JPH0681881B2 - Scroll fluid machinery - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a scroll type fluid machine used for a compressor for a refrigerator, an expander, a vacuum pump and the like.

2. Description of the Related Art The idea of using a sealing band as a means for sealing a leak gap in the axial direction of a working space having a scroll type mechanism in which spiral blades are combined is found in US Pat. No. 801,182.

FIG. 3 is a cross-sectional view of a mechanical portion of a scroll-type electric compressor which is a conventional general fluid machine.
FIG. 6 and FIG. 6 show details of the spiral blade portion.

A scroll-type mechanism unit 2 and an electric motor 3 including a stator 4 and a rotor 5 are arranged inside the sealed container 1, and the rotor 5 is connected to a crankshaft 6 of the mechanism unit 2.

The mechanism unit 2 includes a fixed spiral blade component 8 having a fixed spiral blade 7, a swirl spiral blade component 11 having swirl spiral blades 10 meshing with the fixed spiral blade 7 to form a plurality of working spaces 9, and a crankshaft. 6 and a thrust bearing 13 for supporting the force by which the swirling spiral blade component 11 is pressed against the opposite side of the work space 9 by the pressure of the work space 9.
And a swirl spiral blade part disposed on the outer periphery of the thrust bearing 13.
11 is composed of a rotation restraint component 15 having a structure in which keys are provided on both surfaces of a circular annular body for restraining rotation.

A sealing ring 14 is arranged on the outer periphery of the fixed spiral blade component 8 to partition the sealed container 1 into a discharge port 16 and a suction side space 17.

The suction refrigerant sucked from the suction pipe 18 of the compressor enters the suction port 19 of the mechanism portion 2 via the suction side space 17. Mechanism part 2
The entered refrigerant gas is compressed into high temperature and high pressure through the suction chamber 20, the working space 9, and the discharge port 21, and is discharged from the discharge port 16 to the outside of the compressor through the discharge pipe 22.

A lubricating oil sump 23 is provided at the bottom of the hermetic container 1, and the lubricating oil therein passes through an oil supply hole 25 provided in the crankshaft 6 by an oil pump 24 to lubricate and cool each part of the mechanism part 2.

A sealing band groove 26 and a sealing band 27 are respectively provided at the tips of the fixed spiral blade 7 and the swirling spiral blade 10, and seal between a groove bottom surface 28 of the sealing band groove 26 and a back surface 29 of the sealing band 27. Obi groove 26
A minute gap is formed between the groove bottom surface 30 and the side surface 31 of the sealing band 27.

By the swirling of the swirling spiral vane component, the working space 9 is gradually reduced in volume from the outer periphery and communicates with the central discharge port 21 while increasing the pressure.

Both swirling and fixed spiral vanes 7, 10 are close to each other at points Ta, Tb, Tc, Td to form a working space 9 (C0, C1, C2, C0 ', C1', C2 '),
The pressure of each space is (P0, P1, P2, P0, P1, P2).

By the swirling motion of the swirling spiral blade part 11, the working space 9 moves toward the discharge port 21 provided in the vicinity of the center one by one while increasing the internal pressure thereof.

In the cross-sectional view of FIG. 7, pressures P1 and P2 are applied to both sides of the sealing band 27 on the side of the swirling spiral blade 10, and the fixed spiral blade 7 is formed between the sealing band 27 and the sealing groove 26. In a small gap
The state where the pressure of P2 is acting is shown.

Thus, when the pressure P1 in the working space outside the sealing band 27 is lower than the pressure P2 in the working space inside, the sealing band 27 is
In 26, it is pressed against the groove side surface A on the lower pressure side and also against the bottom surface B of the working space 9.

The pressing force dFS per unit length of this portion along the spiral in the direction of the bottom B is in contact over the length L between the contact ends T1 and T2 as shown in FIG. Then, assuming that the gas pressure in the contact surface is proportional to the distance from the contact end, it is expressed as follows.

dFS = (1/2) × L × (P2-P2) (1) In addition, the swirling spiral blade due to the pressing force FS of this sealing band 27
Loss power per rotation dWF of this part of 10 is dWF = 2π × KF × dFS × RS ......, where the friction coefficient of this contact surface is KF and the swirling radius of the swirling spiral blade 10 is RS. (2)

Problems to be Solved by the Invention As described above, in the scroll-type fluid machine having the conventional sealing band 27, the friction loss force due to the pressing force of the sealing band 27 against the bottom surface B greatly reduces the efficiency of the fluid machine. It is an element.

Means for Solving the Problems The present invention has been made to solve these problems, and in a scroll type fluid machine, a fixed swirl vane and a tip end portion of the swirl swirl vane are provided with a sealing band groove. ,
A sealing band is fitted in the sealing band groove, and the width of the surface of each side of the sealing band, which is in contact with the bottom surface of the spiral vane, in the direction perpendicular to the center line of the spiral winding is made smaller than the width of the sealing band groove. It is also narrowed and is offset to the outside with respect to the center line of the spiral of the spiral blade.

Therefore, as is clear from the above formula (1), the pressing force dFS of the sealing band is proportional to the length L on the contact surface of FIG. 7, so the shorter L is, the smaller dFS becomes. From equation (2), it can be seen that the power loss due to the friction of the sealed band can be reduced. Also, the load per unit area of the contact surface of this part
PS is PS = dFS / L (1/2) × (P2-P1) (3), which is a value unrelated to L.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2 of the accompanying drawings.

Here, the same parts as those in the conventional example will be described with reference to FIG.

In FIGS. 1 and 2, reference numeral 32 denotes a sealing band disposed in each sealing band groove 26 of the fixed spiral blade 7 and the swirling spiral blade 10, and is located outside the center line OO of the sealing band groove 26. A seal portion 32a that abuts the contact surface B is provided so as to project. The width L of the seal portion 32a is set so that the power loss due to friction is minimized and the sealing performance is secured.

EFFECTS OF THE INVENTION As described above, the effect of the present invention is that the pressing force in the axial direction of the sealing band becomes small and the power loss due to the friction of the sealing band is reduced accordingly. Further, since the load per unit area of the contact surface of the sealing band does not increase, there is no fear of accelerating the wear of the sealing band.

Moreover, since the cross-sectional shape of the sealing band is extremely simple, its manufacturing cost does not increase.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an embodiment of a scroll fluid machine according to the present invention, FIG. 2 is a perspective view of the same sealing band, and FIG. 3 is a scroll type electric compressor having a conventional sealing band. A sectional view, FIG. 4 is an explanatory view of a spiral blade portion of the electric compressor seen from a plane, and FIG. 5 is a sectional view taken along the line VV in FIG.
FIG. 6 is a perspective view of a sealing band of the electric compressor, and FIG. 7 is a sectional view of a sealing band portion of the electric compressor. 1 ... Sealed container, 2 ... Mechanical part, 3 ... Electric motor, 4 ...
Stator, 5 ... Rotor, 6 ... Crank shaft, 7 ... Fixed spiral blade, 8 ... Fixed spiral blade part, 9 ... Working space,
10 …… Swirl spiral blade, 18 …… Suction pipe, 21 …… Discharge port, 22
...... Discharge pipe, 26 …… Sealing band groove, 32 …… Sealing band, 32a ……
Seal part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuharu Fujio 1006, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor, Hiroshi Karado 1006, Kadoma, Kadoma, Osaka Prefecture

Claims (1)

[Claims] Claim: What is claimed is: 1. A fixed spiral vane component having a fixed spiral vane, a swirl spiral vane component having swirl swirl vanes that mesh with the fixed spiral vane to form a plurality of working spaces, and swirl drive the swirl spiral vane component. A crankshaft, a bearing component that supports the main shaft of the crankshaft, and a rotation restraining component that prevents rotation of the swirl vane component to rotate only, and the fixed swirl vane and the tip end portion of the swirl swirl vane are provided. A sealing band groove is provided, the sealing band is fitted into the sealing band groove, and the width of the surface of each side of the sealing band that abuts the bottom surface of the spiral vane is perpendicular to the center line of the spiral winding. A scroll fluid machine that is narrower than the width of the sealing band groove and is offset to the outside with respect to the center line of the spiral of the spiral blade.