JPH0311189A - Scroll compressor - Google Patents

Abstract

PURPOSE:To securely return lubricant oil into an oil sump during a normal operation while restrain the reverse flow of the lubricant oil by a foaming phenomenon at the start of an operation by forming a spiral groove at a surface opposed to at least one of a press plate and a shaft disposed in a penetrating portion. CONSTITUTION:After lubricating each bearing during a normal operation, a force in an advance direction of a screw is exerted on lubricant oil dropped on a press plate 30 by the rotation of a shaft 9, that is, the rotation of a spiral groove 32a disposed in an oil cap 26 so that the lubricant oil is securely returned into a lower oil sump 25. At the start of an operation of a compressor, a refrigerant melted in the lubricant oil or the like is abruptly foamed so as to flow out together with the lubricant oil above the press plate 30 from the oil sump 25 through a space formed between the press plate 30 and the oil cap 26. However, the spiral groove 32a on the oil cap 26 is rotated by the rotation of the shaft 9 so that the force in the advance direction is applied to the lubricant oil in the space. Therefore, the lubricant oil is returned to the oil sump 25 to be restrained from flowing reversely by a so-called foaming phenomenon.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a scroll compressor, and particularly relates to depletion of lubricating oil in its oil sump. This invention relates to improvements in suppressing means.

[Prior Art J The principle of the scroll fluid machine has already been shown in many documents and patent publications and is well known, but since it is the basic principle, this principle will be explained first1.

FIG. 3 is a diagram illustrating the principle of a scroll fluid machine described in, for example, Japanese Patent Laid-Open No. 60-206988. In the figure, (1) a fixed scroll having a Fi spiral (1a) and fixedly disposed, (2) a fixed scroll (
It is a rocking nuclear crawler that has a spiral body (2a) in the opposite direction that is engaged with the spiral body (18) of 1), and performs rotational motion without rotation, that is, rocking motion at a predetermined crank radius (rocking radius). be. As mentioned above, the spiral body (1a) of these fixed scrolls (1) and the oscillating flow /'(
The spiral body (2a) of 2) is composed of spiral bodies having the same shape and opposite winding directions, and its form is a combination of involutes, circular arcs, etc., as is conventionally known. (3) is Ryoma Makitai (is) (2a
), the compression chamber compresses the fluid by the oscillating motion of the oscillating scroll (2), and the compression chamber (4) is formed by the fixed scroll (
1) A discharge port is provided in the center and discharges compressed fluid. Here, both scrolls (1) and (2) are shown in Fig. 3 (a).
), (bL (c) If the motion is as shown in 1(d), both scrolls (1) and (2) both spiral bodies (la), (
Since the crescent-shaped compression chamber (3) formed between 2a) gradually reduces its volume, the fluid taken into the scroll is compressed and discharged from the discharge port (4). The above is the operating principle of the scroll fluid machine.

FIG. 4 is a longitudinal cross-sectional view of a compressor using a conventional scroll fluid machine disclosed in, for example, Japanese Patent Laid-Open No. 60-166784. In the figure, (1) or 4)
are the same or equivalent parts as described in the explanation of FIG. 3 above. (5) is a container, (6) is a discharge pipe that discharges the fluid discharged from the discharge port (4) to the outside of the container (5), and (7) is a swing provided on the back of the swing scroll (2). axis, (8)
is the electric motor that is the driving source, (9) is this electric motor 411 (8)
A balance way (10) that supports the swing shaft (7) and maintains dynamic balance is fixed to the end face facing the swing scroll (2).

(11) is an Oldham joint that prevents the rotation of the oscillating scroll (2) and maintains the angular position between the fixed scroll (1) and the oscillating flow /l/ (2); An annular sufusto bearing that supports the internal pressure and the weight of the oscillating scroll (2), (13) is an oscillating bearing that supports the oscillating shaft (7), and (14) and (15) support the shaft above and below. Bearings (16) and (17) are the bearing frame, and (18) and (19) are the bearing frame (16).
, (17) is the oil return hole provided, (20) is the container (
5) Fluid suction pipe that sucks compressed fluid into the container (5) from outside, (21) and (22) are this fluid suction pipe (20)
After death, the inhaled fluid is circulated through the electric motor (8).
Communication hole for feeding into the upper Souflo tvf4 roll part (23
) is each spiral body (la) of both scrolls (1) and (2)
, (2a) A fluid inlet that is an inlet to the compression chamber (3) formed by K, (24) a baffle plate that blocks direct communication between this fluid inlet and the thrust bearing (12), (25)
is an oil reservoir provided at the bottom of the container (5), (26) is an oil cap attached to the lower end of the shaft (9) and forms a hollow inside, (27) is a lubricating oil inlet, and (28) is a shaft ( 9
) is a lubricating oil supply hole that passes through the shaft in the axial direction and is located centroidally from the shaft center. A holding plate is provided above the reservoir (25) to partition the container into upper and lower parts, and has a hole in the center thereof through which the shaft (9) passes. (33
) is a balance weight that maintains the dynamic balance of the rotation of the shaft (9) at the bottom.

First, the operation and fluid flow of the scroll compressor configured as described above will be explained.

When electric motor (8) is powered by 1&, torque is generated and 411I
! (9) rotates. This rotational force is transmitted to the swing shaft (7), and the swing scroll (2) is guided by the Oldham joint (11) and performs swing motion without rotating. The fluid flowing into the container from the suction pipe (20) is transferred to the electric motor (8).
After cooling the fluid, it reaches the fluid intake port (23) through the communication holes (21) and (22), is taken into the compression chamber, and is compressed as shown in Figure 3. After that, it is discharged from the discharge pipe (6).

Next, the flow of lubricating oil will be explained.

The tZ lubricating oil is pumped from the oil reservoir (25) by the centrifugal pump action by the hollow cylindrical part in the oil cap (26) disposed on the shaft (9) and the lubricating oil supply hole (28) as shown by the arrow. The lubricant is pumped up from the lubricant inlet (27) of the cap (26) through the lubricant supply hole (28), and is supplied to the bearings (12), (13), (14), and (15). The oil used for lubrication is mainly supplied to the oil return holes (23) provided in the bearing frames (16) and (17).
, (24) and is discharged downward through the holding plate (30
) is returned to the oil sump (14) provided at the bottom of the container (5) through the gap in the shaft penetrating portion. Note that lubricating oil leaking from the Sufst bearing (12), etc. directly flows into the fluid intake port (
A baffle plate (24) is provided so as not to be sucked into 23). In addition, a gas vent hole (29) provided in the shaft (9)
This is to quickly discharge the gas inside the oil cap to the outside of the shaft during operation, increasing pump efficiency.

(Problems to be Solved by the Invention) In the conventional scroll compressor as described above, there is a gap between the shaft (9) and the holding plate (30).If the gap in this penetrating portion is small, each bearing There was a problem in that efficient oil supply could not be carried out because the oil returned to the oil reservoir (25) and accumulated on the upper surface of the holding plate (30). If the gap is large, the holding plate (30) will not be effective.In other words, when the pressure in the compressor starting special container (5) decreases, it will dissolve in +l!I lubricant in the oil sump (25). The trapped refrigerant foams, and the lubricating oil along with the refrigerant gas passes through the gap in the penetration part and enters the room! A large amount of oil is sucked in from (23), causes liquid compression, and is discharged outside the compressor, often depleting the lubricating oil in the oil sump.As a result, lubrication failure occurs, and each There were problems that caused bearing damage or seizing accidents.

This invention was made to solve this problem, and includes a scroll that reliably returns lubricating oil to the oil reservoir during normal operation and suppresses movement of lubricating oil in the opposite direction due to the forming phenomenon at startup. [Means for Solving the Problem] A scroll compressor according to the present invention includes a container, a fixed scroll and an oscillating scroll provided on the upper part of the container, and a scroll compressor according to the present invention. a holding plate provided at the bottom to partition the container into upper and lower parts; an oil reservoir provided at the bottom of the holding plate for storing lubricating oil; the upper end is connected to the swinging scroll, and the lower end passes through the holding plate to The lubricating oil is immersed in the lubricating oil stored in the oil sump, and is supplied to the sliding part of the scroll through a hole penetrating in the axial direction, and then supplied to the oil sump through a part penetrating the holding plate. A helical groove is provided on an opposing surface of at least one of the presser plate and the shaft in the penetrating portion.

[Operation J] The helical groove formed on the surface facing the penetrating portion of the presser plate and shaft of the scroll compressor configured as described above allows lubricating oil to flow from the upper surface of the presser plate toward the oil reservoir as the shaft rotates. Promote flow.

〔Example〕

Figure 1 is one of the features of this invention! It is a sectional view showing the main part of the scroll compressor showing an example. In the figure, (5) is a container, (8a) and (8b) are the rotor and stator of an electric motor that is a driving source, and (9) is connected to an oil cap (26) formed hollow in this electric motor. There is. (25) is an oil reservoir provided at the bottom of the container (5) and stores lubricating oil, and (27) is an oil cap (26).
), (28) is the lubricating oil inlet provided at the bottom of the shaft (9).
) is penetrated in the axial direction, and the lubricating oil supply hole provided at a position eccentric from the axis draws up the lubricating oil in the oil reservoir (25) sucked from the lubricating oil suction port (27) by the action of a centrifugal pump. Lubricate each part of the raised swinging scroll and bearings. (
29) is a gas vent hole formed approximately in the center of the shaft (9), and (30) is a holding plate that partitions the oil reservoir (25) and the inside of the container (5). shaped protrusion (31
) is formed, and an oil cap (26) passes through it. (32a) is a spiral groove formed on the opposing surface of this cylindrical protrusion (31) and the oil cap (26),
It is a screw threaded in the same direction as the rotational direction of the shaft (9), and is formed on the oil cap side.

In the Nuclor compressor configured as described above, after lubricating each bearing part during normal operation, lubricating oil descends onto the holding plate (30) and falls onto the oil cap (26) as soon as the shaft (9) rotates. The rotation of the helical groove (32a) receives the force in the advancing direction of the screw, ensuring that the lower oil sump (25)
Therefore, the lubricating oil level in the oil sump (25) is always maintained without overfilling on the holding plate (30), and the efficiency of the oil pump does not decrease.

Furthermore, when the scroll compressor is started, the refrigerant dissolved in the lubricating oil rapidly foams, and together with the lubricating oil, it flows from the oil reservoir (25) to the holding plate (30) and the oil cap (26).
The liquid tends to flow to the upper part of the presser plate (30) through the gap formed by the liquid. However, due to the rotation of the shaft (9), the spiral groove (32a) on the oil cap (26)
rotates, applying force in the direction of screw movement to the lubricating oil in the gap,
111f'l! Since the oil is returned to the oil sump (25) and the backflow of lubricating oil due to the so-called forming phenomenon is suppressed, the lubricant in the oil sump (25) does not run out.

In the above embodiment, the helical groove is provided on the oil cap side, but it may be provided on the presser plate side or on both sides of the main shaft and the presser plate.

Further, in the above embodiment, a helical groove is provided on the oil cap, but when the shaft portion passes through the presser plate, the groove may be provided on the shaft.

Fig. 2 is a sectional view of the main parts of an eight-scroll pressure machine in another embodiment of the present invention, in which a wire (34) or the like is wound around an oil cap to form a helical groove (32b). In this case, the same effects as in the above embodiment can be achieved.

Effect for one shot] The scroll compressor according to @Ming includes a container, a fixed scroll and an oscillating scroll provided at the top of the container, and a presser plate provided at the bottom of the container to partition the container into upper and lower parts. and an oil reservoir provided at the bottom of the holding plate to store lubricating oil; an upper end connected to the swinging scroll and a lower end penetrating the holding plate and immersed in the lubricating oil stored in the oil reservoir. The lubricating oil is supplied to the sliding part of the scroll through a hole penetrating in the axial direction, and then the lubricating oil is returned to the oil reservoir through a part penetrating the holding plate, and this shaft is rotationally driven. A helical groove is provided on the facing surface of at least one of the drive source, the metal retainer, the presser plate of the penetrating portion, and the shaft, so that it is secure during normal operation. It is possible to provide a scroll compressor that returns the lubricating oil to the oil reservoir at the time of operation and suppresses movement of the lubricating oil in the opposite direction due to the forming phenomenon at the start of operation.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main parts of a scroll compressor in one embodiment of the present invention, FIG. 2 is a sectional view of the main parts of a scroll compressor in another embodiment of the invention, and FIG.
L (b) + (c), (dl is a diagram explaining the compression principle of a scroll fluid machine, and FIG. 4 is a sectional view of a conventional scroll compressor. In the figure, (1) is a fixed scroll, (2 ) is an oscillating scroll, (3) is a compression chamber, (5) is a container, (8),
(8a), (8b) are driving sources, (9) are shafts, (2
5) is the oil reservoir, (28) is the lubricating oil supply hole, (30)
(32a) and (32b) are helical grooves. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] A container, a fixed scroll and an oscillating scroll provided at the top of the container, a presser plate provided at the bottom of the container to partition the container into upper and lower parts, an oil reservoir provided at the bottom of the presser plate to store lubricating oil, and an upper end. is connected to the oscillating scroll, and its lower end passes through the holding plate and is immersed in the lubricating oil stored in the oil reservoir, and the lubricating oil is transferred to the scroll through a hole penetrating in the axial direction. A shaft that supplies the oil to the oil reservoir through a portion that passes through the holding plate, and a drive source that rotationally drives this shaft, and includes at least one of the holding plate and the shaft in the portion that passes through the holding plate. A scroll compressor characterized by having helical grooves on the opposing surfaces of the scroll compressor.