In general, a compressor is a device for compressing a fluid, consisting of a hermetic container having an inner space, an electric mechanism unit mounted in the hermetic container and generating a driving force, and a compression mechanism unit compressing a gas upon receiving the driving force.
The compressor is generally classified into a rotary compressor, a reciprocating compressor, a scroll compressor, or the like, according to a type of the compression mechanism unit which compresses a gas.
As shown in FIGS. 1, 2 and 3, the compressor includes the electric mechanism unit consisting of a stator 2 fixedly coupled at one inner side of the hermetic container 1 and a rotor 3 inserted into the stator 2.
The stator 2 is made by winding a winding coil 2b at a stacking body 2a in an annular bar form with a certain length, and fixedly coupled at an inner wall of the hermetic container 1. At this time, a gas passage in which a refrigerant gas flows is formed between the inner wall of the hermetic container 1 and an outer circumferential surface of the stator 2.
The rotor 3 is formed in an annular bar form with a predetermined length and insertedly coupled inside the stator 2 with a certain space therebetween.
A discharge pipe 4 is coupled at one side of the hermetic container 1 so as to be positioned at an upper side (in view of drawing) of the stator 2 and the rotor 3.
The compression mechanism unit includes a cylinder assembly (D) having an inner space (V), a suction passage (f1) and a discharge passage (f2) communicating with the inner space and fixedly coupled at an inner wall of the hermetic container 1 spaced apart from the electric mechanism unit, and a rotational shaft 20 coupled to penetrating the center of the inner space (V) of the cylinder assembly (D).
One side of the rotational shaft 20 is press-fit to the rotor 3 of the electric mechanism unit.
The cylinder assembly (D) includes a cylinder 30 having a through hole, and an upper bearing plate 40 and a lower bearing plate 50, respectively, coupled to cover an upper surface and a lower surface of the cylinder 30 to thereby form the inner space (V) together with the cylinder 30 and supporting the rotational shaft 20.
The rotational shaft 20 includes an axial portion 21 with a predetermined outer diameter and length inserted into axial insertion holes 43 and 53 respectively formed at the upper bearing plate 40 and the lower bearing plate 50, and a dividing plate 22 extendedly formed at one side of the axial portion 21 to section the inner space (V) of the cylinder assembly (D) into first and second spaces V1 and V2.
The dividing plate 22 of the rotational shaft 20, formed as a wave curved surface in a sine wave shape, includes an upper convex curved portion r1 formed with a convex surface in view of side section, a lower concave curved portion r2 formed with a concave surface, and a connection curved portion r3 connecting the convex curved portion r1 and the concave curved portion r2.
A vane 70 is inserted into a vane slot 44 formed at one side of the upper bearing plate 40 and a vane slot 54 formed at one side of the lower bearing plate 50, and an elastic support unit 80 supporting the vane 70 is coupled at the upper bearing plate 40 and the lower bearing plate 50.
An opening and closing unit 90 is coupled at the cylinder assembly (D) to discharge a gas compressed in the compression areas V1b and V2b of the first and second spaces V1 and V2 by opening and closing the discharge passage f2, and a suction pipe 100 is coupled to the hermetic container 10 in a manner of communicating with the suction passage f1.
Reference numeral 110 denotes a noise muffler.
The operation of the compressor will now be described.
First, when power is applied to the electric mechanism unit (M), the rotor 3 is rotated by the interaction between the stator 2 and the rotor 3 of the electric mechanism unit. The rotational force of the rotor 3 is transferred to the rotational shaft 20 coupled at the rotor 3 and the rotational shaft 20 is rotated. Then, the dividing plate 22 of the rotational shaft 20 is rotated in the inner space (V) of the cylinder assembly (D).
As the dividing plate 22 of the rotational shaft 20 is rotated in the inner space (V) of the cylinder assembly (D), vanes 70 being in contact with the dividing plate 22 interwork to change the first space V1 and the second space V2 to suction areas V1a and V2a and compression areas V1b and V2b, and with the opening and closing unit 90 operating, a refrigerant gas is sucked into the first and second spaces V1 and V2, compressed and discharged. This process is repeatedly performed.
The high temperature and high pressure refrigerant gas discharged from the compression mechanism unit into the hermetic container flows to the gap (G) between the rotor 3 and the stator 2 and the gas passage formed between an outer circumferential surface of the stator 2 and an inner circumferential surface of the hermetic container 1 and is discharged outwardly of the hermetic container 1 through the discharge pipe 4.
However, as for the compressor with such a structure, since the lower surface of the rotor 3 of the electric mechanism unit positioned at the upper side of the compression mechanism unit is formed plane, it is at a right angle to the outer circumferential surface of the rotational shaft 20 press-fit to the rotor 3. Thus, as shown in FIG. 4, in the process that the high temperature and high pressure refrigerant gas discharged from the compression mechanism unit flows to the gap (G) between the stator 2 and the rotor 3, the flowing of the refrigerant gas is not smoothly made and a flowing resistance occurs, resulting in that a flow channel loss and a noise are made.