FR2483534A1 - DEVICE FOR ATTENUATING THE NOISE PRODUCED BY A HERMETIC PISTON COMPRESSOR, AND COMPRESSOR COMPRISING SUCH A DEVICE - Google Patents

Abstract

TO ATTENUATE THE NOISE PRODUCED BY THE PISTON 6 OF A HERMETIC COMPRESSOR, A TAB 19 IS FIXED TO THE SHAFT END 8 OF THE CRANKSHAFT 4, THE END OF WHICH 20 IS IMMERSE IN OIL 10. ROTATION OF THE TONGUE 19 EMULSIZES THE OIL AND THE FOAM PRODUCED REDUCE NOISE. APPLICATIONS: REFRIGERATOR, FREEZER, AIR CONDITIONER AND HEAT PUMP, ETC.

Description

2L248 3534

  The present invention relates to an attenuation device

  noise produced by a hermetic piston compressor.

  The compressors currently used in heating and refrigeration heat pumps are for the most part of the hermetic piston type. Such compressors are simple in construction and have a long service life, but the noise caused in particular by the reciprocating movement of the piston is relatively

high and can be annoying in some cases.

The subject of the present invention is a device allowing

  reduce the noise produced by a hermetic piston compressor.

  According to the present invention, the driving crankshaft is fixed to

  piston between the connecting rod and the lower bearing of the crankshaft, a tongue arranged so that its free end is

immersed in the compressor lubricating oil. Preferably

rence, the tongue is arranged radially with respect to the axis of

  rotation of the crankshaft. Advantageously, the tongue can

  be flat and rectangular, the major axis of the rectangle it forms being parallel to the axis of rotation of the crankshaft, this tongue being an integral part of. ring fixed on the crankshaft for example. In a preferred embodiment, the tongue has dimensions of 12 by 6 mm approximately, and the length taken along the axis of rotation of the crankshaft of the part of the immersed tongue

  in oil, is about 4 to 6 mm.

The present invention will be better understood using the

  detailed description of an embodiment taken as an example

nonlimiting and illustrated by the appended drawing, in which: - Figure 1 is a partial sectional view of a compressor comprising a noise reduction device according to the present invention, and - Figure 2 is a plan view of the noise reduction device

of figure 1.

The compressor shown in Figure 1 is a conventional compressor of the lower piston type. This compressor is enclosed

THR / GLT

- 2483534

  in a hermetic envelope 1, and essentially comprises an electric motor 2, the rotor shaft 3 of which is integral with a crankshaft 4 driving, by means of a connecting rod 5, a piston 6 moving in a cylinder 7. The crankshaft 4 is extends by a shaft end 8 coaxial with respect to the rotor shaft 3. The end

shaft 8 is supported by a bearing device 9.

The hermetic envelope 1 contains a certain quantity of lubricating oil 10 the upper level of which, at rest, is

-figured by a dashed line Il. This higher level arrives sensi-

  clearly at the height of the upper face of the bearing 9, slightly below the piston 6..The compressor being well known in itself, do not

will not be described in more detail.

On the upper part of the shaft end 8 between the upper face of the bearing device 9 and the connecting rod 5, the device 12 is attenuated by force fitting.

noise according to the invention.

The device 12 is produced for example by cutting and stamping a metal sheet having a thickness of approximately 1 mm. The device 12 consists of a ring 13, having an internal diameter practically equal to that of the shaft end 8, this ring 13 extending on one side by a wall 14 extending radially and then by a wall 15 extending axially . The walls 14 and 15 form a cylindrical bowl whose internal diameter is

higher than that of ring 13.

The wall 15 ends in a rim 16 extending radially.

  lement. The rim 16 has a circular crown shape and has an appendage 17 consisting of two parts: a first part 18 lying in the same plane as the rim 16, and a second part or tab 19 perpendicular to the first part and folded towards the ring 13. The tongue 19 extends in a radial plane passing through the axis of the shaft end 8 and has a rectangular shape. In the embodiment shown in the drawing, the rectangle formed by the tongue 19 has dimensions of approximately 12 x 6 mm. The device 12 is fixed to the end of the shaft 8 so that the tongue 19 is directed away from the motor 2 and its lower part 20 is immersed in the oil 10. It is understood that any other suitable device fixing the tongue 19 on the shaft end 8 may be suitable. The height, taken in the axial direction, of the part 20 of the tongue 19 is, in the example shown in the drawing, approximately 6 mm, but could be approximately 4 mm without the acoustic result obtained being

markedly decreased.

  It has been found that for a tongue 19 of the same dimensions, the best result is obtained when the tongue is

  found in a radial plane passing through the axis of the shaft end 8.

  In the example shown, the vertical axis of the tongue 19 is approximately 23 mm from the axis of the shaft end 8, but could be distant from it by a distance of between 20 mm and approximately 26 mm,

taking into account the space available between the bearing 9 and the cylinder 7.

However, this spacing is not very critical and could have other values in the application to compressors of other types.

or other dimensions.

As soon as the engine 2 starts to rotate, the tongue 19 emulsifies the oil 10, mixed with the fluid (for example Freon) compressed by the compressor, and the foam thus produced spreads at least throughout the lower part of the envelope 1 and in particular covers the piston 6 with its connecting rod 5. As long as the engine 2 is running, the foam produced is maintained, and this foam

  attenuates compressor operating noise.

It has been found, in the case of a compressor of the type described above

above, that is to say with lower piston not immersed in the lubricating oil, an attenuation of approximately 6 to 7 dBA of the overall level

  noise produced by the compressor.

2-4 83534

Claims (7)

  1. A device for attenuating the noise produced by a hermetic piston compressor, characterized in that it comprises a tongue (19) fixed on the crankshaft (4) driving the piston (6) between the connecting rod (5) and the lower bearing (9) of the crankshaft, this tongue (19) being arranged so that its free end (20) is immersed in the lubricating oil (10) of the compressor. 2. Device according to claim 1, characterized in that the tongue (19) is arranged radially relative to the axis of rotation of the crankshaft (4).   3. Device according to any one of claims 1 and 2,   characterized by the fact that the tongue (19) is flat and rectan   gular, the large axis of the rectangle which it forms being parallel to the axis of rotation of the crankshaft (4). 4. Device according to any one of the preceding claims.   teeth, characterized in that the tongue (19) is part integral with a ring (13) fixed on the crankshaft (4).   5. Device according to any one of claims 3 and 4,   characterized in that the tongue (19) has dimensions of 12 x 6 mm approximately. 6. Device according to claim 5, characterized in that the length, taken along the axis of rotation of the crankshaft (4), of the part (20) of the tongue (19) immersed in the oil (10), at rest, is approximately 4 to 6 mm.   7. Hermetic piston compressor 'characterized in that it comprises a noise attenuation device according to any one of the preceding claims.