JPH0219675A - Thrust bearing mechanism for scroll compressor - Google Patents

Abstract

PURPOSE:To make the speed of a compressor higher and prevent the autorotation of a revolving scroll by providing an auxiliary crank which is revolved eccentrically or rotated at the same time as the eccentric revolving movement of the revolving scroll and supporting both ends by means of antifriction bearings which receive thrust. CONSTITUTION:When a main crank shaft 4 is rotated taking an axis Z1 as a center, the portion 4b of the shaft 4 is eccentric in an eccentric quantity (e) so as to perform revolving movement. This movement is transmitted to an auxiliary crank 12 through a revolving scroll 1, and the eccentric quantity E of the crank 12 is equal to the eccentric quantity (e) of the shaft 4, and thereby the crank 12 is rotated taking an axis Z3 as a center. As a result, the portion 4b of the shaft 4, the scroll 1, the crank 12 and an end portion 18 on the scroll 1 side perform revolving movement with the eccentric quantity (e) at the same time. The crank 12 functions in the same way as an Oldham's coupling for prevention of autorotation, and the scroll 1 is connected to a lower casing 7 through the crank 12 at three places, and thereby the autorotation of the scroll 1 prevented. Also the rotation increase of the axis Z3 of the crank does not influence the thrust load of bearings 14, 16, and thereby higher speed can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a scroll compressor for compressing air, gas, water vapor, and other gases, such as a dry oilless scroll compressor.

[Prior Art] First, a scroll compressor will be described with reference to FIG.

In FIG. 3, the scroll compressor is an orbiting scroll 1
, a fixed scroll (upper casing) 2, a main crankshaft 4, and a lower casing 7. Main crankshaft 4
consists of a portion 4a having a central axis at Zl and a portion 4b having a central axis at Z2.A bearing 3 is attached to the portion 4b, and a bearing 8 supports the portion 4a. Here, the symbol e indicates the displacement of the central axes Z1 and Z22, that is, the amount of eccentricity of the main crankshaft 4.

A mechanism 6 is arranged between the orbiting scroll 1 and the lower casing 7 to receive a force in the thrust direction and to prevent the orbiting scroll 1 from rotating. Note that numeral 5 indicates a balance weight.

During operation, when the main crankshaft 4 rotates around the axis Z1, the orbiting scroll 1 performs an eccentric rotation movement with an eccentric amount e, whereby the gas sucked in from the suction port A is compressed and discharged from the discharge port B. . Here, the mechanism 6 is
It acts to prevent the orbiting scroll 1 from rotating around the axis Z2 during the eccentric rotation movement.

Here, the scroll compressor has a pressure of 1! on a so-called dry oil-less scroll that does not inject liquid during the orbiting scroll! ! In the case of a machine, oil-less dry metal has conventionally been used as a means for receiving force in the thrust direction in the mechanism 6.

[Problem M to be Solved by the Invention] However, due to friction between the oilless dry metal and the orbiting scroll, mechanical loss occurs when the scroll pressure m machine rotates. In addition, if the eccentric rotation speed of the orbiting scroll becomes high, it will exceed the allowable limit of oil-less dry metal, so conventional scroll compressors using oil-less dry metal select a high rotation speed (swivel speed). However, there was a problem in that the volumetric efficiency and compressor efficiency would become low.

The present invention has been proposed in view of the problems of the prior art described above, and is capable of reducing mechanical loss during rotating motion, increasing the permissible rotating speed of a scroll compressor, and reducing the mechanical loss during eccentric rotating motion. It is an object of the present invention to provide a thrust bearing mechanism for a scroll compressor that can prevent rotation of an orbiting scroll.

[Means for Solving the Problems] The thrust bearing mechanism for a scroll compressor of the present invention includes three or more auxiliary bearings in the circumferential direction in the thrust bearing mechanism for a scroll compressor disposed between an orbiting scroll and a casing. A crankshaft is disposed, and both ends of the auxiliary crank are supported by rolling bearings provided on the orbiting scroll and rolling bearings provided on the casing, respectively.

In order to allow the eccentric rotation movement of the orbiting scroll, the eccentricity of the auxiliary crank is set to be the same as the eccentricity of the main crankshaft.

Further, when used in a dry oilless scroll compressor, it is preferable to select a shielded rolling bearing as the rolling bearing.

[Function] According to the thrust bearing for a scroll compressor of the present invention, the thrust generated in the orbiting scroll during eccentric orbiting movement is transferred to the casing via the rolling bearing provided in the orbiting scroll, the auxiliary crank, and the rolling bearing provided in the casing. transmitted to the side. Here, since the allowable limit for eccentric rotation speed is much larger for rolling bearings than for oil-less dry metal, scroll compressors using the thrust bearing structure of the present invention do not use conventional oil-less dry metal. Its turning speed can be increased compared to previous models. As a result, volumetric efficiency and compressor efficiency are also improved. Furthermore, since rolling bearings have a longer lifespan than oilless dry metal bearings, the thrust bearing mechanism for scroll compressors of the present invention can be used for a longer period of time without being replaced than conventional ones. .

Further, since the orbiting scroll and the casing are connected by an auxiliary crank having a predetermined eccentricity, smooth eccentric rotation movement of the orbiting scroll is possible. and,
The auxiliary crank functions in the same manner as an Oldham joint for preventing rotation, and the orbiting scroll does not rotate on its own axis (rotating around axis Z2 in FIG. 3).

Furthermore, during eccentric turning motion, the auxiliary crank rotates in accordance with the turning speed, but its ends are supported by rolling bearings and the frictional resistance is extremely small, resulting in mechanical loss (so-called mechanical loss) during turning. ) also becomes extremely small.

[Example] Examples of the present invention will be described below.

Scroll pressure using the thrust bearing fill of the present invention! ! ! The structure of the machine is almost the same as that shown in Figure 3, but
The structure of the portion corresponding to the mechanism 6 in the figure is different.

That is, in contrast to the conventional mechanism 6 shown in FIG. 3, the thrust bearing mechanism 10 for a scroll compressor of the present invention has a structure as shown in FIG. 1.

In FIG. 1, the thrust bearing mechanism 10 includes an auxiliary crank 12, a shielded rolling bearing 14 provided on the orbiting scroll 1, and a shielded rolling bearing 16 provided on the lower casing 7. The shielded rolling bearing 14 supports the end 18 of the auxiliary crank 12 on the orbiting scroll 1 side, while the shielded rolling bearing 16 supports the end 20 of the auxiliary rank 12 on the lower casing 7 side. Here, the eccentricity E of the auxiliary crank 12 is:
Same as eccentricity C of main crankshaft 4 (Fig. 3) (e=E)
For example, if the eccentricity e of the main crankshaft 4 is 3ym, the eccentricity E of the auxiliary crank 12 is also set to 3IIIT+.

As is clear from Fig. 2, this thrust bearing a treetop 10
are provided at three locations in the circumferential direction, and are arranged at equal intervals in order to equalize the thrust load on each thrust bearing mechanism 10.

When operating the scroll compressor equipped with the above-mentioned thrust bearing mechanism 10, the main crankshaft 4 is rotated about the axis Z1 by a power source not shown in FIG. Then, the portion 4b of the main crankshaft 4 is eccentric by the eccentricity jle and performs a turning movement. This eccentric turning movement is transmitted to the auxiliary crank 12 via the orbiting scroll 1, and here, the eccentricity IE of the auxiliary crank 12 (Fig. ) is equal to the eccentricity e of the main crankshaft 4, so the auxiliary crank 12 rotates about the axis Z3 (FIG. 1). As a result, the portion 4b of the main crankshaft 4 (Fig. 3), the orbiting scroll 1, and the auxiliary crank 12 (the end portion 18 on the orbiting scroll 1 side in Fig. 1) synchronously perform the orbiting motion of the eccentricity jle (=E). Here, the auxiliary crank 12 functions similarly to an Oldham joint for preventing rotation, and the orbiting scroll 1 is connected to the lower casing 7 via the auxiliary crank 12 at three points.
Rotation of the orbiting scroll (rotation movement around axis Z2)
is completely prevented.

At this time, the thrust generated in the orbiting scroll 1 is transmitted to the lower casing 7 via the shield rolling bearing 14, the auxiliary crank 12, and the shield rolling bearing 16. Here, even if the orbiting speed of the orbiting scroll 1, that is, the rotation speed of the shaft Z3 of the auxiliary crank 12 becomes considerably large, the thrust load function of the shielded rolling bearings 14 and 16 is not affected. This makes it possible to increase the operating speed of the scroll compressor by increasing the

Furthermore, during eccentric turning, the auxiliary crank 12 rotates around the axis Z3 as described above, but this rotation is supported by the shielded rolling bearing 16 and the frictional resistance is extremely small, so the mechanical loss (mechanical loss) is also extremely small. Become.

In the illustrated embodiment, three thrust bearings 10 are provided, but four or more thrust bearings may be provided.

[Effects of the Invention] According to the thrust bearing mechanism for a scroll compressor of the present invention as described above, an auxiliary crank is provided which rotates or rotates eccentrically in synchronization with the eccentric rotation movement of the orbiting scroll, and both ends of the auxiliary crank are provided with rolling bearings that receive thrust. By supporting the scroll, mechanical loss is reduced, the speed of the scroll compressor can be increased, and rotation of the orbiting scroll is prevented.

Further, if a shielded rolling bearing is used as the rolling bearing, it can be suitably used for dry oilless scroll pressure 5e11 in which oil does not enter the compressor. Furthermore, by filling the shielded rolling bearing with long-life grease, the lubrication life of the shielded rolling bearing becomes considerably long, so that the life of the entire thrust bearing mechanism is also extended.

The thrust bearing mechanism for scroll compressors of the present invention is not only applicable to dry oil-less scroll pressure IA machines, but can also be used as is for oil-cooled scroll compressors that inject oil into the scroll. can. In this case, open-type rolling bearings may be used.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view showing a thrust bearing machine for scroll pressure MNa according to the present invention, Fig. 2 is a view taken along the X arrow in Fig. 1, and Fig. 3 is a scroll compressor using a conventional thrust bearing mechanism. FIG. 1... Orbiting scroll 2... Fixed scroll (
Upper casing) 4... Main crankshaft 6...
・Conventional ja side 7...lower casing 10・
・・Thrust bearing R structure for scroll pressure wIR 12・
... Auxiliary crank 14 ... Shield rolling bearing provided in the orbiting scroll 16 ... Shield rolling bearing A provided in the lower casing ・ ・ ・ Suction port/discharge port/eccentricity amount... Shaft diagram Diagram

Claims (1)

[Claims] In a thrust bearing mechanism for a scroll compressor disposed between an orbiting scroll and a casing, three or more auxiliary crankshafts are arranged in the circumferential direction, and both ends of the auxiliary cranks are connected to rolling bearings provided on the orbiting scroll and A thrust bearing mechanism for a scroll compressor, characterized in that each is supported by rolling bearings provided in a casing.