JP3073889U - Compound twin screw rotor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compound twin screw rotor device which effectively reduces fluid backflow, reduces power consumption, reduces noise, has a small volume, is easy to process, and has a low manufacturing cost. SOLUTION: First and second screw rotors are provided,
The first screw rotor includes a first low-pressure screw stage and a first low-pressure screw stage.
With a high-pressure screw stage and a second screw rotor
A low-pressure screw stage and a second high-pressure screw stage, wherein the threads of the first and second low-pressure screw stages mesh with each other;
Also, having a relatively long pitch, the threads of the first and second high pressure screw stages also mesh with each other and have a relatively short pitch, so that when the meshing operation is performed, the fluid has a relatively large air chamber volume. The compression was transferred from the first and second low-pressure screw stages to the first and second high-pressure screw stages having a relatively small air chamber volume, and the pressure difference between them and the high-pressure section at the outlet end was reduced.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a kind of twin screw rotor device, and more particularly, to a multi-stage or so-called compound twin screw rotor device for changing fluid pressure, which is applicable to a gas vacuum pump and a compressor.

[0002]

[Prior art]

 Known twin screw rotors include U.S. Patent No. 1 shown in FIG. 5,444,644, wherein the screw-type vacuum pump described therein comprises a pair of intermeshing screw rotors 81, 82, which have the same pitch P 'and the same tooth height H', thereby providing rotational transmission. During the process, the volumes and pressures of the air chambers 810, 820 cannot be modified. After a certain period of operation, a high-pressure zone is gradually formed near the outlet end 80, and when relatively low-pressure gas in the chambers 810 and 820 reaches the outlet end 80, the gas suddenly flows into the high-pressure zone and the pressure difference becomes excessive. This is not ideal because it generates noise, generates gas backflow, and wastes energy resources.

[0003] US Patent No. 1 shown in FIG. 5,667,370 twin screw rotors differ in outer dimensions and pitch length of the first pair of screw rotors 32 ', 33 and the second pair of screw rotors 34, 35, and have two cases 91, 9; One partition 93 is provided in the middle of the two to increase the volume, increase the number of parts, and take up space.

[0004] FIG. 3 shows the above-mentioned "patent type" twin screw rotor claimed in the US patent, in which the screw rotors 4 'and 5' have a variable pitch, and the air chamber volume is reduced. Although it is gradually reduced and has a compressive action, it is difficult to machine and cannot be manufactured unless expensive dedicated equipment and cutting tools are used, and the manufacturing cost cannot be reduced.

[0005]

[Problems to be solved by the invention]

 The main purpose of the present invention is to provide a kind of compound twin screw rotor device, which effectively reduces the situation of fluid backflow at the outlet end, reduces power consumption, and reduces operating noise. Assume that the device has been reduced.

Another object of the present invention is to provide a kind of compound twin screw rotor device, which has advantages of small volume, small space, easy processing, and low manufacturing cost. Device.

[0007]

[Means for Solving the Problems]

 The invention according to claim 1 is a composite twin screw rotor device, comprising at least a case, a hollow storage chamber formed by being surrounded by an inner wall thereof, and the case having an inlet and an outlet. A first screw rotor having at least a first low-pressure screw stage and a first high-pressure screw stage formed from one inlet end to an outlet end of the case along one rotation axis and the axial direction; Two first threads are formed on the outer periphery of the first screw rotor and extend over the first low-pressure screw stage and the first high-pressure screw stage, and the first threads located at the first low-pressure screw stage are compared. A first screw rotor having a relatively long fixed pitch and a first thread of the first high-pressure screw stage having a relatively short fixed pitch; And at least a second low-pressure screw stage and a second high-pressure screw stage formed from the inlet end to the outlet end of the case along one rotation axis and the axial direction, and at least one second screw thread is provided. The second thread formed on the outer periphery of the second screw rotor and extending across the second low-pressure screw stage and the second high-pressure screw stage, and the second thread located at the second low-pressure screw stage has a relatively long fixed pitch. The second thread of the second high pressure screw stage has a relatively short fixed pitch; the first and second low pressure screw stages of the first and second screw rotors mesh with each other; , The second high-pressure screw stage also meshes with each other, and the first and second screw rotors are housed together in the hollow housing chamber of the case. twin It is a screw rotor device. According to a second aspect of the present invention, in the compound twin screw rotor device according to the first aspect, the two rotation shafts are pivotally connected to two sets of bearings installed in parallel near the outlet end of the case. And a compound twin screw rotor device. According to a third aspect of the present invention, in the compound twin screw rotor device according to the second aspect, the height of the first and second high-pressure screw stages is adjusted between the first and second high-pressure screw stages and the bearing. In order to achieve this, a composite twin screw rotor device is provided, in which a supplementary piece is provided.

[0008]

[Embodiment of the invention]

 The present invention provides a case, which includes a hollow storage chamber formed by being surrounded by an inner wall thereof, and includes the above-described case having an inlet and an outlet, and a first screw rotor, and one rotating shaft and one shaft. At least a first low-pressure screw stage and a first high-pressure screw stage formed along the direction from the inlet end to the outlet end of the case, at least one first thread being formed on the outer periphery of the first screw rotor, and The first low-pressure screw stage extends over the first high-pressure screw stage, and the first thread located at the first low-pressure screw stage has a relatively long fixed pitch, and the first high-pressure screw stage (1) The first screw rotor and the second screw rotor, each having a relatively short fixed pitch, formed from the inlet end to the outlet end of the case along one rotation axis and the axial direction. At least a second low-pressure screw stage and a second high-pressure screw stage, and at least one second thread is formed on the outer periphery of the second screw rotor, and straddles the second low-pressure screw stage and the second high-pressure screw stage. The second thread, which is elongated and located in the second low-pressure screw stage, has a relatively long fixed pitch, and the second thread of the second high-pressure screw stage has a relatively short fixed pitch. A first and second low-pressure screw stages of the first and second screw rotors mesh with each other, and first and second high-pressure screw stages also mesh with each other; Are also housed in the hollow housing chamber of the case.

[0009] Two sets of bearings to which the above-mentioned two rotating shafts are pivotally connected are installed in parallel near the outlet end of the case. The two rotating shafts and the first and second low-pressure screw stages or the first and second high-pressure screw stages are fixed by a key free bush, a key or other fixed structure. Since the first and second screw rotors are driven by the timing gear, and the first and second threads do not directly contact each other, there is no interference abrasion or contamination formation.

[0010]

【Example】

 FIG. 4 shows an embodiment in which the present invention is applied to an air vacuum pump. This embodiment includes a case 1, a first screw rotor 2, and a second screw rotor 3.

The case 1 is composed of an upper lid 11, an annular case 12, and a lower lid 13, and the upper lid 11 has an inlet 111 connected to a container to be evacuated and evacuated. Inside the annular case 12, there is a hollow accommodation room 10 formed by being surrounded by an inner wall 121. The lower lid 13 is provided with an outlet 131 communicating with the atmospheric pressure (not shown) of the outside world, and has two sets of bearings 46, 46 'installed in parallel. , Are used to pivotally connect the rotation shafts 4, 5 of the second screw rotors 2, 3 to the lower lid 13.

According to this embodiment, the first screw rotor 2 extends from the inlet 111 end to the outlet 131 end of the case 1 along the axial direction, and has two stages, a first low-pressure screw stage 21 and a first high-pressure screw stage 22. Are divided into As shown, a single first thread 20 is spirally provided around the first screw rotor 2 and is provided across the first low-pressure screw stage 21 and the first high-pressure screw stage 22. . The first thread 201 of the first low-pressure screw stage 21 has a relatively long fixed pitch P1, and the first thread 202 located at the first high-pressure screw stage 22 has a relatively short fixed pitch P2. I have.

Similarly, the second screw rotor 3 also extends from the inlet 111 end to the outlet 131 end of the case 1 along the axial direction, and is divided into a second low-pressure screw stage 31 and a second high-pressure screw stage 32. ing. A single second thread 30 is spirally provided around the second screw rotor 3 and is provided across the second low-pressure screw stage 31 and the second high-pressure screw stage 32. The second thread 301 of the second low-pressure screw stage 31 has a relatively long fixed pitch P1, and the second thread 302 located in the second high-pressure screw stage 32 has a relatively short fixed pitch P2.

In the assembly of the present embodiment, first, two rotating shafts 4 and 5 are inserted into two sets of bearings 46 and 46 ′ and pivotally connected to the lower lid 13, and then the first and second high-pressure screw stages 22 and 32 are engaged with each other, and two rotary shafts 4 and 5 are inserted into each of them. At this time, first, it is checked whether the upper end surfaces A and B of the first and second high-pressure screw stages 22 and 32 have the same height, and if not, the first high-pressure screw stage 22 and the bearing are relatively low. A supplementary piece 40 having an appropriate thickness is supplemented between 46 to make the height equal. Thereafter, two timing gears 42, 52 which are further engaged with each other are provided on one end of the rotating shafts 4, 5, respectively, so that the phase angles of the two timing gears 42, 52 and the first and second high-pressure screws are respectively provided. After fine adjustment of the gaps between the stages 22 and 32, they are tightly positioned by one key free bush 43 and 53, respectively, and thereby transmitted to the first and second high-pressure screw stages 22 and 32 by the two timing gears 42 and 52. And the first and second high-pressure screw stages 22, 32 have a pre-designed gap to prevent direct contact friction with each other during transmission so that noise, damage, and the like do not occur. To do.

Thereafter, the first and second low-pressure screw stages 21, 31 are engaged with each other and mounted on the other ends of the two rotating shafts 4, 5 respectively. Since the first threads 201 and 202 or the second threads 301 and 302 are each designed as a continuous stretched thread at the time of processing and manufacturing, the alignment of each of them is sufficiently easy. Finally, the first and second low-pressure screw stages 21 and 31 are adjusted so as to maintain a pre-designed gap, and the key free bushings 44 and 54 are further tightened to complete the assembly. It should be noted in this embodiment that the two rotating shafts 4 and 5 can be pivotally connected and positioned only by the two sets of bearings 46 in the high pressure zone near the end of the outlet 131, and the low pressure near the end of the inlet 111. There is no need to provide bearings in the section, which simplifies the structure significantly compared to the well-known technique of FIG. 2 in which bearings are provided at each of the two ends. The present invention can improve the yield of the semiconductor chip process, especially for semiconductor manufacturing process equipment chambers where cleanliness requirements are relatively strict, which can prevent contamination by entering a vacuum vessel. Can be.

As shown, the first thread 201 of the first low-pressure screw stage 21 and the second thread 301 of the second low-pressure screw stage 31 mesh with each other, have a relatively long fixed pitch P1, The first thread 202 of the first high-pressure screw stage 22 and the second thread 302 of the second high-pressure screw stage 32 also mesh with each other and have a relatively short fixed pitch P2 (ie, P2 <P1). As a result, the volumes of the air chambers 204 and 304 of the first and second high-pressure screw stages 22 and 32 are smaller than the volumes of the air chambers 203 and 303 of the first and second low-pressure screw stages 21 and 31. During operation, the fluid in the air chambers 203 and 303 is first pressurized once and reaches the air chambers 204 and 304, so that the pressure difference between the high-pressure section at the outlet end and the fluid is effectively reduced. And reduce power consumption, reduce operating noise, and have a small volume, take up little space, are easy to process and reduce manufacturing costs.

[0017]

[Effect of the invention]

 The combined twin screw rotor device of the present invention can effectively prevent the backflow of fluid, reduce power consumption, reduce operating noise, and have a small volume, take up little space, and are easy to process. The manufacturing cost can be reduced, and the purpose, means and function of the invention are different from those of the well-known technology, and satisfy the requirements for utility model claims. The above description relates to a preferred embodiment of the present invention and does not limit the scope of the present invention. Any modification or alteration of details that can be made based on the present invention is not limited to the scope of the present invention. Shall belong to

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a known twin screw rotor device.

FIG. 2 is a cross-sectional view of another known twin screw rotor device.

FIG. 3 is a sectional view of still another known twin screw rotor device.

FIG. 4 is a cross-sectional view of the embodiment of the present invention;

[Explanation of symbols]

1 case 10 hollow accommodation room 11
Upper lid 111 Entrance 12 Annular case 121
Inner wall 13 Lower lid 131 Outlet 2 First screw rotor 21 First low-pressure screw stage 20, 201, 202 First thread 22 First high-pressure screw stage 203, 204, 303, 304 Air chamber 3 Second screw rotor 31 Second low pressure Screw stage 30, 301, 302 Second thread 32 Second high-pressure screw stage 4, 5 Rotary shaft 41, 51 Key 42, 52 Timing gear 43, 44, 53, 54 Key free bush 46, 46 'Bearing 80 Outlet end 81 , 82 Screw rotor 810, 820 Air chamber P1, P2, P 'Pitch H' Tooth height

Claims (3)

[Utility model registration claims] 1. A compound twin screw rotor device, comprising: at least a case, a hollow storage chamber formed by being surrounded by an inner wall thereof, and the case having an inlet and an outlet; A rotary shaft having at least a first low-pressure screw stage and a first high-pressure screw stage formed from an inlet end to an outlet end of the case along an axial direction and at least one first screw; A ridge is formed on the outer periphery of the first screw rotor and extends over the first low-pressure screw stage and the first high-pressure screw stage, and the first thread located at the first low-pressure screw stage has a relatively long fixed pitch. The first screw rotor of the first high-pressure screw stage has a relatively short fixed pitch, and the first screw rotor and the second screw rotor At least a second low-pressure screw stage and a second high-pressure screw stage formed from the inlet end to the outlet end of the case along the axis of rotation of the case, and at least one second thread is formed around the outer periphery of the second screw rotor. And stretched across the second low-pressure screw stage and the second high-pressure screw stage;
The second thread located at the low pressure screw stage has a relatively long fixed pitch, the second thread of the second high pressure screw stage has a relatively short fixed pitch, and the first and second screw rotors The first and second low-pressure screw stages mesh with each other, and the first and second high-pressure screw stages also mesh with each other,
A composite twin screw rotor device comprising: the second screw rotor, wherein the first and second screw rotors are housed together in a hollow housing chamber of the case. 2. The compound twin screw rotor device according to claim 1, wherein the two rotation shafts are pivotally connected to two sets of bearings installed in parallel near an outlet end of the case. , Compound twin screw rotor device. 3. The compound twin screw rotor device according to claim 2, wherein a gap between the first and second high-pressure screw stages and the bearing is compensated for adjusting the height of the first and second high-pressure screw stages. A compound twin screw rotor device, wherein a piece is provided.