JPS6157478B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improvements in rotary compressors, particularly rolling piston type rotary compressors for residential, commercial and vehicle air conditioning applications.

Prior Art FIG. 1 shows the compression mechanism of a conventional rolling piston type rotary compressor.

In this figure, reference numeral 1 denotes a crankshaft driven by a motor or engine (not shown), which rotates eccentrically in the direction of the arrow. A cylindrical rotor 2 is fitted into the crankshaft 1. The cylinder 3 is provided with a blade 4 which is always kept in contact with the rotor 2 by a spring 5. The refrigerant sucked into the cylinder 3 through the suction hole 6 has a volume of the space surrounded by the blades 4, the rotor 2, and the cylinder 3.
is compressed by decreasing as the rotation of
It is discharged into a housing (not shown) through the discharge hole 7 and the discharge valve 8.

Problems to be Solved by the Invention The rolling piston rotary compressor configured as described above discharges air once per crankshaft rotation. At this time, the torque applied to the crankshaft due to gas pressure is 1 as shown by dotted line A in Figure 8.
The maximum value of torque in the rotation period is 300% of the average torque
~400%. Due to this large torque fluctuation,
Large vibrations occur in the compressor, causing parts such as piping and frames to vibrate, causing an increase in noise.
Furthermore, hermetic compressors for air conditioning require motors with large starting torque.

Means for Solving the Problems The present invention aims to improve the above-mentioned drawbacks of conventional rolling piston type rotary compressors. That is, the present invention provides a rolling piston type rotary compressor that includes a crankshaft that rotates eccentrically within a cylinder and a cylindrical rotor fitted to the crankshaft, which includes at least two sets of blades, suction holes, and discharge valves. at least two compression chambers are provided, each suction hole is connected to a low pressure gas refrigerant circuit, and
The rotary compressor is characterized in that each suction passage is provided with means for preventing backflow of gas within the cylinder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to FIG. 2 of the accompanying drawings.

The first embodiment of the present invention shown in FIG. 2 is an embodiment in which two sets of blades, suction holes, and discharge valves are provided.

In the figure, the same members as in FIG. 1 are given the same reference numerals. That is, in addition to the conventional blade 4, spring 5, suction hole 6, discharge hole 7, and discharge valve 8, the second blade 9, spring 10, suction hole 11, discharge hole 12, and discharge valve 13 are arranged in a point-symmetric manner. It is added to the position.

In addition, a suction valve 1 is provided in the suction passage of the suction holes 6 and 11.
4, 16 and springs 15, 17 are provided.

FIG. 6 shows the relationship between the crankshaft rotation angle and the cylinder volume in this embodiment. (The inside of the cylinder is divided into three chambers by the two blades and their contact points, and the figure shows the volume change in one of the chambers.) Figure 7 shows a suction valve in the suction passage in Figure 2. 14,1
6 and springs 15 and 17 (hereinafter referred to as "without suction valve"), the change in the cylinder pressure is shown by a solid line. The discharge valve opens when the cylinder internal pressure exceeds the discharge pipe internal pressure, and the cylinder internal pressure does not increase during discharge. Only when the rotation angle reaches 360 degrees, the intake port is closed by the rotor, the inside of the cylinder is sealed, and compression begins. The maximum volume is the crank rotation angle
Although the displacement occurs at 270 degrees, it is larger than 1/2 of the displacement of a conventional single blade with the same cylinder and rotor dimensions, and is about 1.5 times that amount. However, without a suction valve, while the crankshaft rotates from 270° to 360°, the refrigerant gas inside the cylinder is slightly compressed and the pressure becomes higher than the refrigerant gas pressure in the suction passage, so the refrigerant that enters the cylinder The gas passes through the suction passage,
I'm back. Therefore, no compression action is performed during this period, and the change in the cylinder internal pressure is as shown by the solid line in FIG. If there is a suction valve, when the crankshaft further rotates from the maximum cylinder capacity of 270°, the suction valve 16 closes due to the spring 17 and the pressure difference between the cylinder internal pressure and the suction passage internal pressure.
The gas in the cylinder does not return to the suction passage 11 and compression therefore begins. The change in cylinder pressure at this time is shown by the broken line in FIG. Also, the torque acting on the crankshaft is indicated by the chain line B in Figure 8.
(without suction valve) to solid line C (with suction valve).

As shown in the solid line C in Fig. 8, the blade is
By adding a suction valve to the compressor, the maximum torque value can be further reduced, the minimum torque value is positive, torque fluctuations are further reduced, and the vibration and noise of the compressor can be reduced. can.

Furthermore, the displacement amount can be increased by 1.5 times for cylinders and rotors of the same size, and the compressor can be made lighter and smaller.

Although FIG. 2 shows an example of a plate-shaped intake valve, it may be of any shape, such as a ball-shaped one, as long as it functions as a so-called check valve, and a spring is not necessarily required.

In a second embodiment shown in FIG. 3, fluidic diodes 18, 19 are used in place of the intake valves described above.
A first inlet pipe 20 of the fluidic diode is connected to the suction hole 6 or 11, and a second inlet pipe 21 is connected inside the cylinder. (See Figure 4) The fluidic diode 18 or 19 has a low flow resistance and exhibits a normal flow when gas flows from the first introduction pipe 20 to the second introduction pipe 21 as shown in Figure 4a. As shown in b, from the second introduction pipe 21 to the first
When flowing into the introduction pipe 20, the flow path resistance is high and backflow can be prevented. Therefore, it performs the same function as a suction valve.

Although a spiral diode is shown as a fluid diode in FIGS. 3 and 4, the present invention is not limited to this. If there is a high resistance to backflow from inside the cylinder,
It can be anything.

In this embodiment, in addition to the effects of the above-mentioned case with a suction valve, reliability can be improved because there is no moving part of the fluid diode. Also,
Low noise is achieved because there is no valve clicking sound.

In the third embodiment shown in FIG. 5, an unload piston hole 24 is provided near the suction valve, the unload piston 22 is inserted into the hole 24, and the suction is controlled by turning on and off the control pressure Pd applied to the unload piston. The operation of the valve 14 is turned on and off. Reference number 23 is a control pipe for applying the control pressure Pd.

According to this embodiment, no pressure is applied to the control pipe 23 during normal times, as shown in FIG. 5b. The unload piston 22 is accommodated in the unload piston hole 24, and the suction valve functions similarly to the suction valve of the two-blade rotary compressor with a suction valve shown in FIG. When the cooling load decreases or when the cooling capacity becomes too large such as during high speed rotation in the case of a vehicle, the unload piston 22 pushes down the suction valve by applying high pressure Pd to the control pipe 23. (Fig. 5a) At this time, the suction valves 14 and 16
If both are pushed down to unload, the compressor functions similarly to a two-blade rotary compressor without an intake valve, and the cooling capacity is reduced to approximately 65%. Furthermore, if only one of the suction valves 14 or 16 is pushed down, the cooling capacity will be reduced to approximately 78%. That is, by unloading (deactivating) the suction valve, capacity control can be performed in three stages at most.

In this way, there are 3 stages (when there are 2 blades)
By controlling the capacity of the rotary compressor (for example, 100%, 78%, 65%), you can reduce the number of times the rotary compressor is turned on and off, and by adjusting the cooling capacity to match the load, you can save energy throughout the year. At the same time, it is possible to improve the feeling.

Although an example using an unload piston operated by pressure is shown here, an unload piston operated by electromagnetic force or engine negative pressure in the case of a vehicle, bypassing the intake valve or fluid diode, etc. , any suction valve or fluid diode that disables it. Further, the suction valves and fluid diodes do not necessarily need to be provided in all suction passages.

Effects of the Invention According to the present invention described above, as shown in FIG. 8, torque fluctuations and starting torque are small, and therefore vibration and noise can be reduced. Furthermore, although it has the same cylinder and rotor dimensions as the conventional model, it can achieve 1.5 times the displacement.
This results in a compact, high-performance compressor.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional rolling piston rotary compressor, FIG. 2 is a similar view of a first embodiment of the rolling piston rotary compressor of the present invention, and FIG. 3 is a second embodiment of the rolling piston rotary compressor of the present invention. 4 is a longitudinal sectional view of the fluid diode used in the second embodiment, FIG. 5 is a longitudinal sectional view of the main part of the third embodiment of the present invention, and FIG. A graph showing the change in cylinder volume with respect to the crankshaft rotation angle of a rotary compressor with two blades. Figure 7 is a graph showing the difference in cylinder internal pressure with respect to the crankshaft rotation angle depending on whether there is an intake valve or not. It is a graph showing changes in torque with respect to rotation angle. 1...Crankshaft, 2...Rotor, 3...
...Cylinder, 4,9...Blade, 5,10...
Spring, 6, 11... Suction hole, 7, 12... Discharge hole, 8, 13... Discharge valve, 14, 16... Suction valve, 15, 17... Spring, 18, 19... Fluid diode, 20 ...first introduction pipe, 21 ... second introduction pipe, 22 ... unloading piston, 23 ... control piping, 24 ... hole for unloading piston.

Claims (1)

[Claims] 1. In a rolling piston type rotary compressor that includes a crankshaft that rotates eccentrically within a cylinder and a cylindrical rotor fitted to the crankshaft, at least two sets of blades, suction holes, and discharge valves are provided. What is claimed is: 1. A rotary compressor comprising two compression chambers, a low-pressure gas refrigerant circuit connected to each suction hole, and means for preventing backflow of gas in the cylinder in each suction passage.