WO2002053916A1

WO2002053916A1 - Scroll pump with pressure chamber and low pressure chamber

Info

Publication number: WO2002053916A1
Application number: PCT/KR2001/002283
Authority: WO
Inventors: Pill-Chan Rha; Nam-Sik Joo; Jin-Woong Choi; Hun-Kun Lim; Su-Youn Lee
Original assignee: Pill-Chan Rha; Nam-Sik Joo; Jin-Woong Choi; Hun-Kun Lim; Su-Youn Lee
Priority date: 2000-12-28
Filing date: 2001-12-28
Publication date: 2002-07-11

Abstract

Disclosed is a scroll pump. The scroll pump comprises a driving rotation member rotated by a driving shaft; a housing unrotatably held while surrounding the driving rotation member, with the driving shaft passing through a center of the housing; an orbiting rotation member coupled to the driving rotation menber by three camshafts such that it is supported by front and rear walls of the housing with a predetermined eccentricity to be orbitally rotated about the camshafts; a high pressure section possessing three high pressure scroll chambers into which fluid is sucked to be compressed to a high pressure; and a low pressure section possessing one low pressure scroll chamber into which high pressure fluid outputted from the high pressure scroll chambers is colected to be compressed to a low pressure and then be stably discharged out of the housing.

Description

SCROLL PUMP WITH HIGH PRESSURE CHAMBER AND LOW PRESSURE CHAMBER

Technical Field

The present invention relates to a scroll pump having a high pressure chamber and a low pressure chamber, and more particularly, the present invention relates to a scroll pump having a high pressure section and a low pressure section, which is adapted for allowing the high pressure section and the low pressure section to be operated in an interlocked manner by rotation of a single driving shaft, thereby augmenting fluid suction force and stably discharging fluid sucked under a high pressure.

Background Art

In general, scroll fluid machines are well known in the art. Since the scroll fluid machines can perform functions of compressing, expanding, and pumping fluid, they can be manufactured as a compressor, an expander, a vacuum pump, etc.

A conventional scroll pump performs a compression function using orbiting motion of an orbiting scroll member around a fixed scroll member. The fixed scroll member is fixed to a pump body, and the orbiting scroll member is coupled to a separate driving section. As a consequence, at and orbits around the fixed scroll member, the orbiting scroll member is brought into line contact with the fixed scroll member to compress or expand fluid.

The conventional scroll pump constructed as mentioned above has a structural limitation in that it can be used for a low level of but not for a high level of output pressure.

To cope with this structural limitation, recently, various scroll pumps capable of accomplishing a high level of output pressure have been disclosed in the art . Referring to FIGs. 17 and 18, there is illustrated a multi-scroll pump as described in Korean Patent Application

No. 2000-31805 filed in the name of the present applicant. A construction of the multi-scroll pump will be described below.

/ The conventional multi-scroll pump includes a housing 100 and an orbiting member 200. The housing 100 has a fluid collecting chamber 101, and at least three scroll chambers 102 which are defined around and communicated with the fluid collecting chamber 101 in a manner such that they are spaced apart one from another by the same angle along a circumferential direction. An outlet hole 101a is defined at a center portion of a front wall of the housing 100 to be communicated with the fluid collecting chamber 101, and an inlet hole 101b is defined at a center of each scroll chamber 102 through a rear wall of the housing 100 to be communicated with the scroll chamber 102. A space is defined between two adjoining scroll chambers 102 in the housing 100 to extend in a radial direction. The orbiting member 200 is disposed in spaces defined in the housing 100. The orbiting member 200 has at least three orbiting scroll sections 201 which are respectively disposed in the scroll chambers 102. A driving camshaft 202 is centrally fitted through the orbiting member 200, and at least three support camshafts 203 respectively pass through the orbiting scroll sections 201 around the driving camshaft 202 to extend in an axial direction. Both ends of each support camshaft 203 are respectively inserted into grooves which are defined on inner surfaces of the front and rear walls of the housing 100. At least one fluid passing hole 204 is defined through the orbiting member 200.

Hence, upon operation of the conventional scroll pump constructed as mentioned above, as the driving camshaft 202 centrally extending through the housing 100 is rotated, an eccentric cam portion which is formed at a middle portion of the driving camshaft 202 is integrally rotated, and thereby, the orbiting scroll sections 201 having base portions through which the eccentric cam portion of the driving camshaft 202 is fitted, are orbitally rotated. At the same time, the support camshafts 203, which are spaced apart one from another by the same angle along the circumferential direction, are integrally rotated through the orbiting rotation of the orbiting scroll sections 201. Each support camshaft 203 serves to limit an orbiting rotation range of the orbiting scroll section 201 to a certain extent .

That is to say, if the orbiting member 200 is orbitally rotated, the orbiting scroll sections 201, which are integrated with the orbiting member 200 while spaced apart one from another by the same angle along the circumferential direction, are orbitally rotated in their respective scroll chambers 102 defined in the housing 100. By this fact, a shape and a displacement of each transfer plenum bounded in each scroll chamber 102 by wall portions of an orbiting scroll of the orbiting scroll section 201 and of a fixed scroll of the housing 100 continuously vary in a state wherein the orbiting scroll and the fixed scroll are interleaved one on the other. Therefore, fluid introduced into the scroll chambers 102 through inlet holes 101b is transferred to the fluid collecting chamber 101 defined in a center portion of the housing 100, in a state wherein it is filled in transfer plenums defined in the respective scroll chambers 102. Then, the fluid is discharged through the outlet hole 101a which is defined through the front wall of the housing 100 and communicated with the fluid collecting chamber 101, to an appropriate fluid delivery line.

The conventional scroll pump constructed as mentioned above, while able to accomplish a high level of output pressure, suffers from defects in that, since vibration is induced due to cam operation of the driving camshaft 202 and the support camshafts 203, operation noise is substantially generated.

Further, in view of the fact that the formerly mentioned low-pressure scroll pump can stabilize fluid discharge and the latterly mentioned high-pressure scroll ^'pump can obtain augmented fluid suction force, a scroll pump capable of ensuring stable fluid discharge and augmenting fluid suction force has drawn considerable attention in the art.

Disclosure of the Invention

Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to provide a scroll pump having a high pressure section and a low pressure section, which is adapted for allowing the high pressure section and the low pressure section to be operated in an interlocked manner by rotation of a single driving shaft, thereby improving a fluid suction efficiency and ensuring stable fluid discharge . Another object of the present invention is to provide a scroll pump which is configured to enable a driving rotation member to be rotated integrally with a driving shaft and an orbiting rotation member to be orbitally rotated in a housing, and is adapted for allowing fluid to be transferred between high and low pressure sections formed between the driving rotation member and orbiting rotation member, thereby minimizing vibration upon operation of the high and low pressure sections and enhancing its operational precision. Still another object of the present invention is to provide a scroll pump which allows high and low pressure sections to be formed in a single housing, thereby contributing to a decrease in its volume .

Yet still another object of the present invention is to provide a scroll pump which allows high and low pressure sections to be respectively formed in two separate housings, thereby maximizing a fluid suction efficiency and ensuring stabilized fluid discharge.

According to one aspect of the present invention, there is provided a scroll pump comprising: a driving rotation member rotated by a driving shaft through which fluid is sucked into the scroll pump; a housing for surrounding the driving rotation member, the housing being unrotatably held, the driving shaft passing through a center of the housing; an orbiting rotation member coupled to the driving rotation member in the housing by means of at least three camshafts in a manner such that it envelops the driving rotation member and is supported by front and rear walls of the housing with a predetermined eccentricity with respect to a center of the driving shaft to be orbitally rotated about the camshafts through rotation of the driving rotation member; a high pressure section formed between a front surface of the driving rotation member and a front wall of the orbiting rotation member, and possessing at least three high pressure scroll chambers into which fluid is sucked after flowing through the driving shaft and first fluid paths defined in the driving rotation member, to be compressed to a high pressure; and a low pressure section formed between a rear surface of the driving rotation member and a rear wall of the orbiting rotation member, and possessing at least one low pressure scroll chamber which has a fluid accommodating capacity greater than the high pressure scroll chamber and into which high pressure fluid outputted from the high pressure scroll chambers is collected to be compressed to a low pressure and then be stably discharged.

According to another aspect of the present invention, there is provided a scroll pump comprising: first and second driving rotation members mounted on and rotated by a driving shaft through which fluid is sucked into the scroll pump; first and second housings for respectively surrounding the first and second driving rotation members, the first and second housings being unrotatably held, the driving shaft passing through a common center of the first and second housings; first and second orbiting rotation members coupled to the first and second driving rotation members in the first and second housings, respectively, each by means of at least three camshafts, in a manner such that they envelop the first and second driving rotation members and are supported by front and rear walls of the first and second housings with a predetermined eccentricity with respect to a center of the driving shaft to be orbitally rotated about the camshafts through rotation of the first and second driving rotation members; a high pressure section formed, in the first housing, between front and rear surfaces of the first driving rotation member and front and rear walls of the first orbiting rotation member, and possessing at least three pairs of high pressure scroll chambers into which fluid is sucked after flowing through the driving shaft and first fluid paths defined in the first driving rotation member, to be compressed to a high pressure; a low pressure section formed, in the second housing having an outlet port, between front and rear surfaces of the second driving rotation member and front and rear walls of the second orbiting rotation member, and possessing a pair of low pressure scroll chambers each of which has a fluid accommodating capacity greater than the high pressure scroll chamber and into which high pressure fluid outputted from the high pressure scroll chambers is collected to be compressed to a low pressure; and a connection tube for connecting the first and second housings with each other to allow fluid to be delivered from the high pressure section to the low pressure section.

Brief Description of the Drawings

The above objects, and other features and advantages of the present invention will become more apparent after a reading of the following detailed description when taken in conjunction with the drawings, in which:

FIG. 1 is a cross-sectional view illustrating a scroll pump in accordance with a first embodiment of the present invention; FIG. 2 is a cross-sectional view taken along the line A-

A of FIG. 1;

FIG. 3 is a cross-sectional view taken along the line B- B of FIG. 1;

FIG. 4 is a partial enlarged cross-sectional view of the ^λC part of FIG. 1;

FIG. 5 is a schematic view illustrating a positional relationship among a driving shaft, camshafts and an orbiting rotation member in the scroll pump according to the first embodiment of the present invention; FIG. 6 is a cross-sectional view illustrating a scroll pump in accordance with a second embodiment of the present invention;

FIG. 7 is a cross-sectional view taken along the line D- D of FIG. 6; FIG. 8 is a cross-sectional view taken along the line E- E of FIG. 6;

FIG. 9 is a partial enlarged cross-sectional view of the ^λF' part of FIG. 6; FIG. 10 is a schematic view illustrating a positional relationship among a driving shaft, camshafts and an orbiting rotation member in the scroll pump according to the second embodiment of the present invention;

FIG. 11 is a cross-sectional view illustrating a scroll pump in accordance with a third embodiment of the present invention;

FIG. 12 is a cross-sectional view taken along the line G-G of FIG. 11;

FIG. 13 is a cross-sectional view taken along the line H-H of FIG. 11;

FIG. 14 is a partial enlarged cross-sectional view of the 'I' part of FIG. 11;

FIG. 15 is a partial enlarged cross-sectional view of the J' part of FIG. 11,- FIG. 16 is a schematic view illustrating a positional relationship among a driving shaft, camshafts and an orbiting rotation member in the scroll pump according to the third embodiment of the present invention;

FIG. 17 is a cross-sectional view illustrating a conventional scroll pump; and FIG. 18 is a cross-sectional view taken along the line K-K of FIG. 17.

Best Mode for Carrying Out the Invention Reference will now be made in greater detail to a preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts . FIG. 1 is a cross-sectional view illustrating a scroll pump in accordance with a first embodiment of the present invention; FIG. 2 is a cross-sectional view taken along the line A-A of FIG. 1; and FIG. 3 is a cross-sectional view taken along the line B-B of FIG. 1. A construction of the scroll pump according to the first embodiment of the present invention will be described below.

The scroll pump comprises a driving rotation member 2, a housing 3, an orbiting rotation member 4, a high pressure section 5, and a low pressure section 6. The driving rotation member 2 can be rotated by a driving shaft 1 through which fluid is sucked into the scroll pump. The housing 3 surrounds the driving rotation member 2 and is unrotatably held with respect to the driving shaft 1. The driving shaft 1 passes through a center of the housing 3. The orbiting rotation member 4 is coupled to the driving rotation member 2 in the housing 3 by means of at least three camshafts C in a manner such that it envelops the driving rotation member 2 and is supported by front and rear walls of the housing 3 with a predetermined eccentricity with respect to a center of the driving shaft 1 to be orbitally rotated about the camshafts C through rotation of -the driving rotation member 2. The high pressure section 5 is formed between a front surface of the driving rotation member 2 and a front wall of the orbiting rotation member 4. The high pressure section 5 possesses at least three high pressure scroll chambers 51 into which fluid is sucked after flowing through the driving shaft 1 and first fluid paths 21 which are defined in the driving rotation member 2 , to be compressed to a high pressure . The low pressure section 6 is formed between a rear surface of the driving rotation member 2 and a rear wall of the orbiting rotation member 4. The low pressure section 6 possesses at least one low pressure scroll chamber 61 which has a fluid accommodating capacity greater than the high pressure scroll chamber 51 and into which high pressure fluid outputted from the high pressure scroll chambers 51 is collected to be compressed to a low pressure and then be stably discharged.

In particular, at least three high pressure scroll chambers 51 are defined between the front surface of the driving rotation member 2 and the front wall of the orbiting rotation member 4 in a manner such that they are spaced apart one from another by the same angle along a circumferential direction and fluid is sucked into the high pressure scroll chambers 51 after flowing through the driving shaft 1 and the first fluid paths 21 which are defined in the driving rotation member 2, to be compressed to the high pressure. Further, a single low pressure scroll chamber 61 is defined between the rear surface of the driving rotation member 2 and the rear wall of the orbiting rotation member 4 in a manner such that high pressure fluid outputted from the high pressure scroll chambers 51 is collected into the low pressure scroll chamber 61 after passing through second fluid paths 22 which are defined in the orbiting rotation member 4, to be compressed to the low pressure and then be discharged out of the housing 3. A pair of sleeve portions 42 are projectedly formed integrally with the front and rear walls, respectively, of the orbiting rotation member 4 in a manner such that they have the predetermined eccentricity with respect to the center of the driving shaft 1. The orbiting rotation member 4 is supported around the pair of sleeve portions 42 by the front and rear walls of the housing 3 via a pair of first bearings B, respectively.

A pair of circular openings 31 are respectively defined through the front and rear walls of the housing 3 in a manner such that they have the same center as the driving shaft 1. A pair of second bearings B are respectively intervened between inner edges of the housing 3, defining the circular openings 31, and the driving shaft 1, to allow the housing 3 to be fixedly held with respect to the driving shaft 1 even when the driving shaft 1 is rotated.

In each of the high and low pressure scroll chambers 51 and 61, a rotating scroll SI, which is formed integrally with the driving rotation member 2, and an orbiting scroll S2 , which is formed integrally with the orbiting rotation member 4, are interleaved one on the other to compress fluid to the high or low pressure.

FIG. 4 is a partial enlarged cross-sectional view of the ^λC part of FIG. 1. The driving rotation member 2 is defined, adjacent to an outer edge thereof, with at least three cam fitting holes 23 in a manner such that an eccentric cam portion Cl which is formed at a middle portion of each camshaft C is rotatably fitted into each cam fitting hole 23. The front and rear walls of the orbiting rotation member 4 are defined, adjacent to a common outer edge where they are integrated with each other, with at least three pairs of shaft fitting holes 41 in a manner such that a pair of shaft portions C2 which are formed at both ends of the eccentric cam portion Cl of each camshaft C are rotatably fitted into each pair of shaft fitting holes 41, respectively. FIG. 5 is a schematic view illustrating a positional relationship among the driving shaft, camshafts and orbiting rotation member in the scroll pump according to the first embodiment of the present invention. A distance LI measured between a center of the sleeve portions 42 and the center of the driving shaft 1 corresponds to a distance L2 measured between a center of the eccentric cam portion Cl and a center of the shaft portions C2 of each camshaft C.

Hereafter, operation of the scroll pump according to the first embodiment of the present invention will be described. As shown in FIGs . 1 through 5, if the driving rotation member 2 is rotated by actuation of the driving shaft 1, the orbiting rotation member 4 which envelops the driving rotation member 2 is orbitally rotated about the camshafts C in an interlocked manner. Namely, the driving rotation member 2 is rotated about the driving shaf 1. And, other than the driving rotation member 2, the orbiting rotation member 4 is eccentrically rotated around the driving shaft 1 while being supported by the housing 3 with the predetermined eccentricity with respect to the center of the driving shaft 1. That is to say, the orbiting rotation member 4 is orbitally rotated about the camshafts C.

Thus, if the orbiting rotation member 4 is orbitally rotated outward of the driving rotation member 2, fluid is sucked into the high pressure scroll chambers 51 which are defined between the front surface of the driving rotation member 2 and the front wall of the orbiting rotation member 4, after flowing through the driving shaft 1 and the first fluid paths 21 which are defined in the driving rotation member 2. Then, the fluid is compressed to the high pressure. Thereafter, the fluid compressed to the high pressure is collected through the second fluid paths 22 into the low pressure scroll chamber 61 which is defined between the rear surface of the driving rotation member 2 and the rear wall of the orbiting rotation member 4, and compressed to the low pressure. Then, the fluid is discharged out of the housing 3.

In other words, if the driving rotation member 2 is rotated and the orbiting rotation member 4 is orbitally rotated, in each of the high pressure scroll chambers 51 which are defined on the front surface of the driving rotation member 2, as a shape and a displacement of each transfer plenum bounded by wall portions of the rotating scroll SI and the orbiting scroll S2 continuously vary in a state wherein the rotating scroll SI and the orbiting scroll S2 are interleaved one on the other, the fluid can be compressed to the high pressure as described above. Also, in the single low pressure scroll chamber 61 which is defined on the rear surface of the driving rotation member 2, as a shape and a displacement of each transfer plenum bounded by wall portions of the rotating scroll SI and the orbiting scroll S2 continuously vary in a state wherein the rotating scroll SI and the orbiting scroll S2 are interleaved one on the other, the fluid can be compressed to the low pressure as described above .

Therefore, since fluid is sucked into the high pressure scroll chambers 51 after flowing through the driving shaft 1 and the first fluid paths 21, a fluid suction force is maximized, and thereby, a high level of output pressure can be accomplished. Also, since the high pressure fluid outputted from the high pressure scroll chambers 51 is compressed to the low pressure in the low pressure section 6, it. is possible to stably discharge fluid out of the housing 3.

Further, due to the fact that the driving rotation member 2 and the orbiting rotation member 4 are simultaneously rotated while the scrolls SI and S2 are brought into orbital contact with each other, it is possible to minimize vibration upon operation of the scroll pump according to the present invention.

Meanwhile, when the rotating scroll SI is brought into contact with the orbiting scroll S2, although contact portions between the rotating scroll SI and the orbiting scroll S2 are continuously changed, it is to be noted that a contact position between the rotating scroll SI and the orbiting scroll S2 always resides on a line which connects the center of the driving shaft 1 and the center of each camshaft C, whereby operation of the entire scroll pump can be stabilized. FIG. 6 is a cross-sectional view illustrating a scroll pump in accordance with a second embodiment of the present invention; FIG. 7 is a cross-sectional view taken along the line D-D of FIG. 6; and FIG. 8 is a cross-sectional view taken along the line E-E of FIG. 6. A construction of the scroll pump according to the second embodiment of the present invention will be described below.

The scroll pump comprises a driving rotation member 2, a housing 3 , and an orbiting rotation member 4. The driving rotation member 2 can be rotated by a driving shaft 1 through which fluid is sucked into the scroll pump. The housing 3 surrounds the driving rotation member 2 and is unrotatably held with respect to the driving shaft 1. The driving shaft 1 passes through a center of the housing 3. The orbiting rotation member 4 is coupled to the driving rotation member 2 in the housing 3 by means of at least three camshafts C in a manner such that it is supported by front and rear walls of the housing 3 with a predetermined eccentricity with respect to a center of the driving shaft 1 to be orbitally rotated about the camshafts C through rotation of the driving shaft 1.

In this second embodiment of the present invention, a cover part 23 is formed integrally with an edge of the driving rotation member 2, and the orbiting rotation member 4 comprises a pair of separate orbiting rotation segments which are coupled to the driving rotation member 2 and respectively interposed between front and rear surfaces of the driving rotation member 2 and front and rear walls of the cover part 23.

At least three pairs of high pressure scroll chambers 51 are defined between the front and rear surfaces of the driving rotation member 2 and the pair of orbiting rotation segments of the orbiting rotation member 4 in a manner such that the three pairs are spaced apart one from another by the same angle along a circumferential direction and fluid is sucked into the high pressure scroll chambers 51 after flowing through the driving shaft 1 and first fluid paths 24 defined in the driving rotation member 2 to be compressed to a high pressure. A pair of low pressure scroll chambers 61 are defined between the front and rear walls of the cover part 23 and the pair of orbiting rotation segments of the orbiting rotation member 4 in a manner such that high pressure fluid outputted from the high pressure scroll chambers 51 is collected into the low pressure scroll chambers 61 after passing through second fluid paths 25 defined in the cover part 23 to be compressed to a low pressure and then be discharged out of the housing 3 through the driving sha t 1.

A pair of sleeve portions 42 are projectedly formed integrally with the pair of orbiting rotation segments, respectively, of the orbiting rotation member ^'4 in a manner such that they have the predetermined eccentricity with respect to the center of the driving shaft 1. The orbiting rotation member 4 is supported around the pair of sleeve portions 42 by the front and rear walls of the housing 3 via a pair of first bearings B, respectively. A pair of circular openings 31 are respectively defined through the front and rear walls of the housing 3 in a manner such that they have the same center as the driving shaft 1. A pair of second bearings B are respectively intervened between inner edges of the housing 3 , defining the circular openings 31, and the driving shaft 1, to allow the housing 3 to be fixedly held with respect to the driving shaft 1 even when the driving shaft 1 is rotated.

In each of the high and low pressure scroll chambers 51 and 61, a rotating scroll SI, which is formed integrally with the driving rotation member 2 or the cover part 23, and an orbiting scroll S2, which is formed integrally with the orbiting rotation member 4, are interleaved one on the other to compress fluid to the high or low pressure.

FIG. 9 is a partial enlarged cross-sectional view of the ^XF' part of FIG. 6. The driving rotation member 2 is defined, adjacent to an outer edge thereof, with at least three cam fitting holes 21 in a manner such that an eccentric cam portion Cl which is formed at a middle portion of each camshaft C is rotatably fitted into each cam fitting hole 21. The pair of orbiting rotation segments of the orbiting rotation member 4 are defined, adjacent to outer edges thereof, with at least three pairs of shaft fitting holes 41 in a manner such that a pair of shaft portions C2 which are formed at both ends of the eccentric cam portion Cl of each camshaft C are rotatably fitted into each pair of shaft fitting holes 41, respectively.

FIG. 10 is a schematic view illustrating a positional relationship among the driving shaft, camshafts and orbiting rotation member in the scroll pump according to the second embodiment of the present invention. A distance LI measured between a center of the sleeve portions 42 and the center of the driving shaft 1 corresponds to a distance L2 measured between a center of the eccentric cam portion Cl and a center of the shaft portions C2 of each camshaft C. Hereafter, operation of the scroll pump according to the second embodiment of the present invention will be described.

As shown in FIGs. 6 through 10, if the driving rotation member 2 is rotated by actuation of the driving shaft 1, the pair of orbiting rotation segments of the orbiting rotation member 4 are orbitally rotated about the camshafts C in an interlocked manner. Namely, the driving rotation member 2 is rotated about the driving shaft 1. And, other than the driving rotation member 2, the pair of orbiting rotation segments of the orbiting rotation member 4 are eccentrically rotated around the driving shaft 1 while being supported by the housing 3 with the predetermined eccentricity with respect to the center of the driving shaft 1. That is to say, the pair of orbiting rotation segments of the orbiting rotation member 4 are orbitally rotated about the camshafts C. Thus, if the pair of orbiting rotation segments of the orbiting rotation member 4 are orbitally rotated outward of the driving rotation member 2 , fluid is sucked into the high pressure scroll chambers 51 which are defined between the front and rear surfaces of the driving rotation member 2 and the pair of orbiting rotation segments of the orbiting rotation member 4, after flowing through the driving shaft 1 and the first fluid paths 24. Then, the fluid is compressed to the high pressure.

Thereafter, the fluid compressed to the high pressure is collected through the second fluid paths 25 into the low pressure scroll chambers 61 which are defined between the front and rear walls of the cover part 23 and the pair of orbiting rotation segments of the orbiting rotation member 4, and compressed to the low pressure. Then, the fluid is discharged out of the housing 3.

In other words, if the driving rotation member 2 is rotated and the pair of orbiting rotation segments of the orbiting rotation member 4 are orbitally rotated, in each of the high pressure scroll chambers 51 which are defined between the front and rear surfaces of the driving rotation member 2 and the pair of orbiting rotation segments of the orbiting rotation member 4, as a shape and a displacement of each transfer plenum bounded by wall portions of the rotating scroll SI and the orbiting scroll S2 continuously vary in a state wherein the rotating scroll SI and the orbiting scroll S2 are interleaved one on the other, the fluid can be compressed to the high pressure as described above. Also, in each of the low pressure scroll chambers 61 which are defined between the front and rear walls of the cover part 23 and the pair of orbiting rotation segments of the orbiting rotation member 4, as a shape and a displacement of each transfer plenum bounded by wall portions of the rotating scroll SI and the orbiting scroll S2 continuously vary in a state wherein the rotating scroll SI and the orbiting scroll S2 are interleaved one on the other, the fluid can be compressed to the low pressure as described above.

Therefore, since fluid is sucked into the high pressure scroll chambers 51 after flowing through the driving shaft 1 and the first fluid paths 24, a fluid suction force is maximized, and thereby, a high level of output pressure can be accomplished. Also, since the high pressure fluid outputted from the high pressure scroll chambers 51 is compressed to the low pressure in the low pressure scroll chambers 61, it is possible to stably discharge fluid out of the housing 3. FIG. 11 is a cross-sectional view illustrating a scroll pump in accordance with a third embodiment of the present invention; FIG. 12 is a cross-sectional view taken along the line G-G of FIG. 11; and FIG. 13 is a cross-sectional view taken along the line H-H of FIG. 11. A construction of the scroll pump according to the third embodiment of the present invention will be described below.

The scroll pump comprises first and second driving rotation members 2 and 2 ' , first and second housings 3 and 3 ' , first and second orbiting rotation members 4 and 4', a high pressure section 5, a low pressure section 6, and a connection tube 7. The first and second driving rotation members 2 and 2 ' are mounted on and rotated by a driving shaft 1 through which fluid is sucked into the scroll pump. The first and second housings 3 and 3 ' respectively surround the first and second driving rotation members 2 and 2'. The first and second housings 3 and 3' are unrotatably held with respect to the driving shaft 1. The driving shaft 1 passes through a common center of the first and second housings 3 and 3' . The first and second orbiting rotation members 4 and 4' are coupled to the first and second driving rotation members 2 and 2' in the first and second housings 3 and 3', respectively, each by means of at least three camshafts C, in a manner such that they envelop the first and second driving rotation members 2 and 2' and are supported by front and rear walls of the first and second housings 3 and 3' with a predetermined eccentricity with respect to a center of the driving shaft 1 to be orbitally rotated about the camshafts C through rotation of the driving shaft 1. The high pressure section 5 is formed, in the first housing 3, between front and rear surfaces of the first driving rotation member 2 and front and rear walls of the first orbiting rotation member 4. The high pressure section 5 possesses at least three pairs of high pressure scroll chambers 51 into which fluid is sucked after flowing through the driving shaft 1 and first fluid paths 21 defined in the first driving rotation member 2, to be compressed to a high pressure. The low pressure section 6 is formed, in the second housing 3' having an outlet port, between front and rear surfaces of the second driving rotation member 2' and front and rear walls of the second orbiting rotation member 4'. The low pressure section 6 possesses a pair of low pressure scroll chambers 61 each of which has a fluid accommodating capacity greater than the high pressure scroll chamber 51 and into which high pressure fluid outputted from the high pressure scroll chambers 51 is collected to be compressed to a low pressure and then be stably discharged out of the second housing 3' . The connection tube 7 connects the first and second housings 3 and 3' with each other to allow fluid to be delivered from the high pressure section 5 to the low pressure section 6. A pair of sleeve portions 42 are projectedly formed integrally with the front and rear walls, respectively, of each of the first and second orbiting rotation members 4 and ' in a manner such that they have the predetermined eccentricity with respect to the center of the driving shaft 1. Each of the first and second orbiting rotation members 4 and 4' is supported around the pair of sleeve portions 42 by the front and rear walls of each of the first and second housings 3 and 3' via a pair of first bearings B, respectively. A pair of circular openings 31 are respectively defined through the front and rear walls of each of the first and second housings 3 and 3 ' in a manner such that they have the same center as the driving shaft 1. A pair of second bearings B are respectively intervened between inner edges of each of the first and second housings 3 and 3', defining the circular openings 31, and the driving shaft 1, to allow each of the first and second housings 3 and 3' to be fixedly held with respect to the driving shaft 1 even when the driving shaft 1 is rotated. In each of the high and low pressure scroll chambers 51 and 61, a rotating scroll SI, which is formed integrally with each of the first and second driving rotation members 2 and 2', and an orbiting scroll S2 , which is formed integrally with each of the first and second orbiting rotation members 4 and 4', are interleaved one on the other to compress fluid to the high or low pressure .

FIG. 14 is a partial enlarged cross-sectional view of the ^λI' part of FIG. 11; and FIG. 15 is a partial enlarged cross-sectional view of the 'J' part of FIG. 11. Each of the first and second driving rotation members 2 and 2' is defined, adjacent to an outer edge thereof, with at least three cam fitting holes 23 in a manner such that an eccentric cam portion Cl which is formed at a middle portion of each camshaft C is rotatably fitted into each cam fitting hole 23. The front and rear walls of each of the first and second orbiting rotation members 4 and 4' are defined, adjacent to a common outer edge where they are integrated with each other, with at least three pairs of shaft fitting holes 41 in a manner such that a pair of shaft portions C2 which are formed at both ends of the eccentric cam portion Cl of each camshaft C are rotatably fitted into each pair of shaft fitting holes 41, respectively.

FIG. 16 is a schematic view illustrating a positional relationship among the driving shaft, camshafts and orbiting rotation member in the scroll pump according to the third embodiment of the present invention. A distance LI measured between a center of the sleeve portions 42 and the center of the driving shaft 1 corresponds to a distance L2 measured between a center of the eccentric cam portion Cl and a center of the shaft portions C2 of each camshaft C. Hereafter, operation of the scroll pump according to the third embodiment of the present invention will be described.

As shown in FIGs . 11 through 16, if the first and second driving rotation member 2 and 2' are rotated by actuation of the driving shaft 1, the first and second orbiting rotation members 4 and 4' which respectively envelop the first and second driving rotation members 2 and 2' are orbitally rotated about the camshafts C in an interlocked manner. Namely, the first and second driving rotation members 2 and 2' are rotated about the driving shaft 1. And, other than the first and second driving rotation members 2 and 2', the first and second orbiting rotation members 4 and 4' are eccentrically rotated around the driving shaft 1 while being supported by the first and second housings 3 and 3 ' with the predetermined eccentricity with respect to the center of the driving shaft 1. That is to say, the first and second orbiting rotation members 4 and 4' are orbitally rotated about the camshafts C.

Thus, if the first and second orbiting rotation members 4 and 4' are orbitally rotated outward of the first and second driving rotation members 2 and 2', fluid is sucked into the high pressure scroll chambers 51 which are defined between the front and rear surfaces of the first driving rotation member 2 and the front and rear walls of the first orbiting rotation member 4, after flowing through the driving shaft 1 and the first fluid paths 21 which are defined in the first driving rotation member 2. Then, the fluid is compressed to the high pressure .

Thereafter, the fluid compressed to the high pressure is collected through the connection tube 7 into the low pressure scroll chambers 61 which are defined between the front and rear surfaces of the second driving rotation member 2' and the front and rear walls of the second orbiting rotation member 4', and compressed to the low pressure.' Then, the fluid is discharged out of the second housing 3' . In other words, if the first and second driving rotation members 2 and 2' are rotated and the first and second orbiting rotation members 4 and 4' are orbitally rotated, in each of the high pressure scroll chambers 51 which are defined on the front and rear surfaces of the first driving rotation member 2, as a shape and a displacement of each transfer plenum bounded by wall portions of the rotating scroll SI and the orbiting scroll S2 continuously vary in a state wherein the rotating scroll SI and the orbiting scroll S2 are interleaved one on the other, the fluid can be compressed to the high pressure as described above. Also, in each of the low pressure scroll chambers 61 which are defined on the front and rear surfaces of the second driving rotation member 2', as a shape and a displacement of each transfer plenum bounded by wall portions of the rotating scroll SI and the orbiting scroll S2 continuously vary in a state wherein the rotating scroll SI and the orbiting scroll S2 are interleaved one on the other, the fluid can be compressed to the low pressure as described above .

Therefore, since fluid is sucked into the three pairs of high pressure scroll chambers 51 after flowing through the driving shaft 1 and the first fluid paths 21, a fluid suction force is maximized, and thereby, a high level of output pressure can be accomplished. Also, since the high pressure fluid outputted from the high pressure scroll chambers 51 is compressed to the low pressure in the pair of low pressure scroll chambers 61, it is possible to stably discharge fluid out of the second housing 3 ' .

Further, due to the fact that the first and second driving rotation members 2 and 2' and the first and second orbiting rotation members 4 and 4' are simultaneously rotated while the scrolls SI and S2 are brought into orbital contact with each other, it is possible to minimize vibration upon operation of the scroll pump according to the present invention. Meanwhile, when the rotating scroll SI is brought into contact with the orbiting scroll S2 , although contact portions between the rotating scroll SI and the orbiting scroll S2 are continuously changed, it is to be noted that a contact position between the rotating scroll SI and the orbiting scroll S2 always resides on a line which connects the center of the driving shaft 1 and the center of each camshaft C, whereby operation of the entire scroll pump can be stabilized.

Industrial Applicability

As apparent from the above description, the scroll pump according to the present invention provides advantages in that a fluid suction efficiency is improved and stable fluid discharge is ensured. Consequently, it is possible to render a scroll fluid machine which is capable of separately developing a fluid suction pressure and a fluid discharge pressure from each other.

Also, since it is possible to prevent vibration from being induced upon operation of high and low pressure sections, operational precision of the scroll pump is enhanced and operation noise is suppressed. Further, because the high and low pressure sections can be formed in a single housing, a volume of the scroll pump can be decreased, whereby it is possible to render a scroll fluid machine which has high and low pressure sections capable of accomplishing a high level of output pressure, while occupying a minimized space.

Moreover, by the fact that the high and low pressure sections can be respectively formed in two separate housings, a fluid suction efficiency can be maximized and stabilized fluid discharge is ensured.

Claims

1. A scroll pump comprising: a driving rotation member rotated by a driving shaft through which fluid is sucked into the scroll pump; a housing for surrounding the driving rotation member, the housing being unrotatably held, the driving shaft passing through a center of the housing; an orbiting rotation member coupled to the driving rotation member in the housing by means of at least three camshafts in a manner such that it envelops the driving rotation member and is supported by front and rear walls of the housing with a predetermined eccentricity with respect to a center of the driving shaft to be orbitally rotated about the camshafts through rotation of the driving rotation member; a high pressure section formed between a front surface of the driving rotation member and a front wall of the orbiting rotation member, and possessing at least three high pressure scroll chambers into which fluid is sucked after flowing through the driving shaft and first fluid paths defined in the driving rotation member, to be compressed to a high pressure; and a low pressure section formed between a rear surface of the driving rotation member and a rear wall of the orbiting rotation member, and possessing at least one low pressure scroll chamber which has a fluid accommodating capacity greater than the high pressure scroll chamber and into which high pressure fluid outputted from the high pressure scroll chambers is collected to be compressed to a low pressure and then be stably discharged.

2. The scroll pump as set forth in claim 1, wherein, in each of the high and low pressure scroll chambers, a rotating scroll, which is formed integrally with the driving rotation member, and an orbiting scroll, which is formed integrally with the orbiting rotation member, are interleaved one on the other to compress fluid to the high or low pressure .

3. The scroll pump as set forth in claim 1, wherein the driving rotation member is defined, adjacent to an outer edge thereof, with at least three cam fitting holes in a manner such that an eccentric cam portion formed at a middle portion of each camshaft is rotatably fitted into each cam fitting hole; and the front and rear walls of the orbiting rotation member are defined, adjacent to a common outer edge where they are integrated with each other, with at least three pairs of shaft fitting holes in a manner such that a pair of shaft portions formed at both ends of the eccentric cam portion of each camshaft are rotatably fitted into each pair of shaft fitting holes, respectively.

4. The scroll pump as set forth in claim 1, wherein a pair of sleeve portions are projectedly formed integrally with the front and rear walls, respectively, of the orbiting rotation member in a manner such that they have the predetermined eccentricity with respect to the center of the driving shaft; and the orbiting rotation member is supported around the pair of sleeve portions by the front and rear walls of the housing via a pair of first bearings, respectively.

5. The scroll pump as set forth in any one of the claims 1, 3 or 4, wherein a distance measured between a center of the sleeve portions and the center of the driving shaft corresponds to a distance measured between a center of the eccentric cam portion and a center of the shaft portions of each camshaft .

6. The scroll pump as set forth in claim 1, wherein a pair of circular openings are respectively defined through the front and rear walls of the housing in a manner such that they have the same center as the driving shaft ; and a pair of second bearings are respectively intervened between inner edges of the housing, defining the circular openings, and the driving shaft, to allow the housing to be fixedly held with respect to the driving shaft even when the driving shaft is rotated.

7. The scroll pump as set forth in claim 1, wherein at least three high pressure scroll chambers are defined between the front surface of the driving rotation member and the front wall of the orbiting rotation member in a manner such that they are spaced apart one from another by the same angle along a circumferential direction and fluid is sucked into the high pressure scroll chambers after flowing through the driving shaft and the first fluid paths defined in the driving rotation member to be compressed to the high pressure; and a single low pressure scroll chamber is defined between the rear surface of the driving rotation member and the rear wall of the orbiting rotation member in a manner such that high pressure fluid outputted from the high pressure scroll chambers is collected into the low pressure scroll chamber after passing through second fluid paths defined in the orbiting rotation member to be compressed to the low pressure and then be discharged out of the housing.

8. The scroll pump as set forth in claim 1, wherein a cover part is formed integrally with the edge of the driving rotation member; the orbiting rotation member comprises a pair of separate orbiting rotation segments which are coupled to the driving rotation member and respectively interposed between the front and rear surfaces of the driving rotation member and front and rear walls of the cover part; at least three pairs of high pressure scroll chambers are defined between the front and rear surfaces of the driving rotation member and the pair of orbiting rotation segments in a manner such that the three pairs are spaced apart one from another by the same angle along a circumferential direction and fluid is sucked into the high pressure scroll chambers after flowing through the driving shaft and first fluid paths defined in the driving rotation member to be compressed to the high pressure; and a pair of low pressure scroll chambers are defined between the front and rear walls of the cover part and the pair of orbiting rotation segments in a manner such that high pressure fluid outputted from the high pressure scroll chambers is collected into the low pressure scroll chambers after passing through second fluid paths defined in the cover part to be compressed to the low pressure and then be discharged out of the housing through the driving shaft .

9. A scroll pump comprising: first and second driving rotation members mounted on a driving shaft through which fluid is sucked into the scroll pump; first and second housings for respectively surrounding the first and second driving rotation members, the first and second housings being unrotatably held, the driving shaft passing through a common center of the first and second housings; first and second orbiting rotation members coupled to the first and second driving rotation members in the first and second housings, respectively, each by means of at least three camshafts, in a manner such that they envelop the first and second driving rotation members and are supported by front and rear walls of the first and second housings with a predetermined eccentricity with respect to a center of the driving shaft to be orbitally rotated about the camshafts through rotation of the first and second driving rotation members ; a high pressure section formed, in the first housing, between front and rear surfaces of the first driving rotation member and front and rear walls of the first orbiting rotation member, and possessing at least three pairs of high pressure scroll chambers into which fluid is sucked after flowing through the driving shaft and first fluid paths defined in the first driving rotation member, to be compressed to a high pressure; a low pressure section formed, in the second housing having an outlet port, between front and rear surfaces of the second driving rotation member and front and rear walls of the second orbiting rotation member, and possessing a pair of low pressure scroll chambers each of which has a fluid accommodating capacity greater than the high pressure scroll chamber and into which high pressure fluid outputted from the high pressure scroll chambers is collected to be compressed to a low pressure; and a connection tube for connecting the first and second housings with each other to allow fluid to be delivered from the high pressure section to the low pressure section.

10. The scroll pump as set forth in claim 9, wherein, in each of the high and low pressure scroll chambers defined in the high and low pressure sections, a rotating scroll, which is formed integrally with each of the first and second driving rotation members, and an orbiting scroll, which is formed integrally with each of the first and second orbiting rotation members, are interleaved one on the other to compress fluid to the high or low pressure.

11. The scroll pump as set forth in claim 9, wherein each of the first and second driving rotation members is defined, adjacent to an outer edge thereof, with at least three cam fitting holes in a manner such that an eccentric cam portion formed at a middle portion of each camshaft is rotatably fitted into each cam fitting hole; and the front and rear walls of each of the first and second orbiting rotation members are defined, adjacent to a common outer edge where they are integrated with each other, with at least three pairs of shaft fitting holes in a manner such that a pair of shaft portions formed at both ends of the eccentric cam portion of each camshaft are rotatably fitted into each pair of shaft fitting holes, respectively.

12. The scroll pump as set forth in claim 9 , wherein a pair of sleeve portions are projectedly formed integrally with the front and rear walls, respectively, of each of the first and second orbiting rotation members in a manner such that they have the predetermined eccentricity with respect to the center of the driving shaft; and each of the first and second orbiting rotation members is supported around the pair of sleeve portions by the front and rear walls of each of the first and second housings via a pair of first bearings, respectively.

13. The scroll pump as set forth in any one of the claims 9, 11 or 12, wherein a distance measured between a center of the sleeve portions and the center of the driving shaft corresponds to a distance measured between a center of the eccentric cam portion and a center of the shaft portions of each camshaft .

14. The scroll pump as set forth in claim 9 , wherein a pair of circular openings are respectively defined through the front and rear walls of each of the first and second housings in a manner such that they have the same center as the driving shaft; and a pair of second bearings are respectively intervened between inner edges of each of the first and second housings, defining the circular openings, and the driving shaft, to allow each of the first and second housings to be fixedly held with respect to the driving shaft even when the driving shaft is rotated.