JPH03275985A - Piston device of compressor - Google Patents

Abstract

PURPOSE:To enhance both the lubricating property of lubricating oil stored in an oil pocket and the oil feed property of a piston device for the oil pocket by forming the oil pocket in the bottom portion of a seat face corresponding to the front face of a spherical body, and forming an oil passage in the linear contact portion of the spherical portion with the seat face, which oil passage is communicated with the oil pocket. CONSTITUTION:An oil pocket 23 is formed in the bottom portion of a seat face 7 opposite to the front face of a spherical body 10 and an oil passage communicated with the oil pocket 23 is formed in the linear contact portion of the spherical body 10 with the seat face 7. The lubricating performance of a piston device is enhanced by enhancing both the lubricating property of lubricating oil stored in the oil pocket 23 and the oil feed property of the piston device for the oil pocket 23. Since the seat face 7 is in the form of a uniformly curved face and no fine oil channels are formed therein, a metal mold corresponding to the seat face 7 has a simple form and the piston device can easily be manufactured and also the life of the piston device is longer.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention provides a sphere at one end of a connecting rod that connects a crankshaft and a piston, and the front surface of this sphere is attached to a sphere seat provided on the inner surface of the piston. This article relates to the piston device of the so-called ball joint type compressor, which is in contact with the piston device.

(b) Conventional technology Conventionally, the piston device of this type of compressor was
As described in Japanese Patent No. 40064, a spherical body is provided at one end of the connecting rod that connects the crankshaft and the piston, and the front surface of this spherical body is brought into contact with a spherical seat provided on the inner surface of the piston. The piston and the sphere are connected by caulking the rear surface with a caulking part provided on the piston, and
The crankshaft is configured so that oil is sprayed onto the piston from an oil spout formed at the upper end of the crankshaft. The spherical seat of the piston is formed with an oil reservoir at its inner bottom and a cross-shaped oil groove communicating with the oil reservoir at its inner bottom during cold forging of the piston.

<C> Problems to be Solved by the Invention However, according to the above configuration, a narrow oil groove recessed from the seating surface in a cross shape must be formed in the seating surface of the piston. Mold production becomes complicated, and the protrusions that correspond to the oil grooves in the mold wear quickly, shortening the life of the mold.In addition, the oil grooves cross the seating surface in a cross shape. However, there was a problem in that the seat surface was easily deformed during forging, and the seat surface and the sphere came into uneven contact, causing noise during operation.

The present invention has been made in view of these points, and aims to improve the oil supply characteristics between the spherical seat and the spherical body of the piston, facilitate the production of molds during piston manufacture, and extend the life of the molds. It is an object of the present invention to provide a piston device for a compressor that achieves the following and further prevents uneven contact between the spherical seat and the spherical surface and has low noise.

(2) Means for Solving the Problems The present invention provides a spherical body at one end of the connecting rod that connects the crankshaft and the piston, and brings the front surface of the spherical body into contact with a seating surface provided on the inner surface of the piston. In the piston device, the piston and the sphere are connected by caulking the rear surface of the sphere with a caulking portion provided on the piston, and the oil is scattered from an oil spout formed at the upper end of the crankshaft. The curvature of the seat surface and the spherical body are changed to bring them into approximate linear contact, and a recess is formed in the spherical body at this contact area.

(f) Function The piston device of the compressor of the present invention has the above-mentioned configuration, and includes an oil pocket formed at the bottom of the seat surface corresponding to the front surface of the sphere, and an oil pocket formed at the line contact portion between the sphere and the seat surface. An oil passage communicating with the oil pocket can be formed, and by improving the lubricating oil stored in the oil pocket and the oil supply characteristics to the pocket, the lubricity of the device can be improved. Here, since the seat surface is in a --like curved state and no fine oil grooves are formed, the corresponding mold has a simple shape, is easy to manufacture, and has a long life. In addition, the recesses of the sphere can be formed only partially by cutting or the like at two locations, upper and lower, where the load is small, so they can be easily formed and the sliding characteristics will not be impaired. Furthermore, since there is approximately linear contact between the seat surface and the sphere, the sliding properties of the sphere are improved, contributing to input reduction, and uneven contact between the seat surface and the sphere is almost eliminated, reducing play in the contact area. This suppresses the generation of noise and reduces noise during operation of the compressor.

(f) Example Embodiments of the present invention will be described below based on the drawings.

1 is a sealed case 2 in which lubricating oil is stored at the bottom, a compressor part 3 is housed in the upper part, and an electric motor part 4 is housed in the lower part, and both parts 3 and 4 are connected by a crankshaft 14. It is a compressor. Reference numeral 6 denotes a piston device constituting the compressor section 3, and this device includes a piston 9 having a bottom surface 7 on its inner surface and a cylindrical caulking portion 8 at its rear end, and a piston 9 whose front surface is in contact with the seat surface 7 of the piston 9. A sphere 10 whose rear surface is fixed by caulking of the caulking part 8, an elastic body 11 made of synthetic resin interposed between this sphere and the caulking part 8, and the sphere 10 connected to one end and the other end. The piston 9 is provided with a connecting rod 13 having a cylindrical body 12, and the cylindrical body 12 of the connecting rod is fitted into a crank pin 15 of a crankshaft 14, thereby causing the piston 9 to reciprocate within the cylinder 16. 17 is caulking part 8
A plurality of holes are formed at intervals on the circumferential surface of the crimping part 8, and these holes are provided in advance before the crimping part 8 is crimped.
After the caulking portion 8 is caulked, the opening thereof is formed so as to extend over both the elastic body 11 and the sphere 10.

Reference numeral 18 denotes a plurality of holes provided at intervals on the circumferential surface of the skirt portion 19 of the screw 9, and these holes are connected to the caulking portion 8.
The holes 17 are formed at positions opposite to each other. Further, an oil jet hole 21 is formed in the crank bin 15 and communicates with the oil hole 20 of the crankshaft 14 .

The seat surface 7 of the piston 9 is formed into an egg shape, and the contact portion with the sphere 10 is in line contact with the center point A in FIG. Therefore, an oil pocket 23 is formed at the bottom of the seat surface 7. Further, cut portions 22 are formed in two places on the front side of the sphere, upper and lower, on the sphere 10 at the contact portion between the seat surface 7 and the sphere 10 described above. This cut portion 22 locally eliminates the above line contact and forms an oil passage from the hole 17 of the caulked portion 8 to the oil pocket 23 via the gap between the seat surface 7 and the sphere 10.

In the compressor piston device configured in this way,
The lubricating oil stored at the bottom of the sealed case 2 is pumped up through the oil hole 20 by the centrifugal pump action of the crankshaft 14, and then is scattered in the rotational direction from the oil spout hole 21 of the crank pin 15. , here, the caulking part 8 and the skirt part 19 of the piston 9 are provided with the plurality of holes 17.1 described above.
8, the lubricating oil that is ejected from the oil ejection hole 21 and scattered toward the piston is transferred to the seat surface 7 and the sphere 10.
The lubricating oil is supplied to the sliding surfaces of the elastic body 11 and the sphere 10, and the lubricating oil that falls onto the outer peripheral surface of the piston 9 is passed through the hole 18 of the piston to the hole of the caulked part 8. 17, thereby further increasing the amount of oil supplied to the sliding parts mentioned above.

Further, the seating surface 7 of the piston 9 is formed into a mold with a curvature different from that of the spherical body 10, and the contact portion with the spherical body 10 is at a point A.
There is a line contact which is a collection of , and an oil passage communicating between the hole 17 of the caulked part 8 and the oil pocket 23 is formed in the part other than the line contact, that is, the cut part 22 of the sphere 10. The oil supply characteristics of the sliding surface between the seat surface 7 and the sphere 10 can be improved.

Further, since the seat surface 7 is a molded mold and does not have particularly fine grooves or the like formed therein, the mold corresponding thereto has a simple shape, is easy to manufacture, and has a long life.

Furthermore, since there is approximately linear contact between the seat surface 7 and the sphere 10, the sliding properties of the sphere 10 are improved, contributing to input reduction, and uneven contact between the seat surface 7 and the sphere 10 is almost eliminated, resulting in less contact. The occurrence of backlash in the compressor is suppressed, and noise during operation of the compressor can be reduced.

In addition, since the cut portions 22 of the sphere 10 are partially formed by cutting at two locations on the top and bottom where the load is small,
Machining is easy and does not impair the sliding characteristics on the sliding surface.Incidentally, the actual cutting process is easier if the sphere 10 is welded to the connecting rod 13.

(G) Effects of the Invention As described above, according to the present invention, an oil pocket is formed at the bottom of the seat surface corresponding to the front surface of the sphere, and a groove communicating with the oil pocket is formed at the line contact portion between the sphere and the seat surface. An oil passage can be formed, and the lubricating oil stored in the oil pocket and the oil supply characteristics to the pocket can be improved, thereby improving the lubrication performance of the device. Here, since the seat surface is in a curved state and no fine oil grooves are formed, the corresponding mold has a simple shape, is easy to manufacture, and has a long life. In addition, the recesses of the sphere can be formed only partially by cutting or the like at two locations, upper and lower, where the load is small, so they can be easily formed and the sliding characteristics will not be impaired.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a hermetic compressor showing an embodiment of the present invention, Fig. 2 is a sectional view of the piston device, Fig. 3 is a sectional view of main parts of the piston and sphere before caulking, and Fig. 4 is A sectional view of the sphere and the connecting rod, and FIG. 5 is a front view of the sphere. 6... Piston device, 7... Seating surface, 8...
Caulking part, 9... Piston, 10... Sphere, 22... Cutting part, 23... Oil pocket.

Claims (1)

[Claims] (1) A sphere is provided at one end of the connecting rod that connects the crankshaft and the piston, and the front surface of this sphere is brought into contact with a seating surface provided on the inner surface of the piston, while the rear surface of this sphere is attached to the caulking surface provided on the piston. In a piston device in which a piston and a sphere are connected by caulking at a portion thereof, and oil is splashed from an oil spout formed at the upper end of the crankshaft, the curvature of the seat surface and the sphere are changed to connect both. A piston device for a compressor, characterized in that the piston device is brought into approximate line contact and a recess is formed in the spherical body at this contact portion.