JPH0337385A - Scroll compressor - Google Patents

Abstract

PURPOSE:To secure lubrication and reduce vibration by maintaining each of the lubricating oil quantity and the back pressure constant independently of the variation of the discharge pressure by arranging a constant flow rate valve between a lubricating oil reservoir and a back pressure chamber and arranging a constant pressure valve between the back pressure chamber and a suction chamber. CONSTITUTION:Cooling gas flows into the suction chamber 30 of a sealed container 1 from the suction pipe 29 of a compressor and sucked into a compression mechanism 2 from a suction inlet 31 and compressed in a compression work space 11. Then, the cooling gas flows inside a turning drive shaft 13 and in a communication hole on a crankshaft 15 from a discharge hole 32 on a turning end plate 9, and flows out from an upper gap on a crankshaft surrounding 34, and then flows into an electric motor side space 22 over a motor stator 3 through a communication passage 36 on the periphery of the motor stator 3. Then, after flowing into a discharge chamber 23 through a communication hole 24, the cooling gas is discharged outside the compressor from a discharge pipe 37. In this case, a constant flow rate valve 40 is arranged between a lubricating oil reservoir 4 and the back pressure chamber 38 on a turning end plate 9. Further, a constant pressure valve 50 is arranged between the back pressure chamber 9 and an inflow passage 39.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a scroll type electric compressor.

BACKGROUND ART FIG. 5 is a vertical sectional view of a conventional scroll electric compressor, which is disclosed in Japanese Patent Laid-Open No. 57-70984.

A compression mechanism 102 is provided inside the closed container 101, a stator 103 of an electric motor is fixed below the compression mechanism 102, and a lubricating oil reservoir 104 for storing lubricating oil is provided below the compressing mechanism 102.

The compressor side 102 includes a fixed spiral vane component 10 having a fixed spiral vane 4110G integrally formed on the fixed frame 105.
7, and a swirling spiral vane component 110 in which a swirling spiral vane 108 that meshes with the fixed spiral vane 106 to form a plurality of compression work spaces 111 is formed on a swirling head plate 109;
A crankshaft 11 that includes a rotation restraining component 112 that prevents the rotation of the rotating spiral vane component 110 and allows it to rotate only, and an eccentric drive bearing 114 that eccentrically drives a rotation drive shaft 113 provided on the rotation head plate 109! ff and its main axis 11
6 is supported by a main bearing 117, and the like.

Also, a frame body plane 120 on the rotating head plate side of the fixed frame 105 and a rotating head plate plane 12 on the fixed frame side of the rotating mirror Ifi 109.
1 to slidably abut, and the rotating mirror + & 10
9 is provided with an intermediate pressure hole 122 that communicates with the compression work space 111 to maintain a back pressure chamber 123 on the opposite side of the rotating scroll vane m108 of the rotating head plate 109 at a pressure between the discharge pressure and the suction pressure.

Refrigerant gas is sucked in from the suction pipe 124 of the compressor and into the compression mechanism 102 from the suction chamber 125 and the suction port 126.
After being compressed in the compression work space 111, it exits the discharge hole 127 and is located in the discharge chamber 12B' below the compression mechanism 102! The air is discharged outside the compressor from the discharge pipe 129.

The lubricating oil in the lubricating oil reservoir 104 is supplied to the main shaft 1 of the crankshaft 105.
The main bearing 117 is supplied with oil through a branch oil supply passage 131 which is partially branched from the oil supply passage 130 that penetrates through the main bearing 117 . Some of the other lubricating oil is supplied to the eccentric drive bearing 11 from the oil supply passage 130.
The oil is depressurized through the gap between the oil supply amount limiting portions 132 of No. 4 and is discharged to the back pressure chamber 123.

The lubricating oil in the back pressure chamber 123 is supplied from the intermediate pressure hole 122, etc.
It passes through the compression work space 111, is compressed, and is discharged from the compression mechanism together with the refrigerant.

Figure 6 shows the rotation angle of the crankshaft 105 and the compression work space 1.
The reference of the zero rotation angle indicating the pressure relationship of 11 is the angular position at which the compression work space 111 is just in a sealed state. The pressure while the compression work space 111 is closed depends mostly on the suction pressure and is almost unrelated to the discharge pressure. However, when the compression work space 111 communicates with the discharge side, the compression work space 111
11 is a rotating spiral blade part 11 according to the discharge pressure.
There are two types of pressure force that tries to push 0 toward the back pressure chamber 123: one depends on the suction pressure, and the other depends on the discharge pressure.

The pressure in the compression work space Ill at the intermediate pressure hole 122 changes in accordance with the angular position of the intermediate pressure hole 122, for example, as shown by the thick line in FIG. 5, in one rotation period.

Naturally, the pressure in the back pressure chamber 123 changes more closely with the pressure in the compression work space 111 as the rotational speed of the crankshaft is lower.

Problems to be Solved by the Invention Like the conventional scroll compressor shown in FIG. 5 mentioned above,
In a structure in which an intermediate pressure hole 122 communicating with an appropriate position of the compression work space 111 is provided in the swivel head plate 109 and back pressure is applied over almost the entire rear surface of the swivel head plate 109, this pressure is applied by the pressure of the compression work space 111. Rotating spiral vane parts 11
0 in the direction of the fixed spiral vane component 106 depends on the suction pressure and the discharge pressure, so this compressor is installed in a refrigerator where the discharge pressure and suction pressure vary widely. As a result, the biasing force may become excessive or insufficient.

Further, from the lubricating oil reservoir 104 to the oil supply passage 130, the back pressure chamber 1
23. If the amount of lubricating oil supplied to the compression work space through the intermediate pressure hole 122 is insufficient, the leakage gap in the compression work space will not be completely sealed, and if it is in excess, the suction refrigerant will be heated and the pressure will decrease. The efficiency of MA decreases, but the flow rate of this lubricating oil depends on the difference between the discharge pressure of the refrigerant gas and the back pressure, and in extreme cases, the pressure in the back pressure chamber becomes higher than the discharge pressure, making lubrication impossible. It can be. Therefore, problems may arise in the efficiency and reliability of refrigerators such as air conditioners that have a wide range of discharge pressure fluctuations.

As mentioned above, this back pressure can be as high as 1
Since it fluctuates greatly during rotation, the swirling spiral vane part 11
0 fixed spiral vane part 10? In order to reliably bias in the direction of , the average pressure in the back pressure chamber 123 must be made extra high.
Compressor input becomes large. If the average pressure in the back pressure chamber is insufficient, at the moment when the pressure in the compression work space 111 is low, the rotating mirror plate 109 moves toward the front of the rotating plate a and vibrates.
There are problems in that noise is generated, leakage in the compression work space 111 increases, and the efficiency of the compressor decreases.

Additionally, if the pressure adjustment mechanism in the back pressure chamber is configured with a combination of a fixed passage resistance and a normal control valve, the range of change in the discharge pressure and suction pressure will be extremely large compared to the current air conditioners that are used for cooling and heating. When mounted on a wide object, the force due to the pressure that tries to press the swirling spiral vane component 110 in the direction of the back pressure chamber 123 depends on both the suction pressure and the discharge pressure,
Since the pressing force due to the pressure of the back pressure chamber 123 depends on the suction pressure, it is difficult to create a back pressure that appropriately urges the swivel head plate over the entire range of change.

Means for Solving the Problem The first technical means for solving the above-mentioned tVt problem is to dispose an electric motor and a compression mechanism driven by this electric motor inside a closed container, and to drive this compression mechanism. , a fixed spiral vane component having a fixed spiral vane formed on a fixed frame body, and a swirling spiral vane component having a swirling spiral vane fixed or formed on a rotating mirror plate that engages with the fixed spiral vane to form a plurality of compression chambers. , a rotation restraining part that prevents the rotating spiral blade part from rotating and only allows it to rotate, a crankshaft that drives the spiral blade part to rotate, and a bearing part that has a bearing that supports the main shaft of the crankshaft. The structure is such that the pressure on the discharge side acts on the lubricating oil reservoir that stores the lubricating oil to be supplied to the bearing, and a fluid pressure higher than the pressure on the suction side of the compression mechanism and lower than the pressure on the discharge side is applied to the back surface of the rotating head plate. A back pressure chamber is formed to act, the rotating spiral blade component is energized in the direction of the fixed spiral blade component, and a constant flow type flow control valve is provided between the lubricating oil reservoir and the back pressure chamber to control the back pressure. A constant pressure valve that releases at a constant pressure is disposed between the chamber and the suction side of the compression mechanism.

A second technical means for solving the problem is to form an electric compressor equipped with the first technical means with a swing drive shaft or a swing drive bearing on the back surface of the swing head plate, and to form an eccentric drive shaft or a swing drive bearing on the crankshaft. The eccentric drive shaft and the above-mentioned swing drive shaft or swing drive bearing are engaged, and a portion around the swing drive shaft or swing drive bearing is formed between the back surface of the swing head plate and the bearing component to which the discharge pressure in the center is applied. A sliding sealing ring is provided to slidably partition the back pressure chamber on the outer periphery.

A third technical means for solving the problem is to fit a cylindrical valve body into a valve hole having a cylindrical inner wall in the electric pressure i*i equipped with the first technical means, and to A spring is arranged to bias the valve body in the axial direction of the cylinder from the back pressure chamber side toward the high pressure side of the lubricating oil reservoir, and a notch is provided in the cylindrical surface of the valve body or the inner wall of the valve hole to form a fluid passage. The present invention is to form a fluid passage in a direction in which passage resistance of the fluid passage increases when the valve body moves from the lubricating oil reservoir side toward the back pressure chamber side.

A fourth technical means for solving the problem is an electric compressor equipped with the third technical means, in which a cylindrical valve body is installed in the valve hole having a cylindrical inner wall in the flow rate 111 m valve. A spring is disposed to urge the valve body in the axial direction of the cylinder from the back pressure side toward the lubricating oil side, and a passage cross section is expanded on the cylindrical surface of the valve body and/or the inner surface of the valve hole. A fluid passage having a structure that repeats contraction many times is formed, and the fluid passage is formed in a direction in which passage resistance of the fluid passage increases when the valve body moves from the lubricating oil reservoir side toward the back pressure chamber side. It is to be.

The effect of the first technical means of the present invention described above is that by providing a constant flow valve between the lubricating oil reservoir and the back pressure chamber, a constant lubricating oil flow rate that is not affected by the magnitude of the discharge pressure can be obtained. A constant pressure valve provided between the back pressure chamber and the suction chamber keeps the back pressure constant and prevents the back pressure from becoming higher than the discharge pressure. Further, since the back pressure is generated regardless of the pressure in the compression work space, there is no vibration in the back pressure that would cause the back pressure to fluctuate during one revolution.

The action of the second technical means of the present invention, in addition to the action of the first technical means described above, is achieved by applying pressure on the discharge side to the inside of the sliding sealing ring. A portion of the force pushing the fixed spiral vane toward the fixed spiral vane can be made dependent on the discharge pressure.

The effect of the third technical means of the present invention is to further ensure the @amount control effect of the flow rate control valve of the above-mentioned first technical means, and when the discharge pressure reaches a higher pressure state, the valve body The lubricant moves toward the back pressure chamber by the action of the spring, increasing the passage resistance of the fluid passage of this constant flow valve, and attempts to keep the flow rate of lubricating oil almost constant. When the discharge pressure further decreases, the flow rate of lubricating oil is similarly kept constant by the opposite effect.

The effect of the fourth technical means of the present invention is to further ensure the flow rate control effect of the flow control valve of the third technical means, and the cross section of the passage is structured to repeat expansion and contraction many times. This makes it possible to make the passage resistance independent of the Reynolds number, so that the flow rate does not change significantly even if the temperature of the lubricating oil changes, and by increasing the passage resistance for this gap dimension, it is possible to accurately adjust the passage resistance value. Can be set.

Embodiment FIG. 1 shows an embodiment of a scroll electric compressor according to claims 1 and 2 of the present invention.

A compression mechanism 2 and a stator 3 of an electric motor for driving the compression mechanism 2 are fixed inside a closed container 1, and a lubricating oil reservoir 4 is provided below the electric motor.

The compression mechanism 2 is a fixed structure formed integrally with the fixed frame body 5. 11
A fixed spiral blade component 7 having a winding blade 6, and a rotating spiral blade component 10 in which a swirling vortex blade m8 that engages with the fixed spiral body 16 to form a plurality of compression work spaces 11 is formed on a rotating mirror plate 9. , a rotation restraining component 12 that prevents the rotation of the rotating spiral blade component 1O and allows it to rotate only, and a crankshaft 15 having an eccentric drive bearing 14 that eccentrically drives the rotation drive shaft 13 provided on the rotating mirror [9]. The main shaft 16 of the crankshaft is supported by a bearing component 19 having a main bearing 17 that supports the main shaft 16 below the rotor 12 of the electric motor.

Ball bearing 2 fixed to the partition wall 20 at the upper end of the crankshaft 15
1, and the partition wall 20 connects the stator 3 and rotor 12 of the electric motor.
The space above is partitioned into a motor side space 22 and a discharge chamber 23.

An annular projection 18 provided on the outer periphery of the bearing component 19 is inserted between the lower end of the closed container body 27 and the upper end of the closed container lower portion 28, and are hermetically welded together.

The refrigerant gas enters the suction chamber 30 inside the closed container lower part 28 from the suction pipe 29 of the compressor and is sucked into the compressor tJI2 from the suction port 31. After being compressed in the compression work space 11, the refrigerant gas is The discharge hole 32 passes through the swing drive shaft 13, passes through the communication hole 33 provided in the crankshaft 15, exits from the gap above the crankshaft enclosure 34, and is provided around the stator 3 of the electric motor. The air is guided to the motor side space 22 above the stator 3 through the communication passage 36, passes through the passage hole 24, enters the discharge chamber 23, and is discharged from the discharge pipe 37 to the outside of the compressor.

A constant ff1it valve 40 is provided in the bearing part 19 between the lubricating oil reservoir 4 and a back pressure chamber 38 formed on the back surface of the rotating mirror plate 9, and a constant pressure valve is provided between the back pressure chamber 9 and the suction passage 39. There is.

Second, showing the partial details of the embodiment according to claim 2, an annular sliding sealing ring is disposed in the part of the bearing part 19 that comes into contact with the back surface of the rotating mirror 19, and the inner discharge A portion on which pressure is applied and an outer back pressure chamber 9 are slidably partitioned.

Figure 3 shows claims 1 and 3 of the present invention, respectively.
3 shows details of an embodiment of the constant flow valve according to section 1.

Constant 2I for the inner diameter 42 of the valve case 41! When the valve body 43 biased by the L-volume valve spring 44 is inserted, a fluid passage plane 45 that expands downward is formed on the surface of the valve body 43.

FIG. 4 shows an embodiment of a constant flow valve according to claim 4, in which an uneven surface 45 that slightly expands downward is formed on the surface of a valve body 43A.

Effects of the Invention The effect of the technical means in item 1 of the present invention is that, as stated in the operation section, a constant lubricating oil it and a constant back pressure can be obtained almost unaffected by changes in the discharge pressure of the compressor. It is possible to obtain a compressor with reliable lubrication, less vibration, higher reliability, less rA dynamic noise, and stable power consumption.

The effect of the technical means described in item 2 is that it can be used in a wide range of operating conditions because the rotating head plate pressing that combines both discharge pressure dependence and suction pressure dependence can be obtained.

The effect of the technical means described in item 3 of the present invention is to provide a specific structure of the constant flow valve described in item 1, and a simple, inexpensive, and small constant flow valve can be obtained.

The effect of the technical means of item 4 of the present invention is that a stable and highly reliable compressor is obtained, which has little change in flow rate even when the temperature changes due to lubricating oil temperature or refrigerant dilution, and has little change in valve flow rate. It will be done.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an electric compressor showing an embodiment of the present invention;
Figure 2 is a sectional view of the main parts of the compressor, and Figures 3 (a) and (g).
, and Fig. 4 are sectional views of constant flow valves of different structures in the same compressor, Fig. 5 is a sectional view of a conventional compressor, and Fig. 6 shows the pressure of the compression working space of the same compressor. FIG. 3 is a characteristic diagram showing a fluctuating state. 1... Airtight container, 2... Compression mechanism, 3
...Motor stator, 4...Lubricating oil reservoir,
5...Fixed end plate, 6...Fixed spiral blade, 7...Fixed spiral blade parts, 8...Swivel spiral blade, 9...・Swivel mirror plate, 10...
・Swirling spiral blade parts, 11... Compression work space,
12...Rotation restraint parts! 2A...Rotor, 13...Swivel drive shaft, 15...
Crankshaft, 19...Bearing parts, 29...
...Suction pipe, 31...Suction hole, 37...
・Discharge pipe, 38...Back pressure chamber, 39...
Suction passage, 40... Constant flow valve, 50...
・Constant pressure valve.

Claims (4)

[Claims] (1) An electric motor and a compression mechanism driven by the electric motor are disposed inside an airtight container, and the compression mechanism is connected to a fixed spiral vane component having a fixed spiral vane formed on a fixed frame, and a fixed spiral vane part having a fixed spiral vane formed on a fixed frame; A rotating spiral blade component in which rotating spiral blades that engage with each other to form a plurality of compression work spaces are fixed or formed on a rotating head plate, and a rotation restraining component that prevents the rotation of the rotating spiral blade component and only allows rotation; It is composed of a crankshaft that swings and drives the spiral vane part, and a bearing part that has a bearing that supports the main shaft of the crankshaft, and pressure on the discharge side acts on a lubricating oil reservoir that stores lubricating oil to be supplied to the bearing. A back pressure chamber is formed on the back surface of the rotating head plate on the side opposite to the rotating spiral vane, on which a fluid pressure that is higher than the pressure on the suction side and lower than the pressure on the discharge side of the compression mechanism acts, A rotating spiral vane component is energized in the direction of the fixed spiral vane component, a constant flow type flow control valve is provided between the lubricating oil reservoir and the back pressure chamber, and a flow rate control valve is provided between the back pressure chamber and the suction side of the compression mechanism. A scroll compressor equipped with a constant pressure valve that releases at a constant pressure between the compressor and the compressor. (2) forming a swing drive shaft or a swing drive bearing on the back surface of the swing head plate, and engaging the eccentric drive bearing or the eccentric drive shaft of the crankshaft with the swing drive shaft or the swing drive wheel bearing;
A sliding member around the swing drive shaft or the swing drive bearing that slidably partitions the space between the back surface of the swing head plate and the bearing component into a central portion on which discharge pressure acts and a back pressure chamber on the outer periphery. The scroll compressor according to claim 1, further comprising a sealing ring. (3) A cylindrical valve body is fitted into a valve hole having a cylindrical inner wall, and a spring is disposed to bias the valve body in the axial direction of the cylinder from the back pressure side toward the lubricating oil side, and A notch is provided in the cylindrical surface of the valve body or the inner wall of the valve hole to form a fluid passage, and when the valve body moves from the lubricating oil reservoir side toward the back pressure chamber side, the passage resistance of this fluid passage 2. The scroll compressor according to claim 1, further comprising the flow control valve in which the fluid passage is formed in a direction in which the flow rate increases. (4) A cylindrical valve body is fitted into a valve hole having a cylindrical inner wall, and a spring is arranged to bias the valve body in the axial direction of the cylinder from the back pressure side toward the lubricating oil side, and A fluid passage whose cross section repeatedly expands and contracts many times is formed on the cylindrical surface of the valve body and/or the inner surface of the valve hole, and the valve body moves from the lubricating oil reservoir side toward the back pressure chamber side. 4. The scroll compressor according to claim 3, wherein the flow control valve has the fluid passage formed in a direction in which the passage resistance of the fluid passage increases when the flow rate increases.