JPH03260381A - Piston device of compressor - Google Patents

Abstract

PURPOSE:To improve the characteristic of supplying oil by forming a spherical seat of a piston in polygonal shape so that its contact part with a spherical body makes point contact, in a piston device in which front surfaces of the spherical body is adapted to the spherical seat, provided in internal surfaces of the piston, by providing the spherical body in one end of a connecting rod. CONSTITUTION:A piston device, which constitutes a compressor part of a closed type compressor, is provided with a piston 9 having a seat surface 7 in the internal surface and a cylindrical calking part 8 in the rear end part, spherical body 10 adapted with its front surface to the seat surface 7 of the piston 9 and fixed with the rear surface by calking the calking part 8, synthetic resin- made elastic unit 11 interposed between this spherical body 10 and the calking part 8 and a connecting rod 13 connecting its one end to the spherical body 10 and having a cylindrical unit 12 in the other end, and the piston 9 is reciprocated by rotating a crankshaft 14. Here the seat surface 7 of the piston 9 is formed by continuously combining four curved surface units A of similar shape having a radius of curvature R2 larger than a radius of curvature R1 of the spherical body 10, and a contact part therewith makes point contact (a) in four points.

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 invention relates to a so-called ball joint type compressor piston device that is in contact with each other.

(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 sphere is connected to the piston by caulking the rear surface with a caulking part provided on the piston, and is configured so that oil is splashed 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 in a cross shape from the seating surface of the piston must be formed in the piston seating surface. The mold manufacturing becomes complicated, and the protrusions corresponding 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.

(d) 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 spherical seat provided on the inner surface of the piston. In a piston device in which the rear surface of the sphere is connected to the piston by a caulking part provided on the piston during manufacture, and in which oil is scattered from an oil spout formed at the upper end of the crankshaft, The spherical seat of the piston is formed into a polyhedral shape so that the contact portion with the spherical body makes point contact.

(E) Function The piston device of the compressor of the present invention has a polyhedral shape such that the seat surface makes point contact with the spherical body due to the groove bottom, so there is point contact between the seat surface and the spherical body. Therefore, all parts other than this contact portion can be used as oil passages, and the oil supply characteristics to the abutment surface between the seat and the ball seat can be improved over the entire area from the opening edge of the ball seat to the bottom. Furthermore, since the seat surface is a collection of relatively large surfaces and does not have fine oil grooves formed therein, the corresponding mold has a simple shape and is easy to manufacture, as well as having a long life. Furthermore, since there is point 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. The generation is suppressed, and the noise during operation of the compressor can be reduced.

(f) Example Embodiments of the present invention will be described below with reference to 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 the two parts 3 and 4 are connected by a crankshaft 14. It is a compressor. Reference numeral 6 denotes a piston device for controlling the compressor section 3, and this device includes a piston 9 having a seat surface 7 on the inner surface and a cylindrical caulking section 8 at the rear end, and a piston 9 on the front surface.
a sphere 10 which is in contact with the seat surface 7 of the seat 7 and whose rear surface is fixed by caulking of the caulking part 8; an elastic body 11 made of synthetic FR resin interposed between this sphere and the caulking part 8; and the sphere 10. a connecting rod 1 having a cylindrical body 12 connected to one end and a cylindrical body 12 at the other end.
3, and the cylindrical body 12 of this connecting rod is connected to the crankshaft 14.
By fitting into the crank pin 15 of the piston 9, the piston 9 is caused to reciprocate and slide within the cylinder 16. Reference numeral 17 denotes a plurality of holes drilled at intervals on the circumferential surface of the caulking part 8, and these holes are provided in advance before the caulking part 8 is caulked, and after the caulking part 8 is caulking, the holes are made in advance. The opening is elastic body 1
1 and the sphere 10. A plurality of holes 18 are provided at intervals on the circumferential surface of the skirt portion I9 of the piston 9, and these holes are formed at positions facing each of the holes 17 of the caulking portion 8. In addition, the crankshaft 14 has an oil hole 2 in the crankbin 15.
An oil ejection hole 21 communicating with 0 is formed.

The seat surface 7 of the piston 9 is formed by continuously combining four curved surfaces A having the same shape and having a radius of curvature R2 larger than the radius of curvature R3 of the sphere 10. The contact portions are point contacts at four points a.

A relatively large gap 22 is formed between the seat surface T outside the contact point Any and the sphere 10, extending from the hole 17 of the caulked portion 8 to the bottom of the seat surface 7. Furthermore, since the seat surface 7 is formed by combining four curved surfaces A, the bottom portion of the seat surface 7, which is the collection point of the tips, has a ridge.

A recess 23 communicating with the gap 22 is formed.

In the compressor piston device thus hollowed out,
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 2I of the crank bin 15. , here, the caulking part 8 and the skirt part 19 of the piston 9 are provided with the plurality of holes 17 and 18 described above.
is provided, so that the lubricating oil that is jetted out from the oil jet hole 21 and scattered toward the piston is distributed between the seat surface 7 and the ball #-10.
The lubricating oil is supplied to the sliding surfaces of the elastic body 11 and the spherical body 10, and the lubricating oil that falls onto the outer peripheral surface of the piston 9 is supplied to the caulking portion 8 through the hole 18 of the piston. 17, thereby further increasing the amount of oil supplied to the sliding parts mentioned above.

The seat surface 7 of the piston 9 is formed by continuously combining four curved bodies A having the same shape and having a radius of curvature R2 larger than the radius of curvature R1 of the sphere 10.
0 is in point contact at four points a, and there is a gap between the seat surface 7 and the sphere 10 other than the above contact points from the hole 17 of the caulked portion 8 to the bottom of the seat surface 7. Since a relatively large gap 22 is formed throughout, this gap 22 can be used as an oil passage, and the seat surface 7 and the sphere 10 are in contact with each other over the entire area from the opening edge of the seat surface 7 to the bottom. It can improve the lubrication characteristics of the surface and ＼. In addition, since the seat surface 7 is a collection of relatively large curved surfaces A and does not have fine oil grooves formed therein, the corresponding mold has a simple shape, is easy to manufacture, and has a long life. .

Furthermore, since there is point contact between the seating surface 7 and the spherical body 10 at four points a, the sliding properties of the spherical body 10 are improved, contributing to input reduction, and the contact between the seating surface and the spherical body 10 is There is almost no contact, and the occurrence of backlash at the contact portion is suppressed, thereby reducing noise during operation of the compressor. Further, since a recess 23 is formed in the bottom of the seat surface 7 and communicates with the gap 22, the recess 23 serves as an oil pocket, thereby further improving the lubrication characteristics.

(G) Effects of the Invention As described above, according to the present invention, the seat surface has a polyhedral shape such that the contact with the sphere is a point contact, so the contact between the seat surface and the sphere is a point contact, and this contact The entire area other than the spherical seat can be used as an oil passage, and the oil supply characteristics to the contact surface of the spherical seat and the seating surface can be improved over the entire area from the opening edge of the spherical seat to the bottom. Furthermore, since the seat surface is a collection of relatively large surfaces and does not have fine oil grooves formed therein, the corresponding mold has a simple shape, is easy to manufacture, and has a long service life. Furthermore, since there is point 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. The generation is suppressed, and the noise during operation of the compressor can be reduced.

[Brief Description of the Drawings] Fig. 1 is a vertical sectional view of a hermetic compressor showing an embodiment of the present invention. f, Figure 2 is a sectional view of the piston device, Figure 3 is a sectional view of the piston and sphere before caulking, and Figure 4 is A-A in Figure 3.
A sectional view of the section, FIG. 5 is a perspective view of the seat surface. 6... Piston device, 7... Seat surface, 8... Caulking part, 9... Piston, 10... Sphere, A... Curved surface body.

Claims (1)

[Claims] (1) 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, while the rear surface of this spherical body is provided on the piston. In a piston device in which piston spheres are connected by caulking at a caulking part, and oil is scattered from an oil spout formed at the upper end of the crankshaft, the spherical seat of the piston is brought into contact with the sphere. A piston device for a compressor, characterized in that the piston device is formed in a polyhedral shape so that portions are in point contact.