JPH0435599Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to an improvement of a vane-type rotary compressor used, for example, in a vehicle cooling system.

(Prior art) Conventionally, this type of vane type rotary compressor is
For example, the ones shown in FIGS. 3 and 4 are known (see Japanese Utility Model Application Publication No. 106582/1982). In the figure, 1 is a housing, and a cam ring 3 having a cam surface 2 is housed in the housing 1. A rotor 4 having a front shaft portion 4a and a rear shaft portion 4b is housed in the cam ring 3, and both ends of the cam ring 3 are sealed by a front plate 5 and a rear plate 6, and the front shaft portion 4a and the rear shaft portion are sealed. 4
b are rotatably supported by the front plate 5 and rear plate 6, respectively. A slit 7 is formed in the rotor 4 substantially in the radial direction, and a vane 8 is fitted into the slit 7 so as to be freely retractable. A back pressure passage 9 is formed at the bottom of the slit 7, and the vane 8 is pressed against the cam surface 2 by the pressure of lubricating oil introduced into the back pressure passage 9 (vane back pressure). When the rotor 4 rotates, the vanes 8 rotate in sliding contact with the cam surface 2 due to the centrifugal force accompanying the rotation of the rotor 4 and the vane back pressure in the back pressure passage 9. A pump chamber 10 is defined by the plurality of vanes 8, and the pumping action of this pump chamber 10 causes
Refrigerant gas introduced into the low pressure chamber 12 from the suction port 11 is sucked into the pump chamber 10, compressed, and discharged to the discharge chamber 13 defined at the rear of the housing 1 (on the right side in FIG. 3). Since the discharged refrigerant gas contains lubricating oil, this lubricating oil is separated by the oil separator 14 and stored in the discharge chamber 13. The lubricating oil stored in the discharge chamber 13 passes through the lubricating oil supply passage 24 formed in the rear plate 6 by the discharge pressure of the refrigerant gas in the discharge chamber 13, and fills the gap between the rear plate 6 and the rear shaft portion 4b. From back pressure passage 9
be pumped to. When the vane back pressure of the lubricating oil pumped into the back pressure passage 9 becomes too high, the vane 9 is strongly pressed against the cam surface 2 and the tip of the vane 8 and the cam surface 2 are significantly worn. In order to prevent this wear, an orifice ring 15 is interposed in the gap between the rear plate 6 and the rear shaft portion 4b so that the vane back pressure does not become too high.
The pressure of the lubricating oil in the back pressure passage 9 is reduced by narrowing it in a minute gap 16 formed between the back pressure passage 9 and the rear shaft portion 4b.

(Problems to be solved by the invention) However, in such a conventional vane type rotary compressor, a minute gap 16 is formed between the rear shaft portion 4b of the rotor 4 and the orifice ring 15 as an orifice. By narrowing the gap 16, the pressure of the lubricating oil forced into the back pressure passage 9 is reduced. Therefore, if the lubricating oil is squeezed too much in the minute gap 16, the vane back pressure of the lubricating oil in the back pressure passage 9 will decrease, and especially during low speed operation, the centrifugal force of the rotor 4 will weaken, and the vane The force to press against the cam surface 2 of 8 is insufficient. Therefore, the vane 8 is not constantly pressed against the cam surface 2 and separates from the cam surface 2, resulting in problems such as chattering noise (abnormal noise when the vane 8 collides with the cam surface 2). . Therefore, the outer diameter of the rear shaft portion 4b is precisely cut, and the inner diameter of the orifice ring 15 is also precisely cut at the same time, so that the orifice ring 15 is fitted to the rear shaft portion 4b, and the minute interval 16 is α. For example, 30~
It was necessary to create a precise gap of 40μ. To do this, first, the outer diameter of the precisely cut rear shaft portion 4b and the inner diameter of the orifice ring 15 are graded in units of several microns.
It was necessary to fit an orifice ring 15 of an appropriate grade into b. That is, the process involves precisely cutting the outer diameter of the rear shaft portion 4b and the inner diameter of the orifice ring 15, and then grading the rear shaft portion 4b and the orifice ring 15, and selecting the appropriate orifice ring for the rear shaft portion 4b. 15 was necessary. Therefore, due to these complicated processes, the productivity of this vane type rotary compressor is reduced,
Another problem was that the manufacturing cost was high. In addition, the process of fitting the orifice ring 15 of the correct grade to the graded rear shaft portion 4b requires skill, and the process of fitting the orifice ring 15 of the wrong grade
There was a risk that 5 would fit together. In this case,
As mentioned above, there were also problems in that the tip of the vane 8 and the cam surface 2 were abnormally worn, or that chattering noise was generated.

(Means for Solving the Problems) In order to solve these problems, this invention includes a cam ring housed in a housing, a front plate and a rear plate that seal both ends of this cam ring, and this front plate. and a front shaft portion and a rear shaft portion of a rotor rotatably supported by each of the rear plates, and a vane fitted into and retractably into a slit formed in the rotor;
A vane-type rotary compressor comprising a back pressure passage formed at the bottom of the slit for applying back pressure of lubricating oil to the vane, and a discharge chamber defined in the housing for storing lubricating oil. A vertical hole in the axial direction is formed in the shaft part, and a plug having a small hole is press-fitted into the opening side of the vertical hole, and a horizontal hole in the radial direction with one end open on the outer surface of the inner part of the vertical hole is formed. A communication hole is formed from the outer circumferential surface of the rear shaft portion, and a vertical hole and a horizontal hole provided with a plug are used to squeeze and supply lubricating oil to a predetermined pressure from the discharge chamber to the back pressure passage.

(Function) The small hole formed in the plug according to the present invention described above does not need to be manufactured with high processing precision unlike the orifice of a conventional orifice ring. Therefore, manufacturing of the plug becomes easy, and the conventional grading process and fitting process are unnecessary.

(Example) This invention will be explained below based on the drawings.

FIGS. 1 and 2 are diagrams showing an embodiment of this invention. First, the configuration will be explained. In FIGS. 1 and 2, 31 is a cylindrical housing with a bottom, and a cam ring 33 having a cam surface 32 is accommodated in the housing 31. A rotor 34 is rotatably housed in the cam ring 33, and the rotor 34 has a front shaft portion 34a and a rear shaft portion 3.
4b are integrally formed. Both ends of the cam ring 33 are connected to a front plate 35 and a rear plate 36.
The front shaft portion 34a and the rear shaft portion 34b are sealed by
are rotatably supported by a front plate 35 and a rear plate 36 via bearings 37, respectively. A plurality of slits 38 are formed in the rotor 34 substantially in the radial direction, and a plurality of vanes 39 are respectively fitted into the slits 38 so as to be freely retractable. Back pressure passages 40 are formed in the bottom of the slit 38 in the axial direction, and the plurality of back pressure passages 40 communicate with each other through communication grooves 41 formed on both end surfaces of the rotor 34. Lubricating oil is introduced into the back pressure passage 40, and the tip of the vane 39 is pressed against the cam surface 32 by the vane back pressure of the introduced lubricating oil. When the rotor 34 rotates, the vanes 39 are pressed against the cam surface 32 by the centrifugal force accompanying the rotation of the rotor 34 and the vane back pressure of the lubricating oil in the back pressure passage 40, and rotate while sliding against the cam surface 32. , a pump chamber 42 is defined by the plurality of vanes 39. The pump chamber 42 sucks refrigerant gas from an inlet 44 formed in a head 43 that closes the housing 31, compresses it, and supplies it to a discharge chamber 45 formed at the rear of the housing 31 (on the right in FIG. 1). Exhale. The rear player 36 has an oil separator 4
6 is attached, and the discharged refrigerant gas contains lubricating oil, so when it is discharged, it is blown against the oil separator 46 and the lubricating oil is separated. The separated lubricating oil is stored in the discharge chamber 45. The lubricating oil stored in the discharge chamber 45 is forced through a lubricating oil supply passage 47 formed in the rear plate 36 to a rear chamber 48 disposed behind the rear plate 36. The rear chamber 48 is the rear plate 3
6 and the rear shaft portion 34b, and a rear end plate 50 attached to the rear end of the rear plate 36. A large-diameter hole 51 as a vertical hole is formed in the axial direction from the end surface of the rear shaft portion 34b, and the large-diameter hole 51
A small-diameter hole 52 that forms a vertical hole together with a large-diameter hole 51 is formed on the bottom surface of the hole. One end of a small hole 54 serving as a horizontal hole is opened at the inner outer surface of the small diameter hole 52, and this small hole 54 is bored from the outer peripheral surface of the rear shaft portion 34b so as to intersect with the axis of the small diameter hole 52. The other end is open to the communication groove 41. Further, a plug 57 is press-fitted and fixed to the opening side of the vertical hole, that is, the small diameter hole 52, and a small hole 56 as an orifice is formed in the plug 57. These large diameter hole 51, small diameter hole 52, small hole 54, and small hole 56 are connected as a whole from the discharge chamber 45 to the back pressure passage 40.
A communication hole 55 is formed through which lubricating oil is squeezed and supplied to a predetermined pressure.

Next, the effect will be explained.

The distance between the minute gaps 16 as orifices in a conventional vane type rotary compressor is α. The flow passage area S ₁ of the orifice 16 is obtained by subtracting the cross-sectional view S ₃ of the rear shaft portion _4b from the cross-sectional view S 2 of the inner diameter of the orifice ring 15. That is, if the diameter of the rear shaft portion 4b is D, then S ₁ = S ₂ −S ₃ = π×{(D+2α) ² −D ² }/4 = π×2α×(2D+2α)/4 = πα×(D+α ) becomes. If the allowable error of the interval α is α _nio ≦α≦α _nax , then the allowable error of the channel area S ₁ having a throttling effect is πα _nio × (D + α _nio ) ≦ S ₁ ≦ πα _nax × (D + α _nax )
becomes.

On the other hand, the diameter of the small hole 56 as the orifice of the vane type rotary compressor according to this invention is assumed to be d. The flow path area S ₄ of this orifice 56 is S ₄ =πd ² /4. If the flow path coefficients are equal, S ₁ = S ₄
If we assume that the channel area S ₄ has the same throttling effect as the channel area S ₁ , the allowable error of the channel area S ₄ is πα _nio × (D + α _nio ) ≦ S ₄ ≦ πα _nax × (D + α _nax ) πα _nio ×(D+α _nio )≦πd ² /4 ≦πα _nax ×(D+α _nax ). That is, 2√ _nio × (+ _nio )≦d ≦2√ _nax × (+ _nax ).

Here, suppose that the diameter D of the rear shaft portion 4b is 20 mm, and the tolerance of the interval α of the minute gap 16 is 30μ≦α.
If ≦40μ, that is, the maximum allowable error minus the minimum allowable error is 10μ, then the small hole 56
The diameter d is 2√0.03×20.03≦d≦2√0.04×20.04 1.55≦d≦1.79 ∴ d=1.67±0.12.

That is, the diameter d of the small hole 56 is 240μ, which is the maximum allowable error minus the minimum allowable error. This means that in order for the orifice 56 of this invention to have the same squeezing effect as the conventional orifice 16, the spacing α of the orifice 16 must have a machining accuracy of 10μ, which is the maximum allowable error minus the minimum allowable error. In contrast, the diameter d of the orifice 56 in this invention only needs to have a machining accuracy of 240μ.

Therefore, in order to form the orifice 16 by fitting the orifice ring 15 to the rear shaft portion 4b as in the conventional method, it is necessary to provide the orifice 16 with precise machining accuracy. The small hole 56 does not need to be manufactured with high precision like the orifice of a conventional orifice ring. That is, regarding this invention, plug 57
Since the small hole 56 can be formed with low processing accuracy, the formation is easy, and the conventional grading process and fitting process are unnecessary. As a result, the productivity of this vane type rotary compressor can be improved. Further, since the plug 57 is press-fitted and fixed to the opening side of the vertical hole, a space can be left at the back side of the vertical hole. Furthermore, since the small holes 54 are drilled to intersect with each other in the space at the back of the vertical hole, relatively large tolerances can be given to formation errors such as tilting of the vertical hole in the axial direction and misalignment of the small hole 54. be able to. Furthermore, the tolerance of the small hole 56 formed in the plug 57 can also be increased. As a result, the manufacturing cost of the compressor can be reduced.

(Effect of the invention) As explained above, according to this invention, the plug is provided with a small hole, and a communication hole is provided for squeezing the lubricating oil in the discharge chamber to a predetermined pressure and introducing it into the back pressure path. Since it is formed on the rear shaft of the rotor, small holes can be easily formed, and the conventional grading and fitting processes can be eliminated, allowing vane-type rotary compression. Machine productivity can be improved.

Furthermore, since the plug is press-fitted and fixed to the opening side of the vertical hole, a space can be left on the back side of the vertical hole. Furthermore, since the horizontal holes are drilled to intersect with each other in the space at the back of the vertical holes, it is possible to tolerate relatively large formation errors such as tilting of the vertical holes in the axial direction and misalignment of the horizontal holes. can. Furthermore, the tolerance of the small holes formed in the plug can be increased. As a result, the manufacturing cost of the vane type rotary compressor can be reduced.

[Brief explanation of the drawing]

FIGS. 1 and 2 are views showing an embodiment of a vane type rotary compressor according to this invention, with FIG. 1 being a cross-sectional view thereof, and FIG. 2 being a longitudinal cross-sectional view thereof. 3 and 4 are views showing a conventional vane type rotary compressor, with FIG. 3 being a cross-sectional view thereof, and FIG. 4 being a longitudinal cross-sectional view thereof. 31...housing, 33...cam ring, 3
4... Rotor, 34a... Front shaft portion, 34b... Rear shaft portion, 35... Front plate, 36... Rear plate, 38... Slit, 39... Vane,
40... Back pressure passage, 51... Large diameter hole (vertical hole), 5
2...Small diameter hole (vertical hole), 54...Small hole (horizontal hole), 5
5...Communication hole, 56...Small hole, 57...Plug.

Claims (1)

[Scope of utility model registration request] A cam ring housed in a housing, a front plate and a rear plate that seal both ends of the cam ring, a front shaft portion and a rear shaft portion of a rotor that are rotatably supported by the front plate and rear plate, respectively, and a rotor. A vane that is inserted into a slit formed in the
A vane type rotary compressor comprising a back pressure passage formed at the bottom of the slot for applying back pressure of lubricating oil to the vane, and a discharge chamber defined in the housing for storing lubricating oil. A vertical hole in the axial direction is formed in the shaft part, and a plug having a small hole is press-fitted into the opening side of the vertical hole, and a horizontal hole in the radial direction with one end open on the outer surface of the inner part of the vertical hole is formed. A communication hole is formed from the outer circumferential surface of the rear shaft portion, and a vertical hole and a horizontal hole equipped with a plug are used to squeeze and supply lubricating oil to a predetermined pressure from the discharge chamber to the back pressure passage. Vane type rotary compressor.