Screw compressor

Abstract

A screw compressor that compresses and discharges working medium sucked from a suction port, the screw compressor including: a male rotor and a female rotor that are able to rotate in engagement with each other; a housing provided with a chamber that houses the male rotor and the female rotor and forms, together with the male rotor and the female rotor, a working chamber for compressing the working medium; a drive unit that rotationally drives at least one of the male rotor and the female rotor; a working chamber closing unit that forms a suction port for sucking the working medium into the working chamber and closes the working chamber when the working chamber becomes a prescribed volume; and a suction space that communicates between the suction port and the suction port, an open space that communicates between the suction space and the suction port being provided between a shaft portion of the male rotor and a shaft portion of the female rotor on opposite sides of the suction port with respect to the male rotor and the female rotor.

Description

Technical Field

[0001] This invention applies not only to injection-type screw compressors that inject cooling media such as oil or water during compression, but also to dry-type screw compressors that do not inject anything, and to various other screw compressors. Background Technology

[0002] As an invention concerning screw compressors, the screw compressor disclosed in Patent Document 1 has been known for a long time. This screw compressor is provided with a connecting part that connects the rotor housing and the main body housing, the suction port is arranged on the side of the main body housing, and the screw compressor is configured such that the suction port is an axial suction port arranged at the end of the rotor housing in the axial direction of the screw rotor.

[0003] Based on this structure, since the connecting part is arranged in the suction space to connect the rotor housing and the main housing, it is possible to prevent large vibrations of the rotor housing during the operation of the screw compressor without significantly increasing manufacturing costs. That is, it is possible to reduce vibrations during the operation of the screw compressor and prevent performance degradation and damage, thus eliminating the need to increase the thickness of the main housing as a vibration countermeasure.

[0004] As a result, with this screw compressor, the necessity of increasing the rigidity of the main housing by adding components can be eliminated. Therefore, the vibration of the screw compressor during operation can be reduced without significantly increasing manufacturing costs, thus preventing performance degradation and damage.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2016-8509 Summary of the Invention

[0008] The technical problem that the invention aims to solve

[0009] Screw compressors are widely used as air compressors and compressors for refrigeration and air conditioning. Along with this, there is a strong demand for energy efficiency in screw compressors, making high energy efficiency and large air volume (high performance) increasingly important. In this context, in injection-type screw compressors, to achieve cost reduction and miniaturization, it is inevitable to increase the speed at which the working medium is drawn into the working chamber.

[0010] On the other hand, dry screw compressors cannot rely on the sealing effect of the cooling medium in the working chamber. In order to reduce leakage losses of the working medium in the working chamber, they must operate at a high speed of more than 10,000 revolutions per minute. That is, from the point of view of high energy efficiency, the higher the operating speed, the faster the working medium flows into the working chamber. Therefore, if the intake of the working medium into the working chamber is not smooth, there is a problem of increased acceleration loss of the working medium.

[0011] This invention is made with consideration of the above points, and proposes a screw compressor that reduces the acceleration loss of the working medium and can compress the working medium with high energy efficiency.

[0012] Technical solutions for solving technical problems

[0013] To address this issue, the present invention provides a screw compressor that compresses a working medium drawn in from an inlet and discharges it from an outlet. The screw compressor includes: a male rotor and a female rotor capable of meshing and rotating with each other; a housing having a chamber that houses the male rotor and the female rotor and together forms a working chamber for compressing the working medium; a drive unit for rotating at least one of the male rotor and the female rotor; a working chamber sealing portion that forms an inlet for drawing the working medium into the working chamber and closes the working chamber when it reaches a predetermined capacity; and an inlet space communicating with the inlet and the inlet, wherein an open space communicating with the inlet is provided between the shaft portions of the male rotor and the female rotor, located on opposite sides of the inlet relative to the inlet.

[0014] According to the screw compressor of the present invention, the flow resistance of the working medium drawn in from the suction port is small, enabling smooth intake of the working medium into the working chamber. Therefore, when the male and female rotors rotate at high speeds, the working medium is not slowed down as it flows into the working chamber, thus suppressing the energy required to accelerate the working medium and improving the energy efficiency of the screw compressor. On the other hand, when the male and female rotors rotate at low speeds, the reduced suction resistance of the working medium also increases the flow rate of the working medium.

[0015] Invention Effects

[0016] According to the present invention, a screw compressor can be achieved to reduce acceleration loss of the working medium and compress the working medium with high energy efficiency. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view showing the structure of the screw compressor according to the first embodiment.

[0018] Figure 2 This is a cross-sectional view showing the structure of the screw compressor according to the first embodiment. Figure 1 (AA view).

[0019] Figure 3 This is a cross-sectional view showing the structure of the screw compressor according to the first embodiment. Figure 1 (BB view).

[0020] Figure 4 This is a cross-sectional view showing the structure of the screw compressor according to the first embodiment. Figure 1 (CC view).

[0021] Figure 5 This is a cross-sectional view showing a structural example of an existing screw compressor.

[0022] Figure 6 It means and Figure 2 A cross-sectional view of the corresponding existing screw compressor structure.

[0023] Figure 7 It means and Figure 1 The cross-sectional view of the screw compressor structure of the second embodiment is shown in the CC view.

[0024] Figure 8 It means and Figure 1 The cross-sectional view of the screw compressor structure of the third embodiment is shown in the CC view.

[0025] Figure 9 It means and Figure 1 The cross-sectional view of the screw compressor structure of the fourth embodiment is shown in the CC view. Detailed Implementation

[0026] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0027] (1) First implementation method

[0028] Figures 1-4 This refers to the screw compressor of the first embodiment. Figure 1 yes Figure 2 DD direction view in the middle, Figure 2 yes Figure 1 AA direction view, Figure 3 yes Figure 1 and Figure 2 BB view in the middle, Figure 4 yes Figure 1 and Figure 2 The CC view in the middle.

[0029] like Figure 1 and Figure 2As shown, the screw compressor 1 of this embodiment includes a male rotor 2 and a female rotor 3 as screw rotors, and a housing 4 that houses the male rotor 2 and the female rotor 3.

[0030] The male rotor 2 includes: a plurality of (four in this embodiment) spirally extending teeth 2AA. Figure 3 and Figure 4 The toothed portion 2A; and one end side of the rotor axial direction of the toothed portion 2A ( Figure 1 and Figure 2 The suction side shaft 2B is connected to the left side of the toothed part 2A; and the other end of the rotor shaft axially connects to the toothed part 2A. Figure 1 and Figure 2 The male rotor 2 is formed by connecting the discharge side shaft 2C to the right side of the rotor. The suction side shaft 2B of the male rotor 2 is rotatably supported by the suction side bearing 5, and the discharge side shaft 2C of the male rotor 2 is rotatably supported by the discharge side bearing 7.

[0031] Similarly, the female rotor 3 includes: a plurality of (six in this embodiment) spirally extending teeth 3AA. Figure 3 and Figure 4 The rotor 3 is composed of a toothed portion 3A, an intake-side shaft portion 3B connected to one end of the rotor axial direction of the toothed portion 3A, and a discharge-side shaft portion 3C connected to the other end of the rotor axial direction of the toothed portion 3A. The intake-side shaft portion 3B of the female rotor 3 is rotatably supported by an intake-side bearing 6, and the discharge-side shaft portion 3C of the female rotor 3 is rotatably supported by a discharge-side bearing 8.

[0032] The suction-side shaft 2B of the male rotor 2 passes through the housing 4 and is connected to the rotating shaft 9B of the motor 9A, which constitutes the drive unit 9. Thus, by driving the motor 9A, the male rotor 2 can be driven to rotate integrally with the rotating shaft 9B of the motor 9A. Furthermore, through the meshing of the teeth 2A of the male rotor 2 and the teeth 3A of the female rotor 3, the female rotor 3 can also be driven integrally with the male rotor 2. However, when driving the screw compressor 1, either the male rotor 2 or the female rotor 3 can be driven. Alternatively, the motor can be used to drive both the male rotor 2 and the female rotor 3 synchronously.

[0033] Housing 4 includes a main housing 10 and another end side axially opposite to the rotor of the main housing 10. Figure 1 and Figure 2 The D-shell 11 is connected to the right side of the rotor. Within the D-shell 11 are formed the teeth 2A of the male rotor 2 and the teeth 3A of the female rotor 3 located radially outward from the rotor. Figure 1 The outlet 11A (on the lower side); and the discharge path 11B formed in such a way as to connect the outlet 11A and the working chamber described later.

[0034] In addition, such as Figure 3As shown, a chamber 10A is formed in the main housing 10 to receive the teeth 2A of the male rotor 2 and the teeth 3A of the female rotor 3. The chamber 10A is a space with two cylindrical holes that partially overlap in shape, receiving the teeth 2A of the male rotor 2 and the teeth 3A of the female rotor 3 in an engaged state.

[0035] The inner wall of chamber 10A and the tooth groove 2AB of male rotor 2 ( Figure 3 and Figure 4 ) and the tooth groove 3AB of the female rotor 3 Figure 3 and Figure 4 The working chamber is formed by the volume of the working chamber increasing from one side of the rotor axis. Figure 1 and Figure 2 (from the left) to the other side ( Figure 1 and Figure 2 The working medium, such as air, drawn in from the intake port 12 is gradually compressed in the working chamber and discharged from the outlet 11A via the discharge path 11B.

[0036] The suction port 12 is formed in the main housing 10 at a distance from the radial outer side of the rotor teeth 2A of the male rotor 2 and 3A of the female rotor 3. Figure 1 (The upper side). Inlet 12, as shown Figure 1 and Figure 2 As shown, the working medium drawn in from the suction port 12 is sequentially drawn into the working chamber via the suction space 13 and the suction port 12. Furthermore, the suction port 10A is an orifice provided on a plane perpendicular to the axial directions of the male rotor 2 and the female rotor 3, including the end face of the tooth portion 2A of the male rotor 2 and the end face of the tooth portion 3A of the female rotor 3 within the chamber 10A.

[0037] A plate-shaped chamber sealing member 14 is provided at the suction port, which closes one end face of the tooth portion 2A of the male rotor 2 and one end face of the tooth portion 3A of the female rotor 3 when the chamber is at its maximum capacity (closing the chamber). In fact, the chamber sealing member 14 is disposed between the suction side shaft portion 2B of the male rotor 2 and the suction side shaft portion 3B of the female rotor 3, with the side facing the end face of the tooth portion 2A of the male rotor 2 and the end face of the tooth portion 3A of the female rotor 3 (hereinafter referred to as the rotor facing surface) 14A on the suction port.

[0038] Furthermore, on the opposite side of the suction orifice of the male rotor 2 and female rotor 3, at the location opposite to the suction-side shaft portion 2B of the male rotor 2 on the chamber enclosure 14, an arc-shaped recess 14C is formed that is coaxial with the suction-side shaft portion 2B (centered on the center of the rotor shaft of the male rotor 2) and has a diameter (radius) that is somewhat larger than that of the suction-side shaft portion 2B. As a result, a space of a certain size (hereinafter referred to as the male rotor-side open space) 15A is formed between the suction-side shaft portion 2B of the male rotor 2 and the recess 14C of the chamber enclosure 14.

[0039] Similarly, at the location opposite to the suction-side shaft portion 3B of the female rotor 3 on the chamber enclosure 14, an arc-shaped recess 14D is formed that is coaxial with the suction-side shaft portion 3B (centered on the center of the rotor shaft of the female rotor 3) and has a diameter that is somewhat larger than that of the suction-side shaft portion 3B. As a result, a space of a certain size (hereinafter referred to as the female rotor-side open space) 15B is formed between the suction-side shaft portion 3B of the female rotor 3 and the recess 14D of the chamber enclosure 14.

[0040] In this case, the diameters of the recesses 14C and 14D of the chamber sealing component 14 are set to be smaller than the tooth root radii of the male rotor 2 and the female rotor 3 and larger than the radii of the suction side shaft portion 2B of the male rotor 2 and the suction side shaft portion 3B of the female rotor 3, so as to be able to seal the chamber.

[0041] Furthermore, on the opposite side of the rotor-facing surface 14A of the enclosed chamber component 14 (hereinafter referred to as the reverse rotor-facing surface) 14B, there is an open space (hereinafter referred to as the motor-side open space) 15C located between the suction-side shaft portion 2B of the male rotor 2 and the suction-side shaft portion 3B of the female rotor 3, and communicating with both the suction space 13, the male rotor-side open space 15A and the female rotor-side open space 15B respectively.

[0042] Furthermore, in the following, the motor-side open space 15C, the male rotor-side open space 15A, and the female rotor-side open space 15B will be referred to together as open space 15. This open space 15 is the section that connects the suction space 13 located on the outer side of the suction-side shaft portion 2B of the male rotor 2 and the suction space 13 located on the outer side of the suction-side shaft portion 3B of the female rotor 3 with the suction orifice.

[0043] Here, regarding and Figure 2 and Figure 4 The corresponding parts are marked with the same reference numerals as those in the attached figures and enclosed in single quotes (“′”). Figure 5 and Figure 6 , respectively representing the existing screw compressor 1' and Figure 2 and Figure 4 The construction of the corresponding parts. According to this... Figure 5and Figure 6 It is known that in the existing screw compressor 1′, on the opposite side of the rotor-facing surface 16A of the chamber enclosure 16 corresponding to the chamber enclosure component 14 of this embodiment, there is no space like the open space 15C of this embodiment. In this open space 15C, the chamber enclosure 16 is integrally formed with the main housing 10′ by filling the part.

[0044] Furthermore, in the existing screw compressor 1', although an arc-shaped recess 16B is formed coaxially with the suction-side shaft portion 2B' of the male rotor 2' in the closed chamber 16, the diameter of this recess 16B is selected to a degree that does not hinder the rotation of the suction-side shaft portion 2B' of the male rotor 2. Therefore, only a small gap is formed between the closed chamber 16 and the suction-side shaft portion 2B' of the male rotor 2', and the male rotor-side open space 15A of the screw compressor 1 of this embodiment is absent. Figure 4 That kind of space.

[0045] Similarly, in the existing screw compressor 1', although an arc-shaped recess 16C is formed coaxially with the suction-side shaft portion 3B' of the female rotor 3 at the location opposite to the chamber enclosure 16, the diameter of the recess 16C is selected to a degree that does not hinder the rotation of the suction-side shaft portion 3B' of the female rotor 3'. Therefore, only a small gap is formed between the chamber enclosure 16 and the suction-side shaft portion 3B' of the female rotor 3', and the female rotor-side open space 15B of the screw compressor 1 of this embodiment is absent. Figure 4 That kind of space.

[0046] In a conventional screw compressor 1' with such a structure, the working medium drawn in from the suction port flows into the screw compressor 1' via suction spaces 13' located on the outer side of the suction side shaft portion 2B' of the male rotor 2' and on the outer side of the suction side shaft portion 3B' of the female rotor 3'. The flow of the working medium in these suction spaces 13' is blocked by the chamber enclosure portion 16, thus increasing the flow resistance in the suction spaces 13' and hindering the suction of the working medium into the chamber.

[0047] On the other hand, in the screw compressor 1 of this embodiment, similarly to the conventional screw compressor 1', the working medium drawn in from the suction port 12 flows into the screw compressor 1 through the space portions of the suction space 13 located outside the suction side shaft portion 2B of the male rotor 2 and outside the suction side shaft portion 3B of the female rotor 3. In this case, since the working medium flowing in these space portions of the suction space 13 flows into the open space 15 formed by the male rotor side open space 15A, the female rotor side open space 15B, and the motor side open space 15C, the flow of the working medium flowing into the screw compressor 1 through the space portions of the suction space 13 located outside the suction side shaft portion 2B of the male rotor 2 and outside the suction side shaft portion 3B of the female rotor 3 is not blocked by the working chamber sealing member 14.

[0048] Furthermore, a portion of the working medium flowing from the suction space 13, located outside the suction side shaft portion 2B of the male rotor 2, collides with the side of the male rotor 2 of the chamber enclosure 14 and then flows around the suction side shaft portion 2B of the male rotor 2 via the male rotor side open space 15A between the recess 14C of the chamber enclosure 14 and the suction side shaft portion 2B of the male rotor 2 in the direction of rotation of the suction side shaft portion 2B. Figure 4 The fluid flows in the same direction as the direction of rotation (indicated by arrow a) within the suction space 13 and the open space 15, and is eventually drawn into the working chamber via the suction port.

[0049] In addition, the remaining working medium, after colliding with the working medium flowing through the space portion of the suction space 13 which exists further outward than the suction side shaft portion 3B of the female rotor 3 in the motor-side open space 15C, flows around the suction side shaft portion 2B of the male rotor 2 in the suction space 13 and the open space 15 in a manner that rotates in the same direction as the rotation direction of the suction side shaft portion 2B, and is finally sucked into the working chamber through the suction port.

[0050] Similarly, a portion of the working medium flowing from the space portion of the suction space 13 located outside the suction side shaft portion 3B of the female rotor 3, after colliding with the side of the female rotor 3 side of the chamber closure member 14, passes through the female rotor side open space 15B between the recess 14D of the chamber closure member 14 and the suction side shaft portion 3B of the female rotor 3, and circumferentially around the suction side shaft portion 3B of the female rotor 3 in the direction of rotation of the suction side shaft portion 3B. Figure 4 The fluid flows in the same direction as the direction indicated by the middle arrow b, within the suction space 13 and the open space 15, and is eventually drawn into the working chamber through the suction port.

[0051] In addition, the remaining working medium, after colliding with the working medium flowing through the space portion of the suction space 13 located outside the suction side shaft portion 2B of the male rotor 2 in the motor side open space 15C, flows around the suction side shaft portion 3B of the female rotor 3 in a manner that rotates in the same direction as the rotation direction of the suction side shaft portion 3B, and is finally sucked into the working chamber through the suction orifice.

[0052] Therefore, the screw compressor 1 based on this embodiment, having an open space 15 consisting of an open space 15A on the male rotor side, an open space 15B on the female rotor side, and an open space 15C on the motor side, reduces the flow resistance of the working medium drawn in from the suction port 12 compared to the conventional screw compressor 1′, and enables the smooth intake of the working medium into the working chamber.

[0053] Therefore, when the male rotor 2 and female rotor 3 rotate at high speed, the working medium is not slowed down when flowing into the working chamber. This suppresses the energy used to accelerate the working medium, thus improving the energy efficiency of the screw compressor. On the other hand, when the male rotor 2 and female rotor 3 rotate at low speed, the flow rate of the working medium increases due to the reduction in suction resistance. Therefore, according to this screw compressor 1, the acceleration loss of the working medium can be reduced, and the working medium can be compressed with high energy efficiency.

[0054] (2) Second implementation method

[0055] In Figure 4 The corresponding parts are marked with the same reference numerals, or the same reference numerals are marked with the suffix "X" to indicate this. Figure 7 This illustrates a portion of the structure of the screw compressor according to the second embodiment, and... Figure 1 The CC-direction view corresponds to this. The screw compressor of this embodiment replaces the chamber enclosure component 14 of the first embodiment. Figure 1 , Figure 2 , Figure 4 ), but about Figure 6 At the same location as the existing chamber enclosure 16, a chamber enclosure 20 of the same size as the chamber enclosure 16 is integrally formed with the main housing 10X. Except for this, it is configured in the same way as the screw compressor 1 of the first embodiment.

[0056] In this case, within the sealed chamber 20 of the screw compressor in this embodiment, a motor 9A ( ) is driven axially from the rotor. Figure 1The side portion opposite to the male rotor 2 and the side portion opposite to the female rotor 3 are respectively shaved off from one end of the male rotor 2 to the vicinity of the rotor opposite surface (the surface opposite to the end of the tooth 2A of the male rotor 2 and / or the tooth 3A of the female rotor 3), thereby forming the male rotor side recess 20A and the female rotor side recess 20B. In addition, the male rotor side recess 20A and the female rotor side recess 20B are respectively formed into a curved shape that smoothly joins the inner wall surface of the chamber 10AX when viewed from the direction of the rotor axis of the male rotor 2 and the female rotor 3.

[0057] Furthermore, by forming a male rotor-side recess 20A and a female rotor-side recess 20B in the chamber enclosure 20 as shown, a first male rotor-side open space 21A with the same shape as the male rotor-side recess 20A is formed between the isolation wall 20C of the chamber enclosure 20 that isolates the male rotor-side recess 20A and the female rotor-side recess 20B and the suction-side shaft portion 2B of the male rotor 2, and a first female rotor-side open space 22A with the same shape as the female rotor-side recess 20B is formed between the isolation wall 20C and the suction-side shaft portion 3B of the female rotor 3.

[0058] Furthermore, in the chamber enclosure 20, on the opposite side of the rotor and opposite to the suction-side shaft portion 2B of the male rotor 2, an arc-shaped recess 20D is formed, coaxial with the suction-side shaft portion 2B of the male rotor 2 and having a diameter slightly larger than that suction-side shaft portion 2B. Thus, a second male rotor-side open space 21B of a certain size is formed between the suction-side shaft portion 2B of the male rotor 2 and the chamber enclosure 20, communicating with the first male rotor-side open space 21A and together with the first male rotor-side open space 21A constituting the first open space 21.

[0059] Similarly, in the chamber enclosure 20, on the opposite side of the rotor and opposite to the suction side shaft 3B of the female rotor 3, an arc-shaped recess 20E is formed, which is coaxial with the suction side shaft 3B of the female rotor 3 and has a diameter that is a certain degree larger than that suction side shaft 3B. As a result, a second female rotor side open space 22B of a certain size is formed between the suction side shaft 3B of the female rotor 3 and the chamber enclosure 20, which communicates with the second female rotor side open space 22A and together with the first female rotor side open space 22A constitutes the second open space 22.

[0060] In this case, the diameters of the recesses 20D and 20E of the chamber enclosure 20 are set to be smaller than the tooth root radii of the male rotor 2 and the female rotor 3, and larger than the radii of the suction side shaft portion 2B of the male rotor 2 and the suction side shaft portion 3B of the female rotor 3, so as to be able to close the chamber.

[0061] In the screw compressor of this embodiment with the above structure, the suction space 13 (outer side of the suction side shaft portion 2B of the male rotor 2) Figure 1 and Figure 2 The working medium flowing from the space portion of the chamber flows along the wall of the male rotor side recess 20A of the chamber closure 20, around the suction side shaft 2B of the male rotor 2 in the same direction as the rotation direction of the suction side shaft 2B (indicated by arrow a), and is finally sucked into the chamber through the suction port.

[0062] Additionally, a portion of the working medium flowing from the space portion of the suction space 13, which is located on the outer side of the suction side shaft portion 2B of the male rotor 2, collides with the side wall of the rotor-facing side of the chamber closure portion 20. However, it then flows around the suction side shaft portion 2B of the male rotor 2 via the second male rotor side open space 21B of the chamber closure portion 20, rotating in the same direction as the rotation direction of the suction side shaft portion 2B, and is finally sucked into the chamber through the suction port.

[0063] Similarly, in this screw compressor, the suction space 13 (outer of the suction side shaft portion 3B of the female rotor 3) Figure 1 and Figure 2 The working medium flowing from the space portion of the chamber flows along the wall of the female rotor side recess 20B of the chamber closure 20, around the suction side shaft 3B of the female rotor 3 in the same direction as the rotation direction of the suction side shaft 3B (indicated by arrow b), and is finally sucked into the chamber through the suction port.

[0064] Additionally, a portion of the working medium flowing from the suction space 13, which is located on the outer side of the suction side shaft 3B of the female rotor 3, collides with the sidewall of the rotor-facing side of the chamber closure 20. However, it then flows around the suction side shaft 3B of the female rotor 3 in the suction space 13 and the second open space 22 via the second female rotor side open space 22B of the chamber closure 20, rotating in the same direction as the rotation direction of the suction side shaft 3B, and is finally sucked into the chamber through the suction port.

[0065] In this screw compressor embodiment, because the structure separates the first open space 21 from the second open space 22, it effectively rectifyes the flow of the working medium in the suction space 13 caused by the rotation of the male rotor 2 and the female rotor 3. In particular, this rectification effect is effective when the male rotor 2 and the female rotor 3 rotate at high speeds, resulting in higher suction resistance in screw compressors with lower low-speed operation ratios. Furthermore, in this screw compressor, the male rotor-side recess 20A and the female rotor-side recess 20B of the chamber enclosure 20 are respectively formed in a curved shape that smoothly engages with the inner wall surface of the chamber 10AX, thus further reducing turbulence in the flow of the working medium in the suction space 13.

[0066] Therefore, the screw compressor according to this embodiment, compared with the conventional screw compressor, has a lower suction port 12 ( Figure 1 The flow resistance of the working medium is low, allowing for smooth intake into the working chamber. Therefore, when the male rotor 2 and female rotor 3 rotate at high speed, the working medium is not slowed down as it flows into the working chamber, thus suppressing the energy used to accelerate the working medium and improving the energy efficiency of the screw compressor. When the male rotor 2 and female rotor 3 rotate at low speed, the reduced intake resistance of the working medium also increases its flow rate.

[0067] (3) Third implementation method

[0068] In Figure 4 The corresponding parts are marked with the same reference numerals, or the same reference numerals are marked with the suffix "Y" to indicate this. Figure 8 This illustrates a portion of the structure of the screw compressor according to the third embodiment, and... Figure 1 The view corresponds to the CC direction. The screw compressor of this embodiment is constructed in the same way as the screw compressor of the second embodiment, except that the structure of the working chamber enclosure 30 is different.

[0069] In fact, in the screw compressor of this embodiment, regarding Figure 6 At the same location as the existing chamber enclosure 16 described above, a chamber enclosure 30 of the same size as the chamber enclosure 16 is integrally formed with the main housing 10Y.

[0070] Within the enclosed chamber 30, a motor 9A ( ) is driven axially from the rotor. Figure 1 A male rotor side recess 30A and a female rotor side recess 30B are formed on the side opposite to the male rotor 2 and the side opposite to the female rotor 3, respectively, in such a way that the end of the male rotor 2 tooth 2A and / or the side opposite to the female rotor 3 are close to the rotor opposite surface (the side opposite to the end of the male rotor 2 tooth 2A and / or the side opposite to the female rotor 3 tooth 3A).

[0071] Furthermore, by forming a male rotor-side recess 30A and a female rotor-side recess 30B in the chamber enclosure 30 as shown, a first male rotor-side open space 31A with the same shape as the male rotor-side recess 30A is formed between the isolation wall 30C of the chamber enclosure 30 that isolates the male rotor-side recess 30A and the female rotor-side recess 30B and the suction-side shaft portion 2B of the male rotor 2, and a first female rotor-side open space 32A with the same shape as the female rotor-side recess 30B is formed between the isolation wall 30C and the suction-side shaft portion 3B of the female rotor 3.

[0072] In this case, the side of the male rotor side recess 30A is formed as an arc shape with increasing curvature as the working medium flowing into the first male rotor side open space 31A as described below moves from the inlet side to the outlet side of the first male rotor side open space 31A. Thus, the curvature of the first male rotor side open space 31A is designed to increase as it moves toward the rotation direction of the suction side shaft portion 2B of the male rotor 2.

[0073] Similarly, the side surface of the female rotor side recess 30B is formed as an arc shape with increasing curvature as the working medium flowing into the first female rotor side open space 32A as described below advances from the inlet side to the outlet side of the first female rotor side open space 32A. Thus, the curvature of the first female rotor side open space 32A is designed to increase as it advances in the rotational direction toward the suction side shaft portion 3B of the female rotor 3.

[0074] Furthermore, in the chamber enclosure 30, on the opposite side of the rotor and opposite to the suction-side shaft portion 2B of the male rotor 2, an arc-shaped recess 30D is formed, coaxial with the suction-side shaft portion 2B of the male rotor 2 and having a diameter slightly larger than that suction-side shaft portion 2B. Thus, between the suction-side shaft portion 2B of the male rotor 2 and the chamber enclosure 30, a second male rotor-side open space 31B is formed, communicating with the first male rotor-side open space 31A and together with the first male rotor-side open space 31A constituting a certain size of the first open space 31.

[0075] Similarly, in the chamber enclosure 30, on the opposite side of the rotor and opposite to the suction-side shaft 3B of the female rotor 3, an arc-shaped recess 30E is formed, which is coaxial with the suction-side shaft 3B of the female rotor 3 and has a diameter that is a certain degree larger than that suction-side shaft 3B. Thus, between the suction-side shaft 3B of the female rotor 3 and the chamber enclosure 30, a second female rotor-side open space 32B of a certain size is formed, communicating with the second female rotor-side open space 32A and together with the first female rotor-side open space 32A constituting the second open space 32.

[0076] Furthermore, the diameters of the recesses 30D and 30E of the chamber enclosure 30 are set to be smaller than the tooth root radii of the male rotor 2 and the female rotor 3, and larger than the radii of the suction side shaft portion 2B of the male rotor 2 and the suction side shaft portion 3B of the female rotor 3, so as to be able to enclose the chamber.

[0077] In the screw compressor of this embodiment having the above structure, the suction space 13 (outer side of the suction side shaft portion 2B of the male rotor 2) Figure 1 and Figure 2 The working medium flowing from the space portion of the chamber flows along the wall of the male rotor side recess 30A of the chamber closure 30, around the suction side shaft 2B of the male rotor 2 in the same direction as the rotation direction of the suction side shaft 2B (indicated by arrow a), and is finally sucked into the chamber through the suction port.

[0078] Additionally, a portion of the working medium flowing from the suction space 13, which is located on the outer side of the suction side shaft 2B of the male rotor 2, collides with the side of the rotor opposite to the working chamber closure 30. However, it then flows around the suction side shaft 2B of the male rotor 2 via the second male rotor side open space 31B of the working chamber closure 30, rotating in the same direction as the rotation direction of the suction side shaft 2B, within the suction space 13 and the first male rotor side open space 31A, and is finally sucked into the working chamber through the suction port.

[0079] Similarly, in this screw compressor, the suction space 13 (outer of the suction side shaft portion 3B of the female rotor 3) Figure 1 and Figure 2 The working medium flowing from the space portion of the chamber flows along the wall of the female rotor side recess 30B of the chamber closure 30, around the suction side shaft 3B of the female rotor 3 in the same direction as the rotation direction of the suction side shaft 3B (indicated by arrow b), and is finally sucked into the chamber through the suction port.

[0080] Additionally, a portion of the working medium flowing from the suction space 13, which is located on the outer side of the suction side shaft 3B of the female rotor 3, collides with the sidewall of the rotor-facing side of the chamber closure 30. However, it then flows around the suction side shaft 3B of the female rotor 3 in the suction space 13 and the second open space 32 via the second female rotor side open space 32B of the chamber closure 30, rotating in the same direction as the rotation direction of the suction side shaft 3B, and is finally sucked into the chamber through the suction port.

[0081] In this embodiment of the screw compressor, since it is configured to separate the first open space 31 and the second open space 32, it is similar to the screw compressor of the second embodiment in that it can rectify the working medium flowing in the suction space 13 due to the rotation of the male rotor 2 and the female rotor 3.

[0082] Therefore, the screw compressor according to this embodiment, like the screw compressor of the second embodiment, has a greater advantage over conventional screw compressors in terms of suction port 12 ( Figure 1 The reduced flow resistance of the working medium allows for smooth intake into the working chamber. Consequently, when the male rotor 2 and female rotor 3 rotate at high speed, the working medium is not slowed down as it flows into the working chamber, thus suppressing the energy used to accelerate the working medium and improving the energy efficiency of the screw compressor. When the male rotor 2 and female rotor 3 rotate at low speed, the reduced intake resistance of the working medium also increases its flow rate.

[0083] Furthermore, in this screw compressor, since the outlet sides of the first male rotor side open space 31A and the first female rotor side open space 32A are formed as arcs with a larger curvature than the inlet sides, the flow path area of ​​the working medium flowing in the first male rotor side open space 31A and the first female rotor side open space 31B becomes smaller on the outlet side. Therefore, the working medium flowing out from the outlet sides of these first male rotor side open spaces 31A and the first female rotor side open spaces 31B can be accelerated, and acceleration losses of the working medium can be reduced.

[0084] Furthermore, in this screw compressor, since the side shape of the male rotor side recess 30A and the side shape of the female rotor side recess 30B are formed into approximately cylindrical shapes, the machining of the working chamber enclosure 30 becomes easier, thereby improving the manufacturing efficiency of the screw compressor and reducing the manufacturing cost.

[0085] (4) Fourth Implementation

[0086] In Figure 4 The corresponding parts are marked with the same reference numerals, or the same reference numerals are marked with the suffix "Z". Figure 9 This is a diagram showing a portion of the structure of the screw compressor according to the fourth embodiment, and... Figure 1 The view corresponds to the CC direction. The screw compressor of this embodiment is constructed in the same way as the screw compressor of the third embodiment, except that the structure of the working chamber enclosure 40 is different.

[0087] In fact, in the screw compressor of this embodiment, regarding Figure 6At the same location as the existing chamber enclosure 16, a chamber enclosure 40 is integrally formed with the main housing 10Z, having the same length as the chamber enclosure 16 in the rotor axial direction.

[0088] Within the enclosed chamber 40, a motor 9A ( ) is driven axially from the rotor. Figure 1 The male rotor side recess 40A and the female rotor side recess 40B are formed on the side portion of the male rotor 2 and the side portion of the female rotor 3, respectively, in a manner from the end of the male rotor 2 to the opposite surface of the rotor.

[0089] Furthermore, by forming a male rotor-side recess 40A and a female rotor-side recess 40B in the closed portion 40 of the working chamber, a male rotor-side open space 41A is formed between the male rotor-side recess 40A and the suction-side shaft portion 2B of the male rotor 2, and a female rotor-side open space 41B is formed between the female rotor-side recess 40B and the suction-side shaft portion 3B of the female rotor 3.

[0090] In this case, the diameters of the male rotor side recess 40A and the female rotor side recess 40B of the chamber enclosure 40 are set to be smaller than the tooth root radii of the male rotor 2 and the female rotor 3, and larger than the radii of the suction side shaft portion 2B of the male rotor 2 and the suction side shaft portion 3B of the female rotor 3, so as to be able to close the chamber.

[0091] Furthermore, the side of the male rotor-side recess 40A of the closed chamber 40 is formed as an arc shape with increasing curvature as the working medium flowing into the male rotor-side open space 41A as described below moves from the inlet side to the outlet side of the male rotor-side open space 41A. Thus, the curvature of the male rotor-side open space 41A is designed to increase as it moves toward the rotation direction of the suction side shaft 2B of the male rotor 2.

[0092] Similarly, the side of the female rotor-side recess 40B of the closed chamber 40 is formed as an arc shape with increasing curvature as the working medium flowing into the female rotor-side open space 41B as described below advances from the inlet side to the outlet side of the female rotor-side open space 41B. Thus, the curvature of the female rotor-side open space 41B is designed to increase as it advances in the rotational direction toward the suction side shaft 3B of the female rotor 3.

[0093] In the screw compressor of this embodiment with the above structure, the suction space 13 (outer side of the suction side shaft portion 2B of the male rotor 2) Figure 1 and Figure 2The working medium flowing from the space portion of the chamber collides with the side of the chamber closure 40, and then flows around the suction side shaft 2B of the male rotor 2 in the same direction as the rotation direction of the suction side shaft 2B (indicated by arrow a) via the male rotor side open space 41A. Finally, it is sucked into the chamber through the suction port.

[0094] Similarly, in this screw compressor, the working medium flowing from the space portion of the suction space 13, which is located outside the suction side shaft portion 3B of the female rotor 3, collides with the side of the closed chamber portion 40 and flows through the female rotor side open space 41B, around the suction side shaft portion 3B of the female rotor 3, in the same direction as the rotation direction of the suction side shaft portion 3B (indicated by arrow b), and is finally drawn into the working chamber through the suction port.

[0095] In this embodiment of the screw compressor, similar to the screw compressors of the second and third embodiments, since the structure is configured to separate the male rotor-side open space 41A and the female rotor-side open space 41B, it is possible to rectify the working medium that flows equally within the suction space 13 as the male rotor 2 and the female rotor 3 rotate.

[0096] Therefore, the screw compressor according to this embodiment, compared with the conventional screw compressor, has a lower suction port 12 ( Figure 1 The flow resistance of the working medium is low, allowing for smooth intake into the working chamber. Therefore, since the working medium is not slowed down when it flows into the working chamber even when the male rotor 2 and female rotor 3 are rotating at high speed, the energy used to accelerate the working medium can be suppressed, improving the energy efficiency of the screw compressor. Furthermore, when the male rotor 2 and female rotor 3 are rotating at low speed, the reduced intake resistance of the working medium also increases its flow rate.

[0097] Furthermore, in this screw compressor, similar to the third embodiment, since the side shape of the male rotor side recess 40A and the side shape of the female rotor side recess 40B of the working chamber enclosure 40 are formed into cylindrical shapes with a larger curvature at the outlet side than at the inlet side of the male rotor side open space 41A and the female rotor side open space 41B, the working medium flowing out from the outlet side of the male rotor side open space 41A and the female rotor side open space 41B into the suction space 13 and the like can be accelerated, and the acceleration loss of the working medium can be reduced.

[0098] Furthermore, in this screw compressor, since the side shape of the male rotor side recess 40A and the side shape of the female rotor side recess 40B of the working chamber enclosure 40 are formed into approximately cylindrical shapes, the machining of the working chamber enclosure 40 becomes easier, thereby improving the manufacturing efficiency of the screw compressor and reducing the manufacturing cost.

[0099] (5) Other implementation methods

[0100] Furthermore, in the first to fourth embodiments described above, the present invention was applied to a screw compressor 1 in which the number of teeth 2A of the male rotor 2 is 4 and the number of teeth 3A of the female rotor 3 is 6. However, the present invention is not limited to this and can be widely applied to screw compressors of various other structures.

[0101] Furthermore, in the first to fourth embodiments described above, it was explained that the recesses 14C, 14D, 20D, 20E, 30D, 30E, 40A, and 40B of the chamber sealing member 14 and the chamber sealing portions 20, 30, and 40 were formed into arc shapes coaxial with the male rotor 2 and the female rotor 3. However, the present invention is not limited to this. These recesses 14C, 14D, 20D, 20E, 30D, 30E, 40A, and 40B may also be arc shapes coaxial with the male rotor 2 and the female rotor 3, or they may be shapes other than arc shapes.

[0102] Furthermore, in the first embodiment described above, a motor-side open space 15C was provided on the motor 9A side of the chamber enclosure 14, and a male rotor-side open space 15A and a female rotor-side open space 15B were provided on the side of the chamber enclosure 14. In the second and third embodiments, first and second male rotor-side open spaces 21A and 21B were provided on the male rotor 2 side of the chamber enclosure 20 and 30, and first and second female rotor-side open spaces 22A and 22B were provided on the female rotor 3 side of the chamber enclosure 20 and 30. However, the present invention is not limited to this. For example, in the first embodiment, only one of the motor-side open space 15C, rotor-side open space 15A, and female rotor-side open space 15B may be provided. In the second and third embodiments, only the first male rotor-side open space 21A and the first female rotor-side open space 22A may be provided. Moreover, in the second and third embodiments, the structure in which only the second male rotor-side open space 21B and the second female rotor-side open space 22B are provided is the fourth embodiment.

[0103] Industrial availability

[0104] This invention can be widely applied to screw compressors of various structures.

[0105] Explanation of reference numerals in the attached figures

[0106] 1…Screw compressor; 2…Male rotor; 2A, 3A…Gears; 2B, 3B…Suction side shaft; 2C, 3C…Discharge side shaft; 3…Female rotor; 4…Housing; 9…Drive unit; 9A…Motor; 10, 10X~10Z…Main housing; 10A, 10AX~10AZ…Cavity; 12…Suction inlet; 13…Suction space; 14…Work chamber enclosure; 14C, 14D, 20D, 20E, 30D, 30E, 40A 15, 21, 22, 31, 32... Open space; 15A, 21A, 21B, 31A, 31B, 41A... Open space on the male rotor side; 15B, 22A, 22B, 32A, 32B, 41B... Open space on the female rotor side; 15C... Open space on the motor side; 20, 30, 40... Closed part of the working chamber; 20A, 30A... Recessed part on the male rotor side; 20B, 30B... Recessed part on the female rotor side; 20C... Isolation wall.

Claims

1. A screw compressor that compresses a working medium drawn in from an inlet and discharges it from an outlet, the screw compressor being characterized by comprising: A male rotor and a female rotor that can rotate in a meshing manner; A housing with a chamber that houses the male rotor and the female rotor and together with the male rotor and the female rotor forms a working chamber for compressing the working medium; A drive unit that drives at least one of the male rotor and the female rotor to rotate. The working chamber is enclosed by a suction port for drawing the working medium into the working chamber and for closing the working chamber when it reaches a predetermined capacity. and The suction space connecting the suction inlet and the suction port. An open space is provided between the shaft portions of the male rotor and the female rotor, located on opposite sides of the suction orifice relative to the male and female rotors, to connect the suction space with the suction orifice. The open space is divided into one side of the male rotor and one side of the female rotor. The open space is formed such that the working medium flowing through the outer side of the shaft portion of the male rotor in the suction space flows into the open space on one side of the male rotor, and the working medium flowing through the outer side of the shaft portion of the female rotor in the suction space flows into the open space on one side of the female rotor.

2. The screw compressor as described in claim 1, characterized in that: The male rotor and the female rotor each have a toothed portion with a plurality of spirally extending teeth. The male rotor and the female rotor are housed in the cavity of the housing when their respective teeth are engaged. The suction port is disposed on a plane that includes the axial end faces of the teeth of the male rotor and the female rotor, which are located on the opposite side of the discharge port from the male rotor and the female rotor.

3. The screw compressor as described in claim 1, characterized in that: The suction space is divided into a male rotor side and a female rotor side. The open space is formed such that the working medium drawn in from the inlet passes through the open space and flows past the outside of the shaft portion of the male rotor, and the working medium drawn in from the inlet passes through the open space and flows past the outside of the shaft portion of the female rotor.

4. A screw compressor that compresses a working medium drawn in from an inlet and discharges it from an outlet, the screw compressor being characterized by comprising: A male rotor and a female rotor that can rotate in a meshing manner; A housing with a chamber that houses the male rotor and the female rotor and together with the male rotor and the female rotor forms a working chamber for compressing the working medium; A drive unit that drives at least one of the male rotor and the female rotor to rotate. The working chamber is enclosed by a suction port for drawing the working medium into the working chamber and for closing the working chamber when it reaches a predetermined capacity. and The suction space connecting the suction inlet and the suction port. An open space is provided between the shaft portions of the male rotor and the female rotor, located on opposite sides of the suction orifice relative to the male and female rotors, to connect the suction space with the suction orifice. The open space is divided into one side of the male rotor and one side of the female rotor. Both the open space on the male rotor side and the open space on the female rotor side are formed into a curved surface that smoothly engages with the inner wall of the chamber when viewed from the direction of the rotor axis of the male rotor and the female rotor.

5. A screw compressor that compresses a working medium drawn in from an inlet and discharges it from an outlet, the screw compressor being characterized by comprising: A male rotor and a female rotor that can rotate in a meshing manner; A housing with a chamber that houses the male rotor and the female rotor and together with the male rotor and the female rotor forms a working chamber for compressing the working medium; A drive unit that drives at least one of the male rotor and the female rotor to rotate. The working chamber is enclosed by a suction port for drawing the working medium into the working chamber and for closing the working chamber when it reaches a predetermined capacity. and The suction space connecting the suction inlet and the suction port. An open space is provided between the shaft portions of the male rotor and the female rotor, located on opposite sides of the suction orifice relative to the male and female rotors, to connect the suction space with the suction orifice. The enclosed part of the studio, The space is positioned between the shaft portions of the male rotor and the female rotor, dividing the open space into a male rotor side and a female rotor side. At the location opposite to the shaft of the male rotor, a first arc-shaped recess with a diameter larger than the shaft is formed, and at the location opposite to the shaft of the female rotor, a second arc-shaped recess coaxial with the female rotor and with a diameter larger than the shaft is formed.

6. The screw compressor as described in claim 5, characterized in that: The first recess is formed in the shape of an arc centered on the center of the rotor shaft of the male rotor. The second recess is formed as an arc centered on the center of the rotor shaft of the female rotor.

7. The screw compressor as described in claim 5 or 6, characterized in that: At least one of the first recess and the second recess is formed such that its curvature increases as it advances in the rotational direction of the shaft portion of the opposing male rotor or the shaft portion of the female rotor.

8. The screw compressor as described in claim 5, characterized in that: The radii of the first recess and the second recess are set to be smaller than the tooth root radii of the male rotor and the female rotor and larger than the radii of the shaft portion of the male rotor and the female rotor.

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