KR-20260062283-A - Shaft device for scroll type electric compressor capable of improving back pressure

Abstract

The present invention relates to a shaft device for a scroll-type electric compressor, and more specifically, to a shaft device for a scroll-type electric compressor capable of improving the maintenance of back pressure on a rotating scroll. The shaft device of a scroll-type electric compressor according to the present invention is coupled to enable rotation of the rotational scroll of a scroll-type electric compressor, which comprises a fixed scroll and a rotational scroll that rotates in engagement with the fixed scroll to form a compression chamber. Here, the shaft device includes a shaft, an eccentric pin, and a balancing means. The shaft rotates around a central axis. The eccentric pin is coupled to protrude from one end of the shaft, eccentrically from the central axis. The balancing means is located in the back pressure chamber and comprises a bushing portion and a balancing portion. The bushing portion is inserted into the rotational scroll to support the rotational scroll with a bearing, and the eccentric pin is inserted into the eccentric pin to support it so as to rotate. The balancing portion is coupled to one side of the bushing portion so as to be located on one side of the outer circumference of one end of the shaft. And the upper surface facing the pivot scroll is inclined so that when the balancing part rotates together with the shaft, it can pressurize the refrigerant in the back pressure chamber to apply back pressure to the pivot scroll.

Inventors

• 임종학
• 한상욱
• 장수경

Assignees

• 지엠비코리아 주식회사

Dates

Publication Date

20260507

Application Date

20241029

Claims (1)

1. In a shaft device of a scroll-type electric compressor having a fixed scroll and a rotating scroll that rotates in engagement with the fixed scroll to form a compression chamber, the rotating scroll is coupled to be rotatable, A shaft rotating around a central axis, and An eccentric pin coupled to be eccentrically offset from the central axis and protruding at one end of the shaft, and It includes a bushing portion inserted into the aforementioned slewing scroll to support the slewing scroll with a bearing and having the aforementioned eccentric pin inserted therein to be supported so as to rotate on the aforementioned eccentric pin, and a balancing means located in a back pressure chamber having a balancing portion coupled to one side of the bushing portion so as to be positioned on one side of the outer circumference of one end of the shaft. A shaft device of a scroll-type electric compressor, characterized in that the balancing part has an upper surface facing the pivot scroll that is inclined so as to pressurize the refrigerant in the pivot chamber and apply back pressure to the pivot scroll when rotating together with the shaft.

Description

Shaft device for scroll type electric compressor capable of improving back pressure The present invention relates to a shaft device for a scroll-type electric compressor, and more specifically, to a shaft device for a scroll-type electric compressor capable of improving the maintenance of back pressure on a rotating scroll. FIGS. 4 and 5 are conventional scroll-type electric compressors. The conventional scroll-type electric compressor includes a shaft (11), a fixed scroll (13), a rotating scroll (15), a main housing (17), a ring (19), and a pin (21). The shaft (11) rotates by the operation of a motor, and an eccentric pin (70) is inserted at one end of the shaft (11) so as to protrude at a certain distance from the central axis. The fixed scroll (13) is fixed inside the case (10). The pivot scroll (15) engages with the fixed scroll (13) to form a compression chamber (33) and is mounted to rotate around the eccentric pin (70) of the shaft (11). When the shaft (11) rotates, the pivot scroll (15) moves by the pin (70) and performs a pivoting motion. When the pivot scroll (15) performs a pivoting motion, the refrigerant inside the compression chamber (33) is compressed. As explained above, when the shaft (11) rotates, the swivel scroll (15) must perform a swivel motion instead of a rotational motion. To prevent the swivel scroll (15) from performing a rotational motion, a groove is formed on the back of the swivel scroll (15) and a plurality of rings (19) are inserted therein. Additionally, a pin (21) is press-fitted and fixed to the main housing (17) so that one end is inserted into the ring (19). When the shaft (11) rotates, the swivel scroll (15) cannot rotate due to interference with the pin (21) and can only perform a swivel motion. Here, the ring (19) is inserted into the groove with a certain tolerance so that it can rotate inside the groove. This is because if the ring (19) cannot rotate, the frictional force with the pin (21) increases, or noise or wear occurs. The main housing (17) surrounds the rotating scroll (15) and supports the rotating scroll (15). At this time, a back pressure chamber (31) and a low pressure chamber (35) are formed inside the main housing (17). The back pressure chamber (31) is on the inner side of the rotating scroll (15), and the low pressure chamber (35) is on the outer side of the rotating scroll (15). Refrigerant is introduced from the outside into the low-pressure chamber (35), and the refrigerant is supplied from the low-pressure chamber (35) to the compression chamber (33). In the compression chamber (33), the rotating scroll (15) rotates to compress the refrigerant introduced from the low-pressure chamber (35). The compressed refrigerant is discharged to the outside. At this time, because the pressure in the compression chamber (33) is high, the rotating scroll (15) attempts to detach from the fixed scroll (13). To prevent this, a portion of the compressed refrigerant discharged from the compression chamber (33) is supplied to the back pressure chamber (31). The back pressure chamber (31) serves to press the rotating scroll (15) against the fixed scroll (13) using the pressure of the contained compressed refrigerant. FIG. 1 is an enlarged view of a portion of the cross-section of a scroll-type electric compressor equipped with an embodiment of a shaft device according to the present invention. FIG. 2 is a conceptual diagram of one embodiment of a shaft device according to the present invention, FIG. 3 is a front view of the balancing part of the shaft device of FIG. 2. FIG. 4 is a cross-sectional view of a conventional scroll-type electric compressor, FIG. 5 is an example of the operation of the balancing means in a cross-section viewed from BB of FIG. 4. An embodiment of a shaft device according to the present invention is described using FIGS. 1 to 3 with reference to the scroll-type electric compressor shown in FIGS. 4 and 5. Figure 1 is an enlarged view of the part corresponding to "D" of a scroll-type electric compressor as in Figure 4. The shaft device according to the present invention includes a shaft (11), an eccentric pin, and a balancing means (90). The shaft (11) rotates around the central axis. The eccentric pin is coupled to protrude from one end of the shaft (11) by being eccentric from the central axis of the shaft (11), as shown in FIG. 4 (eccentric pin (70)). The balancing means (90) is equipped with a bushing part (91) and a balancing part (93) and is located in the back pressure chamber (31). The bushing part (91) is inserted into the pivot scroll (15) and supports the pivot scroll (15) with a bearing, and an eccentric pin is inserted and supported so as to rotate on the eccentric pin. The balancing part (93) is coupled to one side of the bushing part (91) so as to be located on one side of the outer surface of one end of the shaft (11). Therefore, since the balancing means (90) is mounted to the eccentric pin so as to be rotatable, when the shaft