JPS63306288A - Compressor - Google Patents

Abstract

PURPOSE:To enhance seal efficiency, by using electric viscous fluid for a sealing medium and providing a means which applies voltage to the electric viscous fluid at least in a compression chamber. CONSTITUTION:A delivery chamber 18 is filled in its internal bottom part with a sealing medium 30 consisting of electric viscous fluid, and voltage, generated in a variable voltage generating device 33, is applied to a male rotor 31 via an electrode 34. When the voltage is applied to the male rotor 31 via the electrode 34, a compressor, which generates in its low speed region the high applied voltage, increases viscosity of the sealing medium 30 sufficiently sealing a clearance between the male rotor 31 and a female rotor 2 and between the rotors 31, 2 and a rotor casing 4.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a compressor such as a screw type compressor used in a vehicle air conditioner, a refrigerator, etc.

(Prior Art) An example of a screw compressor used in a conventional vehicle air conditioner is shown in FIGS. 5 to 8.

5 and 6, 1 is a male rotor, 2 is a female rotor that meshes with the male rotor 1, 3 is a front casing, and 4 is a female rotor that meshes with the male rotor 1.
is a rotor casing, 5 is a rear casing, 6 is a discharge casing, and 7 is a cylindrical cover airtightly attached around the rotor casing 4, with a recess bored in the inner peripheral surface and the outer peripheral surface of the rotor casing 4. The refrigerant gas suction passage 8 is limited by the point 4a.

When power is transmitted through the electromagnetic clutch 9, the female rotor 2 rotates while meshing with the vaginal opening 1, and refrigerant gas is sucked into the compression chamber 11 through the suction side joint 10 and the refrigerant gas suction passage 8. As the volume of the compression chamber 11 decreases, it is gradually compressed and discharged from the discharge pipe 12 into the discharge chamber 18 formed in the discharge casing 6. Then, after colliding with the muffling material 13 and the baffle 14 in the discharge chamber 18 to separate the seal oil mist contained in the discharged gas, it is discharged from the discharge side joint 15 . The seal oil separated from the discharge gas accumulates at the bottom of the discharge chamber 12, and enters the injection boat 1 bored in the rear casing 5.
6 into the compression chamber 11 and the gap between the male rotor 1 and the female rotor 2, the rotors 1 and 2 and the rotor casing 4.
, the gaps between the front casing 3 and the rear casing 5 are also sealed.

As shown in FIG. 7, the refrigerant gas discharged from the compressor 20 enters the oil separator 21, where the seal oil contained in the refrigerant gas is separated, and then enters the condenser 22, where it is condensed and liquefied. 0 Then, after being adiabatically expanded in the process of flowing through the expansion valve 23, it enters the evaporator 24, where it is vaporized seven times and returned to the compressor 20. The seal oil separated by the oil separator 21 is returned to the compressor 20 via an oil return pipe 25.

(Problems to be Solved by the Invention) In the conventional screw type pressure IWfl mentioned above, when operating at low speed, compressed gas leaks from each gap in the compression chamber 11 in large quantities. Volumetric efficiency ηV is poor in the rotation range. To cope with this, if a high viscosity seal oil is used, the frictional resistance during high-speed operation increases, which deteriorates the mechanical efficiency η end and increases the power consumption of the compressor.

Further, the seal oil contained in the refrigerant gas discharged from the compressor 20 adheres to the inner surfaces of the condenser 22 and evaporator 24, but if high viscosity seal oil is used, these condensers
This greatly reduces the heat exchange capacity of the evaporator 24. If the seal oil separated by the oil separator 21 is returned to the compressor 20 as it is, the temperature of the seal oil in the compressor 20 will rise, its viscosity will decrease, and the sealing effect will be reduced. If an oil cooler is provided in the oil return pipe 25 in order to cope with this problem, there is a problem that not only the cost increases but also extra space is required to install the oil cooler.

(Means for Solving the Problems) The present invention was invented to solve the above problems, and its gist is to provide a compressor configured to supply a sealing medium into the compression chamber. In the compressor, an electrorheological fluid is used as the sealing medium, and means is provided for applying a voltage to the electrorheological fluid at least within the compression chamber.

(Function) Since the present invention has the above configuration, by applying a voltage to the sealing medium made of electrorheological fluid in the compression chamber, its viscosity is increased and the sealing effect is improved.

(Example) An example of the present invention will be specifically described with reference to FIGS. 1 to 4.

In FIGS. 1 and 2, the inner bottom of the discharge chamber 18 is filled with a sealing medium 30 made of electrorheological fluid. Regarding electrorheological fluids, see the Journal of the Institute of Electrical Engineers of Japan Vol.
191, No. 1971, etc., this electrorheological fluid has a characteristic that its viscosity increases as the applied voltage increases, as shown in FIG. An insulating coating 32 is applied to the surface of the male rotor 31 to electrically insulate it from other parts. The voltage generated by the variable voltage generator 33 is applied to the male rotor 31 via the electrode 34.

The ground side of the variable voltage generator 33 is connected to the discharge casing 6.

The rest of the structure is the same as the conventional one shown in FIGS. 5 to 7, and corresponding members are given the same reference numerals.

As shown in FIG. 4, the variable voltage generator 33 generates a voltage whose applied voltage decreases as the rotational speed of the compressor increases, and applies this voltage to the male rotor 31 via the electrode 34. . Then, since the applied voltage is high in the low speed rotation range of the compressor, the viscosity of the sealing medium 30 becomes high, and the gap between the male rotor 1 and the female rotor 2 in the compression chamber 11, the rotor 1.2 and the rotor casing 4, and the front The gaps between the casing 3 and the rear casing 5 are sufficiently sealed, and the volumetric efficiency η■ of the compressor is improved.

Since the applied voltage is low in the high-speed rotation range of the compressor, the viscosity of the sealing medium 30 is low (as shown in FIG. 4), and the mechanical efficiency ηm is improved, so that the power consumption of the compressor can be reduced.

Thus, by reducing the applied voltage as the rotational speed of the compressor increases, the compressor can be operated with substantially constant efficiency from its low-speed rotation range to its high-speed rotation range.

Furthermore, the viscosity of the sealing medium 30 increases as a voltage is applied inside the compressor, but its viscosity is low because no voltage is applied outside the compressor. Since the amount of sealing medium to be used is reduced, it is possible to prevent a decrease in the performance of the condenser 22 and the evaporator 24, and it is also possible to omit the oil separator 21. Furthermore, since the low-viscosity sealing medium 30 is cooled together with the refrigerant in the evaporator 24, an oil cooler can be omitted.

(Effects of the Invention) In the present invention, by applying a voltage to the sealing medium made of electrorheological fluid within the compression chamber, the viscosity of the sealing medium can be increased and the sealing efficiency within the compression chamber can be increased.

If the applied voltage is reduced in accordance with the increase in the rotational speed of the compressor, the compressor can be operated with substantially constant efficiency from its low speed rotation range to its high speed rotation range.

[Brief explanation of the drawing]

1 to 4 show one embodiment of the present invention, in which FIG. 1 is a longitudinal cross-sectional view of the compressor, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG. A diagram showing the characteristics of an electrorheological fluid. FIG. 4 is a diagram showing changes in applied voltage, volumetric efficiency, and mechanical efficiency with respect to the rotational speed of the compressor. Figures 5 to 8 show one conventional example, Figure 5 is a longitudinal sectional view of the compressor, Figure 6 is a cross sectional view along the Vl-Vl gland in Figure 5, and Figure 7 is for vehicles. Air conditioner refrigerant system diagram, Part 8
The figure is a diagram showing changes in volumetric efficiency and mechanical efficiency with respect to the rotation speed of the compressor. Compressor - 20, sealing medium - 30, compression chamber - 11, variable voltage generator - 33, electrode - 34 Illustration 8 Ten Thousand Ensen Proverbs

Claims (3)

[Claims] (1) A compressor configured to supply a sealing medium into a compression chamber, characterized in that an electrorheological fluid is used as the sealing medium, and means is provided for applying a voltage to the electrorheological fluid at least within the compression chamber. compressor. (2) The compressor according to claim (1), wherein the voltage applying means is a variable voltage applying means that varies the applied voltage depending on the rotation speed of the compressor. (3) The compressor according to claim (2), wherein the variable voltage applying means is configured to reduce the applied voltage as the rotational speed of the compressor increases.