Rotating screw compressor

Abstract

A self-propelled screw compressor has: a housing (6) with a screw chamber (65); a drive mechanism (10) with a stator (17) and a rotor (11) arranged outside the stator (17) to surround it; and a drive screw (30) with a cover body (37). The cover body (37) has a wall section (37a) with a suction port (374) through which a fluid is drawn from the screw chamber (65) into a compression chamber (12). A first suction channel (71, 75) is formed between the housing (6) and the rotor (11). The fluid flows from the cover body (37) through the first suction passage (71, 75) towards the rotor (11) in the direction of a drive axis (O1) in the screw chamber (65). A second intake passage (72) is formed between the rotor (11) and the stator (17).The fluid flowing through the first intake passage (71, 75) flows from the rotor (11) towards the drive axis (O1) to the cover body (37) and is guided through the second intake passage (72) to the intake port (374).

Description

[0001] The present invention relates to a moving screw compressor. STATE OF THE ART

[0002] Japanese patent application No. H02-227575 discloses a known rotating screw compressor (hereinafter referred to simply as compressor).

[0003] The compressor has a casing, a drive screw, a driven screw, a drive mechanism, and a driven mechanism. The casing has a spiral chamber that houses the drive screw, the driven screw, the drive mechanism, and the driven mechanism. Fluid is drawn into the screw chamber from outside the casing. In Japanese patent application No. H02-227575, a refrigerant serves as the fluid.

[0004] The drive screw is configured to be driven around a drive axis by the drive mechanism. The driven screw is eccentric to the drive screw and is rotated around a drive axis by the drive screw and the driven mechanism. Both the drive screw and the driven screw rotate to change the volume of the compression chamber and to compress the fluid through the rotation of the drive screw and the driven screw. The drive mechanism has a stator and a rotor. The stator is cylindrical, extends along the drive axis, and is mounted within the screw chamber. The rotor is also cylindrical, extends along the drive axis, and has a smaller diameter than the stator, which is located inside the stator.

[0005] The compressor housing has a projection. This projection extends into the screw chamber in the direction of the drive axis, towards the drive screw and the driven screw. The projection has an outlet passage that extends in the direction of the drive axis. The outlet passage has opposite ends that define its extent in the direction of the drive axis, and each of these opposite ends is connected to the outlet chamber and the outside of the housing, respectively.

[0006] The compressor's drive screw has a cover body. The cover body has a cylindrical extension section. This extension section has an outer circumferential surface to which the rotor is attached. The projection extends into the extension section. The drive screw is rotatably mounted over the cover body by this projection. The drive screw has an intake port. This intake port connects to the spiral chamber and the compression chamber.

[0007] Inside the compressor, the rotor of the drive mechanism rotates, causing the drive screw to rotate around the drive axis along with the rotor. The driven screw is powered by the drive screw and the driven mechanism to rotate around the drive axis. Both the drive screw and the driven screw rotate to change the volume of the compression chamber. The fluid in the screw chamber flows along the direction of the drive axis from one side of the compressor to the other and is drawn into the compression chamber through the intake port. The fluid is compressed in the compression chamber and discharged through the outlet to the outside of the casing.

[0008] With this type of compressor, it is necessary to suppress the reduction in performance of the drive mechanism due to heating during operation. In such a known compressor, when the fluid is drawn into the intake port, it flows between the stator and the rotor along the direction of the drive axis. The fluid can cool the stator and rotor of the compressor, i.e., the drive mechanism, but it may not cool the drive mechanism sufficiently. Consequently, it is unlikely that this compressor will achieve sufficient reliability.

[0009] The present invention, which was developed taking into account the above-mentioned problem, is aimed at providing a moving screw compressor which has excellent reliability. SUMMARY

[0010] According to one aspect of the present invention, a self-propelled screw compressor is provided, comprising: a housing with a screw chamber into which fluid is drawn from outside the housing; a drive mechanism accommodated in the screw chamber; a driven mechanism accommodated in the screw chamber; a drive screw accommodated in the screw chamber; and a driven screw accommodated in the screw chamber. The drive mechanism comprises: a stator; and a rotor arranged outside the stator to surround the stator. The rotor is rotated by the stator. The stator comprises: a stator core; a first coil end; and a second coil end. The stator core has a cylindrical shape arranged around a drive axis as its center point and extending in the direction of the drive axis.The first coil end is cylindrical and extends from the stator core toward one side of the rotating screw compressor along the direction of the drive axis. The second coil end is also cylindrical and extends from the stator core toward the opposite side of the rotating screw compressor, along the direction of the drive axis. The drive screw is configured to be rotated around the drive axis by the drive mechanism. The driven screw is positioned eccentrically to the drive screw. The driven screw is configured to be rotated around a driven axis by the drive screw and the drive mechanism. The drive screw and the driven screw form a compression chamber for compressing the fluid through the rotation of the drive screw and the rotation of the driven screw.A projection is provided in the worm chamber. This projection extends towards the drive worm and the driven worm in the direction of the drive axis and is attached to the stator core. The drive worm has a cover body that rotates with the rotor. The cover body has a wall section that extends radially along the drive worm and points towards the first coil end in the direction of the drive axis. This wall section is connected to a cylindrical section that has a cylindrical shape. The cylindrical section extends in the direction of the drive axis and surrounds the first coil end, which lies radially inside the cylindrical section in the direction of the drive worm. The rotation of the rotor is transmitted to the cover body via the cylindrical section.The wall section has a suction port located radially inside the cylindrical section, parallel to the drive screw. The fluid in the screw chamber is drawn into the compression chamber through this suction port. A first suction passage is formed between the housing and the rotor, radially parallel to the drive screw. The fluid flows from the cover body through this first suction passage in the direction of the drive axis within the screw chamber to the rotor. A second suction passage is formed between the rotor and the stator, radially parallel to the drive screw. The fluid flowing through the first suction passage flows from the rotor in the direction of the drive axis to the cover body and is then guided through the second suction passage to the suction port.

[0011] Further aspects and advantages of the invention will become apparent from the following description in conjunction with the accompanying drawings, which exemplify the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The invention, its subject matter and advantages, can best be understood by reference to the following description of the embodiments in conjunction with the accompanying drawings, in which: Fig. 1 a sectional view of a compressor according to a first embodiment; Fig. 2 an enlarged sectional view of the compressor according to the first embodiment, showing a main part of the compressor which has a stator and a rotor; Fig. 3 a sectional view of a compressor according to a second embodiment; and Fig. 4 is a sectional view of a compressor according to a third embodiment. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0013] The first to third embodiments of the present invention are described in detail below with reference to the accompanying drawings. A compressor according to each of the first to third embodiments is mounted on a vehicle (not shown) and is located in an air conditioning system for the vehicle. First embodiment

[0014] Fig. Figure 1 shows a compressor according to the first embodiment. The compressor has a housing 6, an electric motor 10, a drive screw 30, a driven screw 40, and a driven mechanism 20. The electric motor 10 serves, for example, as the drive mechanism of the present invention.

[0015] In the present embodiment, the forward / reverse direction of the compressor is indicated by an arrow in Fig. 1 defined. In Fig. 2 and the following figures, the forward / reverse direction of the compressor corresponds to the forward / reverse direction from Fig. 1. It should be noted that the forward / reverse direction of the compressor is merely an example to facilitate the explanation and the position of the compressor may be changed accordingly depending on the vehicle in which the compressor is installed.

[0016] As from Fig. As can be seen in Figure 1, the housing 6 has a housing body 60, a first housing cover 61 and a second housing cover 62. The housing body 60 serves, for example, as the main body of the present invention.

[0017] The housing body 60 is made of an aluminum alloy. The housing body 60 has a cylindrical shape centered around a drive axis O1 and extends in the direction of the drive axis O1. The front and rear ends of the housing body 60 are open ends. The drive axis O1 runs parallel to the forward / reverse direction. In the present embodiment, for example, the front and rear of the compressor serve as one side and the other side of the compressor, respectively, along the direction of the drive axis of the present invention.

[0018] The housing body 60 has an outer circumferential surface 601 and an inner circumferential surface 602. The housing body 60 has: a first housing section 60a with a first inner diameter L1; and a second housing section 60b with a second inner diameter L2. The second inner diameter L2 is larger than the first inner diameter L1. The second housing section 60b extends from the first housing section 60a in the direction of the drive axis O1.

[0019] The first housing section 60a is located at the front end of the housing body 60 (i.e., on one side along the direction of the drive axis O1 with respect to a rotor 11), and the second housing section 60b is located at the rear end of the housing body 60 (i.e., on the other side along the direction of the drive axis O1 with respect to the first housing section 60a). The housing body 60 has an inner diameter that gradually increases in the direction of the drive axis O1 from the first housing section 60a to the second housing section 60b, such that the second inner diameter L2 of the second housing section 60b is larger than the first inner diameter L1 of the first housing section 60a. That is, the housing body 60 is shaped such that the inner diameter of the housing body 60 increases from the first inner diameter L1 at the front end of the housing body 60 to the second inner diameter L2 at the rear end of the housing body 60.Although the inner diameter of the housing body 60 is increased in this way, the outer diameter of the housing body 60 remains constant. The second section 60b is directed radially towards the rotor 11 in the direction of the drive worm 30.

[0020] The housing body 60 has an intake port 81. The intake port 81 is located on the opposite side with respect to the center point of the housing body 60 in the direction of the drive axis O1. That is, the intake port 81 is located on the rear side with respect to the center point of the housing body 60 in the direction of the drive axis O1. The intake port 81 extends radially along the housing body 60 and connects the inner and outer sides of the housing body 60. The intake port 81 is connected to an evaporator (not shown) via a pipe (not shown).

[0021] The first housing cover 61 is made of steel. The first housing cover 61 is located at the rear end of the housing body 60. The first housing cover 61 has an approximately disc-shaped form, aligned around the drive axis O1 as its center point. The first housing cover 61 has opposing surfaces, i.e., a forward-facing front surface 61a and a rear-facing rear surface 61b, which define the first housing cover 61 in the forward / reverse direction.

[0022] The housing 6 has a projection 64 located within the housing 6. Specifically, the projection 64 is formed integrally with the first housing cover 61. The projection 64 is made of steel. The projection 64 has a solid cylindrical shape and projects forward from the center of the front face 61a in the direction of the drive axis O1. The projection 64 has a first diameter section 64a and a second diameter section 64b.

[0023] The first diameter section 64a forms the front section of the projection 64. As shown from Fig. As can be seen in Figure 2, the first diameter section 64a has a diameter that is smaller than the diameter of an insertion hole 375 described later. The first diameter section 64a has a pin hole 4. The pin hole 4 extends within the first diameter section 64a in the direction of the drive axis O1 and opens at the front end face of the first diameter section 64a.

[0024] The first diameter section 64a has an outer circumferential surface on which a first radial ball bearing 51 is provided. Instead of the first radial ball bearing 51, a plain bearing can be provided on the outer circumferential surface of the first diameter section 64a.

[0025] The second diameter section 64b is formed integrally with the first diameter section 64a and is located behind the first diameter section 64a. That is, the second diameter section 64b forms the rear section of the projection 64. The rear end of the second diameter section 64b is connected to the front face 61a of the first housing cover 61. The second diameter section 64b has a diameter that is larger than the diameter of the first diameter section 64a.

[0026] As from Fig. As can be seen in Figure 1, the second housing cover 62 is arranged in front of the housing body 60. The second housing cover 62 is made of an aluminum alloy. The second housing cover 62 has an approximately disc-shaped form, aligned around the drive axis O1 at its center point. The second housing cover 62 has opposing surfaces, i.e., a forward-facing front surface 62a and a rear-facing rear surface 62b, which define the second housing cover 62 in the forward / reverse direction.

[0027] The second housing cover 62 has a support section 66 and an outlet connection 83. The support section 66 is formed integrally with the rear side 62b approximately at the midpoint of the rear side 62b and extends rearward from the rear side 62b. The support section 66 has a cylindrical shape centered around the drive axis O1 at its midpoint and contains a second radial ball bearing 52 and a shaft sealing element 63. Within the support section 66, the shaft sealing element 63 is located upstream of the second radial ball bearing 52. The shaft sealing element 63 has an annular shape. A plain bearing can be arranged within the support section 66 instead of the second radial ball bearing 52.

[0028] The outlet connection port 83 is formed by the second housing cover 62 in the direction of the drive axis O1 and connects the interior of the support section 66 to the exterior of the second housing cover 62. The outlet connection port 83 is connected to a capacitor (not shown) via a line (not shown).

[0029] In the housing 6, the front 61a of the first housing cover 61 and the rear 62b of the second housing cover 62 are each in contact with the rear end and the front end of the housing body 60, respectively. The first housing cover 61 and the second housing cover 62 are fastened to the housing body 60 in the direction of the drive axis O1 by a plurality of screws (not shown).

[0030] Accordingly, the housing body 60 of the housing 6 is held in the forward / reverse direction by the first housing cover 61 and the second housing cover 62, and the front and rear ends of the housing body 60 are closed by the first housing cover 61 and the second housing cover 62, respectively. A screw chamber 65 is formed inside the housing body 60 of the housing 6. The screw chamber 65 is connected to the intake port 81.

[0031] Accordingly, a refrigerant is drawn from outside the housing 6 through the intake port 81 into the screw chamber 65. The refrigerant serves, for example, as the fluid of the present invention.

[0032] The projection 64 is provided in the screw chamber 65 and extends from the first housing cover 61 in the direction of the drive axis O1. In particular, the projection 64 extends forward from the first housing cover 61 in the direction of the drive screw 30 and the driven screw 40.

[0033] The electric motor 10 is housed in the worm chamber 65. The worm chamber 65 serves as a motor chamber in which the electric motor 10 is housed.

[0034] As from Fig. As can be seen in Figure 2, the electric motor 10 has a stator 17 and a rotor 11. The stator 17 has a stator core 17a and a winding 17b. The stator core 17a has a cylindrical shape, centered around the drive axis O1 and extending in the direction of the drive axis O1. The winding 17b is wound around the stator core 17a. The winding 17b of the stator 17 has a first coil end 171 and a second coil end 172.

[0035] The first coil end 171 has a cylindrical shape and extends forward (i.e., to one side) from the stator core 17a along the direction of the drive axis O1. The second coil end 172 is located on the side of the stator core 17a opposite the first coil end 171. The second coil end 172 also has a cylindrical shape and extends backward from the stator core 17a along the direction of the drive axis O1. That is, the first coil end 171 and the second coil end 172 each extend from the stator core 17a along the direction of the drive axis O1 to one side and to the other side opposite that side, respectively.

[0036] The stator core 17a of the stator 17 is fitted onto the outer circumferential surface of the second diameter section 64b. Accordingly, the stator core 17a is attached to the second diameter section 64b of the projection 64. Although not shown, a plurality of slots are formed on the inner circumferential surface of the stator core 17a, extending in the direction of the drive axis O1. This configuration creates a gap between the slots and the outer circumferential surface of the second diameter section 64b, to which the stator core 17a is attached.

[0037] As from Fig. As can be seen in Figure 2, the rotor 11 has a rotor body 11a, a plurality of magnetic cores 11b, a first retaining plate 11c and a second retaining plate 11d. Fig. Figure 2 shows one of the magnetic cores 11b. From Fig. 1, Fig. 3 and Fig. Figure 4 shows a simplified representation of the shape of the rotor 11.

[0038] As from Fig. As can be seen in Figure 2, the rotor body 11a of the rotor 11 is formed from a plurality of electromagnetic steel sheets 111 stacked one on top of the other in the direction of the drive axis O1, each of the electromagnetic steel sheets 111 having an approximately disk-shaped form. Accordingly, the rotor body 11a has an approximately cylindrical shape and extends in the direction of the drive axis O1. The electromagnetic steel sheets 111 (i.e., the rotor body 11a) have a plurality of magnetic core chambers 112 and a plurality of first screw holes 113.

[0039] Each of the magnetic cores 11b has a columnar shape and extends in the direction of the drive axis O1. Each of the magnetic cores 11b is housed in a corresponding magnetic core chamber 112. The first retaining plate 11c and the second retaining plate 11d are each disc-shaped and made of a metal plate. The first retaining plate 11c is located in front of the rotor 11a. The second retaining plate 11d is located behind the rotor 11a. The first retaining plate 11c has a plurality of through holes 114 corresponding to the plurality of first screw holes 113, and the second retaining plate 11d has a plurality of through holes 115. The through holes 114 and the through holes 115 correspond to the first screw holes 113.

[0040] The first retaining plate 11c and the second retaining plate 11d hold the rotor 11a between them in the forward / reverse direction, with each of the through holes 114 and each of the through holes 115 aligned in the forward / reverse direction with the corresponding first screw hole 113. The rotor body 11a is fastened to the first retaining plate 11c and the second retaining plate 11d in the forward / reverse direction by rivets (not shown), so that the rotor body 11a is integrated with the first retaining plate 11c and the second retaining plate 11d. The front and rear ends of each of the magnetic core chambers 112 are closed by the first retaining plate 11c and the second retaining plate 11d. This configuration prevents the magnetic core 11b from falling out of the magnetic core chamber 112. In this way, the rotor 11 is formed.

[0041] The electromagnetic steel sheet 111, the first retaining plate 11c, and the second retaining plate 11d each have a diameter larger than the diameter of the stator core 17a. That is, the rotor 11 has a cylindrical shape and a diameter larger than the diameter of the stator core 17a. The rotor 11 has an outer surface 110a and an inner surface 110b. In the worm gear chamber 65, the rotor 11 is positioned outside the stator 17 to surround the stator core 17a of the stator 17 in the radial direction of the drive worm 30. The rotor 11 is rotated by the stator 17.

[0042] As from Fig. As can be seen in Figure 1, the drive screw 30 is housed in the screw chamber 65. The drive screw 30 is made of metal, for example, an aluminum alloy. The drive screw 30 has a drive screw end plate 31, a drive screw body 33, a drive screw circumferential wall 35, a cover body 37, and a housing 39.

[0043] The drive worm end plate 31 has an approximately disc-shaped form and is perpendicular to the drive axis O1 and the driven axis O2. The driven axis O2 is eccentric and parallel to the drive axis O1. That is, the driven axis O2 is parallel to the forward / reverse direction. The drive worm end plate 31 has opposing surfaces, i.e., a first front surface 311 facing forward and a first back surface 312 facing backward, which define the drive worm end plate 31 in the forward / reverse direction.

[0044] The drive worm end plate 31 has an outlet 32. The outlet 32 ​​extends through the drive worm end plate 31 in the direction of the drive axis O1. An outlet tongue valve 57 and a bracket 58 are attached to the first front face 311 of the drive worm end plate 31 by a fastening screw 59. This configuration allows the outlet tongue valve 57 to open and close the outlet opening 32. The bracket 58 adjusts the degree of opening of the outlet tongue valve 57.

[0045] The drive worm body 33 is formed integrally with the drive worm end plate 31 and extends from the first rear face 312 of the drive worm end plate 31 rearward in the direction of the driven worm 40 and parallel to the drive axis O1 and the driven axis O2. Although not visible in detail, the drive worm body 33 has a spiral shape centered around the midpoint of the drive worm end plate 31 and extending radially outward from the midpoint of the spiral shape.

[0046] The drive worm circumferential wall 35 has a cylindrical shape centered around the drive axis O1 and extends parallel to the drive axis O1 and the driven axis O2. The front end of the drive worm circumferential wall 35 is integrally formed with the outer circumferential edge of the drive worm end plate 31. The drive worm circumferential wall 35 has a cylindrical shape, extends rearward from the first rear surface 312, and radially surrounds the drive worm body 33. Although not apparent, the outer outer end of the drive worm body 33 is connected to the inner outer surface of the drive worm circumferential wall 35. The cover body 37 has a wall section 37a, an inner cylindrical section 37b, and an outer cylindrical section 37c. The outer cylindrical section 37c serves, for example, as a cylindrical section of the present invention.

[0047] The wall section 37a has an approximately plate-like shape and extends radially towards the drive worm 30. The wall section 37a faces the first coil end 171 in the direction of the drive axis O1. The wall section 37a has opposing surfaces, i.e., a second front surface 371 facing forward and a second rear surface 372 facing backward, which define the wall section 37a in the forward / backward direction.

[0048] Wall section 37a has a recess 373 and an intake port 374. The recess 373 is located approximately at the center of the second front surface 371 and extends backwards into the second front surface 371.

[0049] The intake port 374 is located radially outside the recess 373 in the radial direction of the drive screw 30. The intake port 374 is formed by the wall section 37a in the forward / reverse direction, and the front and rear ends of the intake port 374 are open at the second front surface 371 and the second rear surface 372, respectively. The intake port 374 is formed only in the wall section 37a. In the present embodiment, the single intake port 374 is formed in the wall section 37a; however, multiple intake ports 374 can be formed in the wall section 37a.

[0050] In wall section 37a, a plurality of rings 22 are arranged between the recess 373 and the intake port 374. Although not shown in detail, the rings 22 are arranged at equal intervals in the direction of the recess 373, so that they surround the recess 373 with the rings 22 facing forward. In the present embodiment, six rings 22 are provided. Fig. 1, Fig. 3 and Fig. 4 represent one of the six rings 22.

[0051] The inner cylindrical section 37b is located radially within the stator 17 of the cover body 37. The inner cylindrical section 37b has a cylindrical shape and extends rearward from the second rear face 372 of the wall section 37a toward the drive axis O1. The inner cylindrical section 37b has a diameter larger than the diameter of the first diameter section 64a of the projection 64 and smaller than the diameter of the second diameter section 64b. The inner diameter of the inner cylindrical section 37b is approximately equal to the outer diameter of the first radial ball bearing 51. The outer diameter of the inner cylindrical section 37b may be approximately equal to or larger than the outer diameter of the second diameter section 64b.

[0052] The cover body 37 has an insertion hole 375. The insertion hole 375 extends in the direction of the drive axis O1 and connects the inner cylindrical section 37b and the recess 373.

[0053] The outer cylindrical section 37c is formed integrally with the wall section 37a at the outer circumferential edge of the wall section 37a. Accordingly, the outer cylindrical section 37c is connected to the wall section 37a, has a cylindrical shape, and extends rearward from the wall section 37a in the direction of the drive axis O1. The outer cylindrical section 37c has an outer diameter that corresponds approximately to the outer diameter of the drive worm circumferential wall 35 and the outer diameter of the rotor 11.

[0054] The outer cylindrical section 37c has an inner diameter that is larger than the outer diameter of the inner cylindrical section 37b. In the cover body 37, the inner cylindrical section 37b is arranged radially inside the outer cylindrical section 37c and spaced radially apart from it in the direction of the drive worm 30. Accordingly, a receiving section 38 is formed in the cover body 37 by the wall section 37a, the inner cylindrical section 37b, and the outer cylindrical section 37c. The receiving section 38 has an annular shape with a base and opens to the rear.

[0055] The intake port 374 of the wall section 37a is located radially outside the inner cylindrical section 37b and inside the outer cylindrical section 37c in the radial direction of the drive screw 30. Accordingly, the intake port 374 communicates with the receiving section 38 at a position between the inner cylindrical section 37b and the outer cylindrical section 37c.

[0056] The outer cylindrical section 37c has a plurality of second screw holes 376. Each of the second screw holes 376 extends through the outer cylindrical section 37c in the direction of the drive axis O1. Although not apparent, the number of second screw holes 376 corresponds to the number of first screw holes 113 of the rotor 11. Fig. 1, Fig. 2, Fig. 3 to Fig. Figure 4 illustrates one of the first screw holes 113 and one of the second screw holes 376.

[0057] As from Fig. As can be seen in Figure 1, the front end of the outer cylindrical section 37c of the cover body 37 is in contact with the rear end of the drive screw circumferential wall 35. The rear end of the outer cylindrical section 37c of the cover body 37 is in contact with the rotor 11, specifically with the first retaining plate 11c. The first screw 34a is inserted in this sequence through the through-hole 115 of the second retaining plate 11d, the first screw hole 113 of the rotor 11, the through-hole 114 of the first retaining plate 11c, and the second screw hole 376 of the outer cylindrical section 37c, and screwed into the circumferential wall 35 of the drive screw. In this way, the cover body 37 is held and attached to the circumferential wall 35 of the drive screw and the rotor 11 in the forward / reverse direction. Accordingly, the drive screw 30 is formed in one piece with the rotor 11, so that the cover body 37 rotates together with the rotor 11.

[0058] The housing 39 is a tubular element with a base and has an outer wall 39a and a front wall 39b. The outer wall 39a has a cylindrical shape centered around the drive axis O1. The outer wall 39a has an outer diameter that corresponds approximately to the outer diameter of the outer wall 35 of the drive worm.

[0059] The front wall 39b is located at the front end of the housing 39. The front wall 39b has an approximately disc-shaped form and is perpendicular to the drive axis O1 and the driven axis O2. The outer circumferential edge of the front wall 39b is connected to the front end of the outer circumferential wall 39a. The front wall 39b has a projection 39c. The projection 39c is formed integrally with the front wall 39b at its center point and extends forward from the front wall 39b in the direction of the drive axis O1. The projection 39c has an outer diameter that corresponds approximately to the inner diameter of the second radial ball bearing 52 and the inner diameter of the shaft sealing element 63. The projection 39c has an outlet passage 390. The outlet passage 390 is formed by the projection 39c in the direction of the drive axis O1.

[0060] The outer circumferential wall 39a and the front wall 39b are arranged such that they have a plurality of third screw holes 39d. Each of the third screw holes 39d is formed through the outer circumferential wall 39a and the front wall 39b in the direction of the drive axis O1. Fig. 1, Fig. 3 and Fig. Figure 4 shows one of the third screw holes 39d, from Fig. 1.

[0061] As from Fig. As can be seen in Figure 1, the rear side of the outer wall 39a of the housing 39 and the front end of the outer wall 35 of the drive screw are in contact. A second screw 34b is inserted through the third screw hole 39d and screwed into the outer wall 35 of the drive screw. In this way, the housing 39 is attached to the drive screw's outer wall 35 of the drive screw 30.

[0062] The housing 39 has an outlet chamber 14, which is bounded by the drive screw end plate 31, the outer circumferential wall 39a, and the front wall 39b of the housing 39. The outlet chamber 14 is connected to the outlet opening 32 and the outlet passage 390. The housing 39 is spaced from the cover body 37 in the forward / reverse direction, and the drive screw body 33 and the drive screw circumferential wall 35 of the drive screw 30 are arranged between the housing 39 and the cover body 37.

[0063] The housing 39 is spaced forward / backward from the cover body 37, and the drive worm body 33 and the drive worm circumferential wall 35 of the drive worm 30 are arranged between the housing 39 and the cover body 37. That is, in the present embodiment, the housing 39 is located on the front (i.e., on one side) along the direction of the drive axis O1 with respect to the cover body 37.

[0064] Since the rotor 11 is attached to the outer cylindrical section 37c of the cover body 37, the housing 39 with the outlet chamber 14 is spaced from the rotor 11 in the forward / backward direction.

[0065] The driven screw 40 is made of an aluminum alloy. The driven screw 40 has an end plate 41 and a body 43.

[0066] The end plate 41 of the driven worm has an approximately disc-shaped form and is perpendicular to the drive axis O1 and the driven axis O2. The end plate 41 of the driven worm has opposing surfaces, i.e., a third front surface 411 facing forward and a third rear surface 412 facing backward, which define the end plate 41 of the driven worm in the forward / reverse direction.

[0067] The end plate 41 of the driven screw has a receiving recess 15. The receiving recess 15 is located in the center of the end plate 41 of the driven screw. The receiving recess 15 has a circular shape centered around the center point of the driven axis O2 and is recessed forward in the third rear surface 412 of the end plate 41 of the driven screw. The receiving recess 15 is directed rearward, i.e., it is aligned with the first section 64a of the projection 64.

[0068] As from Fig. As can be seen in Figure 2, a driven shaft 16 is arranged in the receiving recess 15. The driven shaft 16 has a bushing 53 and a driven pin 55. The bushing 53 is housed in the receiving recess 15 via a sliding bearing 13. The driven pin 55 extends through the bushing 53. In particular, the driven pin 55 is positioned eccentrically to the drive axis O2 at the center of the bushing 53. The driven pin 55 projects rearward from the bushing 53, i.e., from the end plate 41 of the driven worm gear.

[0069] As from Fig. As can be seen in Figure 1, a plurality of pivot pins 21, comprising six pivot pins 21 in the present embodiment, are each attached to the end plate 41 of the driven worm at a position facing the ring 22. The pivot pins 21 project rearward from the third rear surface 412. The number of pivot pins 21 corresponds to the number of rings 22. Fig. 1, Fig. 3 and Fig. Figure 4 shows one of the six pivot pins 21.

[0070] As from Fig. As can be seen in Figure 1, the pivot pins 21 and the rings 22 work together to form the driven mechanism 20. The driven mechanism 20 is housed in the screw chamber. As long as at least three pivot pins 21 and three rings 22 are provided, their number can be determined accordingly.

[0071] The body 43 of the driven worm is formed integrally with the end plate 41 of the driven worm and extends forward from the third front surface 411 of the end plate 41 of the driven worm parallel to the drive axis O1 and the driven axis O2. The body 43 of the driven worm has a helical shape centered around the center point of the end plate 41 of the driven worm and extends radially outward from the center point of the helical shape.

[0072] In the compressor, the driven screw 40 is housed within the drive screw 30, specifically between the cover body 37 and the drive screw body 33 and the drive screw circumferential wall 35 of the drive screw 30. The drive screw body 33 engages with the body 43 of the driven screw. The drive screw body 33 faces the body 43 of the driven screw and works together with it to form a compression chamber 12.

[0073] An intake chamber 30a is formed between the drive screw circumferential wall 35 and the driven screw 40. This means that the drive screw 33 and the body 43 of the driven screw are located within the intake chamber 30a. The intake chamber 30a is separated from the screw chamber 65 by the circumferential wall 35 of the drive screw and the cover body 37, and also from the outlet chamber 14 by the end plate 31 of the drive screw. The intake chamber 30a is connected to the intake port 374.

[0074] The driven screw 40 is received in the drive screw 30 such that each of the pivot pins 21 is arranged in a corresponding ring 22. The drive screw 30 is assembled with the driven screw 40 in the forward / reverse direction such that the drive screw 30 and the driven screw 40 interact to form a screw compaction element 100. In particular, the drive screw body 33 engages with the body 43 of the driven screw, and the pivot pin 21 is arranged in the ring 22. The cover body 37 of the drive screw 30 is then attached to the drive screw circumferential wall 35 and the rotor 11.

[0075] This configuration allows the recess 15 and the driven shaft 16 of the end plate 41 of the driven worm to face the recess 373 of the cover body 37.

[0076] The drive worm 30 is located in the worm chamber 65 in front of the stator 17. As shown from Fig. As can be seen in Figure 2, the inner cylindrical section 37b of the cover body 37 is located radially inside the first coil end 171 of the drive worm 30. The first radial ball bearing 51 is inserted into the inner cylindrical section 37b. Accordingly, the cover body 37 is rotatably held by the first diameter section 64a via the first radial ball bearing 51. The receiving section 38 is connected to the worm chamber 65. The front section of the first diameter section 64a is inserted into the insertion hole 375.

[0077] The cover body 37 is held by the first diameter section 64a, so that the first coil end 171 is received in the receiving section 38. Accordingly, the first coil end 171 is covered from the front by the wall section 37a in the receiving section 38 and radially from the inside by the inner cylindrical section 37b of the drive screw 30. In the receiving section 38, the first coil end 171 is located radially inside the outer cylindrical section 37c in the direction of rotation of the drive screw 30 and is surrounded by it. The rotation of the rotor 11 is transmitted to the cover body 37 via the outer cylindrical section 37c.

[0078] In the compressor, the first diameter section 64a, the first radial ball bearing 51, the inner cylindrical section 37b, the first coil end 171, and the outer cylindrical section 37c are arranged in this order from the drive axis O1 along the radial direction of the drive screw 30, with the cover body 37 being held by the first diameter section 64a. The first diameter section 64a, the first radial ball bearing 51, the inner cylindrical section 37b, the first coil end 171, and the outer cylindrical section 37c overlap in the radial direction of the drive screw 30.

[0079] As from Fig. As can be seen in Figure 1, the projection 39c of the housing 39 is inserted into the drive worm 30 by the second radial ball bearing 52 and the shaft sealing element 63. The housing 39 is rotatably held by the support section 66 via the second radial ball bearing 52. Accordingly, the drive worm 30 is arranged in the worm chamber 65 and is held by both the projection 64 and the support section 66 of the housing 6 such that the drive worm 30 is rotatable about the drive axis O1.

[0080] In the driven worm 40, the driven pin 55 is inserted into the pin hole 4 of the driven shaft 16. The driven worm 40 is arranged in the worm chamber 65 and is held by the first diameter section 64a of the projection 64 such that the driven worm 40 is rotatable about the driven axis O2. That is, unlike the drive worm 30, the driven worm 40 is held only by the projection 64 of the housing 6 so that the driven worm 40 is rotatable about the driven axis O2.

[0081] To ensure the rotation of the rotor 11 and the drive screw 30 about the drive axis O1, the outer circumferential surface 110a of the rotor 11 is spaced radially from the inner circumferential surface 602 of the housing body 60 in the compressor, with the rotor 11 and the drive screw 30 being arranged in the screw chamber 65. Similarly, the outer cylindrical section 37c of the cover body 37, the drive screw circumferential wall 35, and the outer circumferential wall 39a of the housing 6 are spaced radially from the inner circumferential surface 602 of the housing 6 in the direction of the drive screw 30.

[0082] The rotor 11 is arranged radially outside the stator 17 in the radial direction of the drive worm 30, and the inner circumferential surface 110b of the rotor 11 is spaced from the outer circumferential surface of the stator core 17a in the radial direction of the drive worm 30.

[0083] The compressor has a first intake passage 71, which is formed between the outer circumferential surface 110a of the rotor body 11a of the rotor 11 and the inner circumferential surface 602 of the housing body 60 of the housing 6 in the radial direction of the drive screw 30. The compressor also has a second intake passage 72, which is formed between the inner circumferential surface 110b of the rotor body 11a of the rotor 11 and the outer circumferential surface of the stator core 17a of the stator 17 in the radial direction of the drive screw 30.

[0084] As described above, the housing body 60 is shaped such that its inner diameter increases from the first inner diameter L1 at the front end of the housing body 60 to the second inner diameter L2 at the rear end of the housing body 60. Accordingly, the distance between the outer circumferential surface 110a of the rotor 11 and the inner circumferential surface 602 of the housing body 60 in the radial direction of the drive screw 30 (i.e., the width of the first intake passage 71) is greater than the distance between the outer cylindrical section 37c and the inner circumferential surface 602, the distance between the drive screw circumferential wall 35 and the inner circumferential surface 602, and the distance between the outer circumferential wall 39a and the inner circumferential surface 602 in the radial direction of the drive screw 30. The width of the first intake passage 71 gradually increases rearward in the direction of the drive axis O1.

[0085] The width of the first intake passage 71 in the radial direction of the drive worm 30 (i.e., the width of the second intake passage 72) is greater than the distance between the inner circumferential surface 110b of the rotor 11 and the stator core 17a. In contrast to the width of the first intake passage 71, the width of the second intake passage 72 remains constant.

[0086] In the compressor, the width of the first intake passage 71 allows the rotation of the rotor 11 to generate a shear force in the refrigerant flowing through the first intake passage 71. That is, in the present embodiment, the housing 6 is spaced radially from the rotor 11 by a distance that allows the rotation of the rotor 11 to generate a shear force in the refrigerant flowing through the first intake passage 71. Specifically, the maximum width of the first intake passage 71 is approximately 1 mm. The maximum width of the second intake passage 72 is approximately 0.5 mm. The width of the first intake passage 71 can be designed accordingly, as long as it is sufficient for the rotation of the rotor 11 to generate a shear force in the refrigerant flowing through the first intake passage 71. For the sake of simplicity, the following are shown in the Fig. 1, Fig. 2, Fig. 3 to Fig. 4 The width of the first intake passage 71 and the width of the second intake passage 72 are exaggerated.

[0087] In the compressor, the drive screw 30 and the rotor 11 are arranged in the screw chamber 65, and the intake connection port 81 is directed radially from the drive screw 30 towards the front part of the rotor 11. That is, the intake connection port 81 is located closer to the rotor 11 (i.e., to the cover body 37) than to the housing 39 in the direction of the drive axis O1. The intake connection port 81 is in direct communication with the first intake passage 71.

[0088] In the compressor, the refrigerant at low temperature and low pressure is drawn in via the evaporator through the intake connection 81 into the screw chamber 65, as indicated by the dashed arrows in the Fig. 1 and Fig. Figure 2 illustrates this. In the worm chamber 65, the rotation of the rotor 11 of the electric motor 10 is transmitted to the drive worm 30, causing the drive worm 30 to rotate about the drive axis O1. That is, the drive worm 30 and the rotor 11 rotate together about the drive axis O1. In the driven mechanism 20, the pivot pin 21 slides on the inner circumferential surface of the ring 22, allowing the ring 22 to rotate about the center point of the pivot pin 21 and relative to it. Thus, the driven mechanism 20 transmits the torque of the drive worm 30 to the driven worm 40.

[0089] Accordingly, the driven screw 40 is driven by the drive screw 30 and the driven mechanism 20 to rotate about the driven axis O2. The drive mechanism 20 prevents the driven screw 40 from rotating about its own axis relative to the drive screw 30. Therefore, the driven screw 40 rotates about the driven axis O2 relative to the drive screw 30. The drive screw body 33 and the driven screw 43 each rotate in the intake chamber 30a, so that the drive screw body 33 and the body 43 of the driven screw change the volume of the compression chamber 12.

[0090] The intake port 374 is located radially inside the outer cylindrical section 37c of the compressor cover body 37, in the radial direction of the drive screw 30. Accordingly, the refrigerant drawn from the intake port 81 into the screw chamber 65 flows rearward through the first intake passage 71 in the screw chamber 65. The refrigerant then flows towards the intake port 374 (see dashed arrows in the Fig. 1 and Fig. 2) The refrigerant drawn into the screw chamber 65 through the intake connection 81 contains lubricating oil. Accordingly, the refrigerant containing lubricating oil flows backwards through the first intake passage 71 in the screw chamber 65.

[0091] In the compressor, not only a gaseous refrigerant, which is a vapor-phase refrigerant, but also a liquid refrigerant, which is a liquid-phase refrigerant, can be drawn from the intake port 81 into the screw chamber 65. Accordingly, the liquid refrigerant also flows through the first intake passage 71. In this respect, the compressor, according to the present embodiment, is able to vaporize the liquid refrigerant into a gaseous refrigerant in the first intake passage 71, since the rotation of the rotor 11 generates a shear force in the refrigerant flowing through the first intake passage 71.

[0092] The refrigerant and lubricating oil flow through the first intake passage 71 and come into contact with the front surface 61a of the first housing cover 61. The refrigerant and lubricating oil then change their direction forward (i.e., from the cover body 37 to the rotor 11) in the direction of the drive axis O1 in the screw chamber 65. Correspondingly, the refrigerant and lubricating oil that flowed through the first intake passage 71 flow forward in the direction of the drive axis O1 in the screw chamber 65 through the second intake passage 72 (i.e., from the rotor 11 to the cover body 37).

[0093] In this way, the refrigerant and lubricating oil flowing through the second intake passage 72 are directed through the second intake passage 72 to the intake port 374. The refrigerant and lubricating oil flowing through the second intake passage 72 reach the intake port 374 through the receiving section 38 and are drawn from the intake port 374 through the intake chamber 30a into the compression chamber 12. The refrigerant and lubricating oil are drawn from outside the end plate 41 of the driven screw through the intake port 374 into the intake chamber 30a and the compression chamber 12.

[0094] In the compressor, the rotation of the rotor 11 also generates a shear force in the refrigerant flowing through the second intake passage 72. Consequently, the remaining liquid refrigerant in the second intake passage 72 evaporates, even if the liquid refrigerant in the first intake passage 71 has not completely evaporated. Furthermore, the refrigerant and lubricating oil that flowed through the first intake passage 71 partially flow through the slots of the stator core 17a and reach the intake section 38. The refrigerant and lubricating oil are then drawn into the compression chamber 12 through the intake port 374.

[0095] The compression chamber 12 compresses the gaseous refrigerant enclosed within it, reducing its volume through the rotation of the drive screw 30 and the driven screw 40. The refrigerant, compressed to an outlet pressure in the compression chamber 12, is expelled through the port 32 into the outlet chamber 14. The lubricating oil in the compression chamber 12, along with the high-pressure refrigerant, is expelled through the outlet port 32 into the outlet chamber 14. The high-pressure refrigerant is then expelled from the outlet chamber 14 through the outlet passage 390 and an outlet connection port 83 to the outside of the compressor.In the compressor, the shaft sealing element 63 seals the outlet passage 390 and the outlet connection port 83 against the screw chamber 65, thus preventing the refrigerant flowing from the outlet passage 390 to the outlet connection port 83 from flowing into the screw chamber 65.

[0096] In the compressor, the rotor 11 is suitably cooled by the low-temperature refrigerant, which is drawn from the intake port 81 into the screw chamber 65 and flows to the rear through the first intake passage 71. Furthermore, the rotor 11 and the stator 17 are suitably cooled by the low-temperature refrigerant, which flows to the front through the second intake passage 72.

[0097] This means that in the compressor, the rotor 11 is cooled not only by the refrigerant flowing through the first intake passage 71 on its outer surface 110a, but also by the refrigerant flowing through the second intake passage 72 on its inner surface 110b. Thus, the compressor rotor 11 is sufficiently cooled by the low-temperature refrigerant.

[0098] In the compressor, the second coil end 172 of the stator 17 is adequately cooled by the refrigerant flowing from the first intake port 71 to the second intake port 72. The first coil end 171 of the stator 17 is adequately cooled by the refrigerant in the receiving chamber 38 upstream of the intake port 374. Accordingly, the stator core 17a, the first coil end 171, and the second coil end 172 of the stator 17 are sufficiently cooled by the low-temperature refrigerant.

[0099] In this way, the compressor sufficiently cools the electric motor 10 with the refrigerant flowing through the first intake passage 71 and the second intake passage 72, thereby suppressing the reduction in power of the electric motor 10 due to heating.

[0100] Therefore, the compressor according to the first embodiment exhibits excellent reliability.

[0101] In particular, the rotor body 11a in the compressor is formed from electromagnetic steel sheets 111, which are stacked in the direction of the drive axis O1. The refrigerant flows through the first intake passage 71 and the second intake passage 72, so that the refrigerant comes into direct contact with the rotor body 11a, i.e., the electromagnetic steel sheets 111. This allows the rotor 11 of the compressor's electric motor 10 to be sufficiently cooled by the refrigerant.

[0102] This eliminates the need to enlarge the rotor body 11a of the rotor 11 in order to suppress core losses in the rotor body 11a due to heating. It also eliminates the need to use a magnetic core with excessively high resistance to demagnetization in order to suppress demagnetization due to heating. This therefore allows for miniaturization of the compressor and reduces its manufacturing costs.

[0103] Furthermore, the high-temperature refrigerant is discharged from the compression chamber 12 into the discharge chamber 14, which can cause the discharge chamber 14 and the housing 39 to become hot. In the compressor, the intake port 81 is located closer to the rotor 11 (i.e., closer to the cover body 37) than to the housing 39, in the direction of the drive axis O1. This configuration reduces the effect of heating the discharge chamber 14 and the housing 39 on the refrigerant, which is drawn into the screw chamber 65 through the intake port 81.

[0104] In the compressor, the intake port 81 is oriented radially towards the front section of the rotor 11, parallel to the drive screw 30, so that the intake port 81 is in direct contact with the first intake passage 71. This configuration allows the flow direction of the refrigerant drawn in through the intake port 81 to change, while the refrigerant is brought into direct contact with a portion of the outer circumferential surface 110a of the rotor 11 in the radial direction of the drive screw 30, thus enabling the refrigerant to flow through the first intake passage 71. This allows the compressor rotor 11 to be adequately cooled by the refrigerant.

[0105] In the compressor, the housing body 60 is shaped such that its inner diameter increases from the first inner diameter L1 at the front end of the housing body 60 to the second inner diameter L2 at the rear end of the housing body 60. Accordingly, the width of the first intake passage 71 (i.e., the distance between the outer circumferential surface 110a of the rotor 11 and the inner circumferential surface 602 of the housing body 60 in the radial direction of the drive screw 30) is greater than the distance between the outer cylindrical section 37c and the inner circumferential surface 602, the distance between the drive screw circumferential wall 35 and the inner circumferential surface 602, and the distance between the outer circumferential wall 39a and the inner circumferential surface 602 in the radial direction of the drive screw 30.This configuration makes it less likely that the lubricating oil will remain in the first intake passage 71, thus facilitating the flow of the refrigerant in the first intake passage 71.

[0106] In particular, the width of the first intake passage 71 gradually increases towards the rear in the forward / backward direction. In this way, the inner surface of the first intake passage 71, i.e., the inner circumferential surface 602 of the housing body 60, gradually moves away from the rotor 11 in the radial direction of the drive screw 30. This shape directs the lubricating oil appropriately to flow rearward in the first intake passage 71. As a result, it is less likely that the lubricating oil will remain in the first intake passage 71.

[0107] Furthermore, the rotation of the compressor rotor 11 generates a shear force in the refrigerant flowing through the first intake port 71 and the refrigerant flowing through the second intake port 72, in order to evaporate the liquid refrigerant. This allows the compressor to prevent the liquid refrigerant from being drawn into the compression chamber 12. Second embodiment

[0108] As from Fig. As can be seen in Figure 3, the housing body 60 in a compressor according to the second embodiment does not have an intake connection 81. Instead, the second housing cover 62 has an intake connection 82. The intake connection 82 is connected to an evaporator (not shown) via a line (not shown).

[0109] In the second housing cover 62, the intake connection 82 is arranged radially outside the outlet connection 83. The intake connection 82 is connected to the screw chamber 65 in the direction of the drive axis O1. Accordingly, the intake connection 82 is located in front of the front wall 39b of the housing 39 in the direction of the drive axis O1 and faces it.

[0110] The compressor has a third intake passage 73, which is formed in the screw chamber 65. The third intake passage 73 is defined by the inner circumferential surface 602 of the housing body 60, the outer circumferential wall 39a of the housing 39, the drive screw circumferential wall 35, and the outer cylindrical section 37c of the cover body 37. The third intake passage 73 is located in the direction of the drive axis O1 upstream of the first intake passage 71 (i.e., on one side along the direction of the drive axis O1 with respect to the first intake passage 71). The width of the third intake passage 73 gradually increases rearward in the direction of the drive axis O1. The rear end of the third intake passage 73 communicates with the front end of the first intake passage 71.It should be noted that other components of the compressor according to the second embodiment are identical to those of the compressor according to the first embodiment, and that components of the second embodiment that correspond to those of the first embodiment are designated with the same reference numerals and are not further explained here.

[0111] The refrigerant flows from the intake connection 82 into the screw chamber 65. Along the direction of the drive axis O1, the refrigerant comes into contact with the outer wall 39a of the housing 39 and flows through the third intake passage 73. The refrigerant flows through the third intake passage 73 towards the rear in the direction of the drive axis O1 to the first intake passage 71. Accordingly, in the compressor according to the second embodiment, the electric motor 10 is cooled appropriately by the refrigerant that flows through the first intake passage 71 and the second intake passage 72 into the compression chamber 12.

[0112] In the compressor according to the second embodiment, the intake connection 82 is located upstream of the first intake passage 71. However, the presence of the third intake passage 73 allows the refrigerant flowing from the intake connection 82 into the screw chamber 65 to flow appropriately into the first intake passage 71. This appropriately prevents the refrigerant flowing through the intake connection 82 into the screw chamber 65 from remaining in the screw chamber 65 without flowing through the first intake passage 71.

[0113] Furthermore, the lubricating oil in the refrigerant, which is drawn from the intake port 82 into the screw chamber 65, is appropriately separated from the refrigerant when the refrigerant in the screw chamber 65 comes into contact with the outer wall 39a. Accordingly, the screw chamber 65 of the drive screw 30, the first radial ball bearing 51, the second radial ball bearing 52, and the like are appropriately lubricated by the lubricating oil. The remaining operating functions of this compressor correspond to those of the compressor according to the first embodiment. Third embodiment

[0114] As from Fig. As can be seen in Figure 4, in a compressor according to the third embodiment, the housing 6 has a housing body 68 instead of the housing body 60. In particular, the housing 6 has the housing body 68, the first housing cover 61 and the second housing cover 62.

[0115] The housing body 68 is made of an aluminum alloy and has a cylindrical shape positioned around the drive axis O1 as its center point. The housing body 68 has an outer surface 681 and an inner surface 682. The housing body 68 comprises: a first section 68a with the first inner diameter L1; and a second section 68b with the second inner diameter L2. The first section 68a forms the front section and the center point of the housing body 68, and the second section 68b forms the rear section of the housing body 68.

[0116] The housing body 68 has a stepped section 68c. The stepped section 68c is located between the first section 68a and the second section 68b in the direction of the drive axis O1. The stepped section 68c is located behind the center point of the housing body 68 in the direction of the drive axis O1.

[0117] The housing body 68 has an intake connection port 84. The intake connection port 84 is located approximately in the center of the housing body 68 in the forward / reverse direction. The intake connection port 84 is located upstream of the stage section 68c. The intake connection port 84 is connected to the evaporator (not shown) via the pipe (not shown).

[0118] The compressor has a first intake passage 75 between the outer surface 110a of the rotor body 11a of the rotor 11 and an inner surface 682 of the housing body 68 in the radial direction of the drive screw 30. The stage section 68c is arranged in the first intake passage 75. The presence of the stage section 68c causes the distance between the outer circumferential surface 110a of the rotor 11 and the inner circumferential surface 682 of the housing body 68 in the radial direction of the drive screw 30 (i.e., the width of the first intake passage 75) to be greater on the rear side than on the front side in the direction of the drive axis O1. That is, the width of the first intake passage 75 changes at section 68c. In other words, the width of the first intake passage 75 changes in stages. The remaining operating procedures of this compressor correspond to those of the compressor according to the first embodiment.

[0119] In the compressor according to the third embodiment, the refrigerant drawn from the intake connection 84 into the screw chamber 65 flows through the first intake passage 75 and the second intake passage 72 into the compression chamber 12. Accordingly, the electric motor 10 is cooled in a suitable manner by the refrigerant flowing through the first intake passage 75 and the second intake passage 72.

[0120] Furthermore, the width of the first intake passage 75 in the radial direction of the drive screw 30 is greater on the rear side than on the front side, so that the lubricating oil is less likely to remain in the first intake passage 75. The other operating modes of this compressor correspond to those of the compressor according to the first embodiment.

[0121] Although the present invention has been described with reference to the first to third embodiments, it is not limited to the first to third embodiments and can be modified within the scope of the present invention.

[0122] For example, according to the compressor in each of the first to third embodiments, the projection 64 is formed integrally with the first housing cover 61. However, the present invention is not limited to this configuration. The projection 64 can be formed independently of the first housing cover 61 and attached to it. This configuration allows the projection 64 and the first housing cover 61 to be made of different materials.

[0123] According to the compressor of the first to third embodiments, the cover body 37 has an outer cylindrical section 37c. However, the present invention is not limited to this configuration. The cover body 37 is provided without the outer cylindrical section 37c, and the rotor 11 can serve as the cylindrical section of the present invention. In this configuration, the rotor 11 extends in the direction of the drive axis O1, so that it is connected to the wall section 37a of the cover body 37.

[0124] According to the compressor of the first to third embodiments, the outer cylindrical section 37c can be formed separately from the rotor 11 and the wall section 37a of the cover body 37.

[0125] According to the compressor of the first to third embodiment, the compressor can have a return passage so that the lubricating oil contained in the refrigerant discharged into the outlet chamber 14 is returned to the first radial ball bearing 51 and the like, and lubricates it.

[0126] This description includes the following embodiments. Supplementary Note 1

[0127] A rotating screw compressor that has: a housing with a screw chamber into which a fluid is drawn from outside the housing; a drive mechanism that is housed in the worm chamber and which has: a stator that has: a stator core having a cylindrical shape centered around a drive axis and extending in the direction of the drive axis; a first coil end, which has a cylindrical shape and extends from the stator core to one side of the rotating screw compressor along the direction of the drive axis; and a second coil end, which has a cylindrical shape and extends from the stator core to the other side of the rotating screw compressor opposite one side along the direction of the drive axis; and a rotor that is positioned outside the stator to surround the stator, with the rotor being rotated by the stator; a driven mechanism that is housed in the screw chamber; a drive screw which is housed in the screw chamber and configured to be rotated around the drive axis by the drive mechanism; and a driven screw which is received in the screw chamber and eccentrically to the drive screw, wherein the driven screw is configured to be rotated about a driven axis by the drive screw and the driven mechanism, wherein the drive screw and the driven screw form a compression chamber for compressing the fluid with the rotation of the drive screw and the rotation of the driven screw, wherein a projection is provided in the worm chamber, which extends towards the drive axis to the drive worm and the driven worm, and which is attached to the stator core, the drive screw has a cover body that rotates together with the rotor, the cover body has a wall section that extends in a radial direction of the drive screw and is directed towards the first coil end in the direction of the drive axis, the wall section is connected to a cylindrical section which has a cylindrical shape, the cylindrical section extends in the direction of the drive axis and surrounds the first coil end which lies radially inside the cylindrical section in the radial direction of the drive worm, and the rotation of the rotor is transmitted to the cover body via the cylindrical section, the wall section has a suction port which lies radially inside the cylindrical section in the radial direction of the drive screw, and the fluid in the screw chamber is drawn into the compression chamber through the suction port, a first intake passage is formed between the housing and the rotor in the radial direction of the drive screw, and the fluid flows from the cover body through the first intake passage in the direction of the drive axis in the screw chamber to the rotor, and A second intake passage is formed between the rotor and the stator in the radial direction of the drive screw, and the fluid that has flowed through the first intake passage flows from the rotor towards the drive axis to the cover body and is directed through the second intake passage to the intake port. Supplementary Note 2

[0128] Rotating screw compressor according to supplementary note 1, wherein the housing has a suction connection port through which the fluid is drawn from outside the housing into the screw chamber, the drive screw has a housing that has an outlet chamber into which the fluid compressed in the compression chamber is expelled, the housing is located on one side along the direction of the drive axis in relation to the cover body, and The intake connection is located closer to the cover body than to the housing in the direction of the drive axis. Supplementary Note 3

[0129] Rotating screw compressor according to supplementary note 2, wherein The intake connection is directed in the radial direction of the drive screw towards a section of the rotor. Supplementary note 4

[0130] Rotating screw compressor according to supplementary note 1, wherein the housing has a suction connection through which the fluid is drawn from outside the housing into the screw chamber, the drive screw has a housing that has an outlet chamber into which the fluid compressed in the compression chamber is expelled, the housing is located on one side along the direction of the drive axis in relation to the cover body, the intake connection is directed towards the housing in the direction of the drive axis, a third intake passage is formed in the screw chamber, and the third intake passage is located on one side along the direction of the drive axis with reference to the first intake passage, and The fluid flows through the third intake passage in the direction of the drive axis, in the direction of the first intake passage. Supplementary note 5

[0131] A rotating screw compressor according to one of the supplementary notes 1 to 4, wherein a refrigerant serves as the fluid, and The housing is spaced from the rotor in the radial direction of the drive screw by a distance that allows the rotation of the rotor to generate a shear force in the refrigerant flowing through the first intake passage. Supplementary Note 6

[0132] A rotating screw compressor according to one of the supplementary notes 1 to 5, wherein the housing has a main body that extends in the direction of the drive axis, the main body has: a first housing section located on one side along the direction of the drive axis in relation to the rotor; and a second housing section located on the opposite side along the direction of the drive axis with respect to the first housing section, and extending from the first housing section in the direction of the drive axis, the second housing section being directed in the radial direction of the drive worm towards the rotor, and The inner diameter of the second housing section is larger than the inner diameter of the first housing section. Supplementary note 7

[0133] Rotating screw compressor according to supplementary note 6, wherein the main body has an inner diameter that gradually increases in the direction of the drive axis from the first housing section to the second housing section. Supplementary Note 8

[0134] A rotating screw compressor in accordance with one of the supplementary notes 1 to 7, wherein the rotor has a rotor body which has a cylindrical shape and is formed from a multitude of electromagnetic steel sheets stacked in the direction of the drive axis, the first intake passage is formed between an inner circumferential surface of the housing and an outer circumferential surface of the rotor body in the radial direction of the drive screw, and The second intake passage is formed between an inner circumferential surface of the rotor body and an outer circumferential surface of the stator in the radial direction of the drive worm.

[0135] The present invention is applicable to air conditioning systems for vehicles or the like. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 02-227575

[0002] JP 02-227575

[0003]

Claims

[1] A rotating screw compressor that has: a housing (6) with a screw chamber (65) into which a fluid is drawn from outside the housing (6); a drive mechanism (10) which is housed in the worm chamber (65) and which has: a stator (17) that has: a stator core (17a) having a cylindrical shape centered around a drive axis (O1) and extending in one direction of the drive axis (O1); a first coil end (171) having a cylindrical shape and extending from the stator core (17a) to one side of the rotating screw compressor along the direction of the drive axis (O1); and a second coil end (172) which has a cylindrical shape and extends from the stator core (17a) to the other side of the rotating screw compressor opposite one side along the direction of the drive axis (O1); and a rotor (11) arranged outside the stator (17) to surround the stator (17), wherein the rotor (11) is rotated by the stator (17); a driven mechanism (20) which is housed in the screw chamber (65); a drive screw (30) which is received in the screw chamber (65) and is configured to be rotated about the drive axis (O1) by the drive mechanism (10); and a driven screw (40) which is received in the screw chamber (65) and eccentrically to the drive screw (30), wherein the driven screw (40) is configured to be rotated about a driven axis (O2) by the drive screw (30) and the driven mechanism (20), wherein the drive screw (30) and the driven screw (40) form a compression chamber (12) for compressing the fluid with the rotation of the drive screw (30) and the rotation of the driven screw (40), wherein a projection (64) is provided in the worm chamber (65) which projects in the direction of the drive axis (O1) to the drive worm (30) and to the driven worm (40), and which is attached to the stator core (17a), the drive screw (30) has a cover body (37) which rotates together with the rotor (11), the cover body (37) has a wall section (37a) which extends in a radial direction of the drive screw (30) and is directed in the direction of the drive axis (O1) towards the first coil end (171), the wall section (37a) is connected to a cylindrical section (37c) which has a cylindrical shape, the cylindrical section (37c) extends in the direction of the drive axis (O1) and surrounds the first coil end (171) which lies radially inside the cylindrical section (37c) in the radial direction of the drive worm (30), and the rotation of the rotor (11) is transmitted via the cylindrical section (37c) to the cover body (37), the wall section (37a) has a suction port (374) which lies radially inside the cylindrical section (37c) in the radial direction of the drive screw (30), and the fluid in the screw chamber (65) is drawn into the compression chamber (12) through the suction port (374), a first intake passage (71, 75) is formed between the housing (6) and the rotor (11) in the radial direction of the drive screw (30), and the fluid flows from the cover body (37) through the first intake passage (71, 75) in the direction of the drive axis (O1) in the screw chamber (65) to the rotor (11), and a second intake passage (72) is formed between the rotor (11) and the stator (17) in the radial direction of the drive screw (30), and the fluid that has flowed through the first intake passage (71, 75) flows from the rotor (11) in the direction of the drive axis (O1) to the cover body (37) and is guided through the second intake passage (72) to the intake port (374). [2] A rotating screw compressor according to claim 1, wherein the housing (6) has a suction connection port (81, 84) through which the fluid is drawn from outside the housing (6) into the screw chamber (65), the drive screw (30) has a housing (39) which has an outlet chamber (14) into which the fluid compressed in the compression chamber is expelled, the housing (39) is located on one side along the direction of the drive axis (O1) in relation to the cover body (37), and the intake connection port (81, 84) is located closer to the cover body (37) than to the housing in the direction of the drive axis (O1). [3] A rotating screw compressor according to claim 2, wherein the suction connection port (81, 84) is directed in the radial direction of the drive screw (30) to a section of the rotor (11). [4] A moving screw compressor according to claim 1, wherein the housing (6) has a suction connection port (82) through which the fluid is drawn from outside the housing (6) into the screw chamber (65), the drive screw (30) has a housing (6) which has an outlet chamber (14) into which the fluid compressed in the compression chamber (12) is expelled, the housing (6) is located on one side along the direction of the drive axis (O1) in relation to the cover body (37), the intake connection port (82) is directed towards the drive axis (O1) towards the housing (6), a third intake passage (73) is formed in the screw chamber (65), and the third intake passage (73) is located on one side along the direction of the drive axis (O1) with reference to the first intake passage (71), and the fluid flows in the direction of the first intake passage (71) in the direction of the drive axis (O1) through the third intake passage (73). [5] A rotating screw compressor according to any one of claims 1 to 4, wherein a refrigerant serves as the fluid, and the housing (6) is spaced in the radial direction of the drive screw (30) from the rotor (11) by a distance which allows the rotation of the rotor (11) to generate a shear force in the refrigerant flowing through the first intake passage (71, 75). [6] A rotating screw compressor according to any one of claims 1 to 5, wherein the housing (6) has a main body (60, 68) which extends in the direction of the drive axis (O1), the main body (60, 68) has: a first housing section (60a, 68a) located on one side along the direction of the drive axis (O1) with respect to the rotor (11); and a second housing section (60b, 68b) located on the other side along the direction of the drive axis (O1) with respect to the first housing section (60a, 68a), and extending from the first housing section (60a, 68a) in the direction of the drive axis (O1), wherein the second housing section (60b, 68b) is directed in the radial direction of the drive worm (30) to the rotor (11), and an inner diameter (L2) of the second housing section (60b, 68b) is larger than an inner diameter (L1) of the first housing section (60a, 68a). [7] A rotating screw compressor according to claim 6, wherein the main body (60, 68) has an inner diameter which gradually increases in the direction of the drive axis from the first housing section (60a, 68a) to the second housing section (60b, 68b). [8] A rotating screw compressor according to any one of claims 1 to 7, wherein the rotor (11) has a rotor body (11a) which has a cylindrical shape and is formed from a plurality of electromagnetic steel sheets (111) stacked in the direction of the drive axis (O1), the first intake passage (71, 75) is formed between an inner circumferential surface (602, 682) of the housing (6) and an outer circumferential surface (110a) of the rotor body (11a) in the radial direction of the drive screw (30), and the second intake passage (72) is formed between an inner circumferential surface (110b) of the rotor body (11a) and an outer circumferential surface (110a) of the stator (17) in the radial direction of the drive worm (30).

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