JP2780344B2 - Oiling device for scroll compressor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil supply device for a scroll compression machine used as a fluid compressor for refrigeration and air conditioning.

2. Description of the Related Art The operation principle of a scroll compression machine will be described with reference to FIG. The orbiting scroll 3 and the fixed scroll 4 having the spiral wrap 1 having substantially the same shape on the end plate 2 (see FIG. 6) are engaged with each other with the wrap 1 inside, thereby preventing the orbiting scroll 3 from rotating. The orbiting motion, the compression chamber 5 surrounded by the orbiting scroll 3 and the fixed scroll 4
(5a, 5b,...) Move to the center while gradually reducing the volume, and the fluid sealed in the compression chamber 5 is discharged from the discharge port 6 with increasing pressure.

Next, the basic structure of the scroll compression machine will be described with reference to FIG. Orbiting scroll 3 and fixed scroll 4
The rotation prevention mechanism 8 is provided between the orbiting scroll 3 and the frame 7.
One end of a crankshaft 10 rotatably supported by a bearing 9 at the center of the frame 7 is engaged with the orbiting scroll 3, and is driven to rotate by a drive source 11. The fluid sucked from the suction port 12 is compressed in the compression chamber 5 and is discharged from the discharge port 6 to the discharge passage 13,
It flows to the discharge pipe 14 via the space above the frame 7. These compression mechanisms are housed in a closed container 15,
A high-pressure chamber 18 in which a lubricating oil 16 is stored is formed above the frame 7. On the back of the orbiting scroll 3, a back chamber 17 is formed which is surrounded by the frame 7 and the fixed scroll 4 and is separated in terms of pressure.

In the scroll compression machine, in order to perform an efficient compression operation, the sealing property of the gap Ca between the wrap 1 and the end plate 2 of the orbiting scroll 3 and the fixed scroll 4 forming the compression chamber 5 and the gap Cb between the wraps 1 are required. It is important to maintain it, so that an appropriate amount of lubricating oil is supplied into the compression chamber 5 to perform fluid sealing. Further, the pressure in the compression chamber 5 acts on the orbiting scroll 3 in a direction away from the fixed scroll 4, and the rear chamber 17 needs to have a pressure balanced with the pressure in the compression chamber 5. If the pressure in the rear chamber 17 is too high, the sliding resistance between the orbiting scroll 3 and the fixed scroll 4 increases. Conversely, if the pressure is too low, a gap Ca is generated between the orbiting scroll 3 and the fixed scroll 4 and the fluid in the compression chamber 5 Leakage reduces compression efficiency.

The mechanism for adjusting the oil flow rate and pressure to the rear chamber 17 shown in FIG. 6A will be described with reference to FIG. A high pressure chamber 18 is mounted on the frame 7
A valve cylinder 20 communicating with the rear chamber 17 is mounted, one end of which faces the high pressure side and the other end faces the low pressure side. The piston 21 has a tapered passage and is inserted movably in the axial direction. And an oil flow rate adjusting mechanism configured to be supported by a spring 22 having a force balanced under the pressure of the rear chamber 17. on the other hand,
The fixed scroll 4 is provided with a pressure adjusting mechanism 23 for maintaining the rear chamber 17 at a constant pressure in a form communicating with the rear chamber 17 and the low-pressure portion 5c on the outer periphery of the compression chamber 5. When the pressure rises above a predetermined pressure, the pressure adjusting mechanism 23 operates, and the oil in the rear chamber 17 leaks into the low-pressure section 5c.

An appropriate amount of lubricating oil is supplied to the sliding portion and the seal portion of the orbiting scroll 3 and the fixed scroll 4 to improve the slidability and the sealing performance. Oil is mixed in, resulting in a decrease in compression efficiency or an overload due to a liquid compression state.

In order to obtain a force that balances the force acting in the direction in which the orbiting scroll 3 moves away from the fixed scroll 4 by the pressure in the compression chamber 5, the pressure in the rear chamber 17 is maintained at an appropriate constant pressure. ,
In addition, it is desirable to supply an appropriate amount of lubricating oil into the sliding portion and the seal portion of the orbiting scroll 3 and the fixed scroll 4, that is, into the compression chamber 5.

However, the flow rate of the lubricating oil is susceptible to changes in pressure and temperature, and the change in viscosity of the oil is particularly remarkable with temperature changes, and the flow rate is greatly affected.

SUMMARY OF THE INVENTION The present invention provides an oil supply mechanism for a scroll compression machine that is less dependent on temperature changes as well as pressure changes.

Means for Solving the Problems In order to solve the above problems, a first aspect of the present invention is to provide a high pressure chamber and a rear surface between a high pressure chamber and a rear chamber by using a tapered piston movable in the axial direction of the valve cylinder. In addition to the oil flow valve, which is configured by engaging a spring that expands and contracts according to the pressure of the chamber, the piston is made of a material having a larger thermal expansion rate than the valve cylinder, and the cross-sectional area of the nozzle throttle due to the thermal expansion of the piston is changed to change the oil flow rate. Is configured to reduce the temperature dependency.

According to a second aspect of the present invention, in addition to the above-described structure, a throttle valve made of a material having a higher thermal expansion coefficient than those of the valve cylinder and the piston is provided in a valve cylinder at one end of the piston, and a throttle valve corresponding to a pressure change and a temperature change is provided. This is a step stop configuration.

According to a third aspect of the present invention, in addition to the above configuration, a heat-sensitive deformable body (for example, bimetal) is provided with a throttle gap at one of the high-pressure side and the low-pressure side opening of the piston, and the opening is formed in response to a temperature change. The configuration is such that the temperature dependence of the oil flow rate is reduced by changing the flow path area.

The operation of the first invention is to change the noise gap with the valve cylinder by the taper of the piston to control the amount of lubricating oil flowing from the high-pressure chamber to the rear chamber, and to form the piston from a material having a large thermal expansion coefficient. By changing the nozzle gap according to the lubricating oil temperature change, the flow rate change due to the pressure difference is the change in the flow area due to the taper of the piston, and the flow change due to the temperature change is adjusted by the thermal expansion and contraction of the piston. The flow rate of the lubricating oil can be controlled.

The function of the second invention is to control the amount of lubricating oil flowing from the high-pressure chamber into the rear chamber by changing the nozzle gap with the valve cylinder by the taper of the piston, and to mount a material having a high coefficient of thermal expansion mounted in series with the piston. Can expand and contract due to a change in the temperature of the lubricating oil to vary the throttle gap, and can control the flow rate change due to the pressure difference and the temperature change.

The function of the third invention is to control the amount of lubricating oil flowing from the high-pressure chamber to the rear chamber by changing the nozzle gap of the valve cylinder due to the taper of the piston, The amount of bending varies with temperature change, and the aperture gap changes. Therefore, the flow rate change due to the pressure difference is a change in the flow path area due to the taper of the piston, and the flow rate change due to the temperature change can control the flow rate of the lubricating oil by changing the throttle gap by the amount of curvature of the heat-sensitive deformable body.

Embodiment Hereinafter, an oil supply device for a scroll compression machine according to a first embodiment of the present invention will be described with reference to FIG.

FIG. 1 shows a configuration of the oil supply device. The valve cylinder 25 is mounted on the frame 7 described in the basic structure of the oil supply device of the scroll compression machine in communication with the high-pressure chamber 18 and the rear chamber 17, and a tapered piston 26 is movable in the axial direction.
A spring 22 is provided on the end face of the rear chamber side of the piston 26 to balance the pressure difference between the high-pressure chamber 18 and the rear chamber 17, and the piston 26 moves according to the balance between the pressure difference and the spring force. 26
Controlling the amount of oil inflow from the nozzle gap C ₁ is changed high-pressure chamber 18 between the tapered and valve cylinder 25 to the rear chamber 17.

Furthermore the material of the piston 26 assumes a high coefficient of thermal expansion than the valve cylinder 25, the diameter of the piston 25 expands and contracts with temperature, the nozzle clearance C ₁ is changed in response to temperature.

That is, the flow rate changes due to the pressure difference in the taper of the piston 26, also the flow rate changes due to temperature changes in the thermal expansion and contraction of the piston 26, it is possible to control the flow rate of the adjusted oil nozzle gap C _1, pressure changes and temperature changes Thus, an oil supply device with a small change in the flow rate can be obtained for both changes.

FIG. 2 shows an oil supply device for a scroll compression machine according to a second embodiment of the present invention. The valve cylinder 30 is inserted into the frame 7 described in the basic configuration of the scroll compressor described above in communication with the high-pressure chamber 18 and the rear chamber 17, and a tapered piston 31 is inserted so as to be movable in the axial direction. A spring 22 that balances the pressure difference between the high-pressure chamber 18 and the rear chamber 17 is provided on the rear-chamber-side end surface of the piston 31, and the piston 31 moves in accordance with the balance between the pressure difference and the spring force. nozzle gap C ₃ is changed with the valve cylinder 30, controls the amount of oil flowing from the high pressure chamber 18 into the rear chamber 17.

Further attached to the valve cylinder 30, the valve cylinder 30 and the throttle valve 32 consisting of a large material of coefficient of thermal expansion than the piston 31 is changed to stop the gap C ₄ stretching temperature changes of the lubricating oil 16. Also, communicating with a throttle gap C ₄ nozzle gap C ₂ to flow path 33.

That clearance C ₄ diaphragm at a flow rate change in the taper of the piston 31, also the flow rate change thermal expansion and contraction of the throttle valve 32 according to the viscosity change of the lubricant 16 is dependent on the temperature due to changes in the pressure difference between the high pressure chamber 18 and rear chamber 17 , The lubricating oil flow rate can be controlled, and a lubricating apparatus with a small flow rate change can be obtained for both changes in pressure and temperature.

FIG. 3 shows an oil supply device for a scroll compression machine according to a third embodiment of the present invention. The valve cylinder 40 is inserted into the frame 7 described in the basic configuration of the scroll compression device in communication with the high-pressure chamber 18 and the rear chamber 17, and a tapered piston 41 is inserted so as to be movable in the axial direction. A spring 22 that balances the pressure difference between the high-pressure chamber 18 and the rear chamber 17 is provided on the rear-chamber-side end face of 41, and the ston 41 moves in accordance with the balance of the pressure difference and the spring force, and the taper of the piston 41 nozzle spacing C ₅ is changed with the valve cylinder 40, controls the amount of oil flowing from the high pressure chamber 18 into the rear chamber 17.

Further clearance C ₆ aperture varies according to the amount curvature change in temperature of the oil in the piston 41 thermal deformation member with a gap C ₆ diaphragm opening 42 is disposed in an end portion (e.g., bimetal) 43 is changed.

That is, the flow rate change due to the change in the pressure difference between the high-pressure chamber 18 and the back chamber 17 is a taper displacement due to the movement of the piston 41, and the flow rate change due to the temperature change is a displacement in the bending amount of the heat-sensitive deformable body 43, and the throttle gap C ₆ Is adjusted, and an oil supply device with a small change in flow rate can be obtained for both changes in pressure and temperature.

FIG. 4 is a graph showing the temperature / flow rate characteristics of the lubricating apparatus in each of the above embodiments, where a is a characteristic of only the tapered piston and the flow rate increases linearly with temperature change, Can respond to both pressure change and flow rate change, and the flow rate is almost saturated above a certain temperature.

Effects of the Invention As described above, according to the present invention, the temperature dependency of the oil flow rate can be reduced.

As a result, the pressure in the rear chamber is maintained at an appropriate constant pressure,
In addition, an appropriate amount of lubricating oil can be supplied to the sliding portion and the seal portion of the orbiting scroll and the fixed scroll, that is, the compression chamber, and effects such as a reduction in compression efficiency and prevention of overload due to liquid compression can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of an oil supply device of a scroll compression machine according to a first embodiment of the present invention, FIG. 2 is a sectional view of an oil supply device of a scroll compression machine according to a second embodiment of the present invention, and FIG. FIG. 4 is a sectional view of an oil supply device of a scroll compression machine according to a third embodiment of the present invention, FIG. 4 is a flow rate / temperature characteristic diagram of each oil supply device, and FIG. 5 is a plan view of a compression section showing a basic principle of the scroll compression machine. FIG. 6 is a longitudinal sectional view showing the entire structure of the scroll compressor, and FIG. 7 is a detailed sectional view of a conventional oil flow valve mechanism of the scroll compressor of FIG. 17… Back room, 18… High pressure room, 25,30,40 …… Valve, 26,3
1,41 ... Piston, 22 ... Spring, 32 ... Throttle valve, 42 ...
Opening, 43 ... heat-sensitive deformable body.

──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Masato Morimoto 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-62-10487 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) F04C 18/02 F04C 29/02

Claims (3)

(57) [Claims] 1. Two scroll bodies having wraps standing upright on a mirror plate mesh with each other with the wraps on the inside, and one of the scroll bodies is rotated and interlocked with the other scroll body in a state where rotation of the scroll body is prevented. In a scroll compression machine that performs a compression action, a rear chamber is provided on a surface opposite to a wrap of a orbiting scroll, an oil flow valve is provided between a high-pressure chamber also serving as an oil reservoir and a rear chamber, and a rear chamber and a low-pressure chamber are provided. An oil supply device having a constant pressure valve between the oil supply device and the oil flow valve,
One end faces the high-pressure chamber and the other end faces the rear chamber, and a taper-shaped piston movable in the axial direction of the valve cylinder. An oil supply device for a scroll compression machine, wherein the oil supply device is formed by a spring that expands and contracts according to a difference, and the piston is made of a material having a higher thermal expansion coefficient than the valve cylinder. 2. A throttle valve made of a material having a higher coefficient of thermal expansion than the valve cylinder and the piston is provided in a valve cylinder on the high pressure side of the piston, and a nozzle formed by the valve cylinder and the piston from a gap between the throttle valve. The oil supply device for a scroll compression machine according to claim 1, wherein a flow path is formed in the throttle portion. 3. The oil supply device for a scroll compression machine according to claim 1, wherein a heat-sensitive deformable body is provided with a throttle gap at one of the high pressure side and the low pressure side opening of the oil flow valve.