Scroll compressor

Abstract: A highly reliable scroll compressor adapted to make the amount of a refrigerant taken in through a first suction inlet of a scroll compression element as equal as possible to that taken in through a second suction inlet of the scroll compression element so as to improve the intake efficiency, thereby suppressing pulsation and noise. If the sectional area of the inlet of a refrigerant passage through which a refrigerant taken in flows from an end of a swivel lap via the outer periphery thereof to the second suction inlet is denoted as A1, the sectional area of the inlet of the first suction inlet is denoted as A2, and the sectional area of the inlet of a communication groove is denoted as A3 when the gap between a stationary lap and the swivel lap of the scroll compression element reaches its maximum, then A1, A2, and A3 stay within a range defined by 1.5 ≤ A2 / (A1 + A3) ≤ 2.5 .

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor mounted on an air conditioner, a refrigerating machine, etc. and, more particularly, to a scroll compressor adapted to discharge compressed gas, which has been compressed in a plurality of compression chambers formed by the engagement between a stationary scroll and a swivel scroll, out of a hermetic housing. 2. Description of Related Art A scroll compressor 1A employed for a refrigerating cycle of an air conditioner has a composition, for example (US-A-5 013 225), shown in Fig. 6. A cylindrical hermetic housing 1 with its both ends closed includes an electric element 2 and a scroll compression element 3. The electric element 2 is composed of a stator 4 secured to the inner wall surface of the hermetic housing 1 and a rotor 5 rotatably supported in the stator 4, a rotating shaft 6 being connected to the rotor 5 in a penetrating fashion. One end of the rotating shaft 6 is rotatably supported on a support frame 7 partly constituting the scroll compression element 3. The other end of the rotating shaft 6 juts out of the rotor 5, a lubricating portion 8 being connected to the distal end thereof. An oil inlet pipe 9 is connected to an end of the lubricating portion 8. The end of the intake side of the oil inlet pipe 9 is extended downward so that it is submerged in a lubricant "b" contained in the hermetic housing 1. An oil feed passage 10 for sucking in the lubricant "b" from the lubricating portion 8 and supplying it is bored in the rotating shaft 6 in the axial direction. The lubricant passes through the oil feed passage 10 to be supplied to sliding parts such as the support frame 7, then it is recirculated. The central part of one end of the rotating shaft 6 supported by the support frame 7 in the penetrating manner is formed as a pin or crank 11 provided eccentrically in relation to the axial center of the rotating shaft 6. A swivel scroll 12 is connected to the pin 11. The swivel scroll 12 is formed into a discoid shape. A boss hole 13 for connection with the pin 11 is formed at the center of one side surface of the swivel scroll 12, while a spiral swivel lap 14 is integrally formed on the other side surface of the swivel scroll 12. Joined to the support frame 7 is a stationary scroll 15. The stationary scroll 15 has a spiral stationary lap 16 formed on a portion thereof opposed to the swivel scroll 12, and also a plurality of compression chambers 17 formed between itself and the swivel lap 14. A refrigerant gas introduced into the outer peripheral portion of the scroll compression element 3 via an intake pipe 18 from outside the hermetic housing 1 is taken in through two inlets of the scroll compression element 3, namely, a first suction inlet (not shown) and a second suction inlet (not shown) that is located oppositely with respect to the first suction inlet and that is in communication therewith through a communication groove connected to the first suction inlet. Then, the refrigerant gas is compressed in the compression chambers 17 and the volume thereof is gradually reduced as it moves toward the center before it is discharged into the hermetic housing 1 through a discharge port provided at the center of one side surface of the stationary scroll 15, thus separating the lubricant accompanied the refrigerant gas in this space so as to reduce pulsation. The compressed gas discharged through the discharge port 19 into the hermetic housing 1 flows through passages (not shown) provided in the stationary scroll 15 and the support frame 7 as indicated by the white arrows and reaches the side of electric element 2. And the lubricant in the refrigerant gas is further separated primarily by the centrifugal force generated by the rotation of the rotor 5. The refrigerant gas from which the lubricant has been separated is discharged out of the hermetic housing 1 through a discharge pipe 20. The separated lubricant flows as indicated by the black arrows and accumulates at the bottom of the hermetic housing 1 and it is recirculated. However, there has been a problem in that, if the amount of the refrigerant taken in through a first suction inlet (not shown) of the scroll compression element 3 is different from that taken in through the second suction inlet (not shown) thereof, then the intake efficiency deteriorates, resulting in more pulsation with consequent noise and deteriorated reliability. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a highly reliable scroll compressor adapted to make the amount of a refrigerant taken in through the first suction inlet of the scroll compression element 3 mentioned above as equal as possible to that taken in through the second suction inlet thereby to improve the intake efficiency so as to control pulsation or noise. The inventors have zealously studied the aforesaid problem and found the following solution thereto, leading to the fulfillment of the present invention. To be more specific, if the sectional area of the inlet portion of a particular refrigerant passage is denoted by A1, the sectional area of the inlet portion of the first suction inlet is denotes by A2, and the sectional area of the inlet portion of a communication groove is denoted by A3 when the gap between the stationary lap and the swivel lap reaches the maximum thereof, then the problem can be solved by controlling these values to the range specified by a formula (1) given below, and/or by providing a throttle portion extending from an inlet of the communication groove to a particular position and by setting a sectional area a3 of the communication groove from the throttle portion to a second suction inlet to a value smaller than the sectional area A3. A scroll compressor according to Claim 1 of the present invention has an electric element and a scroll compression element driven by the electric element that are placed in a hermetic housing wherein the scroll compression element includes a stationary scroll having a spiral stationary lap and a swivel scroll having a spiral swivel lap that revolves with respect to the stationary scroll by being driven by the electric element, the stationary scroll and the swivel scroll are meshed with each other to form a plurality of compression chambers, a refrigerant gas, which has been introduced from outside the hermetic housing into a refrigerant introducing portion of the outer peripheral portion of the scroll compression element, is taken in through a first suction inlet and a second suction inlet that is located in a position relative to the first suction inlet and in communication therewith through a communication groove connected with the first suction inlet, and compressed in the compression chambers before it is discharged out of the hermetic housing; and wherein, if the sectional area of the inlet of a refrigerant passage through which a refrigerant taken in flows from an end of the swivel lap via the outer periphery thereof to the second suction inlet is denoted as A1, the sectional area of the inlet of the first suction inlet is denoted as A2, and the sectional area of the inlet of the communication groove is denoted as A3 when the gap between the stationary lap and the swivel lap reaches the maximum thereof, then A1, A2, and A3 stay within a range defined by a formula (1) given below: 1. 5 ≤ A2 / (A1 + A3) ≤ 2.5 A scroll compressor according to Claim 2 of the present invention has an electric element and a scroll compression element driven by the electric element that are placed in a hermetic housing, wherein the scroll compression element includes a stationary scroll having a spiral stationary lap and a spiral swivel lap that revolves with respect to the stationary scroll by being driven by the electric element, the stationary scroll and the spiral swivel lap are meshed with each other to form a plurality of compression chambers, a refrigerant gas, which has been introduced from outside the hermetic housing into a refrigerant introducing portion of the outer peripheral portion of the scroll compression element, are taken in through a first suction inlet and a second suction inlet that is located in a position relative to the first suction inlet and in communication therewith through a communication groove connected with the first suction inlet, and compressed in the compression chambers before it is discharged out of the hermetic housing; and wherein, if the length between two points at which a line passing through the center of the rotational axis of the electric element and also the center of the refrigerant introducing portion intersects with a line running through the center of the width of the communication groove is denoted as L, and a throttle portion is provided so that it extends from the inlet of the communication groove to a point of L/4, then a sectional area a3 of the communication groove from the throttle portion to the second suction inlet is made smaller than a sectional area A3 of the inlet. According to a further aspect of the invention described in Claim 3 of the invention, the aforesaid a3 and A3 stay within a range defined by a formula (2) given below in the scroll compressor described in Claim 2: 0.8 ≤ a3 / A3 ≤ 1.0 According to another aspect of the invention described in Claim 4, in the scroll compressor described in Claim 1, if the length between two points at which a line passing through the center of the rotational axis of the electric element and also the center of the refrigerant introducing portion intersects with a line running through the center of the width of the communication groove is denoted as L, and a throttle portion is provided so that it extends from the inlet of the communication groove to a point of L/4, then a sectional area a3 of the communication groove from the throttle portion to the second suction inlet is made smaller than a sectional area A3 of the inlet. According to another aspect of the invention the aforesaid a3 and A3 stay within a range defined by a formula (3) given below in the scroll compressor described in Claim 4: 0.8 ≤ a3 / A3 ≤ 1.0 BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic representation illustrative of the relationship mainly among a stationary lap, a swivel lap, a refrigerant introducing portion, a first suction inlet, a communication groove, and a second suction inlet when the gap between the stationary lap and the swivel lap of a scroll compressor in accordance with the present invention has reached its maximum. Fig. 2 is a schematic representation illustrative of the relationship mainly among a stationary lap, a swivel lap, a refrigerant introducing portion, a first suction inlet, a communication groove, and a second suction inlet when the gap between the stationary lap and the swivel lap of another scroll compressor in accordance with the present invention has reached its maximum. Fig. 3 is a graph showing the mass weight (kg/s) of a refrigerant taken in through the first suction inlet and the second suction inlet. Fig. 4 is a graph showing the mass weight (kg/s) of a refrigerant taken in through the first suction inlet and the second suction inlet. Fig. 5 is a graph showing the intake flow rate (m/s) of the refrigerant introduced through the first suction inlet and the second suction inlet. Fig. 6 is a sectional view showing the entire composition of a conventional scroll compressor. DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will now be described in detail in conjunction with Fig. 1 and Fig. 2. Figure 1 is a schematic representation illustrative of the relationship mainly among a stationary lap, a swivel lap, a refrigerant introducing portion, a first suction inlet, a communication groove, and a second suction inlet when the gap between the stationary lap and the swivel lap of a scroll compressor in accordance with the present invention has reached its maximum. Fig. 2 is a schematic representation illustrative of the relationship mainly among a stationary lap, a swivel lap, a refrigerant introducing portion, a first suction inlet, a communication groove, and a second suction inlet when the gap between the stationary lap and the swivel lap of another scroll compressor in accordance with the present invention has reached its maximum. In Fig. 1 and Fig. 2, the components denoted by the like reference numerals as those in Fig. 6 have the same functions as those of the components assigned the like reference numerals that have been described in conjunction with Fig. 6. As shown in Fig. 1, a scroll compression element 3 includes a stationary scroll 15 having a spiral stationary lap 16 and a swivel scroll 12 having a spiral swivel lap 14 that revolves with respect to the stationary scroll 15 by being driven by the foregoing electric element 2 (not shown in Fig. 1 or 2). The stationary scroll 15 and the swivel scroll 12 are engaged with each other to form a plurality of compression chambers 17. A refrigerant gas introduced from outside the foregoing hermetic housing 1 (not shown in Fig. 1 or 2) into a refrigerant introducing portion 21 of the outer peripheral of the scroll compression element 3 is taken in through a first suction inlet 22, which is formed between the swivel lap 14 and the stationary lap 16, and a second suction inlet 24 that is oppositely positioned from the first suction inlet 22 and that is placed in communication by a communication groove 23 connected to the first suction inlet 22. The introduced refrigerant gas is compressed in the compression chambers 17 and the volume thereof is gradually reduced as it moves toward the center, then it is discharged through the discharge port 19 (not shown in Fig. 1 or 2) provided at the center of the other side surface of the stationary scroll 15. Approximately half of the refrigerant gas introduced into the refrigerant introducing portion 21 is taken in through the first suction inlet 22 and the rest is taken in through the second suction inlet 24 via a plurality of passages. The first half of the refrigerant gas is taken in through the second suction inlet 24 via a refrigerant passage 25 extending from an end of the swivel lap 14 along the outer circumference thereof to the inner surface of the outermost circumference of the stationary scroll 15. The second half of the refrigerant gas is taken in through the second suction inlet 24 via the communication groove 23. In order to make the amount of the refrigerant introduced through the first suction inlet 22 as equal as possible to that introduced through the second suction inlet 24, it is important to control the values of A1, A2, and A3 to the range defined by the foregoing formula (1) , where the sectional area of an inlet 26 of the refrigerant passage 25 is denoted as A1, the sectional area of an inlet 27 of the first suction inlet 22 is denoted as A2, and the sectional area of an inlet 28 of the communication groove 23 is denoted as A3. Except for the constitution described above, the scroll compressor in accordance with the invention shares the same structure as that of the scroll compressor 1A shown in Fig. 6. If [A2/(A1+A3)] given by the formula (1) is below 1.5 or exceeds 2.5, then the balance between the amount of the refrigerant introduced through the first suction inlet 22 and that introduced through the second suction inlet 24 is disturbed. This leads to deteriorated intake efficiency and increased pulsation with resultant noise and also leads to deteriorated reliability. Figure 3 shows the mass flow rate (kg/s) of the refrigerant taken in through the first suction inlet 22 and the second suction inlet 24 when the value of [A2/(A1+A3)] is 1.5, 2.0, and 2.5, respectively. It can be seen that the amount of the refrigerant introduced through the first suction inlet 22 and that introduced through the second suction inlet 24 are in good balance and nearly equal especially when the value of [A2/(A1+A3)] is 1.5 or 2.0. As shown in Fig. 2, in another scroll compressor in accordance with the invention, in order to make the amount of the refrigerant introduced through the first suction inlet 22 as equal as possible to that introduced through the second suction inlet 24, a throttle portion 29 is provided so that it extends from the inlet 28 of the communication groove 23 to the point of L/4, where the length between two points (x and y) at which a line "c" passing through a center O of the rotating shaft 6 and the electric element 2 (not shown in Fig. 1 or 2) and also a center "a" of the refrigerant introducing portion 21 intersects with a line "d" passing through the center of the width of the communication groove 23 is denoted as L. The sectional area a3 of the communication groove 23 from the throttle portion 29 to the second suction inlet 24 is set to a smaller value than that of the sectional area A3 of the inlet 24. Preferably, the ratio of a3/A3 is set to the range defined by the foregoing formula (3). Except for the constitution described above, another scroll compressor in accordance with the invention shares the same structure as that of the scroll compressor 1A shown in Fig. 6. Figure 4 shows the mass flow rate (kg/s) of the refrigerant taken in through the first suction inlet 22 and the second suction inlet 24 when the value of [A2/(A1+A3)] is set to 2.0, and the position where the throttle portion 29 is provided is set to 0 (immediately behind the refrigerant introducing portion 21), L/4, and L/2, respectively. It can be seen that the balance is disturbed when the throttle portion 29 is provided at the point L/2, whereas good balance is obtained when it is provided so that it extends from the inlet 28 of the communication groove 23 to the position of L/4. Figure 5 shows the suction flow rate (m/s) of the refrigerant introduced through the first suction inlet 22 and the second suction inlet 24 when the value of [A2/(A1+A3)] is set to 2.0, the throttle portion 29 is provided so that it extends to the position of L/4, and the ratio of a3/A3 is set to 0 . 5 , 0.8, and 1, respectively. It can be seen that the balance is disturbed when the ratio of a3/A3 is set to 0.5, whereas good balance is obtained when the ratio of a3/A3 is set to 0.8 or 1.0. The above description of the present invention refers to a horizontal type scroll compressor. The scroll compressor in accordance with the invention, however, is not limited to the horizontal type; the invention is applicable also to a vertical scroll compressor or other types of scroll compressors. The scroll compressor in accordance with the invention is designed to make the amount of the refrigerant introduced through the first suction inlet as equal as possible to that introduced through the second suction inlet, so that the intake efficiency is improved and pulsation or noise can be controlled. This leads to higher reliability and permits stable operation of the scroll compressor.

Claims: A scroll compressor comprising an electric element (2) and a scroll compression element (3) driven by said electric element (2) that are housed in a hermetic housing (1), wherein: said scroll compression element includes a stationary scroll having a spiral stationary lap (16) and a swivel scroll (12) having a spiral lap (14) that revolves with respect to said stationary scroll (15) by being driven by said electric element (2); said stationary scroll (15) and said swivel scroll (12) are meshed with each other to form a plurality of compression chambers (17); and a refrigerant gas, which has been introduced from outside said hermetic housing (1) into a refrigerant introducing portion (21) of the outer peripheral portion of said scroll compression element (3), is taken in through a first suction inlet (22) and a second suction inlet (24) that is located oppositely to said first suction inlet and in communication therewith through a communication groove (23) connected with said first suction inlet (22), and compressed in said compression chambers (17) before it is discharged out of said hermetic housing (1); and wherein, if the sectional area of the inlet of a refrigerant passage through which an introduced refrigerant flows from an end of said swivel lap (14) via the outer periphery thereof to said second suction inlet (24) is denoted as A1, the sectional area of the inlet of said first suction inlet (22) is denoted as A2, and the sectional area of the inlet of the communication groove (22) is denoted as A3 when the gap between said stationary lap and said swivel lap reaches its maximum, then A1, A2 and A3 stay within a range defined by 1.5 ≤ A2 / (A1 + A3) ≤ 2.5. A scroll compressor comprising an electric element (2) and a scroll compression element (3) driven by said electric element (2) that are housed in a hermetic housing (1), wherein: said scroll compression element includes a stationary scroll having a spiral stationary lap (16) and a swivel scroll (12) having a spiral lap (14) that revolves with respect to said stationary scroll (15) by being driven by said electric element (2); said stationary scroll (15) and said swivel scroll (12) are meshed with each other to form a plurality of compression chambers (17); and a refrigerant gas, which has been introduced from outside said hermetic housing (1) into a refrigerant introducing portion (21) of the outer peripheral portion of said scroll compression element (3), is taken in through a first suction inlet (22) and a second suction inlet (24) that is located oppositely to said first suction inlet and in communication therewith through a communication groove (23) connected with said first suction inlet (22), and compressed in said compression chambers (17) before it is discharged out of said hermetic housing (1); and wherein, if the length between two points at which a line passing through the center of said rotational axis of said electric element (2) and also the center of said refrigerant introducing portion intersects with a line running through the center of the width of said communication groove is denoted as L, and a throttle portion is provided so that it extends from the inlet of said communication groove (23) to a point of L/4, then a sectional area a3 of said communication groove from said throttle portion to said second suction inlet (24) is made smaller than a sectional area A3 of said inlet. A scroll compressor according to Claim 1, wherein, if the length between the points at which a line passing through the center of said rotational axis of said electric element (2) and also the center of said refrigerant introducing portion intersects with a line running through the center of the width of said communication groove is denoted as L, and a throttle portion is provided so that it extends from the inlet of said communication groove (23) to a point of L/4, then a sectional area a3 of said commuication groove from said throttle portion to said second suction inlet (24) is made smaller than a sectional area A3 of said inlet. A scroll compressor according to Claim 2 or 3, wherein said a3 and said A3 stay within a range defined by 0.8 ≤ a3 / A3 ≤ 1.0.

Inventors: FUJIWARA KAZUAKI, MATSUMOTO KENZO, MITSUNAGA TOSHIHIKO, NISHIKAWA TAKAHIRO, SATO KAZUYA, SATO TAKASHI, SUGIMOTO KAZUYOSHI, FUJIWARA, KAZUAKI, MATSUMOTO, KENZO, MITSUNAGA, TOSHIHIKO, NISHIKAWA, TAKAHIRO, SATO, KAZUYA, SATO, TAKASHI, SUGIMOTO, KAZUYOSHI
Applicants: SANYO ELECTRIC CO, SANYO ELECTRIC CO., LTD.
Application year: 1998
Main classification: F04C18
IPC codes: F04C18, F04C29