JPH10252646A - Double-ended reciprocating compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an increase in frictional resistance of a cylinder bore and a piston even if oil foaming is caused at starting time by arranging hole parts to come and go between a crank chamber and the inside of the cylinder bore according to reciprocating operation of the piston, on an outer peripheral surface of the piston. SOLUTION: When a compression object fluid is sucked in a swash plate chamber from an intake port, lubricating oil contained in the compression object fluid enters through hole parts 28 and 28 provided in shoe receiving parts 9c and 9c of a piston 9, and is discharged in a cylinder bore 8 when the through hole parts 28 and 28 come and go between the swash plate chamber and the cylinder bore 8 accompanying with reciprocating operation of the piston 9. That is, the lubricating oil entering the through hole parts 28 is easily stored in the through hole parts 28 as it is even if oil foaming is caused at starting time. Therefore, when a compressor is operated in a condition where lubricating oil in the compressor runs out by the oil foaming, the lubricating oil entering the through hole parts 28 is discharged in the cylinder bore 8, and acts as lubricating oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-head reciprocating compressor used for an air conditioner for a vehicle.

[0002]

2. Description of the Related Art As a double-headed reciprocating compressor used in a vehicle air conditioner, a reciprocating compressor called a swash plate type has been known for a long time. This swash plate compressor has a plurality of cylinder bores formed around a cylinder block, and a piston is slidably provided in each of the cylinder bores. A drive shaft is rotatably provided at the center of the cylinder block, and the piston reciprocates in the cylinder bore by the rotation of the swash plate mounted on the drive shaft.

Incidentally, such a swash plate type compressor has a pair of shoe receiving portions at the center of a piston with a swash plate as a cam plate interposed therebetween, and these shoe receiving portions slide on the surface of the swash plate. Since the piston and the swash plate are moored by engaging the shoe in a tiltable manner, the shoe may seize on the swash plate when the drive shaft rotates at high speed. Therefore, conventionally, a fluid to be compressed such as a refrigerant compressed by a piston is taken into a swash plate chamber in a cylinder block in which a swash plate is accommodated from an intake port formed in the cylinder block,
The lubricating oil contained in the fluid to be compressed flowing into the swash plate chamber prevents seizure between the shoe and the swash plate. Also, in the swash plate type compressor described above, when the drive shaft rotates at a high speed, there is a possibility that a radial bearing that rotatably supports the drive shaft or a thrust bearing that rotatably supports the swash plate may cause seizure or the like. The compressed fluid flowing into the swash plate chamber is sucked into the cylinder bore through a gap formed between the cylinder block and the drive shaft, thereby preventing radial bearing and seizure of the thrust bearing.

[0004]

However, in the above-described double-head type reciprocating compressor, when oil forming occurs at the time of starting, the swash plate chamber (crank chamber) is opened from the intake port.
The lubricating oil flowing into the cylinder block is discharged together with the fluid to be compressed from the exhaust port of the cylinder block. For this reason, there is a problem in that the frictional resistance between the cylinder bore and the piston increases due to the lack of lubricating oil in the cylinder bore, causing wear of the piston and the like. Therefore, an object to be solved by the present invention is to provide a double head capable of preventing wear of the piston due to lack of lubricating oil without increasing the frictional resistance between the cylinder bore and the piston even when oil forming occurs at the time of startup. An object of the present invention is to provide a reciprocating compressor.

[0005]

As means for solving the above-mentioned problems, the present invention according to claim 1 is provided with a cylinder block having a cylinder bore in a peripheral portion and a rotatably provided in the center of the cylinder block. A drive shaft, a cam plate mounted on the drive shaft, and a piston reciprocating in the cylinder bore by rotation of the cam plate, a fluid to be compressed by the piston is formed in the cylinder block. In the double-headed reciprocating compressor, the intake port is taken into a crank chamber in the cylinder block in which the cam plate is accommodated, and the compressed fluid flowing into the crank chamber is sucked into the cylinder bore and compressed. The piston moves back and forth between the crank chamber and the inside of the cylinder bore along with the reciprocating operation of the piston. Hole is provided. According to a second aspect of the present invention, in the first aspect of the present invention, the hole is opened on a peripheral side of the cylinder block on an outer peripheral surface of the piston. The invention of claim 3 is
The invention according to claim 2 is characterized in that the hole is a non-through hole. According to a fourth aspect of the present invention, in the second aspect, the hole is a through hole that opens from a peripheral portion of the cylinder block to a center portion of the block. According to a fifth aspect of the present invention, in the third or fourth aspect of the present invention, the hole is opened on a side opposite to the rotation direction of the cam plate with respect to a straight line passing through the center of the swash plate and the center of the piston. It is characterized by the following. According to a sixth aspect of the present invention, in the fourth aspect of the present invention, the opening area of the opening that opens from the peripheral portion of the cylinder block toward the center of the cylinder block and opens toward the center of the cylinder block. Is smaller than the opening area of the opening that opens to the peripheral side of the cylinder block. According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the large-diameter hole opening facing the peripheral portion of the cylinder block and the small-diameter hole opening facing the center of the cylinder block. And a two-stage hole comprising:

According to the first aspect of the present invention, during operation of the compressor, the lubricating oil in the crank chamber enters the hole provided on the outer peripheral surface of the piston and is retained. Due to the reciprocating motion of the piston, the power is effectively supplied between the cylinder bore and the piston. Therefore, even if oil forming occurs at the time of startup, the frictional resistance between the cylinder bore and the piston does not increase, and it is possible to prevent wear of the piston due to lack of lubricating oil. According to the second aspect of the present invention, the lubricating oil diffused to the outer peripheral side of the crank chamber due to the centrifugal force of the cam plate easily enters the hole, and more lubricating oil can be supplied into the cylinder bore. According to the third aspect of the present invention, since the hole provided on the outer peripheral surface of the piston is a non-through hole, the lubricating oil that has entered the hole can be reliably held, and the lubricating oil can be more effectively supplied into the cylinder bore. Can be supplied. According to the fourth aspect of the present invention, since the lubricating oil that has entered the hole is discharged toward the center of the cylinder block, a thrust bearing, a drive shaft, and a cylinder provided between the center of the cylinder block and the cam plate are provided. Lubricating oil can be supplied to the radial bearing provided between the block and the bearing, and seizure of the bearing can be reliably prevented. According to the fifth aspect of the invention, the lubricating oil diffused to the outer peripheral side of the crank chamber becomes easier to enter into the hole due to the centrifugal force of the cam plate, so that a large amount of lubricating oil can be supplied into the cylinder bore, and the lubricating oil shortage occurs. Wear and the like of the piston can be more reliably prevented. According to the sixth and seventh aspects of the present invention, since the flow rate of the lubricating oil flowing out of the hole is increased, the lubricating oil can be reliably supplied to the center portion of the cylinder block, and thereby the seizure of the bearing portion can be more reliably performed. Can be prevented. Also, since all the lubricating oil that has entered the hole does not flow toward the center of the cylinder block, the lubricating oil that has entered the hole can be reliably supplied into the cylinder bore.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show a first embodiment of the present invention.
1 is a front side cylinder block of a swash plate type compressor which is a double-headed reciprocating compressor according to the embodiment, and 2 is a front side cylinder block 1.
2 shows a rear cylinder block in which a front end surface is joined to a rear end surface. These cylinder blocks 1 and 2 are made of aluminum or aluminum alloy or the like, and a drive shaft 3 is provided at the center thereof. The drive shaft 3 is rotatably supported by a pair of front and rear radial bearings 4, 4, and a circular swash plate 5 is mounted at the axial center of the drive shaft 3. The swash plate 5 as a cam plate is made of aluminum or an aluminum alloy or the like, and is obliquely inclined with respect to the drive shaft 3. In addition, the swash plate 5 has a boss 5a at the center, which fits on the outer periphery of the drive shaft 3, and
A swash plate 5 is provided between both end faces of the boss 5a and the front cylinder block 1 and the rear cylinder block 2.
A pair of thrust bearings 7, 7 for rotatably supporting the
Is provided.

On the other hand, a plurality of cylinder bores 8 are formed in the periphery of the front cylinder block 1 and the rear cylinder block 2 as shown in FIG. These cylinder bores 8 are formed on the same circumference around the drive shaft 3, and a double-headed piston 9 (see FIG. 1) is slidably provided in each cylinder bore 8. The piston 9 is made of aluminum or an aluminum alloy or the like, and a front-side compression section 9a and a rear-side compression section 9b for compressing a fluid to be compressed sucked into the cylinder bore 8 are formed at both ends of the piston 9. . Further, a pair of shoe receiving portions 9c, 9c is formed at the center of the piston 9, as shown in FIG. These shoe receiving portions 9c, 9c are opposed to each other with the swash plate 5 interposed therebetween, and a hemispherical shoe 10 sliding on the surface of the swash plate 5 is tiltably engaged with each shoe receiving portion 9c. doing.

The cylinder bores 8 of the front cylinder block 1 and the rear cylinder block 2 are closed by a front cylinder cover 11 and a rear cylinder cover 12, as shown in FIG. These cylinder covers 11 and 12 are made of aluminum or an aluminum alloy or the like. A plurality of bolts 13 penetrating the inside of the front cylinder block 1 and the rear cylinder block 2 are used to secure the front end face of the front cylinder block 1 and the rear cylinder. Block 2 is joined to the rear end face.

[0010] Between the cylinder blocks 1 and 2 and the cylinder covers 11 and 12, annular valve plates 14 and 1 are provided.
4 are provided. These valve plates 14,1
4 is made of aluminum alloy or the like, and each valve plate 1
A plurality of suction ports 15 (see FIG. 3) are bored in the outer peripheral portion of 4. These suction ports 15 open to suction chambers 16 formed on the outer peripheral portions of the cylinder covers 11 and 12, and are connected to the cylinder blocks 1 and 2 and the valve plate 1.
The intake valves 17 and 17 are provided between the intake valves 4 and 14 to open and close. A plurality of discharge ports 18 are formed in the inner peripheral portion of the valve plate 14.
These discharge ports 18 open to discharge chambers 19 formed in the inner peripheral portions of the cylinder covers 11 and 12, and discharge valves 20, provided between the valve plates 14 and 14 and the cylinder covers 11 and 12. 20 is used to open and close.

The suction valve 17 and the discharge valve 20 are formed by pressing a thin metal plate into a predetermined shape.
Gaskets 21, 21 are provided between the cylinder blocks 7, 17 and the cylinder blocks 1, 2. And the discharge valve 20,
Gaskets 22, 22 with retainers formed by coating both sides of a metal plate with a sealing material are provided between the cylinder cover 11 and the cylinder covers 11, 12, and the opening degree of the discharge valve 20 is provided on the gaskets 22, 22 with retainers. Is formed.

As shown in FIG. 4, at the joint between the front cylinder block 1 and the rear cylinder block 2,
Swash plate chamber 24 as a crank chamber for accommodating swash plate 5
Are formed. Compressed fluid such as refrigerant flows into the swash plate chamber 24 from an intake port 25 provided in the front cylinder block 1, and the compressed fluid flowing into the swash plate chamber 24 flows through the inside of the thrust bearing 7. It flows through the gaps 26 formed between the drive shaft 3 and the cylinder blocks 1 and 2 and flows through the suction passages 27 formed in the front cylinder cover 11 and the rear cylinder cover 12. Circulating and suction chambers 16, 16
It is designed to flow into. Note that a refrigerant circuit (not shown) is connected to the intake port 25.

As shown in FIG. 5, the shoe receiving portions 9c of the piston 9 are provided with a pair of through holes 28, 28, respectively. These through holes 28 open from the periphery of the cylinder blocks 1 and 2 toward the center. For example, when the front compression portion 9a of the piston 9 moves from the top dead center to the bottom dead center, the through holes are opened. When one of the parts 28, 28 faces the thrust bearing 7 and the rear compression part 9 b of the piston 9 moves from the top dead center to the bottom dead center, the other of the through holes 28, 28 faces the thrust bearing 7. It has become. The through-holes 28, 28 have a large-diameter hole 28 a that opens to the periphery of the cylinder blocks 1, 2 and a small-diameter hole 28 b that opens to the center of the cylinder blocks 1, 2. The large-diameter hole 28a is formed, for example, by rotating the swash plate 5 in the direction shown in FIG.
When a clockwise rotation as indicated by the middle arrow, is open on the right side of the piston outer peripheral surface of the straight line L passing through the center O _B of the center O _A and the piston 9 of the swash plate 5.

According to this configuration, when the fluid to be compressed is sucked into the swash plate chamber 24 from the intake port 25, the lubricating oil contained in the fluid to be compressed is transferred to the shoe receiving portions 9c, 9c of the piston 9.
The lubricating oil that has entered the through holes 28, 28 provided in the swash plate chamber 24 and the cylinder bore 8 is moved by the reciprocating operation of the piston 9 into the through holes 28, 28. It is discharged into the cylinder bore 8 by going back and forth. That is, in the above-described first embodiment, the lubricating oil that has entered the through-hole portion 28 is easily stored in the through-hole portion 28 as it is even when oil forming occurs during startup. Therefore, when the compressor is operated in a state where the lubricating oil in the compressor is exhausted by oil forming (dry state), the lubricating oil that has entered the through hole 28 is discharged into the cylinder bore 8 and acts as the lubricating oil. .
For this reason, even if oil forming occurs at the time of startup, the frictional resistance between the cylinder bore 8 and the piston 9 does not increase, and wear of the piston 9 due to lack of lubricating oil can be prevented. Further, the lubricating oil that has entered the through-hole portion 28 from the large-diameter hole portion 28a flows out from the small-diameter hole portion 28b that opens toward the center of the cylinder blocks 1 and 2. Therefore, even if a large amount of the lubricating oil in the fluid to be compressed floats around the cylinder blocks 1 and 2 due to the centrifugal force caused by the rotation of the swash plate 5, the lubricating oil in the swash plate chamber 24 is removed from the cylinder block 1 and
2 can be reliably supplied to the thrust bearings 7, 7 and the radial bearings 4, 4. Further, the lubricating oil that has entered the through hole 28 from the large-diameter hole 28a flows out from the small-diameter hole 28b that opens toward the center of the cylinder blocks 1 and 2. , 2 can be increased in flow velocity of the lubricating oil flowing toward the center. As a result, lubricating oil is easily supplied to the central portions of the cylinder blocks 1 and 2, and seizure of the thrust bearings 7, 7 and the radial bearings 4, 4 can be more reliably prevented. A part of the lubricating oil flowing into the through-holes 28, 28 is supplied to the center of the cylinder blocks 1 and 2 through the small-diameter hole 28b, and the remaining lubricating oil enters the large-diameter hole 28a. Since it remains, lubricating oil can be reliably supplied into the cylinder bores 8 of the cylinder blocks 1 and 2. Further, the through hole 28,
28 If (hole 28a of the large-diameter) is a clockwise rotation direction, for example the swash plate 5, on the right side of the piston outer peripheral surface of the straight line L passing through the center O _B of the center O _A and the piston 9 of the swash plate 5 Since the swash plate 5 is opened, a larger amount of lubricating oil flowing in the circumferential direction of the swash plate 5 with the rotation of the swash plate 5 can flow into the through-holes 28. Therefore, the cylinder blocks 1,
A larger amount of lubricating oil can be supplied to the center part of the cylinder 2 and the inside of the cylinder bore 8, thereby reliably preventing wear of the piston 9 due to insufficient lubricating oil and preventing seizure of the thrust bearings 7, 7 and the radial bearings 4, 4. It can be prevented more reliably.

FIG. 6 shows a second embodiment of the present invention. A pair of non-through holes 29, 29 are provided in the shoe receiving portions 9c, 9c of the piston 9. These non-through holes 29, 29 open from the center of the cylinder blocks 1, 2 to the periphery, and move between the swash plate chamber 24 and the cylinder bore 8 as the piston 9 reciprocates. It has become. That is, the non-through hole portions 29, 29
Are cylinder blocks 1, 2 on the outer peripheral surface of the piston 9.
Is opened on the outer peripheral side. In addition, the non-through hole portions 29, 29
For example when the rotational direction of the swash plate 5 is assumed to be clockwise as shown by the arrow in FIG. 6, and opens to the right of the straight line L passing through the center O _B of the center O _A and the piston 9 of the swash plate 5 I have. According to such a configuration, the lubricating oil flowing into the swash plate chamber 24 from the intake port 25 enters the non-through holes 29, 29 provided in the shoe receiving portions 9c, 9c of the piston 9, and the non-through holes 29, 29 are provided. The lubricating oil that has entered tends to remain in the through hole 28 as it is even when oil forming occurs. Therefore, even when the compressor is operated in a state where the lubricating oil in the compressor is exhausted due to the oil forming (dry state), the lubricating oil remaining in the through hole 28 is caused by the reciprocating motion of the piston 9 accompanying the start of the compressor. Cylinder bore 8
Is effectively supplied between the piston 9 and the piston 9, even if oil forming occurs at the time of startup, the frictional resistance between the cylinder bore 8 and the piston 9 does not increase, and wear of the piston 9 due to lack of lubricating oil and the like are reduced. Can be prevented.

In the first embodiment described above, the through hole 28 opening from the periphery of the cylinder blocks 1 and 2 toward the center is formed with a large diameter opening toward the periphery of the cylinder blocks 1 and 2. Although formed by the hole 28a and the small-diameter hole 28b opening toward the center of the cylinder blocks 1 and 2, for example, the opening area gradually decreases from the periphery of the cylinder blocks 1 and 2 toward the center. It may be a through-hole portion as shown in FIG.

[0017]

As described above, according to the first aspect of the present invention, the frictional resistance between the cylinder bore and the piston does not increase even if oil forming occurs at the time of startup, and the wear of the piston due to lack of lubricating oil. Etc. can be prevented. According to the second and third aspects of the present invention, the lubricating oil can easily enter the hole provided on the outer peripheral surface of the piston, so that it is possible to reliably prevent the piston from being worn due to insufficient lubricating oil. According to the fourth, sixth and seventh aspects of the invention, in addition to the effects of the first aspect, a thrust bearing, a drive shaft and a cylinder provided between the center of the cylinder block and the cam plate are provided. Seizure of the radial bearing provided between the block and the block can be reliably prevented. According to the fifth aspect of the present invention, more lubricating oil can easily enter the hole provided on the outer peripheral surface of the piston, so that it is possible to more reliably prevent wear of the piston due to insufficient lubricating oil.

[Brief description of the drawings]

FIG. 1 is a sectional view of a swash plate type compressor according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a sectional view taken along the line CC of FIG. 2;

FIG. 5 is a sectional view taken along line DD of FIG. 1;

FIG. 6 is a cross-sectional view illustrating a configuration of a main part of a swash plate type compressor according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front side cylinder block 2 Rear side cylinder block 3 Drive shaft 4 Radial bearing 5 Swash plate 7 Thrust bearing 8 Cylinder bore 9 Piston 11 Front side cylinder cover 12 Rear side cylinder cover 14 Valve plate 15 Suction port 17 Suction valve 18 Discharge port 20 Discharge Valve 24 Swash plate chamber 25 Compressed fluid suction port 26 Void 28 Through hole 29 Non-through hole

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kiichi Dedo 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation

Claims (7)

[Claims] 1. A cylinder block having a cylinder bore in a peripheral portion, a drive shaft rotatably provided in a center portion of the cylinder block, a cam plate mounted on the drive shaft, and rotation of the cam plate. A piston reciprocating in a cylinder bore, and the fluid to be compressed compressed by the piston is taken into a crank chamber in the cylinder block in which the cam plate is accommodated from an intake port formed in the cylinder block. In a double-headed reciprocating compressor that sucks and compresses a fluid to be compressed flowing into a crank chamber into the cylinder bore and compresses the outer peripheral surface of the piston, the crank chamber and the inside of the cylinder bore with the reciprocating operation of the piston. A double-headed reciprocating compressor characterized by having a hole for passing between the two. 2. The double-headed reciprocating compressor according to claim 1, wherein the hole is opened on a peripheral portion of the cylinder block on an outer peripheral surface of the piston. 3. The double-headed reciprocating compressor according to claim 2, wherein the hole is a non-through hole. 4. The double-headed reciprocating compressor according to claim 2, wherein the hole is a through hole that opens from a peripheral portion of the cylinder block toward a center of the cylinder block. 5. The cam plate according to claim 3, wherein the hole is opened on a side opposite to a rotation direction of the cam plate with respect to a straight line passing through a center of the swash plate and a center of the piston. The double-headed reciprocating compressor described. 6. The cylinder block has an opening area extending from a peripheral portion of the cylinder block to a central portion of the cylinder block, and an opening area opening toward a central portion side of the cylinder block has an opening area around the cylinder block. The double-headed reciprocating compressor according to claim 4, wherein the opening area of the opening that opens on the side of the part is smaller than the opening area. 7. A two-stage hole comprising a large-diameter hole opening to face a peripheral portion of the cylinder block and a small-diameter hole opening to a center portion of the cylinder block. The double-headed reciprocating compressor according to claim 6, wherein: