JPH0547443U - Compressor - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention relates to a compressor that requires an oil lubrication function,
Even when the flow rate is low, the lubricating oil is stored and retained in the compressor to improve the durability of the compressor. [Structure] The present invention is constructed by providing a heating unit in a high pressure chamber of a compressor. [Effect] According to the present invention, the ability to store and retain lubricating oil in the casing can be enhanced even at low flow rates.
It is possible to improve the durability of the compressor (particularly, the durability at a low flow rate at which lubricating oil does not easily return to the compressor).

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a compressor requiring an oil lubrication function, and more particularly to a structure suitable for retaining and retaining a lubricating oil mixed with a working fluid in a compressor.

[0002]

[Prior Art]

 For example, in a conventional vehicle air-conditioning compressor as shown in JP-A-63-138174, a lubricating oil that melts in a refrigerant within a certain temperature range is used, and the lubricating oil dissolved in the refrigerant is in an atomized state, or Lubricating oil separated from the refrigerant by utilizing the inertia of the fluid was stored in the bottom of the compressor and splashed directly, or the sliding part was lubricated through a forced lubrication mechanism. Therefore, since the temperature of the suctioned refrigerant is generally within a temperature range in which the refrigerant and the lubricating oil are not separated into two layers, at least the lubricating oil in which the refrigerant can be dissolved is always sucked into the compression chamber, and most of the lubricating oil passes through the high pressure chamber. , The refrigeration cycle was discharged to the high pressure side.

Here, the main purpose of the lubricating oil used in the refrigeration cycle is to lubricate the sliding parts inside the compressor, and since it is unnecessary for equipment other than the compressor that constitutes the refrigeration cycle, it is compressed as much as possible. It was desired to store lubricating oil in the aircraft.

[0004]

[Problems to be solved by the device]

 In the above conventional technique, that is, the conventional method in which the lubricating oil is dissolved in the refrigerant discharged from the compressor, the low refrigerant flow rate operation (especially, the discharged refrigerant temperature becomes lower than the two-layer separation temperature of the refrigerant and the lubricating oil) Case) At least the lubricating oil in which the refrigerant can be dissolved is discharged to the high pressure side of the refrigeration cycle. The refrigerant discharged to the high pressure side of the refrigeration cycle adiabatically expands by the expansion valve, and when the phase change from the liquid phase to the gas phase in the evaporator, the dissolved lubricating oil is left in the evaporator. Furthermore, during low refrigerant flow rate operation, there is no flow velocity of the refrigerant enough to return the lubricating oil stored in the evaporator to the compressor, and most of the lubricating oil enclosed in the refrigeration cycle is stored in the evaporator. As a result, the amount of lubricating oil in the compressor decreases. For this reason, if the low refrigerant flow rate operation continues for a long time, there is a problem that the sliding part in the compressor is significantly worn.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, a heating unit capable of maintaining a temperature equal to or higher than the two-layer separation temperature of refrigerant and lubricating oil is provided in the high pressure chamber of the compressor.

[0006]

[Action]

 According to the present invention, the temperature of the refrigerant discharged from the compressor is heated to the two-layer separation temperature or higher by the heating unit, so that the high pressure chamber in which the oil separator is installed moves to the high pressure side of the refrigeration cycle. It is never discharged. Therefore, most of the lubricating oil is stored in the compressor, which enables long-term operation even at low refrigerant flow rate operation.

[0007]

【Example】

 An embodiment in which the present invention is applied to a one-sided swash plate compressor for an automobile air conditioner will be described below with reference to FIGS. 1 and 2. A swash plate 2 is supported on the drive shaft 1 which rotates by receiving an input from the outside, with an inclination angle with respect to the axis of the drive shaft 1. The swash plate 2 holds, via a thrust bearing 3 and a radial bearing 4, a piston support 6 having a rotation stop mechanism 5 that faces the rotation direction of the drive shaft 1, and the circumference of the piston support 6 is retained. A ball joint is formed on the top and on the end surface of the piston 7 and is connected by a connecting rod 8. Further, a cylinder head 11 having a suction valve 9 and a discharge valve 10 and a cylinder 12 having a bore in which the piston 7 reciprocally engages form a compression chamber 13 together with the piston 7. A rear cover 16 having a low pressure chamber 14 and a high pressure chamber 15 is fixed to the cylinder 12 via the cylinder head 11. Here, in the high pressure chamber 15, an oil separator 17 having a heating portion 17a is provided. Further, a casing 18 for storing and holding lubricating oil is fixed to the end surface of the cylinder 12 while surrounding the rotating swash plate 2. A bypass hole 19 communicates with the casing 18 from the high pressure chamber 15 so that the lubricating oil separated from the refrigerant by the oil separator 17 can move to the casing 18.

Next, the operation will be described. When the swash plate 2 supported at an inclination angle with respect to the axis of the drive shaft 1 rotates together with the drive shaft 1, the piston support 6 whose rotation is restrained by the detent mechanism 5 swings. I do. The reciprocating motion is transmitted to the piston 7 via the connecting rod 8 by the swinging motion. Here, when the piston 7 reciprocates, the volume of the compression chamber formed together with the cylinder 12 and the cylinder head 11 changes, and the refrigerant flows from the low pressure chamber 14 through the suction valve 9 to It is sucked into the compression chamber 13 and is discharged into the high pressure chamber 15 through the discharge valve 10. The refrigerant discharged into the high pressure chamber 15 contacts the heating part 17a of the oil separator 17 provided in the high pressure chamber 15. Here, since the temperature t1 of the heating unit 17a is set to be equal to or higher than the two-layer separation temperature t2 of the lubricating oil at the pressure Pd in the high pressure chamber 15, the temperature of the refrigerant discharged into the high pressure chamber 15 is The lubricating oil that has been melted in is separated, passes through the bypass hole 19, and is stored in the casing 18. The set temperature of the heat source of the heating unit 17a in the present embodiment is the two-layer separation temperature (t2) of the lubricating oil under the use condition in which the temperature Td of the refrigerant discharged into the high pressure chamber 15 is the lowest. It is set to a value (t1 ') which is equal to or greater than'). Further, the heating source of the heating unit 17a is Joule heat of the coil connected through a constant voltage circuit (not shown). Here, the heat source (set to the two-layer separation temperature t2 or higher) is the cooling water bypassed from the engine cooling system via the thermostat, or the cooling water bypassed from the engine lubrication system via the thermostat. Needless to say, any engine lubricating oil and any other heat source having the two-layer separation temperature t2 or higher can be used. In addition, in applying the present invention, a suitable combination of the refrigerant and the lubricating oil is HFC134a and PAG (polyalkylene glycol), which separate into two layers at a relatively low temperature.

[0009]

[Effect of the device]

 As described above, according to the present invention, it is possible to enhance the ability to retain and retain lubricating oil in the casing even at a low flow rate by a simple method of heating the oil separator provided in the high pressure chamber. It is possible to improve the durability of the compressor (particularly, the durability when the flow rate is low because it is difficult for lubricating oil to return to the compressor). The details of the effect are shown in Fig. 3. By adopting the present invention, it was confirmed that the durability at a low flow rate is improved to three times or more in terms of life.

[Brief description of drawings]

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

FIG. 2 is an explanatory view of the melting characteristics of a refrigerant and lubricating oil showing an embodiment of the present invention.

FIG. 3 is a diagram showing a durability evaluation result at a low flow rate showing the effect of the present invention.

[Explanation of symbols]

15 ... High pressure chamber, 17 ... Oil separator, 17a ... Heating part, 18
… Casing, 19… Bypass hole.

Claims (2)

[Scope of utility model registration request] 1. A compressor comprising a high-pressure chamber having a heating section capable of maintaining a temperature (temperature at which two layers are separated) of a working fluid and a lubricating oil at a temperature higher than the two-layer separation temperature. 2. The compressor according to claim 1, wherein the temperature of the heating section can be controlled as needed.