JPS5932677B2 - Bearing lubrication device for rotary positive displacement compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bearing lubrication device for a rotary positive displacement compressor with oil injection. Used as a compressor for refrigerators.

A screw compressor will be explained as an example of a rotary positive displacement compressor.

As shown in FIG. 1, a screw compressor consists of a pair of male and female rotors 2, which have tooth profiles that mesh with each other in a casing 1.
3 is included.

Both rotors 2゜3 have bearings 4 and 5 on their shafts at both ends.
, 6°7, the casing lVc is supported and is rotatable.

The casing 1 has an oil injection hole 8 near the meshing line of both rotors 2 and 3, and the casing 1 also has oil supply holes 9 and 10 for supplying oil to the shaft portions of both the rotors 2 and 3.

On the other hand, such a compressor includes an oil separator 11 communicating with a discharge port (not shown) and an oil cooler 12 communicating with the oil separator 11.

A separator element 13 is disposed within the oil separator 11 to separate oil from the air passing therethrough.

The lubricating oil enters the oil cooler 12 from the bottom of the oil separator 11 through the pipe 14, where it is cooled, and then passes through the pipe 15.
will be pumped to.

The cooled oil is branched from the pipe 15 to the oil supply hole 9 through the pipe 16, to the oil supply hole 10 through the pipe 17, and to the oil injection port 8 through the pipe 18.

The oil supplied from the oil supply holes 9 and 10 to each shaft of both rotors 2 and 3 seals gas leakage from each shaft, and a portion of the oil is supplied to each shaft of both rotors 2 and 3.
The remaining portion lubricates the bearing 4, 5, 6, 7, passes through the pipe 19, 20, joins in the middle, and is returned to the suction port 11 of the compressor.

The oil from the oil injection port 8 returned to the suction port 11 and the oil flowing from the bearing toward the end face of the rotor are discharged from a discharge port (not shown) together with air and sent to the oil separator 11.

On the other hand, the oil accumulated in the separator element 13 of the oil separator 11 passes through the return pipe 21, joins the flow of the pipes 19 and 20, and is returned to the suction port 11.

At this time, the compressed air returns to the oil.

In the case of a vertical type, when supplying oil to the bearings 4 and 5, use the oil supply hole 9 on the lower side.
When oil is supplied from the oil supply hole 9 and discharged from the upper side, each bearing 4 and 5 is immersed in oil, so the oil is distributed to every corner of the bearing, resulting in good lubrication. It rotates while being immersed in oil sent from the bearings 4 and 5, and the oil is agitated by the bearings 4 and 5, increasing the temperature of the oil.

As a result, various adverse effects occur as the temperature of the compressor increases, and in particular, oil deterioration is severe and the bearing life is shortened.

It is also conceivable to arrange the oil supply holes 9 for the bearings 4 and 5 above the bearings 4.5.

However, because the gap between the rotor shaft and the casing is narrow, the oil is difficult to drain, and it is inevitable that the bearings 4 and 5 will be immersed, and the discharge pressure will be 7icgf/crj't.
In the case of the compressor y, the oil supply pressure is 6 to 9 f/cdi9, which places a high burden on the seal at the casing penetration part of the rotor shaft.

In order to solve this problem, a lubricating device as shown in FIG. 1 is generally used.

An object of the present invention is to provide a bearing oil supply device for a rotary positive displacement compressor that can suppress oil deterioration.

A feature of the present invention is that the bearing oil supply device includes a plurality of intersecting oil supply holes, a passage for introducing oil from the oil separator into one of the plurality of oil supply holes, and a passage for introducing oil from the oil separator into the other oil supply hole. and a passage for introducing compressed gas.

An embodiment of the present invention will be described below with reference to FIG.

In this figure, the same reference numerals as in FIG. 1 indicate the same elements as the conventional one, and the functions are the same.

An oil supply hole 9 is provided in the bearing cover 22, and a pipe 16 is connected to the oil supply hole 9.

Another oil supply hole 23 is provided in the bearing cover 22 and intersects with the oil supply hole 9.
is provided, and the piping 21 is connected to this.

With this configuration, the oil in the oil supply hole 9 is made into a mist by the oil-mixed air from the oil supply hole 23 and is supplied to the bearings 4 and 5.

This oil is then returned to the suction port 11.

As described above, since the piping that returns the oil accumulated in the separator element of the oil separator is used to turn the oil into a mist and supply the oil to the bearing, the lubrication effect is improved and the cooling effect is also improved.

Furthermore, since the heat of stirring the oil is no longer generated, the deterioration of the oil is reduced and the service life is extended.

Further, oil accumulated in the separator element of the oil separator can be recovered without significantly deteriorating the performance of the compressor.

As described above, according to the present invention, a mist-like oil is supplied to the bearing, so that the lubrication effect is improved, and there is no stirring of the oil in the bearing part, thereby providing a bearing oil supply device that can suppress oil deterioration due to the heat of stirring. can.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional rotary positive displacement compressor, and FIG. 2 is a detailed explanatory diagram of the present invention. 4.5, 6, 7... Bearing, 9, 23... Oil supply hole, 1
1... Oil separator, 13... Separator element,
21... Return piping, 22... Bearing cover.

Claims (1)

[Claims] 1. In a rotary positive displacement compressor equipped with a bearing oil supply device and an oil separator, the bearing oil supply device has a plurality of intersecting oil supply holes, and one of the plurality of oil supply holes receives oil from the oil separator. A bearing lubricating device for a rotary positive displacement compressor, comprising a passage for guiding compressed gas from an oil separator to another oil supply hole.