JPS59173578A - Sealed type compressor - Google Patents

Abstract

PURPOSE:To reduce the dimension of a sealed-type compressor by using a full eccentric type crank shaft and projecting the edge part, on the sliding contact surface side, of a crank shaft part of a main bearing, to the cylinder side from the cylinder installation surface of a supporting frame. CONSTITUTION:A full eccentric-type crank shaft 33 having the shaft center O' at the eccentric position departed by a prescribed distance epsilon from the position of the shaft core of a rotary shaft 31 for advancing and retreating a piston 27 is installed onto the rotary shaft 31. Therefore, the length of the rotary shaft 31 can be reduced. The edge part on the sliding contact surface side making contact with the crank shaft part 33 of a main bearing 32 installed onto a supporting frame 22 is projected to the cylinder 26 side from the cylinder installation surface of the supporting frame 22. Therefore, the contact pressure acting between the rotary shaft 31 and the main bearing 32 can be reduced, and the outer diameter of the rotary shaft 31 can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a hermetic compressor equipped with a compression mechanism consisting of a cylinder and a piston.

[Technical background of the invention and its problems]

FIG. 1 shows the compression mechanism of a conventionally known hermetic compressor, where 1 is a cylinder and 2 is a piston.

This cylinder 1 is mounted on a support frame 3. This support frame 3 is provided with a main bearing 4.
A rotary shaft 5 is rotatably mounted on the main bearing 4.

A crank portion 7 is provided on the rotating shaft 5 via a connecting portion 6. The axis A' of this crank part 7 is the rotating shaft 5
It is arranged at an eccentric position spaced apart from the axis A by a predetermined distance ε. Further, one end of a piston rod 8 is connected to the crank portion 7, so that the piston 2 is driven forward and backward as the rotating shaft 50 rotates.

By the way, in the above configuration, when the compression mechanism is operated, a reaction force F is applied to the piston 2 from the compressed gas side, so the position of the sliding surface 9 between the main bearing 4 and the connecting portion 6 of the rotating shaft 5 is The distance between and the position of the center line 10 of the cylinder 1 is a
In this case, a moment M called FXa acts on the sliding surface 9 between the main bearing 4 and the connecting portion 6 of the rotating shaft 50 from the connecting portion 6 side. In this case, the moment acting on the sliding surface 9 depends on the distance a between the sliding surface 9 between the main bearing 4 and the connecting portion 6 of the rotating shaft 5 and the center line 1θ of the cylinder 1)
When the magnitude of M is different, as the distance a increases, the value of the moment M acting on the sliding surface 9 increases. However, in the conventional structure described above, since the cylinder 1 and the support frame 3 are formed of separate members, the distance a between the sliding surface 9 and the center line 10 of the cylinder 1 is relatively large. There was a problem. Therefore, when the compression mechanism is operated, the value of the moment M acting on the sliding surface 9 is not large, and the pressure contact force between the rotating shaft 5 and the main bearing 4 is large, so that when the rotating shaft 5 is driven, e.g. There is a problem in that the resistance force acting on the drive source such as an electric motor becomes large. Furthermore, if the rigidity of the rotating shaft 5 is low, there is a risk that the rotating shaft 5 may break, so it is rarely necessary to increase the rigidity of the rotating shaft 5. Therefore, there is a problem that the rotating shaft 5 has a large diameter, and it is difficult to reduce the overall size.

In addition, as shown in FIGS. 2 and 3, the support frame 3
, a structure in which the cylinder 1 and the main bearing 4 are integrally molded is also often used.

However, in this case, in order to maintain orthogonality between the center line 10 of the cylinder 1 and the center line 1 of the main bearing 4, the main bearing 4 and the connecting portion 6 are
Since it was necessary to provide an appropriate distance between the position of the sliding surface 9 on the inner peripheral surface of the cylinder 1 and the end position 12 on the support frame 3 side, in this case as well, the main bearing 4
It is not possible to make the distance a between the sliding surface 9 of the connecting portion 6 of the rotating shaft 50 and the center line lO of the cylinder 1 smaller than the radius dimension of the cylinder 1, and the sliding contact occurs during the operation of the compression mechanism. The problem that the value of the moment (M) acting on the surface 9 could not be made sufficiently small occurred. Note that the sliding surface 9 and the cylinder 1
If the distance a between the center ff1J10 and the center ff1J10 is made smaller than the radius dimension of the cylinder l, finishing machining becomes slow9 and manufacturability tends to deteriorate.

Furthermore, FIG. 4 shows a Scotchoke-shaped compression mechanism, and 13 is a cylindrical crosshead fixed to the piston 2. This crosshead 13 is provided with elongated holes 14 and 15 extending in the axial direction at the top and bottom, respectively.

Furthermore, a cylindrical slider 16 is provided inside the crosshead 13 so as to be movable back and forth along the inner peripheral surface of the crosshead 13. An insertion hole 17 for the crank portion 7 of the rotating shaft 5 is formed in the slider 16 . The crank part 7 is rotatably inserted into this insertion hole 17, and the crank part 7 is inserted into the insertion hole 17.
As the rotating shaft 50 rotates, the slider 16 moves forward and backward within the crosshead 13, and at the same time, the piston 2 is driven forward and backward within the cylinder 1.

However, with this configuration, it was not possible to make the outer diameter C of the crosshead 13 extremely small in order to allow the piston 2 to move forward and backward smoothly. There was a problem in that the distance a between the sliding surface 9 of the shaft 5 and the connecting portion 6 and the center line 1θ of the cylinder I could not be made sufficiently small.

[Purpose of the invention]

This invention can reduce the overall height dimension, reduce the pressure contact force that acts between the rotating shaft and the main bearing during operation of the compression mechanism, and is airtight, allowing the diameter of the rotating shaft to be reduced. The purpose of this invention is to provide a compact compressor.

[Summary of the invention]

The rotary shaft that drives the piston back and forth is provided with a fully eccentric crankshaft at an eccentric position spaced a predetermined distance from the rotary shaft's fine position, and the crankshaft is connected to the crankshaft in the main bearing provided on the support frame. Place the end on the sliding surface side of cylinder 1 from the cylinder mounting surface of the support frame.
Embodiment of the Invention FIGS. 5 and 6 show an embodiment of the invention. FIG. 5 shows the general structure of the hermetic compressor as a whole. Reference numeral 21 represents a case, and 22 represents a support frame disposed approximately horizontally inside the case ball. A circular hole 23 is provided in the center of this support frame 22. Further, a compression mechanism section 24 is arranged on the upper surface of this support frame 22, and an electric motor 25 serving as a drive source is arranged below this support frame 22. The compression mechanism section 24 includes a cylinder 2 mounted on the support frame 22.
6 and a piston 27. Further, the electric motor 25 is formed from a stator 28 and a rotor 29. The stator 28 of the electric motor 25 is attached to the lower surface of the support frame 22 via a plurality of stays 3θ. Further, the upper part of a rotating shaft 31 provided at the center of the rotor 29 is rotatably supported by a main bearing 32 fitted in a circular hole 23 of the support frame 22. Specifically, a full eccentric crankshaft portion 33 is provided at the upper end of the rotating shaft 31. The crankshaft portion 33 is formed by a crank component 34 fitted to the upper end of the rotating shaft 31. The crank component 34 has a circular outer peripheral surface. moreover,
As shown in FIG. 6, a rotating shaft insertion hole 35 and an escape hole 36 extending in the axial direction are formed inside the crank component 34, respectively. In this case, the rotating shaft insertion hole 35
The 0 axis 0 is formed at an eccentric position spaced a predetermined distance ε from the axis O' of the outer circumferential surface of the crank component 34, and when the crank component 34 is fitted onto the rotating shaft 31, it rotates. The full eccentric crankshaft portion 33 having an axis 0' is formed at an eccentric position spaced a predetermined distance ε from the axis 0 position of the shaft 31. Several cylindrical connecting portions 38 provided at one end of the piston rod 37 are rotatably provided on the outer circumferential surface of the crankshaft portion 33. A spherical connecting body 39 is provided at the other end of the piston rod 37, and this connecting body 39 is attached to the connecting portion 4θ of the piston 27 in a rotational manner.

The upper end portion 4 of the main bearing 32 is still connected to the support frame 22.
It is attached so as to protrude upward (toward the cylinder 26 side) from the circular hole 23 of the cylinder. Therefore, the end of the main bearing 32 on the sliding surface 42 side with the crankshaft portion 33 protrudes from the cylinder mounting surface of the support frame 22 toward the cylinder 26 side, and the end portion of the main bearing 32 on the side of the sliding surface 42 with respect to the crankshaft portion 33 protrudes toward the cylinder 26 side from the cylinder mounting surface of the support frame 22. The center line 43 of the seven cylinders 26 is located at an intermediate position between the end position of the cylinder 26 and the center line 43 of the seven cylinders 26.

Thus, in the above structure, a full eccentric crankshaft 33 is provided at the upper end of the rotating shaft 3, and a connecting portion 6 (see FIG. 1 to FIG. 4) is omitted, the length of the rotating shaft 31 can be made smaller than in the past, and the height of the entire compressor can be made smaller. Also, the sliding surface 4 of the main bearing 32 with the crankshaft portion 33
The end on the second side protrudes from the cylinder mounting surface of the support frame 22 toward the cylinder 26, and is located at an intermediate position between the end position on the support frame 22 side on the inner peripheral surface of the cylinder 26 and the center line 43 of the cylinder 26. Because of this arrangement, the distance a between the sliding surface 42 of the main bearing 32 with the crankshaft portion 33 and the center m de 43 of the cylinder 26 can be made smaller than in the past. Therefore, compression-like 94 parts 2
When the reaction force F acts on the piston 27 from the compressed gas side during the operation of 4, the force of the e-ment M that acts between the main bearing 32 and the crankshaft portion 33 is more than sufficient (r( By making it smaller, the pressure contact force that acts between the rotating shaft 31 and the main bearing 32 can be reduced, so the resistance force that acts on the electric motor 25 can be reduced. When the reaction force F is applied to the piston 27 from the compressed gas side at the time of the structural part 24, the moment M acting on the sliding surface 42 position of the rotating shaft 31 is (Mb'; Fa, IvI, #F・ε).In this case, the crankshaft portion 33 of the main bearing 32
Since the distance a between the sliding surface 42 and the center line 43 of the cylinder 26 can be decreased, the value of the moment M can be decreased, and the section modulus 2 of the rotating shaft 31 can be decreased. can. Therefore, the outer diameter of the rotating shaft 31 can be reduced, and the overall size can be reduced.

Note that this invention is not limited to the above embodiments. For example, as shown in FIG. 7, the main bearing 52 and the mounting portion 53 of the stator 28 may be integrally formed on the support frame 51. Furthermore, it goes without saying that various other modifications can be made without departing from the gist of the invention.

〔Effect of the invention〕

According to this invention, the rotating shaft is provided with a full eccentric crankshaft portion, and the end portion of the main bearing on the contact surface side with the crankshaft portion is made to protrude toward the cylinder side from the cylinder mounting surface of the support frame. Therefore, the overall height can be lowered, and the pressing force that acts between the rotating shaft and the main bearing during operation of the pressure mechanism can be reduced, and the diameter of the rotating shaft can be reduced. can.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a conventional example without showing the main part configuration, Fig. 2 and Fig. 3 show a conventional example different from Fig. 1, and Fig. 2 is a vertical cross-section showing the main part structure. FIG. 3 is a vertical sectional view showing the support frame, FIG. 4 is a vertical sectional view showing the main structure of another conventional example, and FIGS. 5 and 6 show an embodiment of the present invention. FIG. 5 is a longitudinal cross-sectional view showing the overall schematic structure, FIG. 6 is a cross-sectional view showing crank constituent members, and FIG. 7 is a longitudinal cross-sectional view of essential parts showing another embodiment. 22.51...Support frame, 24...Compression mechanism section, 26...Cylinder, 27...Piston, 3...
-Rotating shaft, 32.52...Main bearing, 33...Crankshaft portion, 42...Sliding surface. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 5 Figure 6

Claims (1)

[Claims] A closed type in which a compression mechanism consisting of a cylinder and a piston is arranged on a support frame, and the piston is driven forward and backward as the rotation shaft is rotatably mounted on a main bearing provided on the support frame. In the compressor, the rotating shaft is provided with a full eccentric crankshaft portion having an axis at an eccentric position spaced a predetermined distance from the axial center position of the rotating shaft, and the crankshaft portion is in sliding contact with the crankshaft portion in the main bearing. 1. A hermetic compressor, characterized in that a surface-side end protrudes toward the cylinder from a cylinder mounting surface of the support frame.