JPS588289A - Rotary compressor - Google Patents

Abstract

PURPOSE:To prevent liquid from being compressed by oil in normal operation by boring at the utmost low position of a vane casing an oil discharge hole, which is closed by a flapper valve under a discharge pressure in said operation to achieve a compression stroke and opened to discharge the oil during recess. CONSTITUTION:By forming an oil discharge hole 27 and a flapper valve 50 at the lowest position of a vane casing 39, reflux oil 46' deposited in a cylinder 29 is removed from the cylinder 29 during recess of a compressor so that liquid may be prevented from being compressed to yield a high pressure at the start of revolution. Since the flapper valve 50 is closed by a discharge pressure P2 in normal revolution, a normal compression stroke may be executed. At the same time, the oil 46'' flowing out of the cylinder 29 is mixed with discharge gas under the influence of its pressure or flowing energy, sent to an oil separator, and then stored in the back space of a shell 29 to be used again as lubricating oil.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to preventing liquid compression in a rotary compressor.

As shown in Figure 1 (cross-sectional view) and Figure 2 (longitudinal cross-sectional view), a general sliding vane compressor consists of a cylinder 1 having a cylindrical space inside, and a cylinder 1 fixed to both sides of the cylinder 1. The front plate 3 and the rear plate 4 seal the blade chamber 2, which is an internal space, on their side surfaces, and the rotor 6 is eccentrically and rotatably arranged in the cylinder 1. It is constructed with movably engaged vanes 7. Further, reference numeral 8 denotes a relief hole for preventing liquid compression/overcompression, and is composed of a ball 9, a spring 1o, and a spring retainer 11.

The cylinder 1 has a suction hole 12 for sucking refrigerant gas.
, a discharge hole 13 for discharging compressed refrigerant gas, a discharge valve 14 for preventing backflow of discharged gas, a discharge valve holding plate 15 for protecting the discharge valve, and a head cover 16 for covering these discharge portions.

The vane/7 receives a force in the centrifugal direction due to the centrifugal force caused by the rotation of the rotor 6 and the high pressure oil supplied to the vane rear end 17, and its tip slides on the inner wall surface of the cylinder 1. At the same time, the gas in the blade chamber 2 is sucked in and compressed and discharged.

Conventionally, compressors for car coolers have had the following problems. That is, since oil 18 is supplied to the vane rear end 17 to also lubricate each sliding surface, after the compressor stops rotating, the discharge flows into the vane chamber 2 on the low pressure side in the direction of arrows A and A/. High pressure oil 18 pressurized by gas
flows out in the direction of arrow B and fills the blade chamber 2. Therefore, when the compressor is driven again after being left unused, a large amount of highly viscous oil 18' is forcibly fed to the discharge side.

In particular, in the case of the compressor for a car cooler used in the example, the number of revolutions used by the compressor is determined by the number of revolutions of the vehicle's engine, and especially when the rotor 5 starts rotating at a high speed of about 600 ORPM, the above Excessive liquid compression pressure was generated when the oil 18' flowed out to the discharge side, which became a major cause of damage to the compressor (for example, seizure between the rotor side and both plates 3 and 4).

Conventionally, the following methods have been used to solve the above problems.

(1) Provide functions such as oil control pulp to prevent oil from flowing out when the compressor stops rotating.

(2) Provide a relief valve to prevent liquid compression.

(3) Enlarge the effective area of the discharge hole.

In the case of method (1), under steady operating conditions, rear case 1
7 can be supplied to the vane rear end 15, and a loop function is provided between the rear case 19 and the vane rear end 17 to cut off the oil 16 supply after the compressor is stopped. It is necessary to provide it between the oil paths.

Fig. 3 is a diagram of conventional example a of method (1) during oil supply during steady operation of the compressor, and shows the maximum pressure P1 in the cylinder blade chamber 2.
The piston 20 slides, the steel ball 21 is pushed up, the oil path is opened, and the oil 18 flows out in the direction of arrow C due to the pressure P2 of the discharged gas, and the oil 18 flows out from the vane rear end 17.
supplied to FIG. 4 is a diagram of the oil control pulp in the same conventional example A when the compressor is stopped; the pressure inside the cylinder blade chamber decreases and the piston 18 descends. Accordingly, the steel balls 21 close the oil supply path by the spring 22, cutting off the oil supply when the compressor is stopped, and preventing leakage into the blade chamber 2.

In addition, FIGS. 6 and 6 show the configuration of a conventional example.
The oil 18 is intermittently supplied through the hole 24 of the disc 23 engaged with the tip of the rotor 6, and when the compressor is stopped,
Rotate the rotor 6 until the pressure inside each blade chamber 2, 2' becomes uniform.
is reversed, and the disc 23 stops at the position indicated by the broken line in FIG. 6, thereby blocking the path of the oil 18. 26 is an oil flow path.

As described above, method 1 has the drawback that the structure of the pulp is complicated and the cost is high. In addition, both a and b prevent oil from flowing out by forming a minute gap, but in the case of gaseous oil like in this compressor, it is impossible to completely prevent oil from flowing out. Cylinder blade chamber 2
It is impossible to prevent oil from accumulating in the Therefore, there is a drawback that liquid compression at the time of starting the compressor cannot be completely prevented.

In the case of method (2), as shown in FIG.
In other words, when the pressure inside the blade chamber 2' exceeds the pressure determined by the force of the spring 10, the flow passage blocked by the ball 9 is opened, allowing high pressure to be The oil 18' is configured to be returned to the inside of the rear case 19.

This pulp needs to be placed as close to the discharge side as possible, but due to the structure of the compressor, it is impossible to make the opening area of the part blocked by the ball 9 sufficiently large; It is not as effective as causing the oil 18' filled with water to escape into the hollow case 19 where liquid compression pressure is generated.

Further, the closer the 1/1 noof valve is arranged to the discharge side, the more the loss of volumetric efficiency during steady rotation becomes a problem. That is, the high-pressure gas force remaining in the gap 26 of the 1-no-1 no-f valve was due to re-expansion without being discharged, and was a factor leading to a decrease in volumetric efficiency.

In the case of method (3), the larger the effective discharge area of the discharge section, which is the fluid flow path, is, the more the liquid compression pressure can be suppressed. Fig. 1 - Discharge hole 13° discharge valve 14,
The effective discharge area of the discharge section constituted by the valve holding plate 16 is larger as the curvature diameter R1t:/J of the valve holding plate 15 or as the opening height h75f increases.However, the discharge valve 14
It is necessary to determine the above-mentioned R and h so that the maximum repeated bending stress is within the allowable value, and therefore there is a large restriction on the upper limit value that the effective discharge area can take.

The problems related to liquid compression faced by compressors for car coolers have been explained above.

In ordinary compressors, oil is supplied into the cylinder chamber for lubrication regardless of the type of compressor, and liquid compression measures are a common issue. Moreover, overcompression caused by refrigerant gas is a major problem that compressors face when operating at high speeds after being left at low temperatures. At low temperatures, dense refrigerant (sometimes liquefied) can generate abnormal pressure when passing through the discharge section, which is one of the causes of compressor damage.

The present invention solves the above-mentioned problems in liquid compression measures for compressors. In other words, at the lowest position of the blade chamber,
An oil drain hole is provided to allow oil accumulated in the blade chamber to flow out of the blade chamber when the compressor is stopped, and during steady operation, the flapper pulp seals the oil drain hole due to the discharge pressure and performs the compression stroke. This is what I did. With this method, the oil accumulated in the blade chamber naturally flows out when the compressor is stopped, and it is possible to prevent liquid compression due to oil when the compressor is running.

First, an embodiment of the present invention will be described.

FIG. 7 is a cross-sectional view of a compressor provided with an oil drain hole 27 according to the present invention. This compressor is based on a conventional compressor as shown in FIG. 1, and has a structure in which the main part is enclosed in a shell 28. Compared to the conventional example, the cylinder 29, front plate 3
o, rear plate 31, rotor shaft 32, groove 33
, vane 34° suction hole 35, discharge hole 36. discharge valve 37,
It is composed of a discharge valve holding plate 38, a blade chamber 39, and a shell 28.

FIG. 8 is a longitudinal sectional view of the compressor of the present invention. 3
0.31 is the front plate and rear plate respectively,
40. 41 are the front and rear bearings, 42
43 is an electromagnetic clutch, 43 is a mechanical seal, 44 is a front case that holds the compressor body, 45 is an oil separator that separates oil in the refrigerant gas flowing out from the discharge hole 36, 46 is oil accumulated in the shell 28, 47 is a supply valve for supplying this oil 46 to the vane rear end portion 48 via the bearing 41.

FIG. 9 is a detailed view of the oil drain hole 27 of the present invention. The oil 46' accumulated in the blade housing 39 flows out through the oil drain hole 2A while the compressor is stopped, flows out from the gap of the flapper valve 6o formed by the spacer 49, and flows into the shell 2B.
Accumulates inside.

FIG. 10 is a diagram of the oil drain hole 27 during steady rotation of the compressor. The flow path of the discharged gas flows from the discharge hole 36 of the cylinder 29 (Fig. 7) along the inner surface of the shell 28 as shown in the direction of the arrow, and the gas is mixed with the oil 46'' accumulated in the shell 28, and the gas flows through the oil separator. 45 (Figure 7).

At the same time, the flapper pulp 5o is
is held down, the oil drain hole 27 is sealed, and the compression stroke in the blade chamber 39 is performed as before. Here, since the pressure P0 inside the blade chamber 391° is in the middle of compression, it is lower than the discharge pressure P2.

Here, the diameter d of the oil drain hole 27 and the gap δ between the loop 6o and the cylinder 29 surface are made large enough to allow the oil 46' to naturally flow out, and the flannel valve 5o
The plate thickness t is the pressure Po inside and outside the cylinder.

The thickness is such that it can be activated by a pressure difference of P2.

In this way, by providing the oil drain hole 27 and the flange 5°, the oil 46' accumulated in the cylinder 29 due to backflow can be removed into the cylinder 29 when the compressor is stopped, and when the rotation starts. In addition, the flapper pulp 5o closes during steady rotation, so one normal compression stroke is performed.At the same time, the oil 46'' that has flowed out of the cylinder is caused by the pressure of the discharged gas and Depending on the flow rate, it becomes mixed with the gas, and the oil separator 4
5 (FIG. 8) and after separation, it accumulates at the rear of the shell 28 and can be used again as lubricating oil. In addition, flapper pulp 6
It is also possible to integrate the 0 spacer 49 with the cylinder 7 cylinder 29.

As described above, the present invention eliminates the need for backflow prevention pulps with complicated structures used in conventional compressors.
It is structurally simple and has the effect of reducing costs.

[Brief explanation of the drawing]

Figure 1 (a) is a cross-sectional view of a conventional sliding vane compressor as seen from the front plate side, Figure 1 (b) is a detailed view of the vicinity of the discharge hole of the conventional example, and Figure 2 is the same conventional example. Figure 3 is a cross-sectional view of the conventional one-year-old oil backflow prevention pulp mechanism when oil is supplied, Figure 4 is a cross-sectional view of the same mechanism when oil is shut off, and Figure 6 is the same conventional oil backflow prevention pulp mechanism. 6 is a front view of the disk of the same mechanism, FIG. 7 is a detailed view of the vicinity of the oil drain hole of the present invention, and FIG. The figure shows the state during rotation. 27... Oil drain hole, 46, 46', 46"...
... Oil, 50 ... Flapper pulp, 2
8... Shell, 49... Spacer. 1st drawing size OL 2 8 "Fig. 7 Fig. 8/46" Drawing procedure amendment Showa (June 4, 1970 Relationship with the case of the person amending the name of rotary compressor 3 Patent application
Address 1006 Oaza Kadoma, Kadoma City, Osaka Name (582) Matsushita Electric Industrial Co., Ltd. Representative Yama
Toshihiko Shimo 4 Agent 571 Address Matsushita Electric Industrial Co., Ltd., 1006 Kadoma, Kadoma City, Osaka Prefecture Drawing 6, Contents of Amendment 1 "Method 1" on page 6, line 9 of the letter of specification is replaced with "Method (J)"
1) is corrected as ". 2. Amend ``a, bJ'' on page 6, line 10 of the same page to ``Also, conventional example a, bJ''. 3. Amend ``to connect'' to ``connection'' on page 6, line 19 of the same page. 4 On page 8, line 8 of the same page, ``In Figure 7, j is corrected to ``In Figure 8''. 6 Correct it to ``This is a cross-sectional view. 6 On page 8, lines 17-19, "Figure 8 shows...rear plate" should be completely deleted. 7 "From the gap" on page 9, lines 10 to 11 is corrected to "from the gap δ." 8. Correct Figure 7 on a separate sheet.

Claims (1)

[Claims] A rotary type having a cylinder having a cylindrical wall, a rotor disposed within the cylinder, and a plurality of vanes retractably provided on the rotor to form a refrigerant compression chamber, and a shell surrounding the cylinder. In the compressor, an oil bleed hole having a diameter sufficient to allow lubricating oil to naturally flow out is provided in the lower part of the cylinder, and a flapper pulp that can be actuated by a pressure difference inside and outside the cylinder and can close the oil bleed hole. A rotary compressor characterized by: