JPH01247785A - Two-cylinder compressor - Google Patents

Abstract

PURPOSE:To improve efficiency of a compressor by a method wherein compression timing of a high-stage compression element is set forward of that of a low-stage compression element by approx. 270 deg. in phase. CONSTITUTION:In a two-cylinder rotary compressor, a low-stage compression element 5 and a high-stage compression element 6 are located vertically with respect to two crank shafts 2, 3. Compressed gas sucked from an inlet port 19 of a low-stage cylinder 9 is led from an exhaust port 22 via a passage 23 to an inlet port 24 of a high-stage cylinder 10, and then it is further compressed to be exhausted via an exhaust port 26 out of a casing 1. In this constitution, by setting compression timing of the high-stage compression element 6 forward of that of the low-stage compression element 5 by 270 deg. in phase, sucked volume in the high-stage compression element 6 gradually increased within an exhaust range (120 deg. to 350 deg.) of the low-stage compression element 5, making the sucking completion position of the high-stage compression element 6 differ. This causes the high-stage compression element 6 to start at a position where sucking pressure of the high stage is maximum, so as to eliminate sucking loss and improve efficiency of the compressor.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to a two-cylinder compressor in which a high-stage compression element is connected in series to a low-stage compression element, and in particular, This invention relates to a two-cylinder compressor that improves efficiency by improving the suction timing of a high-stage compression element relative to the discharge of air.

(Prior Art) A two-cylinder rotary compressor that is generally used in air conditioners, etc. consists of an electric element having a crankshaft with two crank parts formed in a sealed gauge, and a rotor fitted in each crank part. and a cylinder accommodating each rotor, and a low-stage and high-stage compression element are arranged, and the discharge port of the cylinder of the low-stage compression element is connected to the suction port of the cylinder of the high-stage compression element. There is.

In such a conventional compressor, in order to further compress the pressure air discharged from the cylinder of the low-stage compression element in the high-stage compression element, the cylinders 9 are arranged in the same phase as shown in FIG. Crank part 2 for ゜10,
As shown in FIG.
The phase was set to be 180° shifted from that of .

(Problem to be Solved by the Invention) However, in the above compressor, the timing at which the low-stage compression element discharges compressed gas and the timing at which the high-stage compression element sucks in the compressed gas do not match well. There were problems with pressure fluctuations and poor efficiency.

To explain this specifically, as shown in FIG. 6, the discharge of the low stage compression element starts at approximately 120° and ends at 350°. On the other hand, the suction of the high-stage compression element has a phase of 1.
Since they are shifted by 80 degrees, the timing starts at approximately 210 degrees and completes one rotation at 210 degrees.

As is clear from the figure, the high stage side suction pressure PsH fluctuates periodically. The reason for this will be explained with reference to FIG. 5. Between the time when the low stage compression element 5 starts and ends the discharge (from 120' to 350'), the suction internal volume of the high stage compression element 6 is 180'. (The upper fulcrum of the lower blade is based on 0°)
is maximum and minimum near 210°. Therefore, as shown in Fig. 6, the PSH
is low, and the internal volume decreases with respect to the discharge amount, so PsH
increases and reaches its maximum around 270°.

Therefore, since the high stage compression element completes suction at around 210°, compression must be started from a low pressure (low stage side discharge pressure), resulting in compression loss (as shown by diagonal lines in Fig. 7).
(suction loss), resulting in a decrease in compressor efficiency.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a two-cylinder compressor that can eliminate compression loss and significantly improve efficiency.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention provides a two-cylinder compressor in which a high-stage compression element is connected in series to a low-stage compression element. The compression timing is set to be approximately 270° in phase ahead of that of the low-stage compression element.

(Function) As a result, the suction internal volume of the high-stage compression element gradually increases during the discharge section (120° to 350'') of the low-stage compression element. The completion point shifts from 210° to around 27°, and compression starts at the maximum PSH position in FIG. 6, eliminating suction loss and greatly improving compressor efficiency.

(Example) Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings.

In FIG. 2 showing a two-cylinder rotary congressor, 1 is a vertical closed gauging, and within this gauging 1 is a crankshaft 4 in which two crank parts 2.3 are formed.
A low-stage compression element 5 and a high-stage compression element 6 are disposed above and below the crank portion 2.degree.3. The low-stage and high-stage compression elements 5.6 each include a roller 7.8 fitted to the crank part 2.3, a cylinder 9.10 that accommodates these rollers 7.8 so as to be rotatable on their face center, and a cylinder 9. It is mainly composed of vanes 11 and 12 (see FIG. 1) that partition the inside of the container 10.

The low-stage cylinder 9, which has a larger displacement volume than the high-stage cylinder 10, is fixed by a bolt 14 to the lower surface of the main bearing frame 13 that rotatably supports the center of the crankshaft 4, and the lower end of the crankshaft 4 is The sub-bearing frame 15, which is rotatably supported, has bolts 16 attached to the lower surface of the high-stage cylinder 10.
Fixed by The lower cylinder 9 is formed of a cast metal, and since a cast metal is easy to process, the lower cylinder 9 is formed with a female thread 17 for screwing the bolts 14 and 16 thereinto. High stage cylinder 10
is formed by sintering, and in the case of sintering, a hole can be easily formed in the cylinder state, so a hole 18 for passing the lower bolt 16 is formed in this higher stage cylinder 10.

A suction port 19 is formed in the lower stage cylinder 9, and
Intermediate frame 2 interposed between upper and lower cylinders 9 and 10
0 and the main bearing frame 13 are formed with discharge ports 22 having discharge valves 21, and the gas discharged from these discharge ports 22 passes through a passage 23 as shown in FIG. It is adapted to be introduced into the mouth 24. Sub-bearing frame 15 forming the bottom wall of the high-stage cylinder 10
A discharge port 26 having a discharge valve 25 is formed therein, and the gas discharged from the discharge port 26 rises within the casing 1 and is discharged from an outlet (not shown) formed at the upper part of the gauging l. ing. Valve covers 27.28 covering the discharge ports 22.26 are attached to the main bearing frame 13 and the sub-bearing frame 15.

In this configuration, the compression timing of the high-stage compression element 6 is set to be 270 degrees ahead of that of the low-stage compression element 5 in terms of phase. Specifically, as shown in Fig. 1, the crank parts 2 and 3 are formed with a phase shift of 180 degrees, and the cylinders are formed with a phase shift of 9 degrees, 10 degrees, or 90 degrees, and together with the high-stage compression element. The compression timing of element 6 is 270° ahead of that of lower stage compression element 5 in terms of phase.

These cylinders 9 and 10 have a total of 6 arc spots with their arc spots shifted in the circumferential direction as shown in Fig. 3a and b.
It is fixed within the casing 1 by arc spot welding 30 of the point spont.

According to such a configuration, the suction internal volume of the high-stage compression element 6 gradually increases during the discharge section (120' to 350°) of the low-stage compression element 5, The completion of suction is shifted to the 270° position in FIG. 6, and compression starts at the position where Pstl is at its maximum, eliminating suction loss and greatly improving the efficiency of the compressor.

In addition, since the low-stage and high-stage cylinders 9 and 10 are each fixed to the casing l by spot welding, axial rigidity is increased and axial runout is reduced even at high speeds. By shifting in the direction, the vibration mode of gauging 1 is suppressed at six points, resulting in low noise.

Since the large cylinder 9 on the low stage side is placed closer to the main bearing frame 13 than the small cylinder 10 on the higher stage side, it is possible to arrange the large cylinder 9 in the sub bearing frame 151111 or to separate the low stage side and the high stage side. Unlike cylinders of the same size,
As shown in FIG. 4, it is only necessary to attach one small balancer 31 to the lower side of the rotor 32 of the electric element.

In addition, the low-stage cylinder 9 is formed of easy-to-process casting,
The female threaded portion 17 is tapped, and the high-stage cylinder 10 is formed by sintering that allows the hole 18 to be made in the sintered state, so that each cylinder 9.10
can be produced at minimum cost, reducing costs.

Note that the compression timing of the high-stage compression element 6 can be set to be about 2700 degrees ahead of that of the low-stage compression element 5, so the cylinders 9.10 can be set in the same phase and the phase of the crank part 2.3 can be set to 2700 degrees ahead of that of the low-stage compression element 5. Various combinations are possible, such as shifting by °.

Further, in the above embodiment, both cylinders 9 and 10 are fixed within the casing 1 by spot welding, but the main bearing frame 13 and one cylinder 9 or 10 are fixed within the casing 1 by spot welding. , may be done. The lower stage cylinder 9 may be formed by sintering, and the higher stage cylinder 10 may be formed from 1IJJ material.

[Effects of the Invention] In summary, according to the present invention, the following remarkable effects are achieved.

The compression phase of the high-stage compression element is 2 times higher than that of the low-stage compression element.
Since the setting is advanced by about 70°, the suction internal volume of the high-stage compression element is set to be advanced by about 70°, so the suction internal volume of the high-stage compression element is equal to the discharge section of the low-stage compression element (120°~350'
), the suction loss is eliminated and the compressor efficiency is greatly improved.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, FIG. 2 is a longitudinal cross-sectional view of a compression element portion, FIG. The figure is a balance model diagram of a compressor, Figure 5 is a schematic configuration diagram showing a conventional example, and Figure 6 is a graph showing the relationship between rotation angle and pressure.
FIG. 7 is a graph showing the relationship between cylinder internal volume and pressure. In the figure, 5 is a low-stage compression element, and 6 is a high-stage compression element.

Claims (1)

[Claims] 1. In a two-cylinder compressor in which a high-stage compression element is connected in series to a low-stage compression element, the compression timing of the high-stage compression element is set 2 times in phase relative to that of the low-stage compression element.
A 2-cylinder compressor characterized by being advanced by about 70 degrees.