JPS58117382A - Rotary compressor - Google Patents

Abstract

PURPOSE:To stabilize the movement or travel of vanes of a rotary compressor, by preventing excessive projection of the vanes by forming a slit having a proper fluid resistance in each of the vanes, and forming appropriate connecting passages in a rotor. CONSTITUTION:A slit 11 is formed in each of vanes 5 for communicating a vane chamber 3 with a hollow space 8 formed at the rear end of the vane 5. On the other hand, connecting passages 12 are formed in a rotor 2 for communicating the vane chamber 3 with respective vane slots 4. Since, with such an arrangement, gas in the vane chamber 3 is forced into the hollow space 8 at the rear end of the vane and pressure in the vane chamber 3 is acted directly to the rear end of the vane, the vane 5 is urged onto the inner surface of a cylinder 1. Therefore, it is enabled to prevent excessive projection of the vanes and hence to stabilize the movement or travel of the vanes.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a sliding vane rotary compressor.
This invention relates to an improvement in a method for stabilizing vane travel.

FIG. 1 shows a cross-sectional view of a sliding vane compressor using a conventional method for stabilizing vane travel. This compressor includes a cylinder 1 having a cylindrical space inside;
A rotor 2 is arranged eccentrically within the cylinder 1, and is fixed to both sides of the cylinder 1, sealing the blade chamber 3, which is the internal space of the cylinder 1, on the sides, and supporting the rotor 3 with a bearing such as a needle bearing. a side plate (not shown);
It is composed of a plate 75 that is slidably engaged with a vane sliding groove 4 provided in the rotor 2. 6 is a suction hole formed in the cylinder 1, and 7 is a discharge hole formed in the cylinder 1.

In a conventional sliding vane compressor, oil is supplied to the vane rear end space 8, and the vane is pressed against the cylinder by the oil pressure to stabilize the vane running. 1o is an oil supply groove.

The conventional method described above has the following problems. First, since hydraulic pressure is generated by adding discharge pressure to oil through a throttle, it is difficult to control the hydraulic pressure, and the vane 6 rises from the cylinder 1 due to insufficient force to push out the vane 6. Occurrence of vane noise or vane 5
This causes an increase in sliding torque due to excessive extrusion force acting on the material.

In addition, high-pressure oil mixed with refrigerant in the oil supply groove 10 leaks into the blade chamber 3 through the gap between the side surface of the rotor 2 and the side plate and mixes with the gas, causing a reduction in volumetric efficiency. was.

The present invention solves the above problems, and one embodiment of the present invention will be explained with reference to FIGS. 2 to 7.

In FIG. 2, 11 is a blade chamber 3 formed in the vane 6.
and the vane rear end space 8, and 1
Reference numeral 2 denotes a ventilation hole formed in the rotor 2, which communicates the blade chamber 3 and the vane sliding groove 4.

In this case, the gas in the blade chamber 3 is transferred to the slit 11 and the vent hole 1.
2 into the rear end space 8 of the vane and apply pressure from the vane chamber 3 directly to the rear end 8 of the vane to press the vane 6 against the cylinder 1 and stabilize the vane running. .

In FIG. 3, the width of the vane 5 is wr+the thickness of the vane 6 is t, the width of the slit 11 is Ws, and the depth of the slit 11 is d.

The rotary compressor shown in FIG. 3a can be modeled into the cylinder-piston system shown in FIG. That is, the blade chamber 3 in FIG. 3a. Vane 6° Vane rear end space 8. The slits 11 (and the ventilation holes 12) are the fourth
Space 13° Piston 14 inside the container shown in the figure. Cylinder chamber 16
．． It can be equivalently replaced with the thin conduit 16.

Next, an analytical method according to the present invention for determining the difference ΔP between the pressure P in the blade chamber 3 and the pressure Pb in the vane rear end space 8 will be described.

First, we will list the main setting conditions for analysis.

1. Changes in the pressure P in the blade chamber 3 shall follow standard polytropic changes.

2 Assume that the fluid is an ideal gas.

3. It is assumed that the temperature Tb of the fluid in the vane rear end space 8 is constant.

4 Assuming that the fluid flow inside the slit 11 is laminar,
Therefore, the average volumetric flow rate Q of the fluid in the slit 11 is
It is proportional to the pressure difference ΔP and inversely proportional to the fluid resistance H of the slit 11.

5. Fluid leakage in the gaps between the sides of the rotor 2 and the sides of the vanes 6 and the side plates is ignored.

Based on the above setting conditions, the following basic equation is introduced into the control volume 17 in FIG.

Equation of continuity where γb and vb are the specific weight and volume of the control volume 17, Qb is the volumetric flow rate flowing into the control volume 17, and t is time.

Ideal gas equation of state %formula% However, the waist is a gas constant.

By differentiating both sides of the above equation with respect to time t and rearranging it, the following equation is obtained.

Relationship between the center of gravity of the average volume flow in the slit 11 and the fluid resistance R By solving and rearranging the above three equations (1), (2), and (3) simultaneously, the following differential equation regarding the pressure difference ΔP can be obtained. .

However, ΔP2P-PbAid represents the cross-sectional area of the vane 5, and y represents the amount of displacement of the vane 5.

The relationships between P, Y, R and time t in equation (4) can be determined separately.

However, the compressor in this example was constructed under the conditions shown in the table below.

Below is a margin table 1 Conditions of the compressor in the example Fig. 6 shows that the vane 5 has a Wll of 15M and a depth of d-50.
7 blood and form a 100 μm slit 11, rotor 2
shows the steady-state characteristics of ΔP at rotational speeds of the rotor 2 of 11,000 rpm and 5,000 rpm when the ventilation hole 12 is not provided.

As can be seen from the graph in Figure 5, the rotor rotation angle ψ value is
The smaller the depth d of the slit 11 and the higher the rotation speed, the larger the depth d becomes. As ΔP increases, the force due to the pressure difference in the direction of pushing the vane 6 into the rotor 2 becomes stronger, causing the vane 5 to float up from the cylinder 1, generating vane noise and reducing the volumetric efficiency due to fluid leakage between the blade chambers. cause a decrease in

As an improved method for suppressing the increase in ΔP between π and ψ, vent holes 12 shown in FIGS. 2 and 3 are provided in the rotor. In FIG. 6, the base 76 has d=50 μm, 1
0071m, wB=15m slit is formed in the rotor 2, and a vane rear end space 8 is formed in the rotor 2 at a diameter of 0.5.
This is a graph showing fluctuations in fluid resistance R when the vane 5 is provided so as to be open to the vane 5 and blocked by the vane 5 at other rotor rotation angles ψ.

FIG. 7 shows a sixth case using both the slit 11 and the ventilation hole 12.
The steady-state characteristics of the pressure difference ΔP are shown in the case of having the fluid resistance R shown in the figure. As shown in FIG. 7, this can be achieved by using the slit 11 and the ventilation hole 12 together.

As described above, according to the present invention, by forming slits with appropriate fluid resistance in the vanes and further providing appropriate ventilation holes in the rotor, the pressure in the blade chamber can be applied directly to the rear end of the vane, and the vane extrusion force can be increased. The centrifugal force acting on the vanes allows the vanes to be pressed against the cylinder with a moderate amount of force, allowing for stable travel.

Therefore, compared to the conventional method of supplying oil to the rear end of the vane and using the oil pressure to press the vane against the cylinder to stabilize the vane running, this method works by applying a vane pushing force according to the pressure in the vane chamber. Since floating is prevented and excessive normal force is not exerted on the vane tip, sliding torque is reduced, and furthermore, volumetric efficiency can be improved by reducing the amount of oil mixed into the blade chamber.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a conventional sliding vane compressor, FIG. 2 is a front sectional view of a sliding vane compressor according to an embodiment of the present invention, FIG. 3a is an enlarged view of the vicinity of the same vane, and FIG. Figure bfi is an A-A sectional view of Figure 3a, Figure 4 is a cylinder/piston system model diagram equivalent to the embodiment shown in Figure 3a, and Figure 6 is a vane of an embodiment of the present invention. Form only a slit in the
A graph showing the analysis results of the pressure difference ΔP when no ventilation holes are provided in the rotor, and FIG. FIG. 7 is a graph showing the variation in fluid resistance between the chamber and the rear end of the vane, and FIG. 7 is a graph showing the analysis results of the pressure difference ΔP in the case of the fluid resistance shown in FIG. 1.010. + Cylinder, 2-1-1- Rotor, 3-
--7-0 Vane chamber, 4... Vane sliding groove, 5.
...Vane, 6...Suction hole, 7...
...Discharge hole, 8... Vane rear end space, 9...
... Oil supply hole, 1o ... Oil supply groove, 11 ... Slit, 12 ... Ventilation hole, 13 ... Space inside the container, 14...Piston, 16...Cylinder chamber, 16...
・Narrow pipe, 17...φ control volume. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure C1 ＼ Figure 4 Tsu & 1. θoorpm ) 6 to 111t, f, oo
orprnU

Claims (2)

[Claims] (1) A rotor with slidable vanes, a cylinder housing the rotor and the vanes, and a blade chamber fixed to both sides of the cylinder and formed by the vanes, the rotor, and the cylinder. A rotary compressor comprising a side plate that seals a space on its side surface, wherein a flow path is formed in the vane to connect the blade chamber and the rear end space of the vane. (2) The rotary compressor according to claim 1, wherein the rotor is provided with a ventilation hole that communicates the blade chamber and the rear end space of the vane at a predetermined rotor rotation angle.