Description

VANE COMPRESSOR HAVING ENHANCED AIRTIGHTNESS

Technical Field

[1] The present invention relates to a positive displacement rotary compressor, and more particularly, to a vane compressor that has a rotor having a single sliding vane and adapted to be rotated inside a cylinder, such that when the rotor is rotated, a fluid (gas or liquid) is sucked, compressed, and discharged. Background Art

[2] A positive displacement compressor, which draws a predetermined volume of fluid to a closed space and diminishes the size of the closed space to compress the fluid, is classified into two types: a rotary compressor and a reciprocating piston compressor. Especially, the rotary compressor has a relatively lower energy loss when compared with the reciprocating piston compressor, thereby providing a substantially high compression efficiency.

[3] The rotary compressor is largely classified into three types as will be discussed below in accordance with the difference of the structures thereof. As the first type rotary compressor is provided a roots type compressor using cocoon- shaped two rotors, as the second type rotary compressor is provided a screw compressor using two screw type rotors, and as the third type rotary compressor is provided a vane compressor using a vane coupled to a rotor in such a manner as to be rotated together with the rotor. Especially, the vane compressor makes use of a single rotary shaft, which makes the configuration very simple and enables the manufacturing to a small size. Further, the blockage between the compressed fluid and the decompressed fluid is easily conducted to allow the energy loss to be substantially reduced and to allow ultra high-pressure compression to be achieved.

[4] When the compression speed and the compression ratio in the vane compressor are relatively high, even the vane compressor may cause the fluid in the compressed space to be leaked to the decompressed space inside a cylinder (positive displacement).

[5] As one of the prior arts, Korean Patent No.684124 issued to the same applicant as the present invention suggests a rotor adapted to be employed for the vane compressor. As another prior art, moreover, Korean Patent No. 684122 issued to the same applicant as the present invention discloses a sliding vane adapted to be employed for the rotor as suggested in Korean Patent No.684124.

[6] According to the prior art Korean Patent No.684124, the rotor has a sliding vane in- sertedly mounted along the distance defined between two divided bodies thereof in such a manner as to be slidably reciprocated therealong, such that when the rotor is

rotated, a fluid is compressed. In this structure, the airtightness between the outer periphery of the rotor body and the inner periphery wall of a cylinder, the airtightness between the lateral surface of the rotor body and the inner wall surfaces of cylinder covers, and the airtightness between the two divided rotor bodies and the surface of the sliding vane are firmly maintained.

[7] According to the prior art Korean Patent No.684124, the rotor has a plurality of airtight rods insertedly mounted at given intervals in an axial direction along the outer periphery of the body thereof, each of the airtight rods having an elastic force in a direction of diameter thereof and in a direction of the cylinder covers by means of a spring mounted therein. Moreover, in order to maintain the airtightness between the lateral surface of the rotor body and the inner wall surfaces of the cylinder covers, a plurality of cover side airtight pieces are mounted along the lateral outer periphery of a rotor housing in such a manner as to be arranged between the adjacent airtight rods, each of the cover side airtight pieces being compressed to the cylinder covers by means of a plate spring mounted therein, thereby serving to maintain the airtightness between the lateral surface of the rotor body and the inner wall surfaces of the cylinder covers.

[8] According to the prior art Korean Patent No.684122, a rectangular flat plate-shaped sliding vane is provided in such a manner as to be slidingly reciprocated along the center portion of the rotor, such that when the rotor is rotated, the airtightness is maintained between the inner wall surface of the cylinder and the inner wall surfaces of the cylinder covers.

[9] According to Korean Patent Nos.684124 and 684122 as prior arts, the rotor is configured to have substantially good airtightness between the inner wall surface of the cylinder and the inner wall surfaces of the cylinder covers, but when the rotor is employed for the vane compressor, there occur some problems as follows:

[10] First, since the rotor has the airtight pieces and the airtight rods interlaced with each other along the lateral outer periphery of the body thereof in such a manner as to apply the elastic forces caused by the springs mounted therein to the cylinder covers, the airtight pieces and the airtight rods are rotated at the state where their lateral surfaces are always brought into close contact with the inner wall surfaces of the cylinder covers. Furthermore, the cover side airtight pieces mounted on the sliding vane of the rotor are rotated at the state of being always brought into close contact with the inner wall surfaces of the cylinder covers by means of the elastic forces of the springs mounted therein. Therefore, in case where such the rotor is employed for the vane compressor, substantially high friction occurs between the lateral outer periphery of the rotor and the inner wall surfaces of the cylinder covers, which causes the rotor and the cylinder covers to be unavoidably abraded. If the rotor is used for a long period of time, the abrasion becomes serious such that the compressed fluid may be leaked

between the lateral outer periphery of the rotor and the inner wall surfaces of the cylinder covers. The formation of abrasion between the lateral outer periphery of the rotor and the cylinder covers is caused by the close mounting of the plurality of cover side airtight pieces and the plurality of airtight rods along the lateral outer periphery of the rotor. That is, the abrasion is caused in that the edges of each airtight piece and each airtight rod in their rotating directions sharply enter each of the cylinder covers. Disclosure of Invention Technical Problem

[11] Accordingly, the present invention has been made in view of the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide a vane compressor that is capable of minimizing the friction and abrasion at the contact point between the lateral outer periphery of a rotor and the inner wall surfaces of cylinder covers, thereby enhancing the airtightness therebetween. Technical Solution

[12] To achieve the above object, according to the present invention, there is provided a vane compressor having a cylindrical rotor having a sliding vane and eccentrically disposed inside a cylinder having an inlet port and outlet ports by means of cylinder covers mounted to the both sides of the cylinder, so as to compress a fluid therein, the vane compressor including: a plurality of airtight pieces and airtight rods alternately arranged with each other along the outer peripheries of upper and lower rotor housings of a body of the cylindrical rotor, each of the plurality of airtight pieces and airtight rods having an elastic force applied in a direction of the cylinder covers by means of a spring mounted therein; airtight pieces mounted on the sliding vane and having an elastic force applied in the direction of the cylinder covers by means of a spring mounted therein; and heat-resistant ceramic plates insertedly mounted into the cylinder covers in such a manner as to abut against the airtight pieces and the airtight rods of the upper and lower rotor housings as well as the airtight pieces of the sliding vane.

Advantageous Effects

[13] According to the present invention, there is provided the vane compressor having enhanced airtightness that is provided with the plurality of airtight pieces and airtight rods interlaced with each other around the outer periphery of the rotor in such a manner as to pressurize the cylinder covers side, thereby greatly reducing the friction and abrasion between the inner wall surfaces of the cylinder covers and the airtight pieces and rods, such that even though the vane compressor is used at high-speed and high-pressure conditions for a long period of time, the compressed fluid does not leak between the rotor body and the cylinder covers. Especially, when the vane compressor according to the present invention is used as a vacuum compressor or conducts low

rotation compression, it has a substantially excellent airtightness efficiency. Brief Description of the Drawings

[14] FIG.1 is an exploded perspective view showing a vane compressor having enhanced airtightness according to the present invention.

[15] FIG.2 is a perspective view showing a body of the vane compressor in FIG.l.

[16] FIG.3 is a partly exploded perspective view showing a rotor of the vane compressor in FIG.l.

[17] FIG.4 is an assembled perspective view showing the vane compressor having enhanced airtightness according to the present invention.

[18] FIG.5 is a sectional view taken along the line A— A' of FIG.4.

[19] FIGS.6 to 8 are sectional views taken along the line B-B' of FIG.4 by fluid compression steps in the vane compressor according to the present invention. Mode for the Invention

[20] Hereinafter, an explanation on the vane compressor having enhanced airtightness according to the present invention will be given with reference to the attached drawings.

[21] FIG.1 is an exploded perspective view showing a vane compressor having enhanced airtightness according to the present invention, FIG.2 is a perspective view showing a body of the vane compressor in FIG.l, FIG.3 is a partly exploded perspective view showing a rotor of the vane compressor in FIG.1, FIG.4 is an assembled perspective view showing the vane compressor having enhanced airtightness according to the present invention, FIG.5 is a sectional view taken along the line A— A' of FIG.4, and FIGS.6 to 8 are sectional views taken along the line B-B' of FIG.4 by fluid compression steps in the vane compressor according to the present invention.

[22] Referring first to FIG.2, the vane compressor according to the present invention includes a cylinder 5 and a cylinder block 3 having an inlet port 11 adapted to draw a decompressed fluid (gas or liquid) into the cylinder 5 and an outlet port 17 adapted to discharge the compressed fluid by means of a sliding vane 33 of a rotor 21 from the cylinder 5. The inside diameter of the cylinder 5 is somewhat distorted such that the rotor 21 as will be discussed below may be rotated at the state of being eccentrically disposed in the cylinder 5. The inlet port 11 of the cylinder block 3 may be coupled to an inlet flange 9 adapted to connect the inlet port 11 with an outside fluid pipe, and also, the outlet port 17 of the cylinder block 3 may be coupled to an outlet flange 13 adapted to connect the outlet port 17 with an outside fluid pipe. Preferably, the cylinder block 3 has a plurality of heat diffusion fins 19 formed along the outer periphery thereof. The assembled body of the cylinder block 3, the inlet flange 9, and the outlet flange 13 becomes a body 1 of the vane compressor.

[23] Referring to FIGS.1 and 3, the vane compressor according to the present invention includes the rotor 21 adapted to be rotated inside the cylinder 5, thereby compressing the fluid drawn through the inlet port 11 and discharging the compressed fluid to the outlet ports 15 and 17. As shown in FIG.3, the rotor 21 has the body 23 dividable into upper and lower bodies with respect to the sliding vane 33, attaching plates 41a and 41b adapted to attach the body 23 of the rotor 21 on the upper and lower surfaces of the sliding vane 33 with a fine clearance formed therebetween such that the sliding vane 33 is slidingly reciprocated, journals 43a and 43b extended outwardly from the attaching plates 41a and 41b, and a shaft 45 extended outwardly from one side journal 43 a so as to transmit the rotary force of an external power generating unit to the rotor 21. The body 23 dividable into upper and lower bodies of the rotor 21 has semi- cylindrical rotor housings 27 a and 27b and cores 25 a and 25b filling the inside of the rotor housings 27 a and 27b. The attaching plates 41a and 41b are attached on the lateral surfaces of the cores 25a and 25b by means of a plurality of bolts 61. The attachment is achieved by forming a plurality of taps 7 on the cores 25a and 25b.

[24] Each of the rotor housings 27a and 27b has a plurality of airtight rods 29 insertedly mounted in a lengthwise direction of the rotor body along the outer periphery thereof, each of the plurality of airtight rods 29 having an elastic force applied in a radial direction (in a direction of an inner wall surface of the cylinder) and in a direction of the rotor body (in a direction of cylinder covers) by means of a spring mounted therein. Each of the rotor housings 27a and 27b has a plurality of airtight pieces 31 insertedly mounted along the lateral outer periphery thereof such that each airtight piece is disposed between the adjacent airtight rods 29, each of the plurality of airtight pieces 31 having an elastic force applied in a direction of the rotor body (in a direction of the cylinder covers) by means of a spring mounted therein. The sliding vane 33 has a cylinder wall-pressurizing plate 35 insertedly mounted along the contact surface with the cylinder wall thereof, the pressurizing plate 35 having an elastic force applied in the radial direction thereof by means of a spring mounted therein, and the sliding vane 33 has airtight pieces 37 insertedly mounted on the lateral surfaces contacted with the cylinder covers thereof, the airtight piece 37 having an elastic force applied in the direction of the cylinder cover by means of a spring mounted therein.

[25] Referring to FIGS.1 and 4, the vane compressor according to the present invention is configured such that the rotor 21 is received into the cylinder 5 of the body 1 thereof and the body 23 of the rotor 21 is eccentrically disposed in such a manner as to come into close contact with the inner wall surface of the cylinder 5 in the middle point of the inlet port 11 and the outlet port 15 by means of the both side cylinder covers 51a and 51b thereof. In order to conduct the eccentric disposing of the rotor 21 into the cylinder 5, thus, each of the cylinder covers 51a and 51b has a bearing 55 adapted to

support the journals 43a and 43b of the rotor 21, and at this time, the bearing 55 is desirably located at the position where the rotor body 23 is eccentrically disposed in such a manner as to come into close contact with the inner wall surface of the cylinder 5 in the middle point of the inlet port 11 and the outlet port 15. Preferably, each of the cylinder covers 51a and 51b has a plurality of heat diffusion fins 19 formed along the outer periphery thereof.

[26] The body 1 of the compressor and the cylinder covers 51a and 5 Ib are made of cast iron by means of molding. The plurality of airtight pieces 31 and 37 and the plurality of airtight rods 29 of the rotor body 23 having the elastic forces applied in the direction of the cylinder covers 51a and 51b are brought into close contact with the cylinder covers 51a and 51b by means of the elastic forces of the springs mounted therein, so as to maintain the airtightness between the lateral wall of the rotor body 23 and the cylinder covers 51a and 51b. In this case, since the plurality of airtight pieces 31 and 37 and the plurality of airtight rods 29 are separated from one another, their edges may abut against the inner wall surfaces of the cylinder covers 51a and 51b, which causes high friction therebetween. As a result, high heat may be generated from the friction, and the portion where the friction occurs may be seriously abraded.

[27] According to the features of the present invention, heat-resistant ceramic plates 47a and 47b are placed between the cylinder covers 51a and 51b and the side surfaces of the rotor body 23, such that the side surfaces of the rotor body 23 abut against the heat- resistant ceramic plates 47a and 47b, without any direct contact with the inner wall surfaces of the cylinder covers 51a and 51b. The heat-resistant ceramic plates 47a and 47b are not melted at a temperature of 158O ⁰ C or more, and they are made of inorganic compound materials that are chemically stable. They are selected from an alumina ceramic plate, a chrome-magnesite ceramic plate, and a chrome ceramic plate, and preferably, they are formed of the alumina ceramic plate. The alumina ceramic plate has a molding plate having substantially high surface hardness, good oxidation resistance, and good surface lubrication.

[28] As the heat-resistant ceramic plates 47a and 47b are attached on the inner wall surfaces of the cylinder covers 51a and 51b, the airtight pieces 31 and 37 and the airtight rods 39 abut against the heat-resistant ceramic plates 47a and 47b, without any direct contact with the inner wall surfaces of the cylinder covers 51a and 51b, thereby preventing the abrasion of the airtight pieces 31 and 37 and the airtight rods 39 and the inner wall surfaces of the cylinder covers 51a and 51b and obtaining substantially excellent airtightness therebetween.

[29] Referring to FIGS.1 and 5, each of the heat-resistant ceramic plates 47a and 47b has a through-hole 49 adapted to insert the attaching plates 41a and 41b of the rotor 21 thereinto, and upon assembling, they are coupled to the attaching plates 41a and 41b.

Further, each of the cylinder covers 51a and 51b has a ceramic plate seat 53 adapted to insertedly mount the heat-resistant ceramic plates 47a and 47b therein. Upon assembling, each of the cylinder covers 51a and 51b insertedly mounts the heat-resistant ceramic plates 47a and 47b in the ceramic plate seat 53 thereof, and next, it is assembled to the rotor 21 and the body 1.

[30] The cylinder block 3 has a plurality of taps 7 adapted to couple the cylinder covers

51a and 51b therewith by means of bolts 61, and upon assembling, after the rotor 21 is received into the cylinder 5, the cylinder covers 51a and 51b are coupled to the cylinder block 4 by means of the bolts 61. The cylinder cover 51a into which the rotary shaft 45 of the rotor 21 is inserted has a sleeve 57 mounted on the outside thereof, and the cylinder cover 51b has a cap 59 mounted on the outside thereof.

[31] Under the above-mentioned configuration, the fluid compression operations of the vane compressor having the enhanced airtightness according to the present invention will be discussed with reference to FIGS.6 to 8.

[32] FIG.6 shows the position of the sliding vane 33 at the point where the rotor body 23 abuts against the inner peripheral wall of the cylinder 5. At this time, the rotor body 23 divides the inner space of the cylinder 5 into spaces 'A' and 'B' In the space 'A', the fluid is compressed, and the compressed fluid is sucked to the space 'B'. At this time, the cylinder wall-pressurizing plates 35 of the sliding vane 33 serve to push the inner peripheral wall of the cylinder 5 by means of the springs mounted therein, thereby preventing the compressed fluid between the spaces 'A' and 'B' from being leaked through the inner peripheral wall of the cylinder 5. Further, the airtight pieces 31 and the airtight rods 29 interlaced with each other along the outer periphery of the rotor 21 come into close contact with the heat-resistant ceramic plates 47a and 47b, thereby preventing the compressed fluid between the spaces 'A'and 'B' from being leaked through the side surfaces of the rotor 21.

[33] FIG.7 shows the position of the sliding vane 33 that is passed over by about 90 at the point where the rotor body 23 abuts against the inner peripheral wall of the cylinder 5. At this time, the rotor body 23 divides the inner space of the cylinder 5 into spaces 'A', 'B', and 'C by means of the sliding vane 33 and the airtight rods 29 being brought into close contact with the inner wall of the cylinder 5. In the space 'A' the fluid is compressed, the compressed fluid is moved to the space 'B' and the moved fluid is sucked to the space 'C At this time, the cylinder wall-pressurizing plates 35 of the sliding vane 33 serve to push the inner peripheral wall of the cylinder 5 by means of the springs mounted therein, thereby preventing the compressed fluid between the spaces 'A' and 'B' and between the spaces 'B' and 'B' from being leaked through the inner peripheral wall of the cylinder 5. Further, the airtight rods 29 are brought into close contact with the inner peripheral wall of the cylinder 6, thereby preventing the

compressed fluid between the spaces 'A' and 'C from being leaked through the inner peripheral wall of the cylinder 5. In the same manner as above, the airtight pieces 31 and the airtight rods 29 interlaced with each other along the outer periphery of the rotor 21 come into close contact with the heat-resistant ceramic plates 47a and 47b, thereby preventing the compressed fluid among the spaces 'A', 'B', and 'C from being leaked through the side surfaces of the rotor 21. [34] FIG.8 shows the position of the sliding vane 33 that is passed over by about 120 at the point where the rotor body 23 abuts against the inner peripheral wall of the cylinder 5. At this time, the rotor body 23 divides the inner space of the cylinder 5 into spaces 'A', 'B', and 'C by means of the sliding vane 33 and the airtight rods 29 being brought into close contact with the inner wall of the cylinder 5. In this case, the spaces 'A' and 'B' communicate with each other by means of the outlet port 17, and in the space 'B' new compression starts. In the space 'C the fluid is sucked. At this time, the cylinder wall-pressurizing plates 35 of the sliding vane 33 serve to push the inner peripheral wall of the cylinder 5 by means of the springs mounted therein, thereby preventing the compressed fluid between the spaces 'B' and 'C from being leaked through the inner peripheral wall of the cylinder 5. Further, the airtight rods 29 are brought into close contact with the inner peripheral wall of the cylinder 6, thereby preventing the compressed fluid between the spaces 'A' and 'C from being leaked through the inner peripheral wall of the cylinder 5. In the same manner as above, the airtight pieces 31 and the airtight rods 29 interlaced with each other along the outer periphery of the rotor 21 come into close contact with the heat-resistant ceramic plates 47a and 47b, thereby preventing the compressed fluid between the spaces 'A' and 'C or between the spaces 'B' and 'C from being leaked through the side surfaces of the rotor 21.