JPH05157049A - Compressor - Google Patents

Abstract

PURPOSE:To prevent drop of compression efficiency by improving constitution of a piston part so as to prevent leakage of air. CONSTITUTION:There are provided a connecting rod 29 which makes a reciprocating motion by rotation of a motor, a piston 101 fixed at the head of the connecting rod 29 and a piston sleeve 39 arranged on the outer circumference of the piston 101. The outer diameter of this piston 101 is somewhat smaller than the inner diameter of the piston sleeve 39, and a side 107 of the piston 101 is formed in the spherical state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor, and more particularly,
The present invention relates to a piston and a structure in the vicinity thereof, which is improved so as to prevent a decrease in compression efficiency due to air leakage.

[0002]

2. Description of the Related Art A conventional compressor is, for example, as shown in FIGS.
It is configured as shown in. FIG. 4 is a plan view of the compressor, and FIG. 5 is a side view of the compressor shown by cutting out a part thereof. First, the pair of housings 3 with the electric motor 1 interposed therebetween,
3 are arranged. The electric motor 1 is composed of a stator 5 and a rotor 7 arranged on the inner peripheral side of the stator 5.

The housing 3 is fixed to the stator 5 by a plurality of fixing bolts (only one is shown in the figure) 9. A rotary shaft 11 is attached to both sides of the rotor 7 (only one side is shown in the figure), and a cooling fan 17 is fixed to the tip of the rotary shaft 11 via a fan band 13 and a fan lock 15. Has been done.
The cooling fan 17 cools the electric motor 1.

A boss 19 is projectingly provided in an annular shape from the housing 3 toward the rotary shaft 11, and an annular stepped portion 20 is formed on the boss 19. A ball bearing 21 is mounted between the rotary shaft 11 and the boss 19 with one end thereof in contact with the stepped portion 20.

The ball bearing 21 and the cooling fan 1
The outer circumference of the rotary shaft 11 between the
3 is fixed by a set screw 25. The ball bearing 2 is provided on the outer periphery of the eccentric 23.
The connecting rod 29 is fixed via the connector 7. A piston 31 is formed at the tip of the connecting rod 29, and a piston ring 33 is provided at the upper end edge of the piston 31 with a piston ring pressing plate 35.
And the screw 37. On the other hand, a piston sleeve 39 is attached to the upper end of the housing 3, and the piston 31 has the piston sleeve 39.
It is movably housed inside.

A valve plate 41 is attached to the upper end of the housing 3, and a cylinder chamber 43 is formed below the valve plate 41. A cap 45 is capped on the valve plate 41. The partition wall 47 of the cap 45 partitions the upper space of the valve plate 41 into two spaces, one of which is the intake space 4
9 and the other is the exhaust space 51. An intake hole 53 and an exhaust hole 55 are formed in the valve plate 41, the intake hole 53 is opened and closed by an exhaust valve 57, and the exhaust hole 55 is opened and closed by an exhaust valve 59. The configuration described above is, as already described, a pair of housings 3, 3
On the side, they are similarly provided.

An intake port 61 is formed in the cap 45 at the upper end of the housing 3 located on the left side in the figure.
Then, on the left side in the drawing, air flows into the intake space 49 via the intake port 61 and then flows into the cylinder chamber 43 via the intake valve 57. On the other hand, on the right side of the drawing, the air flowing in from the intake port 61 passes through the intake space 49 on the left side and the intake pipe 63, and the intake space 4 on the right side of the drawing.
9 is supplied into the cylinder chamber 43 through the intake valve 57.

Further, an exhaust port 65 is formed in the cap 45 of the housing 3 located on the right side in the figure. Compressed air is exhausted through this exhaust port 65 and the cap 45 located on the left side is exhausted. The compressed air in the space for use 51 enters the space for exhaust 51 of the cap 45 on the right side via the exhaust pipe 67, and is exhausted from there through the exhaust port 65. An O-ring 69 is interposed between the cap 45 and the valve plate 41, and an O-ring 71 is interposed between the valve plate 41 and the piston sleeve 39.

[0009]

The above conventional structure has the following problems. That is, the reciprocating motion of the piston 31 causes the piston ring 33 to reciprocate repeatedly while sliding along the inner peripheral surface of the piston sleeve 39. As a result, the piston ring 33 is worn out, and a gap is locally generated, which causes a problem that air leaks through the gap. If air leaks in this way, the compression efficiency will decrease.

The present invention has been made on the basis of such a point, and an object thereof is to improve the structure of the piston portion to prevent air leakage and prevent a decrease in compression efficiency. To provide a possible compressor.

[0011]

To achieve the above object, a compressor according to the present invention comprises a connecting rod which reciprocates by rotation of an electric motor, a piston fixed to the head of the connecting rod, and a piston of the piston. A piston sleeve disposed on the outer circumference, the outer diameter of the piston is slightly smaller than the inner diameter of the piston sleeve, and the side surface of the piston is formed into a spherical shape.

[0012]

Operation: The connecting rod reciprocates due to the rotation of the electric motor. The piston also reciprocates due to the reciprocating movement of the connecting rod, and at this time, the piston reciprocates while inclining and gradually changing its inclination direction. Then, any one of the spherical side surfaces is brought into contact with the piston sleeve, and reciprocates while constantly changing the contacted portion.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. Incidentally, the same parts as those of the conventional one are designated by the same reference numerals and the description thereof will be omitted. First, in the case of this embodiment, the piston 101 made of carbon is used. The piston 101 is fixed to the head 103 of the connecting rod 29 by a screw member 105 (shown in FIG. 3). The head 103 is made of an aluminum alloy like the other parts, and is integrally formed with the connecting rod 29.

The outer diameter of the piston 101 is slightly smaller than the inner diameter of the piston sleeve 39.
Further, the side surface 1 of the piston 101 on the piston sleeve 39 side
07 is formed in a spherical shape. That is, when the connecting rod 29 reciprocates due to the rotation of the eccentric 23, the piston 101 moves to the position shown in FIGS.
As shown in (1), it reciprocates while inclining and gradually changing its inclining direction. At this time, the piston sleeve 39 is abutted through any one of the spherical side surfaces 107, and the abutted one is constantly changed. The piston sleeve 39 is made of an aluminum alloy, the inner peripheral surface of which is anodized, and the surface of which is mirror-finished by polishing.

The operation will be described based on the above configuration. Since the basic operation of the compressor is the same as the conventional one, it is omitted. Although a slight gap is formed between the piston 101 and the piston sleeve 39, this does not cause air leakage, which interferes with the basic operation of the compressor. There is nothing that can happen.
When the connecting rod 29 reciprocates due to the rotation of the eccentric 23, the piston 10
1 is inclined as shown in FIGS. 1 and 2, and
It reciprocates while gradually changing its inclination direction. Specifically, in the case of the compression process, the state shown in FIG. 1 is obtained, and in the case of the suction process, the state shown in FIG. 2 is obtained. At that time, as described above, the piston 101 reciprocates while inclining and gradually changing its inclining direction, and any one of the side surfaces 107 having an arc shape is brought into contact with the piston sleeve 39 side. Let And the one place that abuts is always changing,
Further, the clearance at that time is substantially constant.

According to this embodiment, the following effects can be obtained. First, since the contact portion of the spherical side surface 107 of the piston 101 with respect to the piston sleeve 39 is constantly changing, a specific portion is not always contacted and worn, and therefore, in the conventional case. It is possible to eliminate a situation where the piston ring 33 (shown in FIG. 5) is used, which is worn out. Therefore, leakage of air can be prevented and the compression efficiency can be improved. Further, for the same reason, the sliding resistance does not increase, so that the power consumption can be reduced and the durability can be improved.

The present invention is not limited to the above-mentioned one embodiment. For example, as the material of the piston 101,
Other than carbon, a Teflon compound, polyacetal, or the like may be used. As means for fixing the piston 101 to the head 103 of the connecting rod 29, various means other than the screw member 105 can be considered.

[0018]

As described in detail above, according to the compressor of the present invention, a piston having a spherical side surface is used instead of the conventional piston ring, and one portion of the side surface is used as a piston sleeve. Since it is configured to reciprocate while abutting and constantly changing one place, it is possible to prevent local wear and thereby prevent air leakage and reduction in compression efficiency. You can

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention and is a diagram showing a part of a compressor.

FIG. 2 is a diagram showing an embodiment of the present invention and is a diagram showing a part of a compressor.

FIG. 3 is a diagram showing an embodiment of the present invention and is a diagram showing a piston portion of a compressor.

FIG. 4 is a plan view of a compressor showing a conventional example.

FIG. 5 is a side view showing a conventional example with a part of the compressor cut away.

[Explanation of symbols]

 1 Electric motor 29 Connecting rod 39 Piston sleeve 101 Piston

Claims (1)

[Claims] 1. An outer diameter of the piston, comprising: a connecting rod reciprocating by rotation of an electric motor; a piston fixed to a head of the connecting rod; and a piston sleeve arranged on an outer circumference of the piston. Is slightly smaller than the inner diameter of the piston sleeve, and the side surface of the piston is formed into a spherical shape.