Compressor, air conditioning system and starting method of compressor

Abstract

The invention provides a compressor, an air conditioning system and a starting method of the compressor. The compressor includes: a compressor body including a compressor rotation shaft; the motor comprises a motor rotating shaft, and the compressor rotating shaft and the motor rotating shaft have a driving connection state and a disconnection state; and an oil pump configured to supply oil to a bearing of the compressor; the compressor rotating shaft and the motor rotating shaft are configured to be switched to the driving connection state when the pressure of oil at an outlet of the oil pump is larger than or equal to the preset pressure and switched to the disconnection state when the pressure of oil at the outlet of the oil pump is lower than the preset pressure.

Description

Technical Field

[0001] The present application relates to the technical field of compressors, and in particular to a compressor, an air-conditioning system and a method for starting the compressor. Background Art

[0002] Compressor load starting is one of the main factors for failure of the working system where the compressor is located, such as the air-conditioning system. When the compressor is started under load, it needs to overcome the resistance brought by the load, so the motor starting current will increase significantly. Excessive starting current may cause overload or even damage to related electrical equipment such as circuit breakers and contactors. At the same time, during the compressor load starting process, a large amount of electrical energy is converted into useless heat energy and mechanical energy, resulting in energy waste and increased operating costs. When starting under load, the moving parts inside the compressor will be subjected to greater mechanical shock, which may accelerate the wear of key components and shorten the service life of the compressor. Compressor load starting may also cause pressure fluctuations in the working fluid flow path of the working system, such as the working fluid in the refrigeration circuit of the air-conditioning system, affecting the stable operation of the working system.

[0003] The above statements are only used to provide background information related to the present application and do not necessarily constitute prior art. Summary of the invention

[0004] The purpose of the present application is to provide a compressor, an air-conditioning system and a compressor starting method, aiming to reduce or eliminate the harm caused by starting the compressor under load.

[0005] A first aspect of the present application provides a compressor, comprising:

[0006] A compressor body, including a compressor rotating shaft;

[0007] A motor, including a motor rotating shaft, wherein the compressor rotating shaft has a driving connection state and a disconnection state with the motor rotating shaft; and

[0008] an oil pump configured to supply oil to a bearing of the compressor;

[0009] Wherein, the compressor rotating shaft and the motor rotating shaft are configured to switch to the drive connection state when the pressure of the oil at the outlet of the oil pump is greater than or equal to the preset pressure, and switch to the disconnection state when it is lower than the preset pressure.

[0010] In some embodiments of the compressor,

[0011] The compressor body further includes a compressor side coupling portion connected to the compressor rotating shaft;

[0012] The motor further comprises a motor-side coupling portion connected to the motor rotating shaft;

[0013] The compressor side coupling part and the motor side coupling part have an engaged state and a disengaged state, in which the compressor rotating shaft and the motor rotating shaft are in the driving connection state, and in the disengaged state, the compressor rotating shaft and the motor rotating shaft are in the disconnected state;

[0014] The outlet of the oil pump is connected to the compressor side coupling part and / or the motor side coupling part to deliver oil to the compressor side coupling part and / or the motor side coupling part, and is used to drive the compressor side coupling part and the motor side coupling part to switch between the engaged state and the disengaged state through the pressure of the oil.

[0015] In the compressor described in some embodiments, the compressor side coupling part or the motor side coupling part includes:

[0016] A coupling cylinder, fixedly connected to the compressor rotating shaft connected to the compressor side coupling portion or fixedly connected to the motor rotating shaft connected to the motor side coupling portion; and

[0017] The coupling piston is located in the coupling cylinder body, can reciprocate along the axial direction of the coupling cylinder body and is arranged without relative rotation along the circumferential direction of the coupling cylinder body. The outlet of the oil pump is connected to the coupling cylinder body and communicates with the coupling cylinder cavity formed by the coupling cylinder body and the coupling piston.

[0018] In the compressor described in some embodiments, the compressor also includes a force-applying portion, which is coupled to the compressor side coupling portion and / or the motor side coupling portion to apply a force to the compressor side coupling portion and / or the motor side coupling portion so as to cause the compressor side coupling portion to separate from the motor side coupling portion.

[0019] In the compressor described in some embodiments, the force applying part includes an elastic device and / or a magnetic device.

[0020] In some embodiments of the compressor, the compressor is a screw compressor, further comprising:

[0021] a slide valve configured to adjust a load of the compressor body;

[0022] A valve drive cylinder, comprising a valve drive cylinder body, a valve drive piston disposed in the valve drive cylinder body, and a piston rod connected to the valve drive piston, wherein the piston rod is drivingly connected to the slide valve;

[0023] a first oil pipe connected to the valve drive cylinder body and communicating with a valve drive cylinder cavity surrounded by the valve drive cylinder body and a side of the valve drive piston facing away from the piston rod;

[0024] a second oil pipe connected to the first oil pipe or the valve drive cylinder body to communicate with the valve drive cylinder cavity, and configured to input oil into the valve drive cylinder cavity;

[0025] a first load regulating valve connected to the first oil pipe, wherein the first load regulating valve is configured such that when the screw compressor is in operation and the first load regulating valve is opened, the piston rod drives the slide valve to move to a position where the screw compressor has a minimum load; and

[0026] The third oil pipe is connected between the outlet of the oil pump and the compressor side coupling part and / or the motor side coupling part.

[0027] In the compressor described in some embodiments, the second oil pipe is connected to the outlet of the oil pump.

[0028] In the compressor described in some embodiments, a throttling device is provided on the second oil pipe.

[0029] A second aspect of the present application provides an air conditioning system, comprising the compressor described in the first aspect of the present application.

[0030] The third aspect of the present application provides a method for starting the compressor according to the first aspect of the present application, comprising:

[0031] Step 10, when the compressor rotating shaft and the motor rotating shaft are in the disconnected state, starting the motor and placing the compressor in a minimum load state; and

[0032] Step 30: The pressure of the oil at the outlet of the oil pump is greater than a preset pressure, so that the compressor rotating shaft and the motor rotating shaft are switched to the driving connection state.

[0033] In the compressor of the present application, the compressor rotating shaft and the motor rotating shaft have a drive connection state and a disconnection state. The compressor rotating shaft and the motor rotating shaft switch to the drive connection state when the pressure of the oil at the outlet of the oil pump that supplies oil to the bearing of the compressor is greater than the preset pressure, and switch to the disconnection state when it is less than the preset pressure. The pressure of the oil at the outlet of the oil pump must meet the minimum pressure requirements required by the oil circulation volume of the compressor, the driving force of the components driven by the oil pump (such as the valve drive piston), etc. The preset pressure can be a certain pressure greater than or equal to the minimum pressure, for example, a certain pressure greater than the minimum pressure by 200kPa~300kPa. When the compressor is started, the motor can be started when the compressor rotating shaft and the motor rotating shaft are in a disconnected state so that the motor can be started without load. Before switching to the drive connection state, the compressor can be adjusted to the lowest load state. At the same time, the compressor body can switch the compressor rotating shaft and the motor rotating shaft to the drive connection state after the motor 7 realizes no-load start only when the pressure of the oil at the outlet of the oil pump satisfies the condition that the pressure of the oil is greater than the preset pressure. The motor that has been started without load drives the compressor body to start in the lowest load state, realizing the no-load start of the motor and the low-load start of the compressor. Since the motor is started without load, the starting current is small, and the related electrical equipment will not be overloaded or even damaged due to excessive starting current, and part of the electric energy will be converted into useless heat energy and mechanical energy, resulting in energy waste and increased operating costs. The compressor body of the compressor can be at the lowest load when it starts, and the moving parts of the compressor are subjected to less mechanical impact, and the key parts will not be easily worn due to the large impact during startup, shortening the service life of the compressor. The compressor will not cause the pressure fluctuation of the working fluid flow path of the working system where the compressor is located, such as the working fluid in the refrigeration circuit of the air-conditioning system, during the startup process, and affect the stable operation of the working system. Therefore, the compressor of the present application is conducive to avoiding the harm caused by the compressor starting under load, is conducive to the stable operation of the compressor and its working system, and improves long-term reliability. At the same time, since the oil pressure at the outlet of the oil pump is lower than the preset pressure, it indicates that the oil supply of the compressor is reduced, and long-term operation will damage the bearings. In the compressor of the embodiment of the present application, the compressor rotating shaft and the motor rotating shaft are switched to a disconnected state when the pressure at the outlet of the oil pump is lower than the preset pressure, so that the compressor body is no longer driven by the motor, and the compressor body stops running, which is conducive to preventing the bearing wear caused by insufficient oil supply to the compressor body and increasing the service life of the compressor body.

[0034] The air conditioning system and the compressor starting method of the present application have the advantages of the compressor of the present application.

[0035] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0037] Figure 1 This is a schematic diagram of the principle of a compressor according to an embodiment of the present application.

[0038] Figure 1 In the figure, each reference numeral represents:

[0039] 1. The first load regulating valve;

[0040] 2. Valve drive cylinder; 21. Valve drive cylinder body; 22. Valve drive piston; 23. Piston rod; 21A. Valve drive cylinder cavity;

[0041] 3. Slide valve;

[0042] 4. compressor; 41. compressor rotating shaft; 42. compressor side coupling portion; 421. coupling cylinder body; 422. coupling piston; 42A. coupling cylinder cavity;

[0043] 5. Spring;

[0044] 7. Motor; 71. Motor rotating shaft; 72. Motor side coupling part;

[0045] 8. Second load regulating valve;

[0046] 9. First oil pipeline;

[0047] 10. Second oil pipe;

[0048] 11. The third oil pipeline;

[0049] 12. Fourth oil pipeline;

[0050] 13. Oil pump;

[0051] 14. Throttling device. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the application. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0054] In the description of the present application, it should be understood that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present application.

[0055] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0056] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0057] In order to solve the various adverse effects caused by the load starting of the compressor involved in the background technology, the embodiments of the present application provide a compressor, an air-conditioning system and a compressor starting method.

[0058] like Figure 1As shown, the compressor of the embodiment of the present application includes a compressor body 4, a motor 7 and an oil pump 13. The compressor body 4 includes a compressor rotating shaft 41. The motor 7 includes a motor rotating shaft 71. The compressor rotating shaft 41 and the motor rotating shaft 71 have a drive connection state and a disconnection state. The oil pump 13 is configured to supply oil to the bearings of the compressor. Among them, the compressor rotating shaft 41 and the motor rotating shaft 71 are configured to switch to the drive connection state when the pressure of the oil at the outlet of the oil pump 13 is greater than the preset pressure, and switch to the disconnection state when it is less than the preset pressure.

[0059] In the compressor of this embodiment, the compressor rotating shaft 41 and the motor rotating shaft 71 have a driving connection state and a disconnection state. The compressor rotating shaft 41 and the motor rotating shaft 71 are switched to the driving connection state when the pressure of the oil at the outlet of the oil pump 13 that supplies oil to the bearing of the compressor is greater than the preset pressure, and switched to the disconnection state when it is less than the preset pressure. The pressure of the oil at the outlet of the oil pump 13 must meet the minimum pressure requirements required by the oil circulation volume of the compressor, the driving force of the components driven by the oil pump 13 (such as the valve driving piston 22), etc. The preset pressure can be a certain pressure greater than or equal to the minimum pressure, for example, a certain pressure greater than the minimum pressure of 200kPa~300kPa. When the compressor is started, the motor 7 can be started when the compressor rotating shaft 41 and the motor rotating shaft 71 are in a disconnected state so that the motor 7 can be started without load. Before switching to the drive connection state, the compressor can be adjusted to the minimum load state. At the same time, the compressor body 4 can switch the compressor rotating shaft 41 and the motor rotating shaft 71 to the drive connection state after the motor 7 is started without load only when the pressure of the oil at the outlet of the oil pump 13 satisfies the condition that the pressure of the oil is greater than the preset pressure. The motor 7 that has been started without load drives the compressor body 4 to start in the minimum load state, realizing the motor no-load start and the compressor low-load start. Since the motor is started without load, the starting current is small, and the related electrical equipment will not be overloaded or even damaged due to excessive starting current, and part of the electrical energy will not be converted into useless heat energy and mechanical energy, resulting in energy waste and increased operating costs. The compressor body 4 of the compressor can be at the lowest load when it starts, and the moving parts of the compressor are subjected to less mechanical impact, and the key parts will not be easily worn due to a large impact during startup, shortening the service life of the compressor. The compressor will not cause pressure fluctuations in the working fluid flow path of the working system where the compressor is located, such as the working fluid in the refrigeration circuit of the air-conditioning system, during the startup process, thereby affecting the stable operation of the working system. Therefore, the compressor of the present application is conducive to avoiding the harm caused by the start-up of the compressor under load, is conducive to the stable operation of the compressor and the working system in which it is located, and improves long-term reliability. At the same time, since the pressure of the oil at the outlet of the oil pump 13 is lower than the preset pressure, it indicates that the oil supply of the compressor is reduced, and long-term operation will damage the bearings. In the compressor of the embodiment of the present application, the compressor rotating shaft 41 and the motor rotating shaft 71 are switched to a disconnected state when the pressure at the outlet of the oil pump 13 is lower than the preset pressure, so that the compressor body 4 is no longer driven by the motor 7, and the compressor body 4 stops running, which is conducive to preventing the bearing wear caused by insufficient oil supply to the compressor body 4 and increasing the service life of the compressor body 4.

[0060] like Figure 1As shown, in some embodiments of the compressor, the compressor body 4 also includes a compressor side coupling portion 42 connected to the compressor rotating shaft 41. The motor 7 also includes a motor side coupling portion 72 connected to the motor rotating shaft 71. The compressor side coupling portion 42 and the motor side coupling portion 72 have an engaged state and a disengaged state. In the engaged state, the compressor rotating shaft 41 and the motor rotating shaft 71 are in a driving connection state. In the disengaged state, the compressor rotating shaft 41 and the motor rotating shaft 71 are in a disconnected state. The outlet of the oil pump 13 is connected to the compressor side coupling portion 42 and / or the motor side coupling portion 72 to deliver oil to the compressor side coupling portion 42 and / or the motor side coupling portion 72, for driving the compressor side coupling portion 42 and the motor side coupling portion 72 to switch between the engaged state and the disengaged state by the pressure of the oil.

[0061] The compressor side coupling part 42 and the motor side coupling part 72 are provided, and the compressor rotating shaft 41 and the motor rotating shaft 71 can be switched between the driving connection state and the disconnection state by switching the engagement state and the disengagement state of the compressor side coupling part 42 and the motor side coupling part 72, which is conducive to simplifying the connection relationship between the compressor rotating shaft 41 and the motor rotating shaft 71, so that the compressor rotating shaft 41 and the motor rotating shaft 71 can switch between the state quickly and accurately. By providing an oil pump 13 to deliver oil to the compressor side coupling part 42 and / or the motor side coupling part 72, the compressor side coupling part 42 and the motor side coupling part 72 are driven by the pressure of the oil to switch between the engagement state and the disengagement state, so that the compressor side coupling part 42 and the motor side coupling part 72 have a high response speed to the pressure of the oil at the outlet of the oil pump 13, and can switch between the engagement state and the disengagement state in a timely and rapid manner.

[0062] The compressor-side coupling portion 42 and the motor-side coupling portion 72 may be in a coupled state by, for example, mutual meshing or friction.

[0063] like Figure 1 As shown, in the compressor of some embodiments, the compressor side coupling part 42 or the motor side coupling part 72 includes a coupling cylinder 421 and a coupling piston 422. The coupling cylinder 421 is fixedly connected to the compressor rotating shaft 41 connected to the compressor side coupling part 42 or to the motor rotating shaft 71 connected to the motor side coupling part 72. The coupling piston 422 is located in the coupling cylinder 421, reciprocating along the axial direction of the coupling cylinder 421 and arranged without relative rotation along the circumferential direction of the coupling cylinder 421. The outlet of the oil pump 13 is connected to the coupling cylinder 421 and communicates with the coupling cylinder cavity 42A formed by the coupling cylinder 421 and the coupling piston 422.

[0064] By providing the coupling cylinder 421 and the coupling piston 422 , it is possible to realize, with a simple structure, switching of the compressor side coupling portion 42 and / or the motor side coupling portion 72 between the engaged state and the disengaged state by the pressure of the oil.

[0065] like Figure 1 As shown, in some embodiments of the compressor, the compressor also includes a force-applying portion, which is coupled to the compressor side coupling portion 42 and / or the motor side coupling portion 72 to apply a force to the compressor side coupling portion 42 and / or the motor side coupling portion 72 that causes the compressor side coupling portion 42 and the motor side coupling portion 72 to separate.

[0066] The provision of a force-applying portion is beneficial for directly switching the compressor-side coupling portion 42 and the motor-side coupling portion 72 to a separation state under the action of the force-applying portion without special control when the pressure of the oil at the outlet of the oil pump 13 is insufficient, thereby stopping the operation of the compressor body 4. When the pressure of the oil in the third oil pipe 11 can represent the bearing lubrication pressure of the compressor body 4, it is beneficial to prevent the bearing wear of the compressor body 4 due to insufficient oil supply, thereby increasing the service life of the compressor body 4.

[0067] like Figure 1 As shown, in some embodiments of the compressor, the force applying portion includes an elastic device and / or a magnetic device.

[0068] like Figure 1 As shown, in some embodiments of the compressor, the compressor is a screw compressor, and further includes a slide valve 3, a valve drive cylinder 2, a first oil pipe 9, a second oil pipe 10, a first load regulating valve 1 and a third oil pipe 11. The slide valve 3 is configured to adjust the load of the compressor body 4. The valve drive cylinder 2 includes a valve drive cylinder body 21, a valve drive piston 22 disposed in the valve drive cylinder body 21 and a piston rod 23 connected to the valve drive piston 22. The piston rod 23 is drivingly connected to the slide valve 3. The first oil pipe 9 is connected to the valve drive cylinder body 21 and communicates with a valve drive cylinder cavity 21A surrounded by the valve drive cylinder body 21 and the side of the valve drive piston 22 away from the piston rod 23. The second oil pipe 10 is connected to the first oil pipe 9 or the valve drive cylinder body 21 to communicate with the valve drive cylinder cavity 21A, and is configured to input oil into the valve drive cylinder cavity 21A. The first load regulating valve 1 is connected to the first oil pipe 9. The first load regulating valve 1 is configured such that when the screw compressor is in operation and the first load regulating valve 1 is opened, the piston rod 23 drives the slide valve to move to a position where the screw compressor has the lowest load. The third oil pipe 11 is connected between the outlet of the oil pump 13 and the compressor side coupling part 42 and / or the motor side coupling part 72.

[0069] The compressor is a screw compressor, including a slide valve 3, a valve drive cylinder 2, a first oil pipe 9, a second oil pipe 10, a first load regulating valve 1 and a third oil pipe 11, which is beneficial for opening the first load regulating valve 1 to control the position of the valve drive piston 22 of the valve drive cylinder 2 and the slide valve 3 before the compressor body 4 starts to start, so that the compressor body 4 is at the lowest load when starting, and the motor 7 that has been started without load drives the compressor body 4 to start in the lowest load state, thereby realizing the no-load starting of the motor and the low-load starting of the compressor.

[0070] like Figure 1 As shown, in the compressor of some embodiments, the second oil pipe 10 is connected to the outlet of the oil pump 13 .

[0071] The second oil pipe 10 and the third oil pipe 11 are both connected to the outlet of the oil pump 13, so that the action of the valve drive cylinder 2 and the state switching between the compressor side coupling part 42 and the motor side coupling part 72 are driven by the oil pump 13, and there is no need to specially provide an oil source and an oil pump for controlling the action of the sliding valve 3 or for driving the compressor side coupling part 42 to engage with the motor side coupling part 72.

[0072] like Figure 1 As shown, in some embodiments of the compressor, a throttling device 14 is provided on the second oil pipe 10 .

[0073] By providing the throttling device 14 on the second oil pipe 10, when the oil pump 13 supplies oil to the second oil pipe 10 and the third oil pipe 11 at the same time according to operation requirements, the second oil pipe 10 and the third oil pipe 11 can have different pressures.

[0074] A second aspect of the present application provides an air conditioning system, comprising the compressor of the first aspect of the present application.

[0075] The air conditioning system of the embodiment of the present application has the advantages of the compressor of the embodiment of the present application.

[0076] The third aspect of the present application provides a method for starting the compressor of the first aspect of the present application, comprising:

[0077] Step 10, when the compressor rotating shaft 41 and the motor rotating shaft 71 are in a disconnected state, start the motor 7 and put the compressor in a minimum load state; and

[0078] Step 30 : The pressure of the oil at the outlet of the oil pump 13 is greater than the preset pressure, so that the compressor rotating shaft 41 and the motor rotating shaft 71 are switched to a driving connection state.

[0079] The method for starting the compressor of the embodiment of the present application has the advantages of the compressor of the embodiment of the present application.

[0080] The following combination Figure 1The embodiments of the present application are described in more detail by taking a screw compressor as an example.

[0081] like Figure 1 As shown, the screw compressor of the embodiment of the present application includes a compressor body 4, a motor 7, a valve drive cylinder 2, a sliding valve 3, a first oil pipe 9, a first load regulating valve 1, a second oil pipe 10, a second load regulating valve 8, a third oil pipe 11, a fourth oil pipe 12, an oil pump 13 and a throttling device 14.

[0082] The compressor body 4 includes a compressor rotating shaft 41 and a compressor-side coupling portion 42 connected to the compressor rotating shaft 41 .

[0083] The slide valve 3 is configured to adjust the load of the screw compressor.

[0084] The valve drive cylinder 2 includes a valve drive cylinder body 21, a valve drive piston 22 disposed in the valve drive cylinder body 21, and a piston rod 23 connected to the valve drive piston 22. The piston rod 23 is drivingly connected to the slide valve 3.

[0085] The first oil pipe 9 is connected to the valve drive cylinder body 21 and communicates with a valve drive cylinder cavity 21A formed by the valve drive cylinder body 21 and a side of the valve drive piston 22 facing away from the piston rod 23 .

[0086] The second oil pipe 10 is connected to the first oil pipe 9 to communicate with the valve drive cylinder cavity 21A, and is configured to input oil into the valve drive cylinder cavity 21A.

[0087] The oil pump 13 is used to supply oil to the bearings of the screw compressor. The second oil pipe 10 is connected to the outlet of the oil pump 13 .

[0088] The first load regulating valve 1 is connected to the first oil pipe 9 and is configured such that when the screw compressor is in operation and the first load regulating valve 1 is opened, the piston rod 23 drives the slide valve 3 to move to a position where the screw compressor has the lowest load.

[0089] The motor 7 includes a motor rotating shaft 71 and a motor-side coupling portion 72 to which the motor rotating shaft 71 is connected. The compressor-side coupling portion 42 and the motor-side coupling portion 72 have an engaged state and a disengaged state.

[0090] like Figure 1 As shown, in some embodiments of the screw compressor, the compressor side coupling part 42 and the motor side coupling part 72 are switched between the engaged state and the disengaged state by a fluid driving method. In this embodiment, the third oil pipe 11 is connected to the outlet of the oil pump 13 and the compressor side coupling part 42 respectively to deliver oil to the compressor side coupling part 42, and is used to drive the compressor side coupling part 42 and the motor side coupling part 72 to switch between the engaged state and the disengaged state by the pressure of the oil.

[0091] like Figure 1 As shown, the compressor side coupling part 42 includes a coupling cylinder 421 and a coupling piston 422. The coupling cylinder 421 is fixedly connected to the compressor rotating shaft 41 connected to the compressor side coupling part 42. The coupling piston 422 is located in the coupling cylinder 421, and can reciprocate along the axial direction of the coupling cylinder 421 and is arranged without relative rotation along the circumferential direction of the coupling cylinder 421. The third oil pipe 11 is connected to the coupling cylinder 421 and communicates with the coupling cylinder cavity 42A formed by the coupling cylinder 421 and the coupling piston 422.

[0092] like Figure 1 As shown, the screw compressor also includes an elastic device as a force-applying part, which includes a spring 5. The spring 5 passes through the coupling cylinder 421 and is connected to the coupling piston 422 to achieve coupling between the force-applying part and the compressor side coupling part 42, and applies a force to the compressor side coupling part 42 to separate the compressor side coupling part 42 from the motor side coupling part 72.

[0093] The fourth oil pipe 12 is connected to the valve drive cylinder 21 and is in a state of being connected to the valve drive cylinder cavity 21A. The range of the valve drive cylinder cavity 21A changes with the position change of the valve drive piston 22 in the valve drive cylinder 21. When the valve drive piston 22 moves to the right until the left edge is located at the right side of the left edge of the interface where the fourth oil pipe 12 and the valve drive cylinder 21 are connected, the fourth oil pipe 12 is connected to the valve drive cylinder 21 and is in a state of being connected to the valve drive cylinder cavity 21A. The connection between the fourth oil pipe 12 and the valve drive cylinder 21 is closer to the end where the piston rod 23 is connected to the slide valve 3 than the connection between the first oil pipe 9 and the valve drive cylinder 21. The second load regulating valve 8 is connected to the fourth oil pipe 12. The second load regulating valve 8 is configured so that when the screw compressor is in operation and the first load regulating valve 1 is closed and the second load regulating valve 8 is opened, the piston rod 23 drives the slide valve to move to a position where the screw compressor has an intermediate load higher than the minimum load.

[0094] In the embodiment of the present application, the first load regulating valve 1 is a 25% load regulating solenoid valve, and the second load regulating valve 8 is a 50% load regulating solenoid valve. Both the 25% load regulating solenoid valve and the 50% load regulating solenoid valve are normally closed solenoid valves.

[0095] In an embodiment not shown in the figure, the second oil pipe 10 may also be connected to an oil pump that specifically supplies oil to the second oil pipe 10. The third oil pipe 11 may also be connected to an oil pump that specifically supplies oil to the third oil pipe 11.

[0096] When the pressure at the outlet of the oil pump 13 is greater than the preset pressure, the drive connection state is switched, and when it is less than the preset pressure, the compressor side coupling part 42 and the motor side coupling part 72 are switched to the separation state, so that the compressor rotating shaft 41 and the motor rotating shaft 71 are switched to the disconnected state. When the pressure at the outlet of the oil pump is equal to the preset pressure, the compressor side coupling part 42 and the motor side coupling part 72 are maintained in the current state.

[0097] Figure 1 In the illustrated embodiment, the oil pump 13 is configured to supply oil to the bearing of the screw compressor, the second oil pipe 10 and the third oil pipe 11 are both connected to the outlet of the oil pump 13, and a throttling device 14 is provided on the second oil pipe 10. The compressor side coupling part 42 and the motor side coupling part 72 are switched to the driving connection state when the pressure at the outlet of the oil pump 13 is greater than the preset pressure, and are switched to the separation state when the pressure is less than the preset pressure. The function of the throttling device 14 is to maintain the pressure of the oil in the third oil pipe 11 when the first load regulating valve 1 is opened, so as to drive the compressor side coupling part 42 to operate through the pressure of the oil so that the compressor side coupling part 42 and the motor side coupling part 72 are switched to the engagement state. The throttling device 14 can be, for example, a fixed throttling device or a variable throttling device, for example, a throttling hole or a throttle valve, etc.

[0098] In an embodiment not shown in the figure, the third oil pipe 11 can also be connected to an oil pump specifically used to supply oil to the third oil pipe 11. At the same time, the pressure of the oil at the outlet of the oil pump that supplies oil to the compressor body 4 can be detected by a pressure sensor, and the oil pump that supplies oil to the third oil pipe 11 can be turned on and off according to the detected pressure.

[0099] Alternatively, in another embodiment not shown in the figure, the state switching between the compressor rotating shaft and the motor rotating shaft can be driven by other forms of driving mechanisms controlled by the pressure of the oil at the outlet of the oil pump, such as electromagnetic drive, etc. In the screw compressor of the embodiment of the present application, since the compressor side coupling part 42 of the compressor body 4 and the motor side coupling part 72 of the motor 7 have an engaged state and a separated state, and when the first load regulating valve 1 is opened when the screw compressor is in the running state, the piston rod 23 can drive the slide valve to move to a position where the screw compressor has the lowest load, so that when the screw compressor is started, the motor 7 can be started when the compressor side coupling part 42 and the motor side coupling part 72 are in a separated state so that the motor 7 can be started without load, and the first load regulating valve 1 is opened so that the compressor body 4 of the screw compressor is at the lowest load when it starts, and then the compressor side coupling part 42 and the motor side coupling part 72 are switched to an engaged state, and the motor 7 that has been started without load drives the compressor body 4 with the lowest load to rotate, so as to realize the motor no-load start of the screw compressor. Since the starting current of the motor is relatively small, the related electrical equipment will not be overloaded or even damaged due to excessive starting current, and part of the electrical energy will not be converted into useless heat energy and mechanical energy, resulting in energy waste and increased operating costs. When the compressor body 4 of the screw compressor starts to rotate, the moving parts inside the screw compressor are subjected to less mechanical impact, and the key parts will not be worn out and shorten the service life of the screw compressor due to a large impact during startup. The screw compressor will not cause the pressure fluctuation of the working fluid flow path of the working system where the screw compressor is located, such as the working fluid in the refrigeration circuit of the air-conditioning system, during the startup process, and affect the stable operation of the working system. Therefore, the screw compressor is conducive to avoiding the hazards caused by the start-up of the screw compressor with load, and is conducive to the stable operation of the screw compressor and the working system in which it is located, and improves long-term reliability. Since the outlet of the oil pump 13 is connected to the compressor side coupling part 42 through the third oil pipe 11, the pressure of the oil in the third oil pipe 11 drives the compressor side coupling part 42 and the motor side coupling part 72 to switch between the engaged state and the disengaged state, the coupling part 42 and the motor side coupling part 72 can directly and quickly respond to the pressure of the oil at the outlet of the oil pump 13 and automatically realize state switching.

[0100] Figure 1 The starting method of the screw compressor of the illustrated embodiment may include: in step 10, starting the motor 7 and opening the first load regulating valve 1 when the compressor side coupling part 42 and the motor side coupling part 72 are in a separated state; in step 30, the pressure of the oil at the outlet of the oil pump 13 is greater than the preset pressure, so that the compressor side coupling part 42 and the motor side coupling part 72 are in an engaged state.

[0101] The working principle of the screw compressor according to the embodiment of the present application is described below.

[0102] When the compressor-side coupling portion 42 of the compressor body 4 and the motor-side coupling 72 of the motor 7 are in a separated state, the motor 7 can be in a no-load rotation state, and the compressor body 4 is in a stopped state.

[0103] Open the oil pump 13 to supply oil to the compressor body 4, and supply oil to the second oil pipe 10 and the third oil pipe 11 at the same time. Open the first load regulating valve 1 to put the compressor body 4 in a 25% load state. Driven by the pressure of the oil at the outlet of the oil pump 13, the compressor side coupling part 42 on the compressor body 4 and the motor side coupling part 72 of the idling motor 7 are in a state of engagement, and the compressor body 4 starts to start and run. Since the screw compressor is in a 25% load state at this time, it can avoid severe mechanical shock to the internal moving parts of the screw compressor when it is started with load, and the working fluid pressure of the working system where the screw compressor is located changes relatively smoothly, which is conducive to maintaining the stable operation of the working system. It can also reduce the excessive heat generated by the motor 7 and the compressor body 4 at startup, prevent the motor 7 and the compressor body 7 from overheating due to starting with load, and protect the screw compressor from damage.

[0104] When the screw compressor runs stably at 25% load, the first load regulating valve 1 can be opened, and the slide valve 3 moves to the right under the action of the oil pressure in the valve drive cylinder cavity 21A. If the second load regulating valve 8 is opened, it can run at 50% load. If the second load regulating valve 8 is closed, it can run up to 100% full load. The screw compressor works normally to meet the needs of users.

[0105] If the oil supply of the compressor body 4 is reduced, the bearing will be damaged if it runs for a long time. In the screw compressor of the embodiment of the present application, when the pressure at the outlet of the oil pump 13 is greater than the preset pressure, the compressor side coupling part 42 begins to engage with the motor side coupling part 72 and switches to the engaged state. When the pressure is less than the preset pressure, under the action of the spring 5, the compressor side coupling part 42 begins to separate from the motor side coupling part 72 and switches to the separated state, and the compressor body 4 stops running, preventing the screw compressor from wearing the bearing due to insufficient oil supply, and increasing the service life of the screw compressor. The preset pressure can be a certain pressure greater than the minimum pressure of the outlet of the oil pump 13 required by the compressor, for example, a certain pressure greater than the minimum pressure of 200kPa~300kPa. In this embodiment, the preset pressure is greater than the minimum pressure of 250kPa. When the screw compressor is used in an air conditioning system, the minimum pressure can be, for example, the condensing pressure to ensure that the operating conditions of the compressor are the actual conditions required by the user and to prevent the screw compressor from being over-compressed or under-compressed.

[0106] According to the above description, the present application proposes a screw compressor for various factors that cause the compressor to start with load, which can realize the no-load start of the motor and the low-load start of the compressor body. The main principle is to separate the start of the motor 7 of the screw compressor from the compressor body 4, and drive the compressor side coupling part 42 of the compressor body part 4 adjusted to the minimum load to engage with the motor side coupling part 72 of the no-load motor 7 by using hydraulic or magnetic suction, etc., to ensure the no-load start of the motor 7, which is conducive to avoiding the harm caused by the load start of the screw compressor, and ensuring the stable operation and long-term reliability of the working system where the screw compressor is located. The screw compressor has at least one of the following advantages:

[0107] The motor starting current is reduced and does not need to overcome the resistance brought by the compressor body load, which can reduce the pressure on electrical equipment (such as circuit breakers, contactors, etc.), avoid overload and damage, extend the service life of electrical equipment, and reduce maintenance and replacement costs.

[0108] Reducing the mechanical impact on the screw compressor, extending the service life of the compressor, reducing wear and failure, helping to improve the mechanical reliability of the compressor and ensure the long-term stable operation of the screw compressor.

[0109] When the motor of the screw compressor is started at no-load and the compressor body is started at low load, the working fluid pressure in the working system where the screw compressor is located changes relatively slowly, which helps to maintain the stable operation of the working system, while reducing the vibration when the working system is started and improving the stability of the entire working system.

[0110] The screw compressor starts faster when the motor is started at no-load and the compressor body is started at low load, which can reduce the starting time, improve the starting success rate of the screw compressor, and reduce the risk of starting failure.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present application can still be modified or some technical features can be replaced by equivalents, which should all be included in the scope of the technical solution requested for protection in this application.

Claims

1. A compressor, characterized in that: include: A compressor body (4), comprising a compressor rotating shaft (41); The motor (7) comprises a motor rotating shaft (71), the compressor rotating shaft (41) and the motor rotating shaft (71) being in a driving connection state and a disconnection state; and an oil pump (13), the oil pump (13) being configured to supply oil to a bearing of the compressor; The compressor rotating shaft (41) and the motor rotating shaft (71) are configured to switch to the drive connection state when the pressure of the oil at the outlet of the oil pump (13) is greater than or equal to a preset pressure, and to switch to the disconnection state when the pressure is lower than the preset pressure.

2. The compressor according to claim 1, characterized in that The compressor body (4) further comprises a compressor side coupling portion (42) connected to the compressor rotating shaft (41); The motor (7) further comprises a motor-side coupling portion (72) connected to the motor rotating shaft (71); The compressor side coupling part (42) and the motor side coupling part (72) have an engaged state and a disengaged state, wherein in the engaged state, the compressor rotating shaft (41) and the motor rotating shaft (71) are in the drive connection state, and in the disengaged state, the compressor rotating shaft (41) and the motor rotating shaft (71) are in the disconnected state; The outlet of the oil pump (13) is connected to the compressor side coupling portion (42) and / or the motor side coupling portion (72) to deliver oil to the compressor side coupling portion (42) and / or the motor side coupling portion (72), so as to drive the compressor side coupling portion (42) and the motor side coupling portion (72) to switch between the engaged state and the disengaged state by the pressure of the oil.

3. The compressor according to claim 2, characterized in that The compressor side coupling portion (42) or the motor side coupling portion (72) comprises: A coupling cylinder (421) fixedly connected to the compressor rotating shaft (41) connected to the compressor side coupling portion (42) or fixedly connected to the motor rotating shaft (71) connected to the motor side coupling portion (72); and The coupling piston (422) is located in the coupling cylinder (421), is reciprocatingly movable along the axial direction of the coupling cylinder (421) and is arranged without relative rotation along the circumferential direction of the coupling cylinder (421). The outlet of the oil pump (13) is connected to the coupling cylinder (421) and communicates with the coupling cylinder cavity (42A) formed by the coupling cylinder (421) and the coupling piston (422).

4. The compressor according to claim 2, characterized in that The invention also includes a force applying portion, which is coupled to the compressor side coupling portion (42) and / or the motor side coupling portion (72) to apply a force to the compressor side coupling portion (42) and / or the motor side coupling portion (72) so as to cause the compressor side coupling portion (42) and the motor side coupling portion (72) to separate.

5. The compressor according to claim 4, characterized in that The force applying part includes an elastic device and / or a magnetic device.

6. The compressor according to any one of claims 2 to 5, characterized in that The compressor is a screw compressor, and further comprises: A slide valve (3) configured to adjust the load of the compressor body (4); A valve drive cylinder (2), comprising a valve drive cylinder body (21), a valve drive piston (22) disposed in the valve drive cylinder body (21), and a piston rod (23) connected to the valve drive piston (22), wherein the piston rod (23) is drivingly connected to the slide valve (3); A first oil pipe (9) connected to the valve drive cylinder body (21) and in communication with a valve drive cylinder cavity (21A) surrounded by the valve drive cylinder body (21) and a side of the valve drive piston (22) facing away from the piston rod (23); a second oil pipe (10), connected to the first oil pipe (9) or the valve drive cylinder body (21) to communicate with the valve drive cylinder cavity (21A), and configured to input oil into the valve drive cylinder cavity (21A); a first load regulating valve (1) connected to the first oil pipe (9), wherein the first load regulating valve (1) is configured such that when the screw compressor is in operation and the first load regulating valve (1) is opened, the piston rod (23) drives the slide valve to move to a position where the screw compressor has a minimum load; and The third oil pipe (11) is connected between the outlet of the oil pump (13) and the compressor side coupling part (42) and / or the motor side coupling part (72).

7. The screw compressor according to claim 6, characterized in that: The second oil pipe (10) is connected to the outlet of the oil pump (13).

8. The screw compressor according to claim 7, characterized in that: The second oil pipe (10) is provided with a throttling device (14).

9. An air conditioning system, characterized in that: A compressor comprising the compressor according to any one of claims 1 to 8.

10. A method for starting a compressor according to any one of claims 1 to 8, characterized in that: include: Step 10, when the compressor rotating shaft (41) and the motor rotating shaft (71) are in the disconnected state, starting the motor (7) and placing the compressor in a minimum load state; and Step 30: The pressure of the oil at the outlet of the oil pump (13) is greater than a preset pressure, so that the compressor rotating shaft (41) and the motor rotating shaft (71) are switched to the driving connection state.

Images