JPH0447434Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention relates to the improvement of a piston device for a compressor, and in particular, the invention relates to the improvement of a piston device for a compressor. This invention relates to a joint type piston device.

(b) Prior art In general, this type of ball joint type piston device is described in Japanese Patent Publication No. 51-21165, etc.
As shown in FIG. 4, a connecting rod 22 having a sphere 20 at one end and a cylindrical body 21 at the other end, and a piston 24 connected to the sphere 20 by caulking and fixing the sphere 20 to a spherical bearing 23. and a crank pin 26 of the crankshaft 25 into which the cylindrical body 21 is inserted. Further, the connecting rod 22 and the cylindrical body 21 are connected at the center in the axial direction of the cylindrical body 21 so that the axis of the cylindrical body 21 and the axis of the connecting rod 22 are perpendicular. The piston device with such a configuration includes a piston 24 and a connecting rod 2.
By making the connecting part with 2 a sphere 20, a large degree of freedom of the piston is ensured, and the piston 24
This reduces uneven contact in the cylinder 27 during reciprocation, improves the durability of the piston 24, and reduces the number of parts compared to the Scotch yoke type.

(c) Problems to be solved by the invention However, according to the above configuration, the piston 24
Since the connecting rod 22 and the connecting rod 22 are connected by the sphere 20, the connecting rod 22 has a wide range of freedom in the vertical and horizontal directions. , and the force F acting downward due to the own weight of the connecting rod 22, etc., the cylindrical body 21 tends to shift downward with the eccentric rotation of the crank pin 26 and tilt as shown in FIG. α) Uneven wear occurs at the upper and lower ends of the inner peripheral surface of the cylindrical body 21, and the cylindrical body 21
contacts the crank pin 26 unevenly,
There was a problem in that the piston 24 could not reciprocate smoothly, causing locking and the like.

This proposal was developed in consideration of these points, and aims to reduce the downward displacement of the cylinder inserted into the crankpin, and prevent uneven wear on the inner peripheral surface of the cylinder and uneven contact between the cylinder and the crankpin. It is an object of the present invention to provide a ball joint type piston device that can prevent the above problems and perform stable motion.

(d) Means for solving the problem The present proposal concerns a piston device in which a piston and a crank pin of a crankshaft are connected by a connecting rod having a sphere at one end and a cylindrical body at the other end. , the connecting rod and the cylindrical body are connected at an inclined position such that the angle between the axis of the connecting rod and the axis of the cylindrical body is smaller than 90° at the upper portion of the cylindrical body on the piston side.

(E) Effect The piston device of the compressor of the present invention has the above-described configuration, and the cylindrical body is tilted in advance in a direction opposite to the direction in which the force due to the weight of the connecting rod acts on the fitting surface between the cylindrical body and the crank pin. During the reciprocating movement of the piston, the inclination of the cylindrical body relative to the crank pin is suppressed to a minimum, and the force due to the weight of the connecting rod is not biased toward the fitting surface between the cylindrical body and the crank pin, and the inner periphery of the cylindrical body is This reduces uneven wear that occurs at the upper and lower ends of the surface and uneven contact between the cylindrical body and the crank pin, allowing the piston to reciprocate smoothly.

(f) Examples Examples of the present invention will be described below based on the drawings.
Reference numeral 1 denotes a hermetic compressor in which a compressor part 3 is housed in the upper part of a closed container 2, and an electric motor part 4 is housed in the lower part, and both parts 3 and 4 are connected by a crankshaft 5. . 6 is a piston device constituting the compressor section 3. This device consists of a connecting rod 9 having a sphere 7 at one end and a cylindrical body 8 at the other end.
and a piston 11 connected to the sphere 7 by caulking and fixing the sphere 7 to the spherical bearing part 10.
and a cylinder 12 that slides this piston back and forth.
and a crank pin 5a of the crankshaft 5 into which the cylindrical body 8 is inserted. here,
As shown in FIG. 3, the connecting rod 9 and the cylindrical body 8 are such that the angle β between the axis l of the connecting rod 9 and the axis m of the cylindrical body 8 is 90° at the upper part of the cylindrical body 8 on the piston 11 side. They are connected at an angle to make them smaller. When the cylindrical body 8 is inserted into the crank pin 5a, the connecting rod 9 is set so as to be lowered by an angle γ on the side of the cylindrical body 8, as shown in FIG.

In the hermetic compressor configured in this way,
As mentioned above, the connecting rod 9 and the cylindrical body 8 have an angle β between the axis l of the connecting rod 9 and the axis m of the cylindrical body 8.
is connected in advance at an angle smaller than 90 degrees at the upper part of the piston 11 side, so that the force F due to the weight of the connecting rod 9 is applied to the cylinder at the insertion part of the cylinder 8 into the crank pin 5a. It is possible to reduce biased action at the upper and lower ends of the fitting surface between the body 8 and the crank pin 5a, and increase the contact area between the cylindrical body 8 and the crank pin 5a during reciprocating movement of the piston 11. Uneven wear occurring at the upper and lower ends of the inner circumferential surface of the cylinder 8 and the cylinder body 8 and the crank pin 5a
This reduces the uneven contact of the piston 11 and allows the piston 11 to reciprocate smoothly.

(g) Effects of the invention As described above, the present invention provides a piston device in which a piston and a crank pin of a crankshaft are connected by a connecting rod having a spherical body at one end and a cylindrical body at the other end. The connecting rod and the cylindrical body,
Since the connection is made at an angle between the axis of the connecting rod and the axis of the cylindrical body at an angle of less than 90° at the top of the cylindrical body on the piston side, the force due to the weight of the connecting rod is applied to the cylindrical body. This reduces the inclination of the cylindrical body during reciprocating movement of the piston, increases the contact area between the cylindrical body and the crank pin, and increases the This prevents uneven wear that occurs at the upper and lower ends of the inner circumferential surface and uneven contact between the cylindrical body and the crank pin, allowing the piston to reciprocate smoothly.

[Brief explanation of the drawing]

Figures 1 to 3 show examples of the present invention;
The figure is a longitudinal sectional view of a hermetic compressor, FIG. 2 is a longitudinal sectional view of a piston device, FIG. 3 is a sectional view of main parts of the piston device, and FIG. 4 is a longitudinal sectional view of a piston device showing a conventional example. . 1... Hermetic compressor, 5... Crankshaft, 5a
...Crank pin, 6...Piston device, 7...
Sphere, 8...cylindrical body, 9...connecting rod, 11...piston.

Claims (1)

[Scope of utility model registration request] In a piston device in which a piston and a crank pin of a crankshaft are connected by a connecting rod having a spherical body at one end and a cylindrical body at the other end, the connecting rod and the cylindrical body are connected to the axis of the connecting rod. A piston device for a compressor, characterized in that the cylindrical body is connected at an inclined position such that the angle formed by the axis of the cylindrical body and the axis of the cylindrical body is smaller than 90° at the upper part of the piston side of the cylindrical body.