JPS5930918B2 - A method for controlling gas capacity in a vane-type rotary compressor. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a capacity control device for a vane type rotary compressor.

Various devices have been proposed and used in the past as devices for controlling the capacity of compressed gas.

The capacity control device currently used mainly in air compressors and refrigerator compressors is a suction valve open type capacity control device that, in the reciprocating type, releases the pulp in each cylinder one after another to control the capacity in stages. A control device or, in the case of a screw type rotary compressor, a slide valve type capacity control device, that is, a device that moves the slide valve to change the suction cut-off position, increase or decrease the suction volume of the compression chamber, and change the discharge volume of compressed gas. There is.

Control of the compressed gas capacity in the reciprocating type is performed by stopping the compression action of each cylinder one after another, so the compressed gas capacity changes step by step, and is not used in applications that require fine adjustment.

Furthermore, a slide valve type capacity control device used in a screw type rotary compressor can change the suction cut-off position using a slide valve, continuously change the substantial volume of the compression chamber, and change the discharge capacity.

However, this capacity control device has a complicated structure and requires a high degree of precision because the slide valve moves and slides while contacting the rotating body, which not only increases the cost but also increases the cause of failure. Become.

The present invention provides a capacity control device for a vane-type rotary compressor that controls gas capacity using a simple mechanism that does not require much precision in a vane-type rotary compressor that is extremely commonly used and is the simplest and cheapest. The purpose is to provide

A feature of the present invention is that, in a vane-type rotary compressor, a rotatable end plate is provided at both ends or one end in the axial direction of the rotor, and the end plate is provided with an adjacent vane in addition to an intake port provided on the inner surface of the cylinder. A communication groove is provided that opens into a compression chamber surrounded by the inner surface of the cylinder, the outer periphery of the rotor, and the end plate, and the communication groove is communicated with the intake chamber, so that the communication groove does not directly communicate with the discharge port via the compression chamber during capacity control. A device is provided for rotating the rotatable end plate so as to open the communication groove into the compression chamber whose volume is reduced until it communicates with the discharge port after cutting off communication with the intake port. It is in.

The device of the present invention will be explained with reference to the drawings.
In FIG. 3, a cylindrical cylinder 10 has a rotor 5 which rotates in the direction of the arrow through bearings 16 and 17 about a center 4 eccentric to the center 3 of a circle of an inner surface 2 forming a cylinder, The rotor 5 is equipped with vanes 7 that fit into and slide in a plurality of vane grooves 6, and end plates 18 and 19 that are rotatable about the center 4 of the rotor 5 are provided at both ends of the cylinder 10, and bearings 16, The end plates 18 and 19 are covered with a casing 20 and 21 that accommodates the cylinder 1.
be fixed at both ends of the

By connecting the shaft end 22 of the rotor 5 with a prime mover such as an electric motor and an internal combustion engine (none of which are shown) through a coupling, and giving rotation to the rotor 5, the cylinder inner surface 2, vanes 7, rotor outer periphery 8, and The volume of the compression chamber 9 formed by the plates 18 and 19 is reduced as the rotation progresses to suck in, compress, and discharge gas.

An intake chamber 11 having an opening 10 at the upper part of the outer circumference of the cylinder 1 is provided on the outer circumference of the cylinder inner surface 2 forming the compression chamber 9 of the cylinder 1 .

An intake port 12 is provided in the upper part of the cylinder inner surface 2, and a discharge port 13 is provided in the smallest section of the compression chamber 9 where the rotor outer periphery 8 and the cylinder inner surface 2 approach each other, and compressed gas is discharged as the rotor 5 rotates. It is sent to the chamber 14, and further to the communication port 15.
and discharge into a pressure tank (not shown).

The end plates 18 and 19 are provided with a communication groove 23 that opens into the compression chamber 9 and a communication groove 24 that opens into the intake chamber 11.
3 and 24 are the end plates 1 as shown in FIGS. 1, 2, and 3.
8 and 19 are provided on the circumference corresponding to the compression chamber 9 and on the circumference corresponding to the intake chamber 11 at positions having substantially the same opening angle as the intake port 12 provided on the cylinder inner surface 2, respectively.

Communication passages 25, 26 are provided in the casing 20, 21 at positions corresponding to the intake chambers 11 of the cylinder 1, respectively, so as to constantly communicate with the communication grooves 23, 24.

Engaging teeth 27 are provided on the outer peripheries of the end plates 18 and 19 in accordance with the rotation angle, and mesh with the pinion 28.
Rotation is applied via a shaft 29 by a motor or oil field regulator (none of which is shown).

When it is necessary to change the volume of gas, the change in discharge pressure or temperature of the discharged gas is sensed, and this is converted into electrical, hydraulic, pneumatic, etc., and is applied to a motor, hydraulic pressure regulator, etc. , the pinion 28 is rotated via the shaft 29, and the end plates 18 and 19 are rotationally displaced, thereby changing the gas capacity.

In this embodiment, a method of rotating the end plates 18 and 19 using gears is illustrated, but the method of rotating the end plates 18 and 19 is not limited to this embodiment. This includes all other methods such as.

Fig. 1 shows a state in which the communication grooves 23 and 24 of the end plates 18 and 19 are at the same angle i position as the intake port 12 of the cylinder inner surface 2, and normal compression operation is performed. The operation is exactly the same.

That is, in this state, the vane 7a is in the closed position of the intake port 12, the vane 7c is located in the discharge pipe of the discharge port 13, and the gas in the compression chamber 9 gradually increases its volume by the rotation of the rotor 5. , 9b, and is discharged from the discharge port 13.

In Figure 2, it is necessary to control the gas capacity, and the end plates 18, 19
The figure shows when the is rotated approximately 90 degrees to the right.

In this case, the communication grooves 23 and 24 of the end plates 18 and 19 are located at the compression chambers 9 and 9a, and the compression chambers 9 and 9a are located at the communication grooves 24 and 24, respectively.
Communication passages 25 and 26 (see Figure 3) communicate with the intake chamber 11 via the communication groove 23, and as the volume of the compression chambers decreases, the gas in the compression chambers 9, 9a is returned to the intake chamber 11 and is subjected to compression. do not have.

The suction is first shut off by the bay 77b, and the suction gas volume becomes the volume of the compression chamber 9b, so that the compressed gas volume is controlled.

As described above, while the rotation angle of the end plates 18 and 19 is sequentially rotated from 0 degrees, the suction gas capacity is gradually reduced, and the required amount of gas can be sucked and compressed, so the power It is also possible to save a lot of money, which is very effective.

In the explanation so far, both the end plates 18 and 19 have communication grooves 23.
24, but the end plates 18, 19
Even if the communication grooves 23 and 24 are provided in only one of the two, the same operation and effect can be obtained, and this is naturally included in the gist of the present invention.

Conventionally, stepless capacity control of vane type rotary compressors is so-called intake closing type capacity control, which is performed while sequentially closing the intake ports, so as the intake gas decreases, the negative pressure on the suction side of the compression chamber increases. As the intake gas decreases, the compression ratio increases, and even if capacity control is performed, the power consumption does not decrease much. However, with the device of the present invention described above, the power consumption decreases significantly as the compressed gas decreases. However, since stepless control of the compressed gas capacity is performed by adjusting the rotation angle of the end plate, the structure can be simple, inexpensive, and efficient.

In addition, in FIG. 3, the cylinder 20 is connected to the communication passage 25.2.
6 is shown in the figure, the same effect can be obtained even if the communication passages 25 and 26 are not provided and the communication grooves 23 and 24 of the end plates 18 and 19 are made to communicate with each other, and this is included in the present invention. There is no need to discuss it.

As mentioned above, the only practical stepless gas capacity control device known to date is the slide valve type for screw type rotary compressors, but this type of machine has a complicated mechanism and is expensive (and From a personal standpoint, this was extremely disadvantageous.

According to the present invention, the compressed gas capacity can be adjusted in an inexpensive and simple manner using a low-cost vane-type rotary compressor, resulting in a further expansion of the scope of use of stepless capacity adjustment. It is.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a vane-type rotary compressor according to an embodiment of the present invention, in which the communication groove of the end plate is in a position for normal compression operation. FIG. 2 is a cross-sectional view of a vane-type rotary compressor in which the suction cut-off position of the communication groove of the end plate is adjusted, showing an embodiment of the capacity control of the present invention. FIG. 3 is a longitudinal sectional view showing a cross section taken along the line II in FIG. 1. 1...Cylinder, 5...Rotor, 7.
...Vane, 9...Compression chamber, 11...
... Intake chamber, 18, 19 ... End plate, 23, 2
4... Communication groove.

Claims (1)

[Claims] 1. In a vane-type rotary compressor, a rotatable end plate is provided at both ends or one end in the axial direction of the rotor, and the end plate is provided with an air intake port provided on the inner surface of the cylinder, and adjacent vanes, the inner surface of the cylinder, the outer periphery of the rotor, and the inner surface of the rotor. A communication groove that opens into the compression chamber surrounded by the end plate is provided, the communication groove is communicated with the intake chamber, and the communication groove is connected to the intake port within the range where the communication groove does not directly communicate with the discharge port via the compression chamber during capacity control. A vane-type rotating device characterized in that a device is provided for rotating the rotatable end plate so as to open the communication groove into a compression chamber whose volume is reduced until it communicates with the discharge port after communication is cut off. Compressor capacity control device.