted. Here, the engaging concave portion partially exists in the circumferential direction in the engaging portion. Therefore, even if the lip seal is about to be rotated about the axis by the rotation of the drive shaft, the engagement convex portion comes into contact with the engagement concave portion, and further rotation is restricted.

According to the fifth aspect of the present invention, oil leaking from the lip seal to the outside of the housing is recovered through the oil leak passage. Here, the leakage oil passage is opened at the engagement portion, and the engagement projection of the engagement piece is immersed in the opening, thereby restricting the movement of the lip seal in the axial direction.

According to the sixth aspect of the present invention, the lip seal is moved in the axial direction by the elastically engaging engagement of the engaging piece with the engaging portion without providing an engaging recess or the like in the engaging portion. Is regulated.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the mounting structure of the lip seal of the present invention is embodied in a double-headed piston type compressor will be described below.

As shown in FIG. 1, a pair of cylinder blocks 11 are joined to each other at opposite edges. The front housing 12 is joined to the front end face of the cylinder block 11 on the front side, and the rear housing 14 is joined to the rear end face of the cylinder block 11 on the rear side via a valve body 13.

The bolt insertion hole 16 is formed in the rear housing 14 through the cylinder block 11 from the front housing 12. The through bolt 17 is inserted into the bolt insertion hole 16, and has a threaded portion 17 a formed at a tip end thereof.
6 is screwed into the screw hole 16a formed. The front housing 11 and the rear housing 14 are fastened and fixed to the end surfaces of the corresponding cylinder blocks 11 by the same through bolts 17. The cylinder block 11, the front housing 12, and the rear housing 1
4 constitutes the housing of the present embodiment.

The drive shaft 18 is connected to the cylinder block 11.
And, it is rotatably supported at the center of the front housing 12 via a pair of radial bearings 19. The drive shaft 18 protrudes outside through an insertion hole 41 formed through the center of the front housing 12. The drive shaft 18 is operatively connected to an external drive source, such as a vehicle engine, via a clutch mechanism (not shown) connected to the protruding end. When the clutch mechanism is connected, the driving force of the external drive source is transmitted to rotate the drive shaft 18. Is done.

A plurality of cylinder bores 21 are provided on the drive shaft 1.
The cylinder blocks 11 are formed so as to extend in parallel with each other at predetermined intervals on the same circumference between both end portions of each cylinder block 11. The double-headed piston 22 is reciprocally fitted and supported in each of the cylinder bores 21, and a compression chamber 23 is formed in each of the cylinder bores 21 between their both end faces and the corresponding valve forming bodies 13. ing.

The crank chamber 25 is defined in the middle of the cylinder blocks 11. The crank chamber 25 is connected to an external refrigerant circuit (not shown) and forms a suction pressure region. The swash plate 26
Inside, the outer peripheral portion is moored to the intermediate portion of the piston 22 via the shoe 27. A pair of thrust bearings 28 are interposed between both end surfaces of the swash plate 26 and the inner end surfaces of the cylinder blocks 11, and the swash plate 26 is sandwiched and held between the two cylinder blocks 11 via the thrust bearings 28. ing. The piston 22 is driven by the rotation of the drive shaft 18 to move the swash plate 2.
6 is reciprocated.

The suction chamber 29 is provided with the front housing 1.
2 and an outer peripheral portion in the rear housing 14. The suction chamber 29 is provided with the bolt insertion hole 16.
Is connected to the crankcase 25 via the Discharge chamber 32
Are formed on the inner peripheral portions of the front housing 12 and the rear housing 14, respectively, and are connected to an external refrigerant circuit.

A plurality of suction holes 33 are formed in each valve body 13 corresponding to the suction chamber 29. The suction valve 34 is also formed in the valve forming body 13 and opens and closes each suction hole 33.
Then, as the piston 22 moves from the top dead center position to the bottom dead center position, the suction valve 34 is opened, and the corresponding suction chamber 2 is opened.
Refrigerant gas is drawn into each compression chamber 23 from 9. The plurality of discharge holes 35 are formed in each valve forming body 13 corresponding to the discharge chamber 32. The discharge valve 36 is also formed on the valve body 13 and opens and closes each discharge hole 35. And piston 2
2, the refrigerant gas in each compression chamber 23 is compressed to a predetermined pressure by the operation of the discharge valve 36 and discharged to the corresponding discharge chamber 32 with the movement from the bottom dead center position to the top dead center position. You.

The housing 37 is recessed in the outer wall surface of the front housing 12, and a felt 38 as an oil absorbing member is housed in the housing 37. The oil guide groove 40 is annularly recessed on the inner peripheral surface 41 a of the insertion hole 41. The leakage oil passage 39 is formed inside the front housing 12, and is connected at one end to the housing portion 37 and at the other end to the oil guide groove 40.
That is, the leakage oil passage 39 is opened on the inner peripheral surface 41 a of the insertion hole 41 via the oil guide groove 40. Then, the lubricating oil leaking from the inside of the housing to the outside through the insertion hole 41 is collected in the housing portion 37 through the oil guide groove 40 and the leaking oil passage 39, and the felt 38 in the housing portion 37.
Is absorbed and retained by

Next, the features of this embodiment will be described. As shown in FIG. 2, the inner peripheral surface 41a of the insertion hole 41
Are configured to have different diameters via a step 41b before and after in the axial direction. In the inner peripheral surface 41a, the peripheral surface located on the inner side of the housing (right side in FIG. 2) from the step 41b constitutes the seal portion 42, and the peripheral surface on the outer side of the housing (left side in FIG. 2) from the step 41b. The engaging portion 43 has a smaller diameter than the sealing portion 42. The oil guide groove 40 is provided in the engagement portion 43.
Is formed.

The lip seal 50 is inserted into the insertion hole 41 from the opening on the seal portion 42 side, and is pushed into the seal portion 42 to a position where the lip seal 50 contacts the step 41b. Accordingly, the lip seal 50 is interposed between the seal portion 42 and the outer peripheral surface 18a of the drive shaft 18 so that the drive shaft 1
A portion of the housing 8 protruding outside the housing is sealed.

The lip seal 50 will be described. As shown in FIGS. 2 and 3, a metal support fitting 51 is provided.
Has a substantially cylindrical shape, and its front and rear opening edges are bent inward. A synthetic rubber lip ring (hereinafter referred to as a rubber lip) 52 is fixed to the support fitting 51 so as to cover the bent portion on the rear end side and the outer peripheral surface. The rubber lip 52 has an outer peripheral surface 52b pressed against the seal portion 42 and has its own elastic force.
The outer peripheral surface 18a of the drive shaft 18 is pressed against the outer peripheral surface 18a of the drive shaft 18 via the lip portion 52a in an annular region, thereby achieving a sealing effect.

PTFE (polytetrafluoroethylene)
Lip ring (hereinafter referred to as PTFE lip) 53
A rubber lip 52 at an inner peripheral portion of the support fitting 51.
Is located on the front side. The PTFE lip 53
The outer peripheral surface 18a of the drive shaft 18 is in contact with the outer peripheral surface 18a of the drive shaft 18 via the lip portion 53a in an annular region. The lip portion 53a
When the high pressure in the crank chamber 25 is applied, the drive shaft 1
8 is pressed against the outer peripheral surface 18a to perform a sealing action. A metal lip fitting 54 having a substantially ring shape is fitted to the front side in the support fitting 51, and the rubber lip 52 and the PTFE lip 53 are tightly fixed between the support fitting 51 and the lip fitting 54. Have been.

The pair of engaging pieces 55 are formed integrally with the inner peripheral portion of the lip fitting 54 in the lip seal 50, and extend substantially along the axis L toward the outside (front side) of the housing. Has been extended. Both engagement pieces 55
Has elasticity, and in the steady state, the distance from the axis L of the tip is the inner diameter of the engagement portion 43 (<the inner diameter of the seal portion 42).
It is slightly smaller. Therefore, the lip seal 50
Is inserted into the seal portion 42, the distal ends of both the engagement pieces 55 are smoothly inserted into the engagement portion 43 without being interfered by the seal portion 42 and the step 41b.

The engaging projection 55a is cut and raised outward at the tip of each engaging piece 55. In the steady state of the engagement piece 55, the distance between the apexes of the two engagement protrusions 55a and the axis L is smaller than the inner diameter of the seal portion 42 and slightly larger than the inner diameter of the engagement portion 43. Therefore, when the engagement piece 55 whose tip is inserted into the engagement portion 43 is pushed further inward, the engagement piece 55
The elastic force is accumulated by being pushed inward by the engaging portion 43 via the line a.

The engagement recess 43a is annularly recessed in the engagement portion 43 along the circumferential direction. And
When the lip seal 50 is pushed into the seal portion 42 to a position where the lip seal 50 comes into contact with the step 41b, the engaging convex portion 55a of the engaging piece 55 and the engaging concave portion 43a are aligned with each other. The accumulated elastic force is released. Therefore, the engagement projection 55a is immersed in the engagement recess 43a, and the engagement portion 4
3 and the engagement piece 55 are engaged, and the movement of the lip seal 50 in the axial direction is restricted.

The present embodiment having the above configuration has the following effects. (1) The engaging piece 55 is engaged with the engaging portion 43 by a simple assembling operation only by inserting the lip seal 50 into the insertion hole 41, so that the axial movement of the lip seal 50 can be restricted. It is. Therefore, as compared with the related art in which the circlip needs to be assembled, the assembly cost can be reduced, and problems such as forgetting to assemble the circlip do not occur.

When the lip seal 50 is inserted into the insertion hole 41, the engagement piece 55 passes through the inner space of the seal portion 42. However, in the present embodiment, the sealing portion 42
Is configured to have a larger diameter than the engaging portion 43, and the engaging piece 55 can be provided in the lip seal 50 at a position where the engaging piece 55 does not interfere with the sealing portion 42. Therefore, the sealing portion 42
Of the lip seal 50 and the outer peripheral surface of the lip seal 50 (the outer peripheral surface 52b of the rubber lip 52) can be surely adhered. Is done. As a result, the tightness of the crank chamber 25 is improved.

(2) The engaging portion 43 and the engaging piece 55 are
The lip seal 50 is disposed outside the housing with respect to the sealing position. Therefore, the high temperature of the crankcase 25
The high pressure is not directly applied to the engaging portion 43 and the engaging piece 55, so that the engaging portion 43 and the engaging piece 55 can be prevented from being deformed or deteriorated. As a result, both 43, 55
Can be prevented from loosening, and the movement of the lip seal 50 can be reliably restricted even when the compressor is operating.

(3) The engaging portion 43 and the engaging piece 55 are engaged in an uneven relationship through the engaging concave portion 43a and the engaging convex portion 55a. Accordingly, the engagement between the two 43 and 55 becomes strong, and the movement of the lip seal 50 can be reliably restricted.

(4) The step 41 b exists outside the housing with respect to the lip seal 50 in the insertion hole 41. Therefore, for example, due to the high pressure of the crank chamber 25, the engagement convex portion 55a and the engagement concave portion 4
Even if a stress is applied such that the engagement with the step 3a is released, the movement of the lip seal 50 to the outside of the housing is reliably restricted by the contact with the step 41b.

It should be noted that, for example, the following embodiments can be carried out without departing from the spirit of the present invention. (1) As shown in FIG.
3a is removed and the elastic force of the engagement piece 55 is increased.
The engagement piece 55 and the engagement portion 43 are engaged by elastic pressure. By doing so, it is not necessary to provide the engaging recess 43a in the engaging portion 43, and the processing cost can be reduced. Further, the rotation about the axis L of the lip seal 50, which follows the rotation of the drive shaft 18, is also restricted.
0 does not deteriorate due to sliding with the seal portion 42. Therefore, the sealing of the crank chamber 25 by the lip seal 50 is further ensured.

(2) As shown in FIG. 5, the engagement recess 43a is omitted from the above embodiment, and the oil guide groove 40 is replaced with the engagement recess 4
3a. If you do this,
It is not necessary to form the engaging recess 43a in the engaging portion 43, and the processing cost can be reduced.

(3) As shown in FIG. 6, the engagement recess 43a
Are a pair of spline grooves extending in the axial direction corresponding to the respective engagement protrusions 55a. By doing so, the engagement recess 43a is partially present in the circumferential direction of the engagement portion 43, and the rotation about the axis L of the lip seal 50 follows the rotation of the drive shaft 18. Movement can be prevented. Therefore, the outer peripheral surface 52b of the rubber lip 52 is not slid and deteriorated by the seal portion 42, and the lip seal 50 seals the crank chamber 25 more reliably.

(4) Three or more engaging pieces 55 extend from the lip seal 50. (5) Forming an engaging projection on the engaging portion 43 and forming an engaging recess on the engaging piece 55. That is, the concavo-convex relationship between the engaging portion 43 and the engaging piece 55 is reversed from that in the above embodiment.

(6) The lip fitting 54 is made of a synthetic resin material. That is, the engaging piece 55 integral with the lip fitting 54 is made of a synthetic resin material. (7) The engaging piece 55 is formed integrally with the support fitting 51 instead of the lip fitting 54. Alternatively, it is formed integrally with the rubber lip 52 or the PTFE lip 53.

(8) The step 41b is changed to a tapered surface whose diameter gradually decreases toward the engaging portion 43. In this case, the distance between the tip of the engagement piece 55 and the axis L is
Even if the inner diameter is larger than the inner diameter of the engaging portion 43, the leading end is guided by the tapered surface and is smoothly inserted into the engaging portion 43.

The technical idea that can be grasped from the above embodiment will be described.
2. The mounting structure according to claim 1, wherein the engaging portion 43 inserted into the inside from the seal portion 42 side and disposed at the back of the seal portion 42 has a smaller diameter than the seal portion 42.

In this way, when the lip seal 50 is inserted into the insertion hole 41, the engagement piece 50 reaches the engagement portion 43 without being brought into contact with the seal portion 42.
Of the lip seal 50 and the seal portion 42
And the adhesiveness with the film is increased.

[0046]

According to the first aspect of the present invention, the engaging piece and the engaging portion are engaged by a simple procedure of merely inserting the lip seal into the insertion hole, and the shaft of the lip seal is engaged. The movement in the direction can be regulated. Therefore, the cost for assembling the lip seal can be reduced, which leads to a reduction in the cost of the compressor.

Further, for example, in a configuration in which the engagement piece is passed through the inner space of the seal portion, it is possible to prevent the seal portion from being damaged due to sliding of the both. Therefore, the adhesion between the lip seal and the insertion hole is not hindered, and the tightness of the crank chamber is improved.

According to the second aspect of the invention, for example, even when the inside of the housing is at a high temperature and a high pressure, the same temperature and pressure are not directly applied to the engaging portion and the engaging piece. Absent. Therefore, deformation and deterioration of the engaging portion and the engaging piece can be prevented, and the engagement between the two does not become loose. As a result, the movement of the lip seal in the axial direction is reliably restricted.

According to the third aspect of the present invention, the engaging piece and the engaging portion of the insertion hole are securely engaged in an uneven relationship. Accordingly, the movement of the lip seal in the axial direction is reliably restricted. According to the fourth aspect of the present invention, the engagement concave portion partially exists in the engagement portion in the circumferential direction. Therefore, even if the lip seal follows the rotation of the drive shaft and is about to rotate about the axis, the engaging projection comes into contact with the engaging recess, and further rotation is restricted. As a result, the outer peripheral surface of the lip seal does not deteriorate due to sliding with the seal portion, and the sealing of the crank chamber by the lip seal is further ensured.

According to the fifth aspect of the present invention, since the opening of the leakage oil passage also serves as the engagement recess, it is not necessary to separately form the engagement recess. Therefore, the processing cost can be reduced.
According to the invention of claim 6, the axial movement of the lip seal is regulated by the elastically engaging engagement of the engagement piece with the engagement portion. Therefore, the processing cost can be reduced by the time required for forming the engaging concave portion and the like for the engaging portion. In addition, the rotation of the lip seal that follows the rotation of the drive shaft is also restricted, and the outer peripheral surface of the lip seal is not deteriorated by sliding with the seal portion.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a double-headed piston type compressor.

FIG. 2 is an enlarged view of the vicinity of a lip seal of FIG. 1;

FIG. 3 is a front view of a lip seal.

FIG. 4 is an enlarged cross-sectional view near a lip seal showing another example.

FIG. 5 is an enlarged cross-sectional view near a lip seal showing another example.

FIG. 6 is an enlarged cross-sectional view near a lip seal showing another example.

[Explanation of symbols]

11: cylinder block as a housing, 18: drive shaft, 41: insertion hole, 42: seal portion, 43: engagement portion,
50: lip seal, 52b: outer peripheral surface of rubber lip as outer peripheral surface of lip seal, 55: engagement piece.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Satoshi Kitahama 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation

Claims (6)

[Claims] 1. A mounting structure for a lip seal, which is inserted into an insertion hole formed in a housing and seals a drive shaft protruding outside the housing through the insertion hole, wherein the insertion hole is provided. On the inner peripheral surface of the lip seal, there is formed a seal portion with which the outer peripheral surface of the lip seal is in contact, and an engaging portion having an inner diameter different from that of the seal portion. An attachment structure in which the lip seal is restricted from moving in the axial direction by being engaged with the engagement portion. 2. The mounting structure according to claim 1, wherein the engaging portion and the engaging piece are provided on the outer side of the housing with respect to the lip seal. 3. The mounting structure according to claim 1, wherein the engaging portion and the engaging piece are engaged in an uneven relationship. 4. An engagement projection is formed on the engagement piece, and an engagement recess is formed in the engagement section so that the engagement projection is immersed in the engagement section. 4. The mounting structure according to claim 3, wherein the mounting structure partially exists in the direction. 5. The engagement portion and the engagement piece are provided on the outer side of the housing with respect to the lip seal, and a leakage oil passage for collecting leakage oil from the lip seal is opened in the engagement portion. The mounting structure according to claim 3, wherein the opening also serves as an engagement recess. 6. The mounting structure according to claim 1, wherein the engaging piece is elastically engaged with the engaging portion.