JPH03111687A - Scroll fluid device - Google Patents

Abstract

PURPOSE:To prevent the inhibition of oil supply of a journal bearing part at the time of starting, and to ensure sealing of a sliding surface due to the oil filling into a compression chamber at the time of driving by discriminating between atmospheres of a back chamber and the journal bearing part. CONSTITUTION:A journal bearing part 5 is arranged in high pressure atmosphere, while first and second back chambers 10, 20 are provided on the back of first and second scrolls 1, 2 so as to discriminate them from the high pressure atmosphere, and they are communicated to a middle pressure chamber 8 formed between the respective scrolls 1 and 2 so as to form a middle pressure region therein. To the middle pressure region, an oil route 9 extended from the high pressure atmosphere is opened. Since the journal bearing part 5 is placed in the high pressure atmosphere, reverse difference in pressure does not occur between an oil flow-in side and an oil opening side of an oil supply route 7 at the time of initial starting, and the oil can be supplied to the journal bearing part 5 through the centrifugal force concomitant with the rotation of a driving shaft 6. The oil is drawn by the difference in pressure through an oil route 9 at the time of driving, from the high pressure region to the back chamber 20 thereby, and the oil can be supplied to the middle pressure chamber 8 through the back chamber 20.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a scroll-type fluid machine that is widely used as a compressor or the like in a refrigeration system.

(Prior Art) Conventionally, as disclosed in Japanese Unexamined Patent Publication No. Sho E31-98987 and shown in FIG. 2, a so-called high-pressure system in which high-pressure fluid discharged from a discharge hole (H) is released into a sealed casing (C). In a dome-type fluid machine, the first and second scrolls (F) (
In order to prevent large deflection deformation due to excessive back pressure acting on the scroll (F) (0), first and second back chambers (X) (Y) are formed on the back surface of each scroll (F) (0). These are connected by a communication path (R), and communicated with an intermediate pressure chamber (M) in the compression process via a communication path (W) to make the inside an intermediate pressure region, and each scroll (F) ( 0) is made to have an appropriate level of back pressure.

In addition, the second scroll (
A refueling passage (T) extending from the bottom oil reservoir (E) in a high-pressure atmosphere is provided inside the drive shaft (D) that interlocks the drive shaft (D) to prevent centrifugal force and high pressure caused by the rotation of the drive shaft (D). Oil sump (E
) and the intermediate-pressure second back pressure chamber (Y) in which the journal bearing part (G) is located, the journal bearing part (G
), and the oil that is released after oiling the bearing (G) is supplied to the compression chamber side via the communication path (W) to seal the sliding surface.

(Problem to be Solved by the Invention) According to the above configuration, the journal bearing portion (G) is disposed in the back chamber (in this case, the second back chamber (Y)) which is in the intermediate pressure region to prevent deflection deformation. As a result, the oil release side becomes an intermediate pressure region, and a positive differential pressure is generated between the oil reservoir (E) and the high pressure oil reservoir (E), which at first glance seems to be preferable for oil supply. However, if the journal bearing portion (G) is placed in the intermediate pressure range as described above, a problem arises in which oil supply becomes impossible at the beginning of startup.

That is, the inside of the hermetic casing (C) is filled with high-pressure fluid that is compressed in sequence between the scrolls (F) and (0) and is finally discharged from the discharge hole (H), creating a high-pressure atmosphere. Therefore, at the beginning of startup, the pressure of the back chambers (X) and (Y), which are connected to the intermediate pressure chamber in the compression process and generally have a smaller volume, increases first. Therefore, at the beginning of startup, the second rear chamber (Y) on the oil release side becomes high pressure with respect to the oil sump (E) on the oil inflow side in the oil supply passage (T), and a reverse pressure difference occurs in the oil passage, causing the journal bearing No oil is supplied to the bearing part (G).
G) has the problem of burn-in and the like.

In order to prevent deflection and deformation of the scroll, the present invention separates the back chamber from the atmosphere of the journal bearing to prevent oil supply to the journal bearing at startup and prevent oil injection into the compression chamber during operation. An object of the present invention is to provide a scroll-type fluid machine that can also ensure sealing of sliding surfaces.

(Means for Solving the Problems) Therefore, in order to achieve this object, the present invention provides an oil sump (
A first scroll (1) having a discharge hole (3) is interlocked with a drive shaft (6) via a journal bearing (5) in a high-pressure dome-shaped sealed casing (4) provided with a high-pressure dome (40). In the scroll type fluid machine, a second scroll (2) is installed inside the machine, and an oil supply passage (7) extending to the journal bearing part (5) is formed inside the drive shaft (6). ) are arranged in a high pressure atmosphere, and the first and second scrolls (1) (2)
First and second back chambers (10) (20) defining a high-pressure atmosphere are provided on each back side of the back chamber (10) (20).
20) is communicated with the intermediate pressure chamber (8) defined between the scrolls (1) and (2) to make the inside thereof an intermediate pressure region, and an oil passage extending from the high pressure atmosphere into this intermediate pressure region. I decided to open (9).

(Function) Unlike the first and second rear chambers (10) and (20), which are set at intermediate pressure to prevent deflection and deformation, the journal bearing part (5) is placed in a high-pressure atmosphere, so at the beginning of startup, the oil supply passage is closed. No reverse differential pressure is generated between the oil inlet side and the oil release side of (7), and oil can be supplied to the journal bearing portion (5) by the centrifugal force accompanying the rotation of the drive shaft (6). In addition, since the atmosphere of the journal bearing (5) is separated from the first and second rear chambers (10) (20), the oil released after oiling the journal bearing (5) is not supplied to the compression chamber side. However, during operation, through the oil passage (9),
Oil is pumped up from the high pressure region to the back chamber at intermediate pressure due to the differential pressure, and oil can be supplied to the intermediate pressure chamber (8) via the back chamber, and sealing performance on the sliding surfaces in the compression chamber can also be ensured.

(Example) The one shown in Fig. 1 is a high-pressure dome-shaped sealed casing (4) with an oil reservoir (40) at the bottom, a first scroll (1) having a discharge hole (3), and a journal bearing. A second scroll (2), which is interlocked and connected to the drive shaft (6) of the motor (θ0) through the part (5), is installed inside the drive shaft (6) in an opposed manner, and an oil pickup at the lower end is installed inside the drive shaft (6). (70
) is formed with an oil supply passage (7) facing the oil sump (40) and having an upper end extending to the journal bearing (5).

The first scroll (1) has a spiral body (12) on the lower surface of the end plate (11), and an outer peripheral wall (15) having a thrust bearing surface (13) and a supporting surface (14) continuous thereto on the end surface. It protrudes and is supported and fixed via a support surface (14) to a frame (43) consisting of an upper member (41) and a lower member (42). Further, the second scroll (2) has a spiral body (22) protruding from the upper surface of the end plate (21), and the upper surface of the outer peripheral portion of the end plate (21) is brought into contact with the thrust bearing surface (13). Further, the drive shaft (6) is supported by an upper bearing (44) and a lower bearing (45), and a pin part (62) protruding from the end of the upper balancer (61) is attached to the journal bearing part (5). They are mated.

Two systems of compression chambers (
A, B), and as the drive shaft (8) rotates, the second scroll (2) is driven to revolve relative to the first scroll (1), and the suction chamber ( 72) is compressed in each compression chamber (A, B), and high pressure fluid is released from the discharge hole (3) into the upper discharge chamber (3).
1), the discharged fluid is released to the lower part of the motor (60) through the discharge connection pipe (32), and the motor is cooled. 33
) to the outside.

With the above configuration, the journal bearing part (5) is connected to the communication path (4).
6) is arranged in a high-pressure crank housing chamber (47) communicating with the inside of the casing (4).

Further, an annular first recess (16) is provided on the back surface of the first scroll (1), and a discharge hole boss portion (30 ), and a first back chamber (10) defining a high-pressure discharge chamber (31) is formed inside the first recess (16). Furthermore, an annular second recess (26) is provided in the upper member (41) of the bridge (43) located on the back surface of the second scroll (2), and the inner diameter side receiving seat of this recess (26) is provided. (48) and the second scroll (2), a seal ring (27) is interposed to define a high-pressure crank housing chamber (47) inside the second recess (26). Second
A back chamber (20) is formed. The first and second rear chambers (10) and (20) are connected to each other by a communication path (81), and the end plate (11) of the first scroll (1)
It communicates with the intermediate pressure chamber (8) which is in the process of compression through a communication passage (82) provided in the chamber, thereby making the inside thereof an intermediate pressure region.

Furthermore, with the above configuration, a second back chamber (20
), an oil passage (40) extending from the oil reservoir (40) in a high pressure atmosphere
9) Open.

With the above configuration, the journal bearing part (5) has the first and second back chambers (10) and (20) which are set at intermediate pressure to prevent deflection deformation of the first and second scrolls (1) and (2). Because it is placed in a defined high-pressure atmosphere, there is no reverse differential pressure between the oil inflow side and the oil release side of the oil supply passage (7) at the beginning of startup, and centrifugal pressure due to rotation of the drive shaft (6) does not occur. The force allows oil to be supplied to the journal bearing (5). Furthermore, since the atmosphere of the journal bearing part (5) is separated from the first and second rear chambers (10) and (20), the oil released after the journal bearing part (5) is oiled is not supplied to the compression chamber side. However, during operation, oil is pumped up from the oil reservoir (40) to the second rear chamber (20) via the oil passage (9) due to the differential pressure, and the oil is pumped up in the compression chambers (A) and (B). Sealing performance on sliding surfaces can also be ensured.

(Effect of the invention) As described above, in the present invention, the first and second scrolls (1) (2
), it is possible to prevent the deflection deformation of the journal bearing (5), and at the same time, it is possible to ensure oil supply to the journal bearing part (5) at the time of startup.
It is also possible to ensure sealing of the sliding surfaces within the compression chamber during operation.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of the scroll type fluid machine of the present invention, Fig.
The figure is a longitudinal sectional view of a conventional example. (1)...First scroll (2)...Second scroll (3)...Discharge hole (4)...Sealed casing (5)...Journal bearing (θ )... Drive shaft (7)... Oil supply passage (8)... Intermediate pressure chamber (8)... Oil passage (10)... First back chamber (20)... ...Second back chamber (40)...Oil sump second positive

Claims (1)

[Claims] 1) A first scroll (1) having a discharge hole (3) in a high-pressure dome-shaped sealed casing (4) provided with an oil sump (40).
and a second scroll (2) interlockingly connected to the drive shaft (6) via the journal bearing part (5), and the journal bearing part (5) is installed inside the drive shaft (6).
), in which the journal bearing portion (5) is disposed in a high-pressure atmosphere, and the first and second scrolls (
1) First and second back chambers (10) (20) defining a high-pressure atmosphere are provided in each back section of (2), and these back chambers (10) (20) are connected to the scroll (1) ( 2) It is characterized in that it communicates with an intermediate pressure chamber (8) defined between them, making the inside thereof an intermediate pressure region, and an oil passage (9) extending from the high pressure atmosphere is opened in this intermediate pressure region. Scroll type fluid machine.