JPH0737796B2 - Rotary compressor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotary compressor, and particularly to a rolling compressor suitable for reducing sliding loss at the tip of a vane while maintaining good lubrication of the vane. The present invention relates to a piston type rotary compressor.

[Conventional technology]

Conventional rotary compressors, especially rolling piston type rotary compressors used in cooling systems for home air conditioners, etc., are those in which a compression element part and a motor for driving the compression element part are integrated and housed in a sealed case. Generally used, the pressure in the closed case is high pressure (discharge pressure Pd) due to lubrication of each sliding portion.

Therefore, the pressure on the back surface of the vane that partitions the inside of the cylinder into the suction chamber and the compression chamber (the pressure on the outer peripheral portion of the cylinder) is also high because it is released inside the closed case, and the tip of the vane is the pressure difference between the inside and outside of this cylinder. Chattering of the vanes that comes into contact with the outer circumference of a roller that eccentrically rolls inside the cylinder by a rotating shaft, and the chattering of the vanes is the vibration of the vanes that occurs when the vanes are separated from the rollers and the sealing of the vane tip contact part is impaired. This is a phenomenon in which the vane pressing force does not work, and good compression cannot be continued.) The pressure is applied to the roller with a significantly larger vane pressing force than the optimum vane pressing force. Sliding loss due to friction was increased. Further, the excessive vane pressing force causes wear of the tip of the vane and the outer circumference of the roller, which is one of the causes of lowering the reliability of the rotary compressor.

As a rotary compressor that reduces the vane pressing force, a piston is connected to the back of the vane, and the piston is provided slidably in the auxiliary cylinder. There are known configurations for supplying the above pressure (Japanese Patent Laid-Open No. 58-88486 and Japanese Utility Model Laid-Open No. 58-77183).

Also, in Japanese Utility Model Publication No. 51-49607, a fine hole is provided in a cylinder at a position substantially facing the blade, and one side is a cylinder chamber,
The other side is connected to the intermediate pressure valve chamber provided in the cylinder through an intermediate pressure valve that opens and closes in response to pressure, the blade chamber and the intermediate pressure valve chamber are connected by a communication pipe, and the blade chamber is at the intermediate pressure. There is disclosed a rotary compressor adapted to achieve the following.

Further, Japanese Utility Model Laid-Open No. 50-150816 discloses a rotary compressor in which a vane spring chamber communicates with an oil reservoir through an oil passage through a throttle.

[Problems to be Solved by the Invention]

In the above configuration, although the pressure difference between the inside and outside of the cylinder is reduced and the vane pressing force can be kept small, there is a problem to be solved that lubrication of the vane is impaired as a result of the refrigerant in the refrigeration cycle being introduced to the back surface of the vane.

Further, the one disclosed in Japanese Utility Model Publication No. 51-49607 discloses that the intermediate pressure is maintained regardless of the rotation angle of the rotary shaft, the chattering is not sufficiently prevented near the top dead center, and the vane is refueled. It couldn't be done enough. In addition, the actual exploitation 50-15
In the one disclosed in Japanese Patent No. 0816, the discharge pressure acts and the loss is large regardless of the rotation angle of the rotary shaft.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rotary compressor capable of improving the above-mentioned problems of the prior art, reducing sliding loss at the tip of a vane, and maintaining good lubrication of the vane. It is a thing.

[Means for Solving the Problems]

In order to achieve the above object, the rotary compressor of the present invention has a cylinder having end plates provided at the upper and lower ends, a roller rolling in the cylinder, a rotary shaft having a crank fitted to the roller, and a tip. Is a circular arc and is in contact with the roller, reciprocates according to the rotation of the rotary shaft, and has a vane that partitions the inside of the cylinder into a suction chamber and a compression chamber, and a drive device that drives the rotary shaft. In a rotary compressor in which the pressure inside the closed case is maintained at a discharge pressure while the inside of the closed case is held, a vane back pressure surrounded by a cylinder and upper and lower end plates on the rear end side of the vane. A chamber is formed, and an oil passage is provided between the back pressure chamber of the vane and the oil reservoir of the closed case, and the oil passage is communicated with and cut off by the reciprocating motion of the vane. Near top dead center In the rotation period, it is characterized in that constitute the oil passage so as to communicate the vane back pressure chamber.

[Action]

Since it is configured as described above, it is possible to allow the lubricating oil to flow into the vane back pressure chamber through the oil passage between the vane back pressure chamber provided at the rear end of the vane and the oil reservoir of the closed case. ,
Moreover, since the vane can be provided with a check valve action so that the back pressure chamber of the vane and the oil sump are electrically connected only when the vane is near the top dead center, the vane is located near the top dead center. When the vane comes, the vane back pressure pushed back by the vane acts on the back surface of the vane, and when the vane moves away from the top dead center, the check valve closes to reduce the vane back pressure.

〔Example〕

Before going into the description of the embodiments, basic matters relating to the present invention will be described.

At the rear end of the vane, a closed vane back pressure chamber surrounded by a cylinder and upper and lower end plates was provided, and the lubricating oil in the oil reservoir was introduced into the vane back pressure chamber. .

By the way, the crimping force of the vane to the outer periphery of the roller, that is, the vane pressing force, is determined by the pressure in the vane back pressure chamber, that is, the vane back pressure, and the optimal vane back pressure is
Ideally, the vane is kept at a minimum value (hereinafter, referred to as a chattering limit back pressure Pc) that does not cause chattering. The chattering limit back pressure Pc is approximately an intermediate pressure (Ps + Pd) / 2 between the suction pressure Ps and the discharge pressure Pd.

Therefore, by providing a check valve action to the vane, and introducing the lubricating oil into the vane back pressure chamber only in the rotation section near the top dead center of the vane, the vane back pressure is maintained while maintaining good vane lubrication. The sliding loss is reduced by reducing the chattering limit back pressure Pc close to it.

The present invention has been made on the basis of the basic items described above, and will be described below with reference to examples.

FIG. 1 is a longitudinal sectional view of a main part of a rotary compressor according to an embodiment of the present invention, and FIG. 2 is a transverse sectional view of the rotary compressor according to FIG. (I-0-I sectional view), FIG. 3 is a detailed sectional view showing the state of the vane back pressure chamber at various rotation angles θ, and FIG. 4 shows the vane back pressure accompanying the opening / closing operation of the oil injection port. It is a vane back pressure diagram.

1 and 2, 1 is a cylinder of a rotary compressor,
2 is a roller that eccentrically rolls in the cylinder 1;
A crank for rotating the roller 2, the crank 3 being integral with the rotating shaft 4 and driven by a motor 5 associated with a driving device. 6 is a suction chamber 7 inside the cylinder 1.
And a compression chamber 8 that separates the compression chamber 8 from each other, and its arcuate tip is in contact with the roller 2. At the upper and lower ends of the cylinder 1, upper end plates 1 related to end plates that also serve as bearings for the rotating shaft 4
0, a lower end plate 11, a cylinder 1, an upper end plate 10, a lower end plate 11,
The suction chamber 7 and the compression chamber 8 are formed by the roller 2 and the vane 6.
And are formed.

Reference numeral 12 denotes a vane back pressure chamber formed at the rear end of the vane 6 and surrounded by the cylinder 1, the upper end plate 10 and the lower end plate 11 and hermetically sealed. The volume of the vane back pressure chamber 12 is equal to that of the vane. 6 is the smallest when it reaches the top dead center (the vane 6 is the most right side in FIG. 1), and the largest when it is the bottom dead center (the vane 6 is the most left side in FIG. 1). Reference numeral 9 denotes a spring which is arranged in the vane back pressure chamber 12 and biases the contact between the vane 6 and the roller 2. A vane lower end 13 is formed in a part of the surface of the vane 6 that slides with the lower end plate 11, and a lower end plate groove 14 is formed in a part of the surface of the lower end plate 11 that slides with the vane 6. There is. An oil injection port 15a is provided on one end side of the lower end plate 11, and an oil injection pipe 15 whose lower end is open to an oil reservoir 16a of the closed case 16 is attached. The oil injection pipe 15 has a bottom end that collects oil 16 even if the oil level drops to some extent.
As shown in a, it is extended to near the bottom of the closed case 16. Lower end of vane 13, lower end plate groove 14, oil injection pipe 15 described above.
The oil flow path is configured by the above, and only the rotation section near the top dead center of the vane 6 communicates with the vane back pressure chamber 12, and only in this rotation section, the high-pressure lubricating oil 17 in the oil reservoir 16a is in the vane back pressure chamber. 1
It is supposed to be introduced within 2. Therefore, the vane 6 presses the vane back pressure by the lubricating oil 17 introduced into the vane back pressure chamber 12 (the pressure in the vane back pressure chamber 12 is called the vane back pressure) and the pressing force of the spring 9. It is pressed against the roller 2 by force, and reciprocates in the vane groove 1a formed in the cylinder 1 as the rotary shaft 4 rotates.

The compression operation of the rotary compressor 18 configured as described above is performed as follows. When the rotating shaft 4 is driven by the motor 5, the roller 2 freely fitted around the crank 3 rotates in the cylinder 1, and the volumes of the suction chamber 7 and the compression chamber 8 partitioned by the vane 6 change. . When the crank 3 rotates in the direction of the arrow (FIG. 2), the volume of the suction chamber 7 increases and sucks the refrigerant gas from the suction port 19, while the volume of the compression chamber 8 decreases and the refrigerant gas is compressed. The compressed refrigerant gas is discharged from the discharge port 20 through the discharge valve 20a into the closed case 16 to perform a compression action.

Here, the operation of the vane back pressure chamber 12 will be described with reference to FIG. FIG. 3 (a) shows the volume of the vane back pressure chamber 12 when the rotation angle θ = 0 (see FIG. 2), that is, at the top dead center position where the vane 6 projects most into the vane back pressure chamber 12. Is the smallest. At this time, the oil injection port 15a communicates with the lower vane groove 13 formed in the vane 6 and the lower end plate groove 14 formed in the lower end plate 11, and opens into the vane back pressure chamber 12. Therefore, the high-pressure lubricating oil 17 stored in the oil reservoir 16a of the closed case 16 through the oil injection pipe 15 is, as shown by the arrow,
It is introduced into the vane back pressure chamber 12. The rotation angle θ advances,
As shown in FIGS. (B), (c) and (d), when the vane 6 moves away from the top dead center position, the vane 6 acts as a check valve to close the hydraulic inlet port 15a, and the high pressure lubricating oil 17 Is prevented from flowing. At this time, the back pressure of the vane is 12
Since the volume of the volume increases from the top dead center position, it expands and decreases.

This will be described with reference to FIG. 4 in association with the magnitude of the vane back pressure. In FIG. 4, the horizontal axis represents the rotation angle θ, and the oil injection port 15a has a small rotation angle Δθ near the top dead center of the rotation angle θ = 0,2π and only the section of the vane back pressure chamber. It opens with 12, and closes at other angles. The vane back pressure becomes almost the discharge pressure Pd at the top dead center position of θ = 0 where the oil injection port 15a is opened, and as the rotation angle advances, as described above, the vane back pressure chamber 12 and the volume expand to expand. , Θ = π, the vane back pressure becomes the lowest and becomes the intermediate pressure Pm. Thereafter, as the rotation angle advances, the volume of the vane back pressure chamber 12 decreases again, so that the vane back pressure increases, and the discharge pressure Pd is reached again at the top dead center position θ = 2π.
Here, the intermediate pressure Pm is always larger than the chattering limit back pressure Pc, and the magnitude of this intermediate pressure Pm depends on the lubricating oil.
It can be arbitrarily changed by changing the value of the introduction section Δθ of 17 and the flow resistance of the oil passage.

On the other hand, the lubrication of the sliding portion of the vane 6 is maintained very well because the lubricating oil 17 is always supplied into the vane back pressure chamber 12 at the position near the top dead center.

According to the embodiment described above, the closed vane back pressure chamber 12 surrounded by the cylinder 1, the upper end plate 10 and the lower end plate 11 is formed at the rear end of the vane 6, and the inside of the vane back pressure chamber 12 is introduced. By configuring the high-pressure lubricating oil 17 to be injected only in the vicinity of the top dead center of the vane 6, it is possible to reduce the vane back pressure while maintaining good lubrication of the vane 6, and reduce the vane pressing force. Thus, the sliding loss at the tip of the vane can be reduced, and the rotary compressor having high compressor efficiency can be provided.

Next, another embodiment will be described.

FIG. 5 is a longitudinal sectional view of a main part of a rotary compressor according to another embodiment of the present invention, and FIG. 6 is a perspective view showing a vane in FIG.

In the figure, those given the same numbers as in FIG. 1 are the same parts and have the same operation.

The rotary compressor 18A according to the present embodiment is configured such that a vane oil supply hole 13A formed inside the base 6A and an oil injection port 15a perform a check valve action (the lower end plate 11A has a lower end plate groove). (Not provided), and other configurations are the same as those of the rotary compressor according to FIG.

The operation of the rotary compressor 18A configured in this way is similar to that of the above-described embodiment, and the oil injection port 15a and the vane oil supply hole 13A communicate with each other only near the top dead center position of the vane 6A, and the oil injection pipe 15 Through the sealed case 16 oil reservoir 16a lubricating oil 1
7 is introduced into the vane back pressure chamber 12.

In this embodiment, the lower end plate 11A is not provided with the lower end plate groove, and the vane oil supply hole 13A may be formed only inside the vane 6A. Therefore, the structure is simpler than that of the rotary compressor according to FIG.

FIG. 7 is a perspective view showing a modified example of the vane in FIG. This vane 6B has a vane side oil supply groove 13B on the side surface.
And has the advantage of being easier to process than the vane 6A having the vane oil supply hole 13A formed therein.

〔The invention's effect〕

As described in detail above, according to the present invention, when the vane moves away from the top dead center, the vane back pressure can be reduced by the check valve action of the vane, so that the sliding loss at the tip of the vane can be reduced and the vane can be reduced. It is possible to provide a rotary compressor that can prevent the chattering of the vane and can well maintain the lubrication of the vane.

[Brief description of drawings]

FIG. 1 is a longitudinal cross-sectional view of a main part of a rotary compressor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the rotary compressor according to FIG. 1, and FIG. FIG. 4 is a detailed sectional view showing the state of the vane back pressure chamber at θ, FIG. 4 is a vane back pressure diagram showing the vane back pressure accompanying the opening / closing operation of the oil injection port, and FIG. 5 is another embodiment of the present invention. 6 is a perspective view showing a vane in FIG. 5, and FIG. 7 is a perspective view showing a modified example of the vane in FIG. 1 ... Cylinder, 2 ... Roller 3 ... Crank, 4 ... Rotating shaft 5 ... Motor, 6,6A, 6B ... Vane 7 ... Suction chamber, 8 ... Compression chamber 10 ... Upper end plate, 11 , 11A ...... Lower end plate 12 ...... Vane back pressure chamber, 13 ...... Vane lower groove 13A ...... Vane oil supply hole, 13B ...... Vane side oil supply groove 14 ...... Lower end plate groove, 15 ...... Oil injection pipe 15a ...... Oil Injection port, 16 …… Hermetically sealed case 16a …… Oil sump 18,18A …… Rotary compressor Pd …… Discharge pressure

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Bibliography Sho 50-150816 (JP, U) Rikai 52-112512 (JP, U) Kikou 51-49607 (JP, Y1)

Claims (1)

[Claims] 1. A cylinder having upper and lower end plates provided with end plates, a roller rolling in the cylinder, a rotary shaft having a crank fitted to the roller, and a tip having an arcuate shape and abutting against the roller. , Reciprocating according to the rotation of the rotating shaft,
A rotary compressor having a vane that partitions the inside of the cylinder into a suction chamber and a compression chamber and a drive device that drives the rotary shaft are housed in a sealed case, and the pressure in the sealed case is maintained at a discharge pressure. In the rotary compressor described above, a vane back pressure chamber surrounded by the cylinder and the upper and lower end plates is formed on the rear end side of the vane, and an oil flow is provided between the vane back pressure chamber and the oil sump of the closed case. A passage is provided so that the oil flow passage communicates with and is blocked by the reciprocating motion of the vane, and the oil flow passage communicates with the vane back pressure chamber in a rotation section near the top dead center of the vane. A rotary compressor characterized in that