JPS59141781A - Scroll type fluid machine - Google Patents

Abstract

PURPOSE:To operate the scroll compressor stably by a method wherein a gap between a fixed scroll and a rotary scroll at the overlapping part thereof is made larger than the gaps between the other parts of both scrolls. CONSTITUTION:A minute step is provided between the overlapping tip end 2g and the other part 2f at the overlapping end side of the fixed scroll. Due to this step, the gap, larger than the gap between the fixed scroll 2f and the rotary scroll 1f by a dimension corresponding to the dimension of the step, may be secured in the gap between the overlapping tip end 2g of the fixed scroll and the teeth bottom 1g of the rotary scroll. Accordingly, the excess outflow of oil from a mirror plate as well as the leakage of gas from the back surface of the mirror plate into a suction chamber may be prevented and the stable operation of the scroll compressor may be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a scroll-type fluid machine, and particularly to a wrap shape for maintaining a cylindrical shape and performing stable operation.

[Prior art]

As an example of a scroll-type fluid machine, the structure of a conventional hermetic scroll compression machine is explained with reference to FIG. It consists of a mechanism, a motor 5 that drives it, and a casing 6 that houses these.

The orbiting scroll has a thinly wound wrap 1b on a plywood (mirror plate) 1a, and has a rotation prevention mechanism IC for preventing rotation on its back surface and an orbiting bearing 1d into which a crank portion of a crankshaft is inserted.

The end plate 1a of the orbiting scroll is provided with a rotation bearing 1d and a oil supply hole 1e that opens on the end plate surface.The fixed scroll 2 also has a plywood (end plate) 2 & a thinly wound wrap 2b thereon.

Further, the fixed scroll is provided with an intake port 2C and a discharge port 2d.

The fixed scroll and the orbiting scroll are assembled with each other with their laps facing inward.

The frame 4 is provided with a notch 4a having a space in which the end plate 1a of the mirror scroll can perform a turning movement, and the end plate of the orbiting scroll is accommodated in this notch, and the frame and the fixed scroll are fastened to sandwich the orbiting scroll. .

A back pressure chamber 4b is formed by a frame on the back surface of the orbiting scroll. The back pressure chamber is communicated with a compression chamber formed by the orbiting scroll, the wrap of the fixed scroll, and the end plate through a pressure equalization hole (not shown) provided in the orbiting scroll.

The frame is further provided with a bearing 4C for supporting the crankshaft and a leg 4d for supporting the motor.The frame and the fixed scroll are housed in the casing 6, but at this time,
A slight gap is provided or press-fitted between the frame or frame fixed scroll and the casing to prevent oil and gas from flowing, dividing the inside of the casing into upper and lower halves.

A discharge passage 7 that communicates between the upper and lower parts of the casing is provided on the frame or on the outer periphery of the frame and the fixed scroll.

An oil supply hole 3a is provided in the crankshaft 3 to supply oil from the lower part of the casing to the swing bearing 1 (L, bearing 4C).

Due to the simultaneous rotation of the motor, the crankshaft and anti-rotation mechanism cause a relative rotational movement, and as the space (compression chamber) formed by the wraps of both scrolls and the end plate moves toward the center, its volume decreases.

As a result, the gas inhaled from the suction port is compressed and discharged from the discharge port.

The gas discharged from the discharge port is discharged from the lower part of the casing to the outside through the discharge passage.

When the scroll performs a compression action, a force acts to separate the scrolls. To prevent the orbiting scroll from separating, the pressure in the back pressure chamber of the orbiting scroll is set at an intermediate pressure higher than the suction pressure and lower than the discharge pressure, pressing the orbiting scroll against the fixed scroll.

From the oil supply hole 3a of the crankshaft 3 to the swing bearing 1a.

The oil supplied to the bearing 4C flows to the back pressure chamber where the pressure is low.

The oil that has flowed into the back pressure chamber is discharged from the pressure equalization hole in the orbiting scroll to the compression chamber.

Further, from the orbiting bearing 1d portion, oil is supplied to the end plate sliding portion 1f of the orbiting scroll through an oil supply hole 1θ.

The supplied oil is discharged from suction to 2θ.

Conventionally, the crankshaft has balanced the pressure inside the casing, which is applied from below, and the load caused by the oil supply pressure, which is applied to the tip of the crank.

If the orbiting scroll and fixed scroll become separated due to various reasons during the actual purchase, the end plate sliding part 1 of the orbiting scroll
The amount of oil 1 discharged from f into the suction chamber 2θ increases, and the pressure acting on the tip of the crank portion of the crankshaft decreases. As a result, the load acting on the crankshaft becomes unbalanced,
The crankshaft is pushed upwards.

As a result, the crankshaft and the orbiting scroll come into contact.

If a thrust bearing is installed to prevent the crankshaft from moving,
This problem can be solved, but the structure becomes complicated.

One of the reasons why the end plate sliding part 1 of the fixed scroll and the orbiting scroll separates is the dimensional accuracy of the wrap between the fixed scroll and the orbiting scroll.
As shown in the figure, the tip 2g of the wrap and the portion 2f other than the wrap are machined in the same plane.

Further, as for the mirror plate portion of the orbiting scroll, as shown in FIG. 3, the tooth bottom portion 1g of the wrap and the portion 1f without the wrap are machined to be on the same plane.

When the respective wraps are combined, the tooth bottom 2h of the fixed scroll, the wrap tip 1h1 of the orbiting scroll, the wrap tip 2g of the fixed scroll, and the tooth 1g1 of the orbiting scroll.
The fixed scroll 2f corresponds to the orbiting scroll 1f.

Due to machining accuracy, the 2g part of the fixed scroll partially protrudes from 2f, and the 1g part of the orbiting scroll partially protrudes from 1f.
When the orbiting scroll and the fixed scroll protrude from the 2h and 1h portions or the 2g and 1g portions, a gap is created between the 2f and 1f portions.

Such conditions result in the aforementioned excessive oil spillage, resulting in reduced reliability and performance.

[Purpose of the invention]

An object of the present invention is to provide stable operation by making the gap between the wrap ends of the identification scroll and the orbiting scroll larger than the gap between the parts other than the wrap tips of both scrolls. [Summary of the Invention] Wrap A gap can be secured at the tip of the wrap by providing a minute difference between the tip of the tip or the tooth bottom of the corresponding mating scroll and a portion other than the wrap.

Further, by providing a soft surface treatment layer having conformability to a base having such dimensions, it is possible to reduce the gap at the tip of the wrap and obtain the same effect as having a sufficient gap.

[Embodiments of the invention]

Examples will be explained with reference to FIGS. 4 to 9.

Note that the overall structure is the same as the conventional one, so a description thereof will be omitted.

An example of implementation is shown in FIGS. 4 and 5.

On the wrap tip side of the fixed scroll, a minute difference in level is provided between the wrap tip 2g and the portion 2f other than the wrap.

The orbiting scroll is the same as the conventional one.

Due to this step, the fixed scroll's lap tip 2g and the orbiting scroll's tooth bottom 1g are separated from each other by the fixed scroll.
A large clearance can be secured by the difference in clearance between f and 1f of the orbiting scroll.

In this structure, as shown in FIGS. 6 and 7, 2f
It can also be substituted by installing a separate piece 2j of lino/gushing that slightly protrudes from the scroll.In this case, since it is supported by the end plate part 1fVi2j of the orbiting scroll, a gap can be provided between the ends of the wraps of both scrolls.

Another embodiment is shown in FIGS. 8 and 9.

On the mirror plate surface of the orbiting scroll, a slight step is provided between a portion corresponding to the wrap tip 2g of the fixed scroll, that is, a tooth bottom portion 1g and the other portion 1f.

In this case, the fixed scroll is the same as the conventional one.Since 1f of the orbiting scroll is supported by 2f of the fixed scroll, there is a gap between 1f and 2f between the tip 2g of the fixed scroll's wrap and the bottom 1g of the orbiting scroll. A large clearance is ensured by the difference in clearance width.

In either method, a gap is ensured at the tip of the wrap of the orbiting scroll and the fixed scroll, so it is possible to prevent a gap between the mirror plate surfaces 1f of the orbiting scroll.

Therefore, it is possible to prevent excessive oil from flowing out from the end plate and gas leaking into the suction chamber from the back side of the end plate.

The above-described structure is even more effective by using this structure as a base and surface-treating at least the tip of the wrap with a soft material that has a conformability.

That is, the gap at the tip of the wrap can be kept small and the tip of the wrap can be prevented from getting stuck due to the conformability of the soft material.

〔Effect of the invention〕

The tip of the wrap comes into contact with the tooth bottom of the other scroll, and it is possible to prevent the identification scroll from separating from the outer periphery of the end plate of the orbiting scroll.

As a result, excessive oil leakage from the end plate can be prevented, and stable operation can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the overall structure of a conventional scroll compressor. FIG. 2 is a sectional view showing a conventional fixed scroll. Third
The figure is a sectional view showing a conventional rotary scroll. 4 figures of the body,
FIG. 6 is a top view showing the fixed scroll of the present invention. FIG. 5 and FIG. 7 are sectional views showing the fixed scroll of the present invention. 8th
The figure is a top view showing the orbiting scroll of the present invention. FIG. 9 is a sectional view showing the orbiting scroll of the present invention. 1... Orbiting scroll 1a... End plate 1b...
Wrap 1C... Rotation prevention mechanism 1d... Swivel bearing
1e...Oil supply hole 1f...Mirror plate surface without wrap 1g...Tooth bottom 1h...Wrap tip 2...
・Fixed scroll 2a...End plate 2b...Wrap
2c... Suction hole 2d... Discharge hole 2e... Suction chamber 2f... Part without wrap 2g... Wrap tip 2h... Tooth bottom 2j... Ring-shaped separate body 3
...Crankshaft 3a...Oil supply hole 4...Frame 4a...Notch 4b...Back pressure chamber 4C...1
11111 Uke 4d...Legs 5...Motor 6-pipe casing 7...Discharge gas passage prostrate, iPJM+Takahashi Kiyo f) Tei 1m Rod 25Q Ta 1um d Shore sub-q (flJ 2(/ tα 390 Muramatsu, Shimizu City, Hitachi, Ltd. Mechanical Research Laboratory

Claims (1)

[Claims] 1. An orbiting scroll and a fixed scroll consisting of a plywood (end plate) and a thinly wound wrap standing upright on the end plate are combined with each other with the wraps facing inward, and each wrap and end plate form a shape. In a structure in which both scrolls move relative to each other so that the volume of the space decreases as it moves toward the center of the scroll, the gap at the tip of each wrap is determined by the end plate of the orbiting scroll and does not correspond to the wrap of the identified scroll. A scroll-type fluid machine with tighter gaps between parts. 2. A patent claim having a structure in which a gap is provided at the tip of the wrap of the fixed scroll by providing a slight step between the tip of the wrap of the fixed scroll and a portion corresponding to the portion without wrap of the night plate of the orbiting scroll. Scroll type fluid machine according to item 1. 3. Identification of the end plate of the orbiting scroll A patent claim having a structure in which a slight step is provided between a surface corresponding to the wrap of the scroll and a surface corresponding to a surface other than the wrap of the fixed scroll, and a gap is provided at the tip of the wrap of the fixed scroll. Scroll type fluid machine according to item 1. 4. The scroll-type fluid machine according to item 1, which has a structure in which a gap is provided at the tip of the wrap by installing a separate piece having a minute step on the outer periphery of the fixed scroll. 5. The scroll-type fluid machine according to any one of claims 1 to 4, wherein at least the leading end of the wrap of one or both of the scrolls is subjected to a soft surface treatment having conformability.