JPH03980A - Refrigerant compressor with fluid coupling - Google Patents

Abstract

PURPOSE:To enable accurate control for keeping suction side pressure constant by applying the constitution wherein the labyrinth part of a fluid coupling is adjusted on the bases of compressed refrigerant pressure at the suction side of a compressor. CONSTITUTION:A hub 9 is fixed to the drive shaft 2 of a compressor 1 and a blind hole at the enter of a driven disc 11 is coupled to a short axis part 10 at the center of the hub 9, thereby cellularizing a pressure chamber 12. The aforesaid disc 11 and hub 9 are connected to each other via plate springs 13 and so forth arranged radially, and slant gear projection rows 15 are formed on the periphery of the disc 11. In addition, a drive disc 16 having projection rows and grooves to be loosely engaged with the disc 11 and opposite thereto is provided as an integral part of the rear case 17 and front case 18 of a fluid coupling 5. The pressure chamber 12 is made continuous to the suction chamber 23 of the compressor 1 via a passage 21 at the central part of the drive shaft 2, or the like and refrigerant pressure in the suction chamber 23 is made to act on the pressure chamber 12, thereby enabling the driven disc 11 to be pressed left against the spring 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a refrigerant compressor with a fluid coupling suitable for use as a compressor for, for example, an automobile air conditioner.

[Conventional technology]

A fluid coupling is installed on the compressor to suppress excessive increases in compressor rotation speed and optimize the vehicle's cooling capacity.
"Compressor device for air conditioning" is described in Japanese Patent Publication No. 59-46379. This device uses a centrifugal weight that moves according to the rotation speed of the compressor, and when the engine that drives the compressor reaches a high rotation speed above the set rotation speed,
By increasing the slippage of the fluid coupling using the centrifugal weight, the rotation speed of the compressor is controlled so as not to exceed a certain value.

In addition, lubricating oil for the compressor (this is called refrigeration oil) is supplied to the oil passage that bends like a labyrinth seal provided in the fluid coupling (this will be called the labyrinth part), and its viscosity is used to transmit power.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, the rotation speed of the compressor is simply controlled by the rotation speed of the engine, regardless of the heat load of the air conditioner, and the cooling capacity is controlled, so it is necessary to optimize the outlet temperature. I can't.

In addition, the power transmission section consisting of a fluid coupling is placed in the low pressure chamber of the compressor, and the refrigerating machine oil used for lubrication of the compressor is diverted and supplied to the labyrinth section of the fluid coupling. The viscosity of suitable refrigeration oil is 4.
It is about 50 to 200 cst at 0°C, and further,
Since the viscosity of the refrigerant is further reduced by dissolving it in the lubricating oil, there is a drawback that the labyrinth portion must be made larger in order to obtain the driving torque necessary for the compressor.

Furthermore, since a fluid coupling transmits power through a viscous fluid in the labyrinth part while slipping to some extent, when refrigerating machine oil is used as the viscous fluid in the fluid coupling as in the prior art, There is also the problem that the frictional heat of the slip increases the temperature of the lubricating oil of the compressor, thereby causing overheating of the suction refrigerant, which reduces the cooling ability of the air conditioner.

[Means to solve the problem]

The refrigerant compressor with fluid coupling according to the present invention includes:
A drive disk driven by a prime mover and having concentric protrusions and grooves, and connected to a drive shaft of a compressor and loosely fitted into the protrusions and grooves of the drive disk with a slight gap. A driven disk having grooves and protrusions that fit together, a pressure chamber and a spring provided in opposition to adjust the gap between these two disks, an oil storage chamber that accommodates the two disks, and the oil storage chamber. A suitable amount of viscous fluid is sealed in the viscous fluid and flows into the gap between the two disks, and a means for introducing a control pressure into the pressure chamber based on the pressure on the suction side of the refrigerant compressed by the compressor. Features.

[For production]

Since the present invention has the configuration as in the above means, the drive disk that rotates when the prime mover is driven is loosely fitted into the concentric protrusions and grooves with a small gap between them, thereby forming the labyrinth portion. A driven disk having grooves and protrusions forming a groove is rotationally driven by viscous friction when the viscous fluid sealed in the oil storage chamber exists in the gap between them. The suction pressure of the refrigerant compressed by the compressor is introduced into the pressure chamber provided to adjust the distance between these two disks, and the iA ratio between that pressure and the force of the spring opposing it is The distance between the two disks is determined. When the distance between the two discs changes, the amount of overlap of the labyrinth portion formed by the protrusions and grooves of the two discs changes accordingly, and the transmission torque of the fluid coupling changes accordingly. Therefore, the transmission torque of the coupling changes depending on the suction pressure of the refrigerant compressed by the compressor, which in turn determines the driving speed of the compressor. The suction pressure corresponds to the temperature of the object to be cooled, for example, the room temperature, so when the room temperature is high, the air conditioner has a large cooling capacity, and when the room temperature is low, the cooling capacity is small. The rotational speed of the refrigerant compressor changes depending on the room temperature at that time.

〔Example〕

A first embodiment of the invention is shown in FIG. In the figure, 1 is a compressor for refrigerant driven by a vehicle engine (not shown), 2 is a drive shaft thereof, 3 is a front housing of the compressor 1, 4 is a front boss thereof, and 5 is connected to the front boss 4 by a bearing 6. Shows supported fluid couplings.

A hub 9 is fixed to the drive shaft 2 of the compressor 1 by splines 7 and bolts 8, and a blind hole at the center of the driven disk 11 is airtightly mounted on the short shaft section 10 at the center so that it can move in the axial direction. The pressure chamber 12 is formed by fitting into the pressure chamber 12. The disk 11 and the hub 9 are connected by a plurality of radially provided leaf springs I3 and rotate together, but can be relatively moved in the axial direction as described above. In this case, the leaf spring 13 urges the disk 11 to the right in the figure. A large number of protrusions and grooves are formed concentrically on the disk 11, and as shown in FIG. 1, the cross-sectional shape is comb-like. A plurality of openings 14 are bored inside the peripheral portion of the disc 11 provided with the protrusions, so that the front and back sides of the disc 11 are in communication with each other. Further, a helical gear-shaped or gear-shaped protrusion 15 is provided on the circumference of the disk 110.

Opposing the driven disk 11, the driving disk 16 is provided with concentric grooves and ridges that loosely fit into the ridges and grooves of the disk 11, leaving a slight gap. The rear case 17 of the coupling 5, which is rotatably supported by a bearing 6 on the front boss 4 fixed to the front housing 3 of the compressor 1, and the front case 18 attached thereto are integrated together with the disc 16. An oil storage chamber 17' is formed between the disc 16 and the carrier case 17 to accommodate the disc 11 and the like. The gap between the protrusion and the groove in which the discs 11 and 16 fit into each other in this manner constitutes a labyrinth portion 19. The front case 18 of the coupling 5 is integrally provided with a pulley 20 that is driven by a belt placed between the pulley and a crank pulley attached to the crankshaft of an engine (not shown).

In the first embodiment, the pressure chamber 12 communicates with the suction chamber 23 of the compressor 1 through passages 21 and 22 bored in the center of the drive shaft 2 and the bolt 8, and the pressure of the refrigerant in the suction chamber 23 is It acts on the pressure chamber 12 and pushes the driven disc 11 to the left against the bias of the spring 13. Therefore, the disc 11 moves in the axial direction to a position where the pressure of the refrigerant in the suction chamber and the spring 13 are balanced, and the distance and overlapping area between the tip end surface of the protrusion and the bottom surface of the groove change in the labyrinth section 19. Due to the viscosity of the fluid flowing through the disk 19, the torque transmitted from the disk 16 to the disk 11, and therefore the magnitude of the power, changes steplessly. Note that the fins 24 provided on the outer surface of the rear case 17 are
A suitable amount of a special viscous fluid (for example, silicone oil having a viscosity of 6000 C9t at 25° C.) sealed in the oil storage chamber 17' dissipates frictional heat etc. generated when transmitting in the labyrinth portion 19, and the viscous fluid This is to prevent the temperature of the coupling 5 from rising abnormally.

When the pulley 20 is driven at a speed increase ratio of about 1.5 times the engine speed, even if the compressor 1 is relatively small with a capacity of about 80 cc per rotation,
Even in an operating state where the engine speed is not high, the compressor 1 can compress and supply a sufficient flow rate of refrigerant to the vehicle air conditioner. However, it is clear that if such a compressor continues to rotate at high speed for a long time, problems will arise in terms of durability and the like.

Therefore, in the embodiment of the present invention, a fluid coupling 5 is provided to transfer the engine power transmitted to the pulley 20 to the labyrinth portion 19 where the protrusions and grooves of the driving disk 16 and the driven disk 11 are loosely fitted. Silicone oil with a somewhat high viscosity is flowed into the gap, transmission is performed by the viscous friction of the oil, and the compressor 1 is driven at a rotation speed lower than that in the case of direct connection to the engine due to a moderate slip in the labyrinth part 19.

The oil circulation in the labyrinth part 19 is carried out between the rear case 17 and the front case 18 of the fluid coupling 5.
When the oil rotates together with the pulley 20, drive disk 16, etc., the oil is subjected to centrifugal force and spreads in an annular shape within the oil storage chamber 17', immersing the entire labyrinth portion 19 in the oil and causing the disk 11 to immerse in the oil. This is done evenly by creating a circular flow as shown by the arrow through the opening 14. The circulation flow of oil is significantly strengthened by providing helical gear-shaped or ordinary gear-shaped protrusions around the circumference of the disc 110, which produces an effect similar to that of a screw pump or centrifugal pump and forcibly circulates the oil. .

In addition, the compressor 1 compresses a larger amount of refrigerant than a normal compressor by being driven at increased speed, so the air conditioner exhibits a large cooling capacity and lowers the vehicle room temperature to the target temperature within a short time. obtain. FIG. 1 shows a state where the degree of overlapping of the labyrinth portion 19 is maximum and the largest torque is transmitted. When the car temperature drops in this way,
The temperature and pressure of the refrigerant in the suction chamber 23 of the compressor 1 also decrease.

Therefore, the pressure in the pressure chamber 12 into which this pressure is introduced also decreases, and the biasing force of the leaf spring 13 causes the driven disk 11 to move along the axis to the right in FIG. do. In the Ml and labyrinth portion 19, the area where the disk 11 and the protrusions and grooves of the same 16 overlap is reduced, and the torque transmitted as the fluid coupling 5 is reduced by the increased amount of slip, and the compressor 1 The rotation speed of the drive shaft 2 decreases. This means a reduction in cooling capacity and a reduction in power consumption by the air conditioner, and as a result of the reduction in the number of rotations of the drive shaft 20, the durability of the compressor etc. is greatly improved compared to when it is constantly rotating at high speed. When the cooling capacity becomes even more excessive, the overlapping portion in the labyrinth portion 19 disappears, the transmitted torque becomes close to 0, and the compressor 1 stops.

When the vehicle room temperature rises again, the pressure of the refrigerant in the suction chamber 23 increases, and the pressure chamber 12 into which it is introduced increases.
Then, the force pushing the driven disk 11 to the left becomes stronger, the overlapping area in the labyrinth part 19 increases, and the transmitted torque increases by the amount of slip, increasing the rotational speed of the drive shaft 2 of the compressor 1. increases, the refrigerant flow rate also increases, and the cooling capacity increases.

In this way, the transmission torque of the fluid coupling 5 changes steplessly according to the temperature in the vehicle interior, and the room temperature is adjusted quickly and without waste, and the room temperature is maintained at an appropriate constant value. Since the heat generated by the slip in the labyrinth portion 19 is cooled by the fins 24, the circulating oil does not overheat and can maintain the required constant viscosity. In this way, even if high cooling capacity is temporarily demonstrated as a speed-increasing drive, the rotation speed of the compressor 1 is always low due to the fluid coupling 5, so there is no problem in terms of durability, and it is not too expensive. When driven at high rotational speed, even when the vehicle room temperature is high and the heat load is large, the pressure of the refrigerant in the suction chamber 23 of the compressor 1 naturally decreases due to pressure loss in the suction piping, so the fluid coupling 5 slips. The rotational speed of the compressor 1 becomes high, suppressing an excessive increase in rotation of the compressor 1, and naturally protecting the compressor.

Regarding the material, the front case 18 is made of iron to increase its strength, and the rear case 17, disks 11 and 1 are made of iron.
6 is preferably a cast product of aluminum alloy, which is light and has good thermal conductivity and formability. The strength of the leaf spring 13 is, for example, when the refrigerant pressure in the pressure chamber 12 is 2 kg/Cf.
[During IG, it is preferable to set the polymerization area of the labyrinth portion 19 to be maximum.

FIG. 2 shows a second embodiment of the invention, which is similar to the first embodiment.
The controllability of the cooling capacity is further improved than in the embodiment. Common parts are given the same reference numerals as in FIG. 1, and their explanation will be omitted.

The pressure chamber 12 of the fluid coupling 5 shown in FIG.
6, and the pressure of the refrigerant is introduced through the pipe 21'. Then, in order to adjust the pressure in the pressure chamber 12, the piping 27
, a part of the refrigerant pressure is leaked to the suction chamber 23 of the compressor 1 through the pressure control valve 28 and piping 29.

The pressure control valve 28 includes a diaphragm 30, a compression spring 31. The valve body 33 has an adjustment screw 32, a valve body 33, etc., and the valve body 33 is configured such that the pressure in a chamber 34 communicating with the suction chamber 23 of the compressor 1 is adjusted by the compression spring 3.
When the diaphragm 30 is pushed to the right in FIG. 2 against the bias of 1, the valve gap 35 is moved in a direction that narrows the valve gap 35 accordingly.

Therefore, in the chamber 34 into which the suction pressure of the refrigerant of the compressor 1 is introduced, when the suction pressure decreases due to a decrease in room temperature, the diaphragm 30 is pushed by the compression spring 31 and the valve body 33 is moved to the left in the figure. to increase the opening of the valve gap 35. Therefore, the discharge pressure of the compressor, which is led from the discharge port to the pressure chamber 12 through the throttle 26, decreases because the amount of refrigerant escaping to the suction port 23 of the compressor 1 through the pressure control valve 28 increases. However, the driven disk 11 is moved to the right by the leaf spring 13, allowing the overlapping area of the labyrinth portion 19 to decrease. As a result, the transmission torque of the fluid coupling 5 decreases, and the rotation speed of the compressor 1 decreases.

On the other hand, when the room temperature rises and the refrigerant pressure in the suction chamber 23 of the compressor 1 increases, it goes without saying that the opposite effect occurs. In this embodiment, the suction pressure of the compressor 1 is kept constant, and the outlet temperature of the air conditioner can be controlled to be constant.

In the above two embodiments, silicone oil was used as the viscous fluid sealed in the fluid coupling, but in general, various liquids can be used in the present invention. Furthermore, since the two discs that make up the labyrinth part need only have a relative axial distance that changes, they should be configured so that the driven disc is stationary and the driving disc is adjusted by moving in the axial direction. You can also do it.

It should be noted that, for convenience of explanation, the present invention is mainly described with respect to an air conditioner, but it goes without saying that the present invention can be applied to a cooling device equipped with a refrigeration cycle having an equivalent configuration.

〔Effect of the invention〕

According to the present invention, the labyrinth part of the fluid coupling is adjusted based on the pressure of the refrigerant to be compressed on the suction side of the compressor, not on the rotational speed of the shaft, so the pressure on the suction side is controlled to be kept constant. When the temperature of the object to be cooled, for example, the room temperature, is high, the air conditioner has a large cooling capacity, and when the room temperature drops, the cooling capacity is reduced by 1 degree to prevent unnecessary high speed rotation. This allows the air conditioner to operate properly while making full use of its cooling capacity. As a result, it becomes possible to downsize the entire air conditioner, especially the compressor, and its durability also improves.

Furthermore, since refrigerating machine oil is not used as the working fluid of the fluid coupling, but a dedicated viscous fluid is used, the frictional heat will not have an adverse effect on the compressor or cooling capacity.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of the first embodiment, and FIG. 2 is a longitudinal sectional view of the second embodiment. ■... Refrigerant compressor, 5... Fluid coupling, 11... Driven disk, 12... Pressure chamber, 13
...Plate spring, 14...Opening, 15...
Projection, 16... Drive disk, 17'... Oil storage chamber, 19... Labyrinth part, 20... Pulley, 23... Suction chamber, 28... Pressure control valve, 30... diaphragm. Fig. 1... Refrigerant compressor 5... Fluid coupling... Driven disc 2... Pressure chamber 3... Leaf spring 6... Drive disc 7'... Oil storage chamber 9...・Labyrinth part 23... Suction chamber

Claims (1)

[Claims] A drive disk driven by a prime mover and having concentric protrusions and grooves, and connected to a drive shaft of a compressor and loosely fitted into the protrusions and grooves of the drive disk with a slight gap. A driven disk having grooves and protrusions that fit together, a pressure chamber and a spring provided in opposition to adjust the gap between these two disks, an oil storage chamber that accommodates the two disks, and the oil storage chamber. A suitable amount of viscous fluid is sealed in the viscous fluid and flows into the gap between the two disks, and a means for introducing a control pressure into the pressure chamber based on the pressure on the suction side of the refrigerant compressed by the compressor. A refrigerant compressor with a characteristic fluid coupling.