JPH036353B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is used as a mechanical supercharger for intake supercharging in an engine, for example, and has a rotating sleeve that rotates synchronously with a rotor. Regarding rotary compressors.

(Prior Art) Rotary compressors having such a rotating sleeve have been known for some time (for example, "displacement compressor" (published by Sangyo Tosho Co., Ltd. on April 5, 1978)).
(see Figure 15.1(a)). That is, a rotary sleeve is rotatably fitted into a casing formed by a cylindrical center housing and side housings arranged on both sides of the casing, and a rotor driven from the outside is centered at the rotation center of the rotary sleeve. The rotor is arranged eccentrically with respect to the rotor, and a plurality of plate-shaped vanes are fitted in the rotor so as to be freely retractable.
The rotary sleeve is rotated along with the rotor via the vane caused by the rotation of the rotor. Since the rotary sleeve rotates together with the vane, this rotary compressor is advantageous in terms of durability because it prevents heat generation and wear caused by sliding of the vane tip, so it can be used from low to high rotation speeds. Recently, it has been attracting attention as an optimal supercharger for engines that operate over a wide rotation range.

However, in the above conventional device, the rotating sleeve is rotatably supported within the casing by an oil bearing layer, but the airtightness of the compression chamber defined by the inner circumferential surface of the rotating sleeve and the outer circumferential surface of the rotor is not guaranteed. The clearance between the rotating sleeve and the side housing has been narrowed as much as possible in order to ensure smooth rotation of the rotating sleeve by keeping the center axes of the rotating sleeve and center housing parallel. . For this reason, the sliding resistance between the rotating sleeve and the side housing is large.
As a result, the sliding torque loss increases and the inner surface of the side housing wears out, which is a problem that must be solved from a practical standpoint.

(Object of the Invention) An object of the present invention is to realize a practical use of a rotary compressor having a rotary sleeve which is advantageous in terms of durability as described above. The objective is to reduce resistance, reduce drive torque loss, and prevent wear on the inner surface of the side housing.

(Structure of the Invention) In order to achieve the above object, the present invention provides a solution for a rotary compressor having a rotating sleeve as described above. A communication hole is provided, the downstream end of which is open at the inner surface of the side housing that slides on the rotating sleeve, and supplies high-pressure compressed air generated in the discharge port or the high-pressure zone to the inner surface of the side housing that slides on the rotating sleeve. It is characterized by the fact that it has been provided.

As a result, in the present invention, a part of the compressed air in the discharge port or high pressure zone is ejected and supplied between the sliding surface of the rotating sleeve and the side housing through the communication hole, and an air film is formed between the two. This structure reduces the sliding resistance between the two.

In this case, the upstream end opening of the communication hole is provided at a position immediately upstream of the discharge port in the side housing, since the position immediately upstream of the discharge port is the area where the highest pressure is generated. It is advantageous in terms of conversion. In addition, although air was mentioned as the working fluid in the above explanation,
The same can be said for other gaseous fluids.
This is within the technical scope of the present invention.

(Effects of the Invention) Therefore, according to the present invention, the sliding resistance between the rotating sleeve and the side housing in a rotary compressor having a rotating sleeve is reduced by opening the upstream end to the discharge port or high pressure zone, and reducing the sliding resistance between the rotating sleeve and the side housing. This can be reduced by a simple configuration of providing a communication hole that opens on the inner surface of the side housing whose end slides on the rotating sleeve, so the rotation of the rotating sleeve can be performed smoothly, reducing drive torque loss, and the conventional The present invention aims to put into practical use a rotary compressor having a rotary sleeve that can prevent wear on the inner surface of the side housing and thus has excellent durability, thereby making it possible to provide and realize an optimal engine supercharger. In particular, if the upstream end opening of the communication hole is provided at a position immediately upstream of the discharge port in the side housing, even higher pressure compressed air can be ejected and supplied to the inner surface of the side housing, and the above effects can be further enhanced. be.

(Example) Hereinafter, an example as a specific example of the technical means of the present invention will be described based on the drawings.

1 to 6 show an embodiment of the present invention. In FIGS. 1 and 2, 1 is a casing, and the casing 1 includes a cylindrical center housing 2 and a plurality of side housings 3, 3 (four in the figure) arranged on both the left and right sides of the cylindrical center housing 2. It is configured by being fastened by fastening bolts 4, 4, . . . . A cylindrical rotating sleeve 5 whose outer diameter is slightly smaller than the inner diameter of the center housing 2 is fitted into the casing 1 so as to be rotatable and concentric with the axis of the center housing 2. An air bearing chamber 6 is formed by a gap (for example, 30 to 50 microns) between the outer circumferential surface 5a of the center housing 2 and the inner circumferential surface 2a of the center housing 2. Further, inside the rotating sleeve 5, shaft portions 7a, 7a are provided at both ends.
A cylindrical rotor 7 having a rotor 7 is eccentrically arranged with respect to the rotation center of the rotating sleeve 5 (the axis of the center housing 2) and is arranged so as to maintain a minimum clearance to the rotating sleeve 5 at a tangential seal point P, A substantially crescent-shaped space 8 between the inner circumferential surface 5b of the rotating sleeve 5 and the outer circumferential surface 7b of the rotor 7
is formed.

One of the side housings 3 (the left side housing in FIG. 2) has an intake port 9 on the training side (left side in FIG. 1) of the space 8, facing the space 8; A discharge port 10 is opened on the leading side of the pump 8 (right side in FIG. 1). Further, the inner surfaces 3a, 3a of both side housings 3, 3 have annular seal grooves 11, corresponding to both end surfaces 5c, 5c of the rotary sleeve 5.
11 is formed, and a side seal 12 is installed in each of the seal grooves 11 in sliding contact with the rotary sleeve end surface 5c for gas sealing.

Further, the rotor 7 is rotatably supported at its shaft portions 7a and 7b via bearings 14 and 14 in support holes 13 and 13 provided in both side housings 3 and 3, respectively.
(the shaft portion on the right side in FIG. 2) is extended outside the casing 1, and a pulley 15 connected by a belt drive to a rotary drive device (not shown) such as an engine is attached to the extended portion of the shaft portion 7a. The rotor 7 is rotatably driven via a pulley 15 by an external rotary drive device.

Further, on the outer circumferential surface 7b of the rotor 7, a plurality of (four in the figure) vane grooves 16, 16, . A plate-shaped vane 17 is fitted into each of the vanes 16 so as to be slidable and retractable in the radial direction of the rotor 7. The vanes 17, 17... are subjected to centrifugal force when the rotor 7 rotates, and their outer ends are brought into airtight pressure contact with the inner circumferential surface 5b of the rotating sleeve 5, so that the inner circumferential surface 5b of the rotating sleeve and the outer circumferential surface 7b of the rotor The space 8 is defined as four compression grooves 18, 18, . . . , and the rotary sleeve 5 is rotated synchronously with the rotor 7 in this state.

As shown in detail in FIGS. 3 and 4, an annular groove 19 is formed in the bottom wall of the seal groove 11 of each side housing 3 along the groove 11, and the annular groove 19 and the side An air passage 20 is formed by the seal 12. The air passages 20, 20 of both side housings 3, 3 are communicated with each other through a through hole 21 provided through the side housings 3, 3 and the center housing 2. In addition, suction port 9 and discharge port 1
One end 22a of the side housing 3 on the rear side (the left side in FIG. 2) provided with 0 has one end 22a located immediately upstream of the discharge port 10 in the high pressure zone A that is formed around the discharge port 10 and generates high pressure compressed air. A compressed air take-off hole 22 is provided which opens at the position and whose other end 22b opens into the air passage 20. Furthermore, side seals 12, 1 of both side housings 3, 3
2, a plurality of (12 in the figure) jet holes 23 are provided at equal pitches in the circumferential direction, one end 23a opening to the air passage 20 and the other end 23b opening to the surface that slides into contact with the rotating sleeve 5. It is being The air passages 20, 20 and the jet hole 23 communicate with each other via the compressed air take-off hole 22 and the through hole 21, so that the upstream end is located in the high pressure zone A around the discharge port 10, particularly at a position immediately upstream of the discharge port 10. The downstream end is opened at the side housing inner surface 3a (side seal 12) in sliding contact with the rotating sleeve 5, and high-pressure compressed air is spouted between the rotating sleeve end surface 5c and the side housing inner surface 3a (side seal 12). It constitutes a communication hole 24 for supplying the liquid.

Further, each end surface 5c of the rotating sleeve 5 has
As shown in FIGS. 5 and 6, in order to perform a Layleigh step action, the depth is formed in a stepped manner so that the depth is deeper at the front part 25a and shallower at the rear part 25b in the rotational direction X. Compression dimples 25 are provided at equal pitches in the circumferential direction, and the compression dimples 25 open toward the inner circumferential surface 5b of the rotary sleeve 5 at a front portion 25a in the rotational direction.

Furthermore, the rotation sleeve 5 includes a compression chamber 18.
A large number of communication holes 26, 26, .
8 is jetted and supplied to the air bearing chamber 6 to form an air bearing layer between the rotating sleeve 5 and the center housing 2.

Next, to explain the operation of the above embodiment,
The rotor 7 is rotated by an external rotary drive device such as an engine.
When the rotor 7 is rotated in the X direction in FIG.
The vanes 17 fitted in the respective vane grooves 16 are subjected to centrifugal force so that their outer ends are brought into airtight pressure contact with the inner circumferential surface 5b of the rotating sleeve 5, thereby making contact between the inner circumferential surface 5b of the rotating sleeve and the rotor. Outer peripheral surface 7b
The space 8 between the two is defined as four compression chambers 18, 18..., and while this state is maintained, the rotational force of the rotor 7 is transmitted to the rotating sleeve 5 via the vanes 17, 17... The rotating sleeve 5 rotates synchronously with the rotor 7. As the rotor 7 and the rotating sleeve 5 synchronously rotate, the volume of the compression chamber 18 changes synchronously, and as the compression chamber 18 moves from the suction port 9 side to the discharge port 10 side, the volume gradually changes. After reaching the maximum volume, it gradually decreases. As a result, the air sucked into the compression chamber 18 through the suction port 9 is compressed and pressurized within the compression chamber 18, and then is discharged from the discharge port 10 to the outside of the casing 1.

At that time, a part of the high-pressure compressed air in the high-pressure zone A around the discharge port 10 flows into the side housing 3 through the compressed air outlet hole 22 provided in the rear side housing 3 due to the high pressure. After flowing into the air passage 20 and being guided to the air passage 20 of the front side housing 3 through the through hole 21, the air ejection hole 23 provided in the side seal 12 flows.
It is ejected and supplied between the rotary sleeve end face 5c and the side seal 12 of the side housing 3 via... As a result, a high-pressure air film is formed between the two, and as a result, the rotating sleeve end face 5c
The sliding resistance between the side seal 12 of the side housing 3 and the side seal 12 of the side housing 3 is significantly reduced. In particular, the upstream opening 22a of the compressed air outlet hole 22 (communication hole 24)
By providing a position immediately upstream of the discharge port 10, the position immediately upstream of the discharge port 10 generates excess pressure to push out the compressed air, and at high rotations, excessive compression causes extremely high pressure compressed air to be generated. The highest pressure compressed air in the high pressure zone A is supplied between the rotary sleeve end face 5c and the side seal 12, and a very high pressure air film can be formed, which is advantageous in reducing the sliding resistance between the two. It is.

On the other hand, when compression dimples are provided on the rotary sleeve end surface 5c, the high-pressure air jetted and supplied between the rotary sleeve 5 end surface 5c and the side seal 12 is transferred to the compression dimples 25... as the rotary sleeve 5 rotates. Also, a part of the compressed air in the compression chamber 18 is directly introduced into the compression dimples 25 . As the rotary sleeve 5 rotates, the viscous air introduced into the compressed dimples 25 causes each dimple 25 to form a so-called Ray race step in which the front portion 25a is deeper and the rear portion 25b is shallower in the rotational direction X. As a result, the front portion 25a expands and is then recompressed at the rear portion 25b to generate a compression force, which generates a strong compression reaction force between the rotary sleeve end surface 5c and the side seal 12, and as a result, the sliding between them is reduced. Dynamic resistance can be further reduced.

Therefore, by creating a strong air film or a strong compressive reaction force between the rotating sleeve 5 and the side housing 3 (side seal 12), the sliding resistance between them can be significantly reduced. The rotating sleeve 5 can be rotated smoothly, drive torque loss can be reduced, and wear of the side housing inner surface 3a (side seal 12) can be prevented as much as possible.

On the other hand, a part of the high-pressure compressed air in the compression chamber 18 is ejected and supplied to the air bearing chamber 6 through the communication hole 26 provided in the rotating sleeve 5 due to the pressure difference between the compression chamber 18 and the air bearing chamber 6. By filling the air bearing chamber 6 (air bearing layer) with a large amount of high-pressure air, contact between the rotating sleeve 5 and the center housing 2 can be prevented.

Now, specifically, for a rotary sleeve provided with a communication hole that communicates the compression chamber and the air bearing chamber, as in the above embodiment, a communication system for supplying compressed air in the high pressure zone between the side seal and the end face of the rotary sleeve. One with holes (inventive example) and one without (comparative example)
The driving torque of the rotating sleeve with respect to the rotor rotational speed and the wear amount of the side seal after durability operation were measured, and the results are shown in FIGS. 7 and 8, respectively. In addition, as for the above experimental conditions, the rotary compressor has rotor 1.
The discharge volume per revolution is 400c.c./rev, the discharge pressure is 0Kg/cm ² G, the rotating sleeve is made of cast iron without a soft material coating, and the side seal is made of fired carbon resin. It is a quality item. Also,
Durability operation was carried out by continuous operation for 5 hours at a rotor rotation speed of 5000 rpm.

From FIG. 7, it can be seen that in the example of the present invention, the driving torque is smaller than that in the comparative example, and the driving torque loss can be reduced. Further, from FIG. 8, it can be seen that the amount of wear in the example of the present invention is reduced to 1/5 or less compared to the comparative example, indicating that wear can be prevented as much as possible.

In the above embodiment, the upstream opening 22a of the compressed air outlet hole 22 (continuous hole 24) is located in the high pressure zone A.
Although it is provided at a position immediately upstream of the discharge port 10, it may be provided in other high pressure zones A or the discharge port 10, and the object of the present invention can be fully achieved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional front view, FIG. 2 is a cross-sectional view taken along the line -- in FIG. 5 is a partial front view of the end face of the rotating sleeve, FIG. 6 is an enlarged sectional view taken along the line - in FIG. 5, and FIG. 7 is an experimental result diagram showing the driving torque versus rotor rotation speed. FIG. 8 is an experimental result chart showing the amount of side seal wear in a durability test. 1... Casing, 2... Center housing, 3... Side housing, 5... Rotating sleeve, 7... Rotor, 9... Suction port, 10...
Discharge port, 12... Side seal, 17... Vane, 20... Air passage, 21... Through hole, 22
...Compressed air outlet hole, 22a...Opening, 23...
...Ejection hole, 23b... End, 24... Communication hole, 2
5... Compression dimple, A... High pressure zone.

Claims (1)

[Scope of Claims] 1. A casing formed of a cylindrical center housing and side housings arranged on both sides of the cylindrical center housing and having suction ports and discharge ports, and a rotating sleeve rotatably fitted into the casing; A rotor is provided eccentrically with respect to the rotation center of the rotary sleeve and rotationally driven from the outside, and a plurality of plate-shaped vanes are fitted to the rotor so as to be retractable. In the rotary compressor, the rotary sleeve is rotated through the casing, and the upstream end opens to the high pressure zone formed at or around the discharge port, and the downstream end slides into contact with the rotary sleeve. A rotary compressor having a rotary sleeve, characterized in that a communication hole opening on the inner surface of the housing is provided. 2. A rotary compressor having a rotary sleeve according to claim 1, wherein the upstream end opening of the communication hole is provided at a position immediately upstream of the discharge port in the side housing.