JPH06249146A - Swash plate compressor - Google Patents

Abstract

PURPOSE:To lubricate the inside of a crankcase properly according to all operating conditions without impairing the characteristics of a compressor such as response, etc. CONSTITUTION:An oil separating chamber 31 is formed in a delivery flange 30, and a lubricating oil in a refrigerant gas introduced from delivery chambers 20 and 25 is separated and accumulated at the bottom of it. The bottom of the oil separating chamber 31 is connected to a crankcase 5 through an oil return passage 32 and through a spool 33, and the opening degree of the oil return passage 32 is reduced as a pressure in the oil separating chamber 31 is increased by large-capacity operation and increased as that in the oil separating chamber 31 is reduced by small-capacity operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate compressor having an oil separation / return mechanism suitable for use in a vehicle air conditioner or the like.

[0002]

2. Description of the Related Art Among conventional swash plate type compressors (hereinafter, simply referred to as "compressor"), a variable capacity type is known as disclosed in Japanese Patent Laid-Open No. 60-175783. In this variable displacement compressor, a cylinder block having a plurality of bores is arranged in the center of the center housing, the front end of which forms a closed crank chamber and is closed by the front housing, and the rear end of the cylinder block. Is closed by the rear housing via the valve plate. The rear housing is provided with a suction chamber and a discharge chamber that communicate with the bore. The drive shaft is inserted into and supported by the center shaft hole of the cylinder block in the front housing. The rotor is supported in the crank chamber so as to be rotatable synchronously and the sleeve is slidably mounted in the axial direction. Has been inserted. A swash plate is connected to the rotor via a hinge mechanism,
The swash plate is supported by the drive shaft by sliding contact with the sleeve by the inner surface of the spherical zone. In this way, the swash plate is capable of synchronous rotation and tilt displacement with the drive shaft via the hinge mechanism and the sleeve. Further, a single-head piston fitted in each bore is moored to the swash plate via a pair of shoes. The cylinder block is provided with a bleed passage that connects the crank chamber and the suction chamber, and a control valve that controls the opening of the crank chamber to control the pressure of the crank chamber is provided in the bleed passage.

In this variable displacement compressor, when the swash plate rotates in accordance with the drive of the drive shaft, the swinging motion corresponding to the tilt angle of the swash plate is converted into the reciprocating motion of the piston via the shoe. Reciprocates in the bore. As a result, the refrigerant gas is sucked into the bore from the suction chamber, and the refrigerant gas is compressed and then discharged to the discharge chamber. The refrigerant gas thus discharged into the discharge chamber is circulated in the external refrigeration circuit. The compression capacity of the refrigerant gas discharged into the discharge chamber is controlled by adjusting the pressure in the crank chamber by the control valve. That is, when the control valve expands the opening of the extraction passage, the refrigerant gas flows from the crank chamber to the suction chamber, so that the back pressure acting on the piston is reduced, and the tilt angle of the swash plate is activated by the operation of the hinge mechanism and the sleeve. Grows larger. As a result, the stroke of the piston is extended and large-capacity operation is executed. On the contrary, when the control valve reduces the opening degree of the extraction passage, the pressure in the crank chamber is increased by the blow-by gas and the back pressure acting on the piston is increased, so that the inclination angle of the swash plate is decreased.
As a result, the stroke of the piston is shortened and the small capacity operation is executed.

A fixed displacement compressor in which a swash plate is fixed to a drive shaft in a crank chamber is also generally known. In this fixed displacement compressor, the oscillating motion corresponding to a certain tilt angle of the swash plate is converted into the reciprocating motion of the piston through the shoe, and the reciprocating motion of the piston in the bore sucks and compresses the refrigerant gas. -Discharge is executed with a fixed volume. Then, the crank chamber and the suction chamber are connected by a bleed passage or the like, the crank chamber is cooled by a low-temperature refrigerant gas, and deterioration of sealing performance due to abnormal increase in pressure of the crank chamber due to blow-by gas is prevented. ing.

In these compressors, when the intake, compression and discharge steps are executed, the lubricating oil stored in the crank chamber lubricates the swash plate which makes sliding contact in the crank chamber, and the swash plate burns. Prevents sticking.

[0006]

However, in each of the above-mentioned compressors, the lubricating oil stored in the crank chamber is also discharged to the suction chamber by the extraction passage or the like which connects the crank chamber and the suction chamber. Lubricating oil that has flowed out to the suction chamber may flow into the bore due to the reciprocating motion of the piston, and may be returned to the crank chamber together with blow-by gas.However, if it cannot be returned to the crank chamber, it passes through the discharge chamber and circulates in the refrigeration circuit. Will be done.

If the compressor is of a variable displacement type, the lubricating oil will flow out to the refrigeration circuit due to the refrigerant circulation amount in the refrigeration circuit during large-capacity operation or when the drive shaft is rotated at a high speed. Mist-like lubricating oil is often replenished into the crank chamber by blow-by gas, etc. together with the refrigerant, so this does not pose a problem so much, but during small-capacity operation or when the drive shaft is rotating at a low speed, in the refrigeration circuit Since the amount of refrigerant circulation is small and the amount of lubricating oil that remains in the refrigeration circuit is larger than the amount that mist-like lubricating oil is replenished in the crank chamber, the amount of lubricating oil stored in the crank chamber will decrease. .

However, there is also known a variable displacement compressor in which an air supply passage having an orifice in the middle is formed between a discharge chamber and a crank chamber. With this variable displacement compressor,
Since the lubricating oil can be replenished to the crank chamber by the air supply passage other than blow-by gas, the above-mentioned problems can be alleviated, but the cross-sectional area of the air supply passage is constant so that the capacity is small. The amount of lubricating oil replenished in the crank chamber during operation and low speed rotation is still less than the outflow amount. However, if the cross-sectional area of the air supply passage is increased in order to avoid this, the pressure in the crank chamber is less likely to drop, and the responsiveness from small capacity operation to large capacity operation is delayed.

If the compressor is of a fixed displacement type, the lubricating oil flows out into the refrigeration circuit due to a large amount of refrigerant circulating in the refrigeration circuit when the drive shaft is rotating at high speed. Mist-like lubricating oil is also replenished in the crank chamber with blow-by gas etc. together with the refrigerant,
This is not a big problem, but when the drive shaft is rotating at a low speed, the refrigerant circulation amount in the refrigeration circuit is small, and again the mist-like lubricating oil stays in the refrigeration circuit more than the amount replenished in the crank chamber. Since the amount of lubricating oil present is large, the amount of lubricating oil stored in the crank chamber is reduced.

Therefore, in the conventional compressor, there is a risk that the lubricating oil in the crank chamber will run short, and in the worst case, the swash plate or the like may seize. An object of the present invention is to solve the problem that the lubrication of the crank chamber is appropriately performed according to all operating conditions without impairing the characteristics such as responsiveness of the compressor.

[0011]

In order to solve the above-mentioned problems, a swash plate type compressor according to the present invention has a plurality of bores defined concentrically in a cylinder block, and each of the bores has a single-headed piston. And a suction chamber, a discharge chamber, and a crank chamber are formed by joining the housing to the cylinder block, and a swash plate is linked to the drive shaft supported by the housing in the crank chamber. , The piston moored to the swash plate reciprocates in the bore with a swinging motion according to the inclination angle of the swash plate, thereby sucking refrigerant gas from the suction chamber into the bore and In a swash plate compressor configured to discharge a refrigerant gas from inside into the discharge chamber, a refrigerant gas in the discharge chamber is introduced into a discharge flange formed in the cylinder block. The oil separation chamber that separates the lubricating oil in the cylinder and stores the separated lubricating oil in the bottom is formed, and a return oil passage that communicates both is formed between the bottom of the oil separation chamber and the crank chamber. A valve for reducing the opening of the return oil passage in the return oil passage if the pressure in the oil separation chamber is high, and expanding the opening of the return oil passage if the pressure in the oil separation chamber is low. It employs a new configuration in which means are provided.

[0012]

In the compressor of the present invention as well, the lubricating oil stored in the crank chamber flows out to the suction chamber due to the bleed passage which connects the crank chamber and the suction chamber, and through the bore and discharge chamber to the refrigeration circuit. To be leaked. However, in this compressor, the refrigerant gas in the discharge chamber is introduced into the oil separation chamber of the discharge flange to separate the lubricating oil in the refrigerant gas. Then, the separated lubricating oil is stored at the bottom of the oil separation chamber.

Here, the valve means provided in the return oil passage communicating the oil separation chamber and the crank chamber has a large capacity operation and high speed rotation in the variable displacement type compressor, and a high speed rotation in the fixed displacement type compressor. If the pressure in the oil separation chamber increases due to the high discharge pressure due to, the opening degree of the return oil passage is reduced. As a result, the amount of lubricating oil supplied from the bottom of the oil separation chamber to the crank chamber via the return oil passage decreases, but at this time, due to the large amount of refrigerant circulation, the crank chamber is sufficiently lubricated by blow-by gas or the like. Oil is being supplied.

On the other hand, the valve means is a return oil passage if the pressure in the oil separation chamber becomes low due to low discharge pressure due to small capacity operation and low speed rotation in the variable displacement compressor and low speed rotation in the fixed displacement compressor. Expand the opening of. As a result, even if a small amount of lubricating oil is replenished in the crank chamber by blow-by gas or the like due to a small amount of refrigerant circulation, the lubricating oil stored in the bottom portion flows into the crank chamber through the return oil passage.

Therefore, in this compressor, the sum of the amount of lubricating oil corresponding to the refrigerant circulation amount and the amount of lubricating oil corresponding to the opening supplied from the return oil passage is sufficiently secured in the crank chamber. Has been done. Even if this compressor has a variable capacity type having an air supply passage that connects the discharge chamber and the crank chamber, the cross-sectional area of the air supply passage is designed to replenish the crank chamber with lubricating oil during a small capacity operation. Since the pressure is not increased, the pressure in the crank chamber is appropriately reduced as in the conventional case, and the responsiveness from the small capacity operation to the large capacity operation is not delayed.

[0016]

Embodiments Embodiments 1 and 2 embodying the present invention will be described below with reference to the drawings. (Embodiment 1) In FIG. 1, a center housing 4 is joined to the front end of a cylinder block 1 which is the main body of this variable displacement compressor, and a front housing 2 is joined to the front end of this center housing 4. A rear housing 3 is provided at the rear end of the cylinder block 1 so that the intake valve 1
5a, the valve body 15b, the discharge valve 15c, and the retainer 15d are connected. A crank chamber 5 formed by the cylinder block 1, the center housing 4, and the front housing 2 is filled with a predetermined amount of lubricating oil in advance. A drive shaft 6 which is linked to an engine of a vehicle (not shown) is housed in the crank chamber 5. The drive shaft 6 is rotatable by bearings 7 and 8 via a shaft sealing device between the drive shaft 6 and the front housing 2. It is supported. A plurality of bores 9 are formed in the cylinder block 1 so as to surround the drive shaft 6 and are arranged concentrically in parallel with each other. A single-head piston 10 is fitted in each bore 9.

A rotor 11 is fixed to the drive shaft 6 in the crank chamber 5 so as to be rotatable in synchronization with the drive shaft 6, and a sleeve 12 having a spherical bearing surface is rotatably and slidably fitted. . A counter spring 13 is interposed between the step portion of the drive shaft 6 and the sleeve 12, and
Is urged in the rear direction, and a swash plate 14 having an inner surface of a spherical zone that fits with a bearing surface is pivotally supported on the sleeve 12 so as to be tiltable. The piston 10 is anchored to the disk surface formed on the outer peripheral portion of the swash plate 14 via hemispherical shoes 26, 26.

On the other hand, a support shaft 17 is rotatably inserted in a direction perpendicular to the axis of the arm 16 protruding from the outer peripheral edge of the rotor 11. The support shaft 17 has an arm 16
The base ends of the guide pins 18, 18 penetrating in the radial direction with the pinch sandwiched therebetween are fixed, and the distal end portions of the extending guide pins 18 are slidably inserted into the articulation portions 19 formed on the front surface side of the swash plate 14. Has been done. In addition, these arms 16 and spindle 1
7, the guide pin 18 and the articulation portion 19 make the hinge mechanism K
Is configured.

The inside of the rear housing 3 is divided into a suction chamber 21 and a discharge chamber 20 by a partition wall, and the valve plate 15b and the discharge valve 1 are separated.
5c and the retainer 15d are formed with suction ports 23 corresponding to the respective bores 9, and the suction valve 15a and the valve plate 15 are formed.
A discharge port 22 is formed at b in correspondence with each bore 9. A discharge flange 30 connected to the external refrigeration circuit is formed in the cylinder block 1, and an oil separation chamber 31 is formed in the discharge flange 30 between the bores 9. Further, the discharge chamber 2 is provided in the rear housing 3.
A second discharge chamber 25 communicating with 0 is formed, and the second discharge chamber 25 is, as shown in FIG. 2, an introduction path communicating in a tangential direction with an oil separation chamber 31 whose side wall is formed in an arc shape. 24
Is communicated with the oil separation chamber 31. In this way, the refrigerant gas introduced from the discharge chamber 20 to the oil separation chamber 31 via the second discharge chamber 25 produces a centrifugal force.
As shown in FIG. 1, a return oil passage 32 communicating with the crank chamber 5 is provided below the oil separation chamber 31, and a spool 33 as a valve means slides in the return oil passage 32. It is inserted as possible. This spool 33 has a return oil passage 3
A notch 33a is formed so as to have a gap between the spring 2 and 2, and an urging spring 35 is interposed between the notch 33a and the circlip 34 locked to the crank chamber 5 side.

The suction chamber 21 and the crank chamber 5 are connected by a bleed passage 27, and a control valve 28 (not shown) for adjusting the pressure of the crank chamber 5 is provided in the rear housing 3 in the middle of the bleed passage 27. ing. Further, the discharge chamber 20 and the crank chamber 5 are connected by an air supply passage (not shown) having an orifice in the middle. In the compressor configured as described above, when the swash plate 14 rotates as the drive shaft 6 is driven, a swinging motion corresponding to the tilt angle of the swash plate 14 causes the pistons 10 to reciprocate via the shoes 26, 26. Converted to motion. As a result, the refrigerant gas is sucked into the bore 9 from the suction chamber 21, the refrigerant gas is compressed by the piston 10, and then discharged to the discharge chamber 20. At this time, the compression capacity of the refrigerant gas discharged to the discharge chamber 20 is controlled by adjusting the pressure in the crank chamber 5 by the control valve.

That is, if the pressure in the crank chamber 5 is lowered by adjusting the opening degree of the bleed passage 27 of the control valve 28, the back pressure acting on the piston 10 is lowered, and the inclination angle of the swash plate 14 is increased. That is, the sleeve 12 is the counter spring 1.
3, the swash plate 14 rotates in the depression direction along the bearing surface of the sleeve 12 and the articulation portion 19 of the hinge mechanism K inserts the slide pin 18 accompanying the rotation of the support shaft 17. Direction, the tilt angle of the swash plate 14 increases. As a result, the stroke of the piston 10 is extended and the compression capacity is increased.

On the contrary, if the pressure in the crank chamber 5 is increased by adjusting the opening degree of the extraction passage 27 of the control valve 28, the back pressure acting on the piston 10 is increased, and the inclination angle of the swash plate 14 is decreased. That is, the sleeve 12 is the counter spring 13
The swash plate 14 is retracted by the urging force of the swash plate 14 to rotate in the upright direction along the bearing surface of the sleeve 12, and the hinge mechanism K
The articulation portion 19 of the slide pin 18 is accompanied by the rotation of the support shaft 17.
And the inclination angle of the swash plate 14 becomes smaller. As a result, the stroke of the piston 10 is shortened and the compression capacity is reduced.

In the meantime, also in this compressor, the lubricating oil stored in the crank chamber 5 is sucked into the suction chamber 2 by the extraction passage 27 connecting the crank chamber 5 and the suction chamber 21.
It is leaked to 1. The lubricating oil that has flowed out to the suction chamber 21 flows into the bore 9 by the reciprocating motion of the piston 10 and is returned to the crank chamber 5 together with the blow-by gas. It reaches the discharge chamber 20.

Here, in this compressor, the discharge flange 3
The refrigerant gas in the discharge chamber 20 is introduced into the 0 oil separation chamber 31 through the discharge chamber 20, the second discharge chamber 25, and the introduction passage 24. Then, the refrigerant gas is introduced in an arc shape along the side wall of the oil separation chamber 31, so that the contained lubricating oil is separated by centrifugal force. The separated lubricating oil is stored at the bottom of the oil separation chamber 31.

At this time, if the pressure in the oil separation chamber 31 is high due to the high discharge pressure due to the large capacity operation or the high speed rotation of the drive shaft 6, the spool 33 provided in the return oil passage 32 is provided.
Moves toward the crank chamber 5 side until the rear end contacts the circlip 34 against the urging force of the urging spring 35, as shown in FIG. Thereby, the notch 33a of the spool 33
The communication area by is closed by the inner wall of the oil separation chamber 31,
The amount of lubricating oil supplied from the bottom of the oil separation chamber 31 to the crank chamber 5 via the notch 33a of the spool 33 and the return oil passage 32 decreases. However, at this time, the large capacity operation or the high speed rotation is performed, and a large amount of the refrigerant is circulated in the refrigeration circuit.
Lubricating oil is sufficiently supplied inside.

On the other hand, when the pressure in the oil separation chamber 31 becomes low due to the low discharge pressure due to the small capacity operation or the low speed rotation of the drive shaft 6, the spool 33 is provided with a biasing spring 35 as shown in FIG. It moves to the oil separation chamber 31 side until the bulging portion comes into contact with the stepped portion of the return oil passage 32 due to the loss of power. This allows
The communication area by the notch 33a of the spool 33 is opened from the inner wall of the oil separation chamber 31 and enlarged. For this reason, only a small amount of refrigerant circulates in the refrigeration circuit during small-capacity operation or low-speed rotation, and even if the lubricating oil that is replenished in the crank chamber 5 by the air supply passage and blow-by gas is small, the oil separation chamber 31
The lubricating oil stored at the bottom of the spool 33 is notched on the spool 33.
The oil flows into the crank chamber 5 through a and the return oil passage 32.

Therefore, in this compressor, the crank chamber 5 has an amount of lubricating oil corresponding to the amount of refrigerant circulation and the return oil passage 3
The total amount of lubricating oil supplied from 2 and the amount corresponding to the opening of the spool 33 is sufficiently secured. Therefore, in this compressor, the inside of the crank chamber 5 can be suitably lubricated according to all operating conditions, and seizure of the swash plate 14 and the shoes 26, 26, the swash plate 14 and the sleeve 12, etc. is effective. Can be prevented.

Further, in this compressor, since the cross-sectional area of the air supply passage is not increased in order to replenish a large amount of lubricating oil to the crank chamber 5 at the time of small-capacity operation and low speed rotation, the crank chamber 5 of the conventional type is maintained. The pressure drops favorably and does not delay the response from small volume operation to large volume operation. (Embodiment 2) In this variable displacement compressor, as shown in FIG. 5, a spool 36 having a notch 36a that becomes shallower toward the tip is adopted. Since other configurations are the same as those of the first embodiment, the same reference numerals are given and detailed description of the same configurations, operations and effects is omitted.

In this compressor, large capacity operation or drive shaft 6
When the pressure in the oil separation chamber 31 increases due to the high speed rotation of the spool, the spool 36 moves to the crank chamber 5 side against the urging force of the urging spring 35. As a result, the communication area due to the notch 36a of the spool 36 is reduced, and the amount of lubricating oil supplied from the bottom of the oil separation chamber 31 to the crank chamber 5 is reduced.

On the other hand, when the pressure in the oil separation chamber 31 becomes low due to the small capacity operation or the low speed rotation of the drive shaft 6, the spool 36 moves to the oil separation chamber 31 side under the urging force of the urging spring 35. . As a result, the communication area due to the notch 36a of the spool 36 is increased, and the amount of lubricating oil supplied from the bottom of the oil separation chamber 31 to the crank chamber 5 is increased. Therefore, in this compressor, the sum of the amount of lubricating oil according to the refrigerant circulation amount and the amount of lubricating oil according to the opening degree of the spool 33 supplied from the return oil passage 32 is greater in the crank chamber 5. Secured enough. Therefore, in this compressor, seizure can be prevented more preferably.

In the first and second embodiments, the present invention has been described by taking the variable capacity type swash plate compressor as an example, but the present invention can also be applied to a fixed capacity type one side swash plate compressor. is there.

[0032]

As described in detail above, the swash plate type compressor of the present invention employs the structure described in the claims, and therefore the refrigerant is provided in the crank chamber regardless of whether it is a variable displacement type or a fixed displacement type. It is possible to sufficiently secure the total of the amount of lubricating oil that corresponds to the circulation amount and the amount of lubricating oil that corresponds to the opening degree supplied from the return oil passage.

Therefore, in this compressor, it is possible to surely avoid the lack of lubricating oil in the crank chamber and appropriately lubricate the crank chamber according to all operating conditions, so that seizure of the swash plate and the like can be effectively performed. Can be prevented. Even if this compressor has an air supply passage that connects the discharge chamber and the crank chamber, it does not increase the cross-sectional area of the air supply passage to replenish the crank chamber with lubricating oil. Responsiveness from small capacity operation to large capacity operation is not impaired.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a swash plate compressor according to a first embodiment.

FIG. 2 is a partial cross-sectional plan view of the swash plate compressor according to the first embodiment.

FIG. 3 is a cross-sectional view of a main part of the swash plate compressor according to the first embodiment during a large capacity operation.

FIG. 4 is a cross-sectional view of relevant parts of the swash plate compressor according to the first embodiment during a small capacity operation.

FIG. 5 is a cross-sectional view of a main part of a swash plate compressor according to a second embodiment during a large capacity operation.

[Explanation of symbols]

1 ... Cylinder block 2 ... Front housing
3 ... Rear housing 4 ... Center housing 5 ... Crank chamber 6
… Drive shaft 9… Bore 10… Piston 1
1 ... Rotor 12 ... Sleeve 14 ... Swash plate 2
6 ... Shoe K ... Hinge mechanism 21 ... Suction chamber 2
0 ... Discharge chamber 27 ... Extraction passage 30 ... Discharge flange 3
1 ... Oil separation chamber 32 ... Return oil passage 33, 36 ... Spool (valve means)

Front Page Continuation (72) Inventor Tomohiko Yokono 2-1-1 Toyota Town, Kariya City, Aichi Stock Company Toyota Industries Corp.

Claims (1)

[Claims] 1. A plurality of bores are concentrically defined and formed in a cylinder block, and a single-head piston is reciprocally housed in each bore, and a housing is joined to the cylinder block for suction. Chamber, discharge chamber and crank chamber are formed, and a swash plate is linked to the drive shaft supported by the housing in the crank chamber, and the piston moored to the swash plate swings according to the inclination angle of the swash plate. A swash plate compressor configured to reciprocate in the bore by dynamic motion to suck the refrigerant gas from the suction chamber into the bore and discharge the refrigerant gas from the bore to the discharge chamber. In the discharge flange formed on the cylinder block,
The refrigerant gas in the discharge chamber is introduced to separate the lubricating oil in the refrigerant gas, and an oil separation chamber is formed at the bottom for storing the separated lubricating oil, and the oil separation chamber is formed between the bottom of the oil separation chamber and the crank chamber. Is provided with a return oil passage that communicates the two, and if the pressure in the oil separation chamber is high, the opening degree of the return oil passage is reduced in the return oil passage, and if the pressure in the oil separation chamber is low, A swash plate compressor, comprising valve means for expanding the opening degree of the return oil passage.