JPH04191473A - Swash plate type compressor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a refrigerant compressor for an automobile air conditioning system, and in particular to a tilted refrigerant compressor in which a piston support guide mechanism is a mechanism with excellent wear resistance and seizure resistance. Regarding plate compressors.

[Conventional technology]

Conventionally, in this type of refrigerant compressor, a cast material of AQ-5i alloy containing about 12% by weight of silicon was used for the front nozzle, and an iron-based metal material was used for the slide shoe. was. However, with the above combination, the wear resistance and seizure resistance, especially on the aluminum housing side, are not sufficient, and situations such as increased compressor noise due to abnormal wear of the sliding part of the slide shoe, or locking of the compressor due to seizure, often occur. Occurred. Therefore, in order to improve the wear resistance and seizure resistance of the aluminum alloy housing, measures have been taken to increase the silicon content to 16 to 20% by weight.

The refrigerant for these conventional compressors is Freon 12 (
R12), Freon 22 (R22), etc. have been used, and mineral oils such as naphthenic and paraffinic oils have been used as lubricating oils. All of the above refrigerants are fluorocarbon gases containing chlorine in their molecules, and this chlorine acts as an extreme pressure agent on active sliding surfaces, particularly improving the wear resistance and seizure resistance of aluminum materials. In addition, the above mineral oil has a high pressure viscosity index, and forms a relatively good oil film in a high load area.
Improved wear resistance and seizure resistance.

However, due to fluorocarbon regulations implemented in 1989,
CFC gas, which contains chlorine in its molecules, destroys the ozone layer, so its production has been reduced, and it has been decided that it will be completely phased out by the end of this century. For this reason, there is an urgent need to develop an alternative fluorocarbon gas that does not contain chlorine, and currently, 1,1,1,2-tetrafluoroethane, ie, fluorocarbon 134a (R134a), is a promising alternative fluorocarbon gas to R12.

Therefore, no improvement in wear resistance or seizure resistance due to chlorine can be expected in the future. In response to this, lubricating oils have also been changed to PAG, as current mineral oils have no compatibility with CFC substitutes.
There is no choice but to change to synthetic oil such as (polyalkylene gelicol). This synthetic oil has a low pressure viscosity index, which causes problems with oil film formation in high load areas. Furthermore, this synthetic oil is hygroscopic, and there are concerns that it may cause various adverse effects such as corrosion, generation of acid due to hydrolysis, and hydrogen embrittlement.

From the above, it has become clear that it is not possible to improve the wear resistance and seizure resistance of the sliding portion of the slide shoe after transitioning to CFC substitutes simply by increasing the silicon content of the aluminum alloy housing.

In addition, as a conventional example related to this case, for example,
There is an example of a bearing device that combines an aluminum shaft with an alumite layer and a synthetic resin bearing that supports this shaft, as in Japanese Patent No. 80822.

[Problem to be solved by the invention]

In the above conventional technology, if the guide groove sliding part of the piston support becomes extremely insufficiently lubricated, for example, due to regulations on fluorocarbons, there is no consideration given to the transition to alternative refrigerants or alternative refrigerating machine oils that have lower lubricity than the current ones. , using a fluorocarbon that does not contain chlorine in its molecules, such as Freon 134a, as a refrigerant,
When a synthetic oil with a low pressure viscosity index such as AG is used as a lubricating oil, depending on the operating conditions of the compressor, the sliding parts may become insufficiently lubricated, resulting in abnormal wear of the guide groove or damage between the guide groove and the slide shoe. There was a problem that seizure occurred and the compressor became inoperable.

The purpose of the present invention is to improve the wear resistance and seizure resistance of the sliding part of the piston support guide mechanism of the swash plate compressor, and to provide an alternative refrigerant and an alternative refrigeration agent that have lower lubricity than the current one due to fluorocarbon regulations. Even when transferred to machine oil, seizure resistance and
An object of the present invention is to provide a swash plate compressor that has good wear resistance, excellent durability, and high reliability.

[Means to solve the problem]

In order to achieve the above object, in the piston support guide groove sliding part, a guide is provided between the groove and the slide shoe, the surface of which is made of a synthetic resin as a main component having wear resistance and self-lubricating properties. A plate is provided, and the slide shoe slides within the groove via the guide plate.

That is, the present invention includes a housing formed of an aluminum alloy, a drive shaft rotatably supported within the housing, a swash plate rotatably attached around an axis perpendicular to the drive shaft, a piston support that supports a piston rod and swings in response to the inclination angle of the swash plate; a bearing portion that protrudes in the radial direction of the piston support; and a bearing portion that is formed on the inner circumferential portion of the housing in parallel with the drive shaft. A swash plate compressor comprising a guide groove into which a bearing part is fitted, characterized in that a guide plate made of a solid lubricant is provided between the guide groove and the bearing part. .

Further, the present invention includes a housing formed of an aluminum alloy and having a crank chamber, a suction space, and a discharge space inside, a drive shaft rotatably supported within the housing, and a drive shaft that is rotatably supported within the housing. A plurality of cylinders arranged in the circumferential direction with their axes parallel to the drive shaft, a piston fitted to each cylinder so as to be able to reciprocate, and a piston mounted rotatably around an axis perpendicular to the drive shaft. A swash plate, a rod fixed to the piston, a piston support that supports each rod and performs a rocking motion corresponding to the inclination angle of the swash plate, and a guide fixed in the radial direction of the piston support. A pin, a slide ball fitted to the guide pin so as to be reciprocating and rotatable, a slide shoe having the slide ball rotatably fitted therein, and formed on the inner circumference of the housing parallel to the drive shaft direction. a guide groove having a cylindrical groove shape, and the slide shoe is rotatably and slidably mounted in the guide groove, and the swash plate reciprocates the piston in a stroke corresponding to an inclination angle with respect to the drive shaft. In a swash plate compressor in which the movement of the piston support in the rotational direction of the drive shaft is suppressed by fitting the slide shoe into the guide groove, there is a space between the inside of the guide groove and the sliding part of the slide shoe. The present invention is characterized in that a guide plate is provided, at least the sliding surface of which is made of a solid lubricant.

In the compressor, the solid lubricant may be made of synthetic resin, molybdenum disulfide or graphite. Further, the guide plate is preferably one in which a synthetic resin surface forming a sliding surface is provided on the surface of the metal base material. Furthermore, the guide plate is preferably one in which a sintered body layer is formed on the surface of a base material made of metal, and a synthetic resin surface is provided on the surface of the sintered body layer. Further, it is preferable that an additive such as molybdenum disulfide or graphite is added to the synthetic resin surface. Here, examples of the synthetic resin include tetrafluoroethylene resin, polyacetal resin, ketone resin, and imide resin. Further, the slide shoe is preferably made of an iron-based material, and at least the sliding surface with respect to the guide plate is formed to have a surface roughness Rmax of 1 μm or less.

[Effect]

By adopting the above-mentioned guide mechanism for piston support, the slide shoe will wear out abnormally even if the sliding part lacks lubrication due to the self-lubricating property of the solid lubricant such as the surface mainly composed of synthetic resin. It can slide smoothly within the guide groove without causing burn-in.

In addition, since the active torque of the compressor is reduced due to the reduction in the coefficient of friction of the sliding portion, the total adiabatic efficiency of the compressor can be improved, that is, the load on the automobile engine can be reduced.

In addition, when compared with surface treatments such as hard alumite, it is difficult to treat only the inside of the guide groove located on the inner circumference of the housing, and if it is carried out, it is unavoidable to treat unnecessary parts of the housing. On the other hand, in the present invention, it is only necessary to fit a guide plate having a solid lubricant such as a surface mainly composed of synthetic resin into the guide groove, which is a more efficient method, and in terms of cost. It is also advantageous in terms of productivity.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure shows the overall structure of a variable stroke swash plate compressor according to the present invention. This figure shows the case where the swash plate 12 is tilted at its maximum, that is, the piston stroke is at its maximum.

A front housing 1 that rotatably supports a main shaft 13 via a radial bearing 18 in the center is arranged and fixed to one end of the cylindrical cylinder block 2, thereby forming a swash plate chamber 10. The housing 1 is made of AQ-5i alloy (ADC
12) or B590. A plurality of cylinder bores 33 are formed in the cylinder block 2, centered around the main shaft 13, which is an active shaft, and arranged in a circumferential direction parallel to the axis of the main shaft 13. The main shaft 13 is located approximately on the center line of the cylinder block 2, and is rotatably supported by radial bearings 18 and 19 provided at the center of the cylinder block 2 and the front housing 1, and is attached to the drive plate by press fitting, pins, or plastic coupling. 14
is fixed. The drive plate 14 is provided with a cam groove 142, and a fulcrum pin 16 that is fitted into the swash plate lug 121 with a gap is movably attached in the groove 142. Furthermore, the ear portion 141 of the drive plate 14 provided with the cam groove 142 and the swash plate ear portion 121
This means that the sides are in contact with each other. As a result, when the drive plate 14 rotates due to the rotation of the main shaft 13, rotational force is applied from the ear portion 141 of the drive plate 14 to the swash plate ear portion 121, causing the swash plate 12 to rotate.

A sleeve 15 is incorporated into the main shaft 13 so as to be movable in the axial direction of the main shaft 13, and the sleeve 15 and the swash plate 12 are connected to each other.
Swash plate 12 relative to sleeve 15 by pivot pin 17
is rotatably fastened around the pivot pin 17. Therefore, as the main shaft 13 rotates, the drive plate 14, swash plate 12, and sleeve 15 rotate together.

A piston support 21 is fastened to the swash plate 12 via a radial bearing 23, and a spacer 221 and a retaining ring 22 fixed to the swash plate 12 allow the bearing 23 to be connected to the swash plate 1.
The hub portion 12 of the swash plate is
It is fixed at 2.

On the other hand, the piston support 21 is restricted from moving to the right in FIG. Movement in this direction is also restricted.

Further, a guide pin 26 is fixed in the radial direction at a lower position of the piston support 21 by a method such as press-fitting or plastic coupling. A semi-cylindrical slide shoe 29 is mounted so as to be rotatable and movable in the longitudinal direction of the pin. Further, the slide shoe 29 reciprocates within an axial groove 28 provided on the inner circumference of the front housing 1, and functions as a rotation prevention mechanism to prevent the piston support 21 from rotating around the main shaft 13. It regulates exercise.

The piston support 21 has balls 321 and 32 on both ends.
One end of a plurality of connecting rods 32 having a diameter of 2 is rotatably attached around the center of the ball 321, and the piston 31 is attached to the other end of the plurality of connecting rods 32 so as to be rotatable around the center of the ball 322. multiple pistons 31
is incorporated into the cylinder bore 33. The piston 3
1 is fitted with a piston cylinder 34,35.

Further, a suction valve plate 5, a cylinder head 4, a discharge valve plate 6, a packing 7, and a rear cover 3 are arranged in the cylinder block 2, and are fixed to the rear cover 3 integrally with the front housing 1 with bolts (not shown). The airtightness between the front housing 1 and the cylinder block 2 is maintained by an O-ring 38, and the airtightness between the rear cover 3, the cylinder block 2, and the packing 7 is maintained by an O-ring 39. The cylinder head 4 is provided with a suction port 401 and a discharge port 402 corresponding to each cylinder bore 33, and the suction chamber 8 and discharge chamber 9 provided in the rear cover 3 are communicated with the cylinder bore 33, respectively. The rear cover 3 is provided with a suction port 301 and a discharge port (not shown), and a control valve 41 is disposed within the suction passage 302 between the suction port 301 and the suction chamber 8 .

With the configuration described above, the main shaft 13 of the compressor is connected to the main shaft 13 of the compressor from the engine (not shown) via the magnetic clutch 50.
When the piston is opened, the drive plate 14 and the swash plate 12 rotate, and the piston support 21 swings about the rotation axis of the main shaft 13. Therefore, the piston 31 reciprocates within the cylinder bore 33, sucking in and compressing gas. In addition,
The maximum stroke position can be regulated by bringing the sleeve 15 into contact with the drive plate 14, and the minimum stroke position can be regulated by using a retaining ring 1 in a groove provided on the main shaft 13.
31 and applying a sleeve to it.

The cam groove 142 formed in the drive plate 14 is a closed curve such that the top dead center position of the piston 31 does not change even if the fulcrum pin 16 moves within the cam groove 142. The thrust force acting on the main shaft 13 when compressing gas is generated by a thrust bearing 42 installed between the drive plate 14 and the front housing 1.
Further, the radial force acting on the main shaft 13 is supported by radial bearings 19 and 18 provided in the front housing 1 and the cylinder block 2, respectively.

FIG. 2 shows a guide plate 51 made of a solid lubricant that is installed in a guide groove 28 provided on the inner circumference of the front housing 1. As shown in FIG. Guide plate 5 in this embodiment
1 consists of a surface 52 whose main component is synthetic resin.

FIG. 3 is a partial sectional view of the piston support guide mechanism section when the guide plate 51 is attached. In a car air conditioner, the rotational speed of the compressor may reach up to about 8000 r/m, and in that case, the sliding speed of the slide shoe 29 is as high as 16 m/s at maximum.

Therefore, if the sliding part becomes insufficiently lubricated, for example, when starting with the sliding part being cleaned with liquid refrigerant,
There is a problem in that seizing occurs between the slide shoe 29 and the guide groove 28 during high-speed, high-pressure operation, insufficient refrigerant operation, and the like.

Furthermore, since the current CFC 12 is subject to regulations under CFC regulations, CFC 1 is currently being used as an alternative CFC.
34a is the most likely option. However,
Since this Freon 134a does not contain chlorine in its molecules, it has been found that its self-lubricating properties are considerably inferior to that of Freon 12. Additionally, current mineral oils cannot be used as refrigerating machine oils due to compatibility issues, and synthetic oils such as PAG (polyalkylene gelylcol), which have a lower pressure viscosity index than mineral oils, must be used as alternative refrigerating machine oils. Therefore, it is expected that the sliding conditions will be considerably worse than the current situation, and that the compressor will become inoperable due to seizure of the sliding parts.

On the other hand, when the guide plate 51 is installed in the guide groove 28, the slide shoe 29 slides on a surface 52 formed on the inner circumferential surface of the guide plate 51 and mainly made of synthetic resin. Therefore, even if the sliding portion lacks lubrication, seizure will not occur. This means that
As shown in Fig. 4, it is clear from the boundary lubrication friction sliding test results with 5KDII material that the guide plate made of tetrafluoroethylene resin, which is an embodiment of the present invention, is different from AΩ-12Si material. The material has a seizure resistance value that is more than twice that value. In addition, due to the excellent self-lubricating properties of synthetic resins, the friction coefficient of the sliding parts is reduced, which reduces the driving torque of the compressor, which improves the overall adiabatic efficiency of the compressor, which in turn reduces the load on the engine. It can be reduced. Further, in this embodiment, the convex bottom portion of the guide plate 51 plays a role of preventing the guide groove 28 from rotating. Regarding the main component synthetic resin, in addition to tetrafluoroethylene resin, almost the same results were obtained for polyacetal resin, ketone resin, and imide resin. These synthetic resins have a structure that has a sintered body layer of Pb, Sn, etc. inside, and by adding other solid lubricants such as graphite to the synthetic resin and creating a eutectoid surface, they are further improved in seizure resistance. It was confirmed that the wear resistance was improved.

An example thereof is shown in FIG. In the figure, 61 is a synthetic resin containing PB as an additive. 62 is a bronze sintered body layer. In addition to bronze, phosphor bronze or lead bronze may also be used. In terms of chemical composition (% by weight), those shown in Table 1 are preferable. Also 63
The back metal is made of cold rolled steel (SPCC). Its composition (
% by weight) shown in Table 2.

Further, the surface roughness of the surface of the slide shoe 29 that is a mating member that slides and receives friction at least between the slide shoe 29 and the guide plate 51 is preferably Rmax 1 μm or less, and if it is more than that, the amount of wear tends to increase.

In the embodiment described above, the guide plate 51 is integrated, but as shown in FIGS. 6 and 7, it is divided into left and right structures 51 (a) and 51 (b).

52(a) and 52(b). Moreover, it is not necessary to be symmetrical in this case.

Although the embodiment shown in FIG. 1 is a variable stroke swash plate type compressor, it goes without saying that the present invention is also effective for a fixed stroke swash plate type compressor.

〔Effect of the invention〕

As described above, according to the present invention, the wear resistance, seizure resistance, and sliding characteristics of the piston support guide mechanism are improved.
We can provide a highly reliable swash plate compressor.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a variable stroke swash plate compressor according to an embodiment of the present invention, Fig. 2 is a perspective view of a guide plate, Fig. 3 is a sectional view taken along line 11 in Fig. 1, and Fig. 4 is a boundary view. Figures showing the results of the lubrication friction sliding test. Figure 5 is a sectional view of the main part of one embodiment of the guide plate. Figures 6 and 7 are rn sectional views of Figure 1 in other different embodiments. be. DESCRIPTION OF SYMBOLS 1... Front housing, 2... Cylinder block, 12... Swash plate, 13... Main shaft, 21... Piston support, 26... Guide pin, 27... Slide ball, 28... ...Guide groove. 29...Slide shoe, 51...Guide plate.

Claims (9)

[Claims] 1. A housing made of aluminum alloy, a drive shaft rotatably supported within the housing, a swash plate rotatably mounted around an axis perpendicular to the drive shaft, and a piston rod that supports the A piston support that swings in accordance with the inclination angle of the swash plate, a bearing portion protruding in the radial direction of the piston support, and a bearing portion formed parallel to the drive shaft on the inner peripheral portion of the housing are fitted. What is claimed is: 1. A swash plate compressor comprising a guide groove in which a guide plate made of a solid lubricant is provided between the guide groove and the bearing portion. 2. It has a crank chamber, suction space and discharge space inside,
A housing formed of an aluminum alloy, a drive shaft rotatably supported within the housing, and a plurality of cylinders arranged circumferentially around the drive shaft with axes parallel to the drive shaft. , a piston reciprocatably fitted into the cylinder, a swash plate rotatably mounted around an axis perpendicular to the drive shaft, a rod fixed to the piston, and a piston supporting the respective rods; a piston support that performs a rocking motion corresponding to the inclination angle of the swash plate; a guide pin fixed in the radial direction of the piston support; a slide ball fitted to the guide pin so as to be reciprocating and rotatable; a slide shoe having a slide ball rotatably fitted therein; a guide groove formed in the inner circumference of the housing parallel to the drive shaft direction and having a cylindrical groove shape; The piston support is rotatably and slidably mounted, and the slide shoe is fitted into the guide groove when the swash plate reciprocates the piston in a stroke corresponding to the inclination angle with respect to the drive shaft. A swash plate compressor that suppresses movement in the rotational direction of the drive shaft, characterized in that a guide plate is provided between the guide groove and the sliding portion of the slide shoe, at least a sliding surface of which is made of a solid lubricant. A swash plate compressor. 3. 3. The swash plate compressor according to claim 1, wherein the solid lubricant is made of synthetic resin. 4. 3. The swash plate compressor according to claim 1, wherein the solid lubricant is made of molybdenum disulfide or graphite. 5. 3. The swash plate compressor according to claim 1, wherein the guide plate is a metal base material with a synthetic resin surface forming a sliding surface provided on the surface of the metal base material. 6. 3. The swash plate compressor according to claim 1, wherein the guide plate has a sintered body layer formed on the surface of a base material made of metal, and a synthetic resin surface provided on the surface of the sintered body layer. 7. 7. The swash plate compressor according to claim 3, wherein an additive such as molybdenum disulfide or graphite is added to the synthetic resin surface. 8. 8. The swash plate compressor according to claim 3, wherein the synthetic resin is a tetrafluoroethylene resin, a polyacetal resin, a ketone resin, or an imide resin. 9. 9. The swash plate compressor according to claim 2, wherein the slide shoe is made of iron-based material, and at least the sliding surface with the guide plate has a surface roughness Rmax of 1 μm or less.