JPS644077B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a centering method for a rotary compressor.

Generally, a rotary compressor includes a cylinder and a rolling piston that rotates eccentrically within the bore of the cylinder, and a pin portion of a crankshaft supported by front and rear head bearings is inserted into the piston to rotate the piston. By eccentrically rotating within the bore, refrigerant is sucked through a suction hole formed in the cylinder, and the sucked refrigerant is compressed,
It is intended to be discharged to the outside from the discharge hole of the cylinder.

By the way, in the compressor, centering processing is performed to form a minimum distance between the outer circumferential surface of the piston and the inner circumferential surface of the bore to allow eccentric rotation of the piston over the entire circumference during operation. It is desirable to do this, and by doing so, the volumetric efficiency of the compressor, that is, the compression efficiency, can be improved.
The centering process requires a special and expensive centering device, and also requires strict processing accuracy for the piston, bore, crankshaft, front and rear heads, etc., making it difficult to use in practice. be.

However, in order to increase the compression efficiency of a compressor, conventionally, as shown in Japanese Patent Publication No. 55-14278, for example, the center of the bore in the cylinder is displaced with respect to the center of the crankshaft, and Increasing the distance between the inner peripheral surface of the bore and the outer peripheral surface of the rolling piston,
The gap between the inner circumferential surface of the bore corresponding to the refrigerant compression side of the cylinder and the outer circumferential surface of the piston is made smaller than the suction side to suppress refrigerant from flowing out to the suction side during the compression process. It is known what has been done.

However, the compressor requires strict centering between the crankshaft and the cylinder, and as in the case described above, requires a special and expensive centering device.
Moreover, not only on the compression side of the cylinder bore, but also on the entire circumferential surface of the bore in the cylinder,
It cannot be said that an optimum distance is formed between the rolling piston and the rolling piston.

An object of the present invention is to form a resin coating on the inner circumferential surface of a cylinder bore, and to utilize this resin coating, it is possible to perform special processing on component parts such as a rolling piston and cylinder bore without requiring a special centering device. The point is that an optimum distance can be formed between the piston and the bore of the cylinder without requiring precision.

That is, the present invention forms a resin coating on the inner periphery of the bore of the cylinder, and after assembling the rotary compressor, the resin coating is applied by friction caused by sliding contact between the rolling piston and the coating during operation of the compressor. The basic idea is to create an optimal gap between the piston and the rolling piston by scraping off a part of the coating, and use this resin coating to create a gap between the piston and the inner peripheral surface of the cylinder bore. This made it possible to form an optimal distance between the two.

More specifically, in the compressor, fitting gaps are formed between the crankshaft and the front and rear head bearings, and between the crankshaft pin and the rolling piston. Focusing on the fact that there is an initial gap between the inner peripheral surface of the cylinder bore and the inner circumferential surface of the cylinder bore to allow the piston to rotate, using this gap, the inner peripheral surface of the cylinder bore is After forming a resin coating on the circumferential surface with a thickness commensurate with the distance between each other, and installing the piston in a manner biased toward the bore side of the cylinder, the piston is rotated in this state to coat the resin coating on the bore. By scraping, it was possible to form a minimum distance between the coating and the piston over the entire inner circumferential surface of the cylinder, allowing the piston to rotate smoothly.

That is, the present invention forms a resin coating on the inner circumferential surface of the bore of the cylinder, and also biases the crankshaft to the same side in the radial direction so as to contact the bearing and the piston to the pin portion. and the piston and pin portion are assembled into the bore such that the initial setting distance δ between the outer peripheral surface of the piston and the inner peripheral surface of the bore of the cylinder is the minimum distance that allows eccentric rotation of the piston. On the other hand, the film thickness h of the coating is defined as the axis between the crankshaft and the bearing.
distance δ _j and pin distance δ _r between the piston and the pin part,
and the initial setting 〓 interval δ, h2(δ _j
+ _δr )−δ, and by rotating the piston within the cylinder bore under the above conditions, the piston scraped off the resin coating of the bore and formed an optimal distance between the piston and the resin coating. It is something.

The centering method of the present invention will be explained below with reference to embodiments of the drawings.

FIG. 1 shows a rotary compressor to which the present invention is applied,
A motor M is arranged in the upper part of the inside of the sealed casing 1, and a compression element 2 is arranged in the lower part of the inside.

The compression element 2 includes a front head 5 and a rear head 6 provided at the upper and lower parts of a cylinder 4 having a bore 3 therein, a rolling piston 7 installed in the bore 3 of the cylinder 4, and an upper end connected to the motor M. A crankshaft 8 extending in the vertical direction connected to
It is inserted through each of the heads 5 and 6 and the cylinder 4 and supported by the bearings 5a and 6a of each of the heads 5 and 6, and the eccentric pin portion 8a of the crankshaft 8 is inserted into the piston 7 in the bore 3. When the crankshaft 8 is rotated by the motor M, the piston 7 is rotated eccentrically, and refrigerant is sucked into the bore 3 from the suction pipe 9 provided in the casing 1. is compressed in the bore 3 and discharged from the discharge pipe 10 of the casing 1.

Further, a blade 1 is provided in the cylinder 4 so as to be able to move forward and backward into the bore 3 and to be in constant contact with the piston 7.
1, and near this blade 11, a suction port 12 communicating with the suction pipe 9 is formed on one side, and a discharge port 13 communicating with the discharge pipe 10 through the inside of the casing 1 is formed on the other side. There is.

In this way, the piston 7 connects to the intake port 12 of the bore 3.
When the piston 7 is rotated to the side, that is, when the contact surface of the piston 7 to the inner peripheral surface of the bore is rotated to the suction port 12 side with the blade 11 as the center, the blade 11 and the contact surface are formed by the blade 11 and the contact surface. The refrigerant is sucked into the space from the suction port 12, and this sucked refrigerant is transferred to the cylinder bore 3 by the rotation of the piston 7.
The refrigerant is compressed at the outlet 13 side of the refrigerant, and when a predetermined pressure is reached, the refrigerant is discharged from the outlet 13. In this way, the rotation of the piston 7 repeats the suction process and the compression process of the refrigerant. .

Accordingly, the present invention forms an optimal distance between the inner circumferential surface of the bore 3 in the cylinder 4 and the outer circumferential surface of the rolling piston 7 in the following manner.

First, a soft, fluorocarbon-resistant resin coating 14 is coated on the inner circumferential surface of the cylinder 4 .

On the other hand, as shown in FIG. 2, bearings 5a, 6a of the crankshaft 8, front head 5, and rear head 6
There is a shaft distance δ _j between them, and a pin distance δ _r between the rolling piston 7 and the pin portion 8a of the crankshaft 8, but these distances correspond to the shaft diameter. These are the dimensions specified in advance by JIS standards.

To assemble the rolling piston 7 and the crankshaft 8, as shown in FIG. 3, move the crankshaft 8 in the direction of arrow A in FIG. Further, the rolling piston 7 is moved in the direction of arrow B in FIG. 2, and the rolling piston 7 is brought into contact with the pin portion 8a.

That is, the crankshaft 8 and the rolling piston 8a
are both biased upward in FIG. 2, in other words, to the same side in the radial direction. The piston 7 and the pin portion 8a are installed in the bore 3 so that the minimum interval δ, which rotates most efficiently when the piston 7 rotates eccentrically, is formed at the initial setting interval δ.

The thickness h of the resin coating 14 is such that after the piston 7 and the pin portion 8a are assembled into the cylinder 4, the crankshaft 8 is in the state shown in FIG. 4, opposite to FIG. 5a and 6a, and the piston 7 is in contact with the pin portion 8a of the crankshaft 8, respectively, with respect to the axis of the crankshaft 8, biased to the same side in the radial direction of the center side of the pin portion 8a. At times, the thickness is such that the outer circumferential surface of the piston 7 does not come into contact with the inner circumferential surface of the cylinder 4, or even if it does come into contact, no frictional force is generated there. That is, the film thickness h is set so as to satisfy the relational expression h2 (δ _j + δ _r ) − δ with respect to the axis distance δ _j , the pin distance δ _r , and the initial setting distance δ It is.

After forming the coating 14 as described above, the pin portion 8a of the crankshaft 8 and the piston 7 are placed in the state shown in FIG. In addition, the piston 7 is biased to the same side in the radial direction of the axis of the crankshaft 8 with respect to the center of the pin part 8a of the crankshaft 8. The piston 7 and the pin portion 8a of the crankshaft 8 are assembled into the bore 3 so that an initial setting distance δ that allows eccentric rotation of the piston 7 is formed between the outer peripheral surface and the inner peripheral surface of the bore 3. It is.

A gap gauge is used to form the initial setting distance δ between the piston 7 and the bore 3.

Thereafter, the rotary compressor is connected to a refrigerant circuit, and the piston 7 is rotated eccentrically in the bore 3 of the cylinder 4 via the crankshaft 8, and by this rotation, the coating 14 is scraped off by the piston 7. In this way, an optimum distance is formed between the bore 3 and the piston 7.

More specifically, when the contact portion Q of the piston 7 with the inner circumferential surface of the bore 3 of the cylinder 4 is between the discharge port 13 and the suction port 12 of the cylinder 4, as shown in FIG. Since the pressure inside the bore 3 is low, almost no force is generated inside the bore 3 to push the piston 7 further outward with respect to the center O of the cylinder 4. Therefore, the coating 14 is hardly scraped in this portion.

When the crankshaft 8 rotates and the contact portion Q is located between the suction port 12 and the discharge port 13 (for example, point S ₁ shown in FIG. 5),
A high-pressure compression side chamber and a low-pressure suction side chamber are formed within the bore 3. Due to this pressure difference, the piston 7 and the pin portion 8a that contacts the piston 7 are pushed from the compression side chamber to the suction side chamber. Therefore, the contact portion Q is connected to the coating 14.
The coating 3 is strongly pressed against it, generating a large frictional force, and the coating 3 is scraped off. The thickness to be removed varies depending on the position of the inner peripheral surface of the bore 3,
This is determined by the magnitude of the pressure difference between the compression side chamber and the low pressure chamber side at each position, and the direction in which the force due to the pressure difference pushes the piston 7 with respect to the contact portion Q. , these amounts are naturally determined as shown in FIG. 5 by the fitting of the piston 7 and the inner circumferential surface of the bore 3 due to the operation of the compressor. As a result, over the entire inner circumferential surface of the bore 3 of the cylinder 4, there is a minimum distance between the piston 7 and the inner circumferential surface of the bore 3 that allows the piston 7 to rotate eccentrically, that is, the optimum distance. A gap can be formed.

The thickness of the resin coating 14 scraped off by the rotation of the piston 7 is such that the contact portion Q advances radially outward from the state shown in FIG. 3 and reaches the state shown in FIG. 4. The value ( ₂ ( _{δ j} +δ _r )−δ) or less, so the piston 7 is not pressed directly against the inner circumferential surface of the cylinder 4. Therefore, it is possible to prevent the parts 7 and 4 from being worn out due to the sliding contact between the piston 7 and the cylinder 4.

As explained above, in the centering method of the present invention, it is possible to form a minimum distance between the outer circumferential surface of the piston and the inner circumferential surface of the bore that allows eccentric rotation of the piston, thereby improving the compression efficiency of the refrigerant by the piston. Furthermore, the formation of the gap does not require any special centering equipment, nor does it require special machining accuracy for the piston, cylinder bore, or other component parts. We were able to achieve our intended purpose.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a rotary compressor to which the present invention is applied, and FIGS. 2 to 5 are explanatory diagrams illustrating the centering method of the present invention. 3...Bore, 4...Cylinder, 5...Front head, 5a, 6a...Bearing, 6...Rear head, 7...Rolling piston, 8...Crankshaft, 8a...Pin part, 14...Resin Film, h...
Film thickness, δ _j ... between shafts, δ _r ... between pins, δ ... between initial settings.

Claims (1)

[Claims] 1 A cylinder comprising a cylinder and a rolling piston that rotates eccentrically within a bore of the cylinder, and a pin portion of a crankshaft supported by bearings of a front head and a rear head is inserted into the piston to rotate the piston eccentrically. In the rotary compressor, a resin coating is formed on the inner peripheral surface of the bore of the cylinder, and the crankshaft is brought into contact with the bearing, and the piston is brought into contact with the pin portion on the same side in the radial direction. The piston and pin portion are placed in the bore so that the piston and the pin portion are biased and the initial setting distance δ between the outer peripheral surface of the piston and the inner peripheral surface of the bore of the cylinder is the minimum distance that allows eccentric rotation of the piston. On the other hand _, the film thickness _h of the coating is determined by h2( A method for centering a rotary compressor, characterized in that δ _j + δ _r ) − δ.