Rotating shaft assembly, scroll compressor and control method of scroll compressor

Abstract

The invention provides a rotating shaft assembly, a scroll compressor and a control method of the scroll compressor. The rotating shaft assembly comprises a bearing chamber and a bearing arranged in the bearing chamber, and the bearing is sleeved with a rotating shaft. A gap is formed between the outer wall of the bearing and the inner wall of the bearing chamber, and the gap is adjustable. According to the compressor, the bearings in the bearing chamber are arranged in a clearance mode, the clearance size is adjustable, vibration generated in the operation process of the rotating shaft is improved, abnormal noise and vibration possibly generated due to the change of the working condition during operation of the compressor can be reduced, and the user experience is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of scroll compressors, and in particular relates to a rotating shaft assembly and a scroll compressor and a control method thereof. Background Art

[0002] During the operation of a scroll compressor, the bearing stiffness has a significant impact on the shaft system mode, which in turn may affect the noise and vibration level of the compressor. Existing scroll compressor designs generally fail to fully consider the changes in bearing stiffness under dynamic conditions, which may lead to resonance problems under certain operating conditions, thereby affecting the performance and life of the compressor. Therefore, a device and method that can dynamically control the bearing stiffness is needed to avoid resonance and optimize the operating noise and vibration level of the scroll compressor.

[0003] In the patent document disclosed in one patent application, a scroll compressor is disclosed that in order to improve the rigidity of the shaft system, the support position of the lower bracket is changed, the span between the upper bracket and the lower bracket is reduced, the crankshaft deflection is reduced, and the crankshaft modal frequency is increased. However, this method cannot ensure that the shaft system mode will not be excited by the excitation force under different working conditions (different speeds, different temperatures).

[0004] The patent document disclosed in the second patent application discloses a compressor using magnetic suspension bearings, which increases the shaft stiffness and thus the shaft modal frequency by increasing the shaft diameter without being restricted by the bearing size. However, the cost is too high and the shaft modal frequency cannot be adjusted according to the working conditions.

[0005] The above patent documents all improve the compressor shaft stiffness by changing the structure to prevent the shaft mode from being excited and causing resonance to produce abnormal noise and vibration, but they are unable to adjust the shaft mode according to different working conditions to prevent it from being excited. Summary of the invention

[0006] Therefore, the present application provides a rotating shaft assembly and a scroll compressor and a control method thereof, which can solve the problem in the prior art that the shaft system mode cannot be adjusted according to different working conditions to prevent it from being excited.

[0007] In order to solve the above problems, the present application provides a rotating shaft assembly, comprising:

[0008] A bearing chamber and a bearing arranged in the bearing chamber, wherein the bearing sleeve is provided with a rotating shaft;

[0009] A gap is provided between the outer wall of the bearing and the inner wall of the bearing chamber, and the gap is adjustable.

[0010] In some embodiments,

[0011] The bearing comprises a sliding bearing, an annular sealed cavity is formed between the outer wall of the sliding bearing and the inner wall of the bearing chamber, at least two baffles are arranged in the sealed cavity, so that the sealed cavity is divided into two chambers along the circumferential direction: a first chamber and a second chamber; the pressure difference between the first chamber and the second chamber is adjusted so that the sliding bearing moves radially.

[0012] In some embodiments,

[0013] A reset member is provided in the first chamber, and two ends of the reset member abut against the outer wall of the sliding bearing and the inner wall of the bearing chamber; an air hole is provided on the wall of the bearing chamber, and the air hole is connected with the second chamber; the air pressure in the second chamber is adjusted through the air hole to change the radial movement state of the sliding bearing.

[0014] In some embodiments,

[0015] The baffles are provided with two and are symmetrically arranged on both sides of the sliding bearing.

[0016] According to another aspect of the present application, a scroll compressor is provided, comprising the rotating shaft assembly as described above.

[0017] In some embodiments,

[0018] The bearing chamber is arranged in the bracket of the scroll compressor, and the air hole is communicated with the exhaust chamber of the scroll compressor through a pipeline.

[0019] In some embodiments,

[0020] The scroll compressor also includes a frequency converter, which changes the frequency of the frequency converter to adjust the rotation speed of the rotating shaft.

[0021] In some embodiments,

[0022] The scroll compressor also includes a temperature detection module for monitoring the temperature of the lubricating oil between the sliding bearing and the rotating shaft.

[0023] According to another aspect of the present application, a control method for the scroll compressor as described above is provided, comprising:

[0024] Collect the real-time vibration of the scroll compressor;

[0025] If the real-time vibration exceeds a preset range, the radial movement of the sliding bearing is adjusted, or / and the frequency of the frequency converter is adjusted to change the rotation speed of the shaft so that the real-time vibration is within the preset range.

[0026] In some embodiments,

[0027] The preset range includes a bearing stiffness range of the sliding bearing, and the bearing stiffness is defined by the rotation speed of the rotating shaft, the clearance distance of the sliding bearing, and the temperature of the lubricating oil between the sliding bearing and the rotating shaft.

[0028] The present application provides a rotating shaft assembly, comprising: a bearing chamber and a bearing arranged in the bearing chamber, wherein the bearing sleeve is provided with a rotating shaft; a gap is provided between the outer wall of the bearing and the inner wall of the bearing chamber, and the gap is adjustable.

[0029] This application has the following beneficial effects:

[0030] By setting a gap between the bearings in the bearing chamber and adjusting the gap size, the vibration during the operation of the shaft can be improved, which helps to reduce abnormal noise and vibration that may be caused by changes in operating conditions during the operation of the compressor and improve user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the implementation methods or the prior art descriptions. The drawings described below are merely exemplary, and for those of ordinary skill in the art, other implementation drawings can be derived from the provided drawings without creative work.

[0032] Figure 1 This is a schematic diagram of the structure of the shaft assembly of an embodiment of the present application;

[0033] Figure 2 For the embodiment of this application Figure 1 AA section view in the figure;

[0034] Figure 3 This is a flow chart of the control scheme of the scroll compressor according to an embodiment of the present application.

[0035] The reference numerals are as follows:

[0036] 1. Upper bracket; 2. Air hole; 3. Sliding bearing; 4. Lubricating oil; 5. Rotating shaft; 6. Lower bracket; 7. Return spring; 8. Baffle; 9. First chamber; 10. Second chamber. DETAILED DESCRIPTION

[0037] 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.

[0038] 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.

[0039] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0040] In addition, it should be noted 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 this application.

[0041] See also Figures 1 to 3 As shown, according to an embodiment of the present application, a shaft assembly includes:

[0042] A bearing chamber and a bearing arranged in the bearing chamber, wherein the bearing sleeve is provided with a rotating shaft 5;

[0043] A gap is provided between the outer wall of the bearing and the inner wall of the bearing chamber, and the gap is adjustable.

[0044] The present application improves the vibration of the rotating shaft 5 during operation by setting a gap between the bearings in the bearing chamber, the size of the gap being adjustable, which helps to reduce abnormal noise and vibration that may be generated due to changes in operating conditions when the compressor is running, thereby improving user experience.

[0045] During the high-speed operation of the rotating shaft 5, changes in the operating environment, including the angular velocity of rotation, the dynamic viscosity of the lubricating oil 4, and the clearance of the bearings, will cause resonance to be excited, resulting in large vibrations. The present application sets a gap between the bearing and the bearing chamber. When vibration occurs during the operation of the rotating shaft 5, the clearance of the bearing can be adjusted, which is equivalent to changing the state of the shaft system that generates resonance, thus ensuring that the resonant shaft system mode is not excited, and the adjustment and control are performed dynamically.

[0046] The above-mentioned bearings include sliding bearings 3 and rolling bearings. Only by fine-tuning the radial position of the bearings arranged in the bearing chamber can the state of the shaft system be changed, the state of resonance can be eliminated, thereby reducing noise, improving the stability of operation and extending its service life.

[0047] In some embodiments,

[0048] The bearing includes a sliding bearing 3, an annular sealed cavity is formed between the outer wall of the sliding bearing 3 and the inner wall of the bearing chamber, and at least two baffles 8 are provided in the sealed cavity, so that the sealed cavity is divided into two chambers along the circumferential direction: a first chamber 9 and a second chamber 10; the pressure difference between the first chamber 9 and the second chamber 10 is adjusted to make the sliding bearing 3 move radially.

[0049] The following description uses a sliding bearing 3 as the bearing, and a rolling bearing can be used as a reference.

[0050] An oil film layer of lubricating oil 4 is provided between the sliding bearing 3 and the rotating shaft 5 to realize the sliding support function; in the gap setting structure between the sliding bearing 3 and the bearing chamber, the gap is set as an annular sealing cavity structure, and two baffles 8 are set in the annular sealing cavity, which can divide the sealing cavity into two chambers (the two baffles 8 are set in a separated position): a first chamber 9 and a second chamber 10. In this way, the pressure difference between the first chamber 9 and the second chamber 10 is adjusted to cause the sliding bearing 3 to move radially and change the state of the shaft system.

[0051] The rolling bearing is provided with a sealed cavity structure between the outer ring and the inner wall of the bearing chamber, and a baffle 8 is arranged in the sealed cavity, so that the radial movement of the rolling bearing can also be achieved.

[0052] In some embodiments,

[0053] A reset member is provided in the first chamber 9, and two ends of the reset member abut against the outer wall of the sliding bearing 3 and the inner wall of the bearing chamber; an air hole 2 is provided on the wall of the bearing chamber, and the air hole 2 is connected to the second chamber 10; the air pressure in the second chamber 10 is adjusted through the air hole 2 to change the radial movement state of the sliding bearing 3.

[0054] In the structure of the specific adjustment of the gap size between the first chamber 9 and the second chamber 10, a reset member is arranged in the first chamber 9, and the second chamber 10 is arranged to conduct external high-pressure gas to change the pressure therein, so that the sliding bearing 3 moves radially in the bearing chamber, and the gas pressure injected into the second chamber 10 is greater than the effect of the reset member, and the sliding bearing 3 moves toward the first chamber 9 side, while the gas in the second chamber 10 is discharged, and the reset member can push the sliding bearing 3 to move toward the second chamber 10 side.

[0055] In some embodiments,

[0056] Two baffles 8 are provided and are symmetrically arranged on both sides of the sliding bearing 3 .

[0057] There are two baffles 8 and they are symmetrically arranged in position, which improves stability and sealing, prevents the sliding bearing 3 from moving and causing leakage, and ensures that there is no leakage between the two chambers; to further prevent the sealing between the two chambers, the baffle 8 can be set as a telescopic plate structure, so that the baffle 8 always abuts against the outer wall surface of the sliding bearing 3 when the sliding bearing 3 is moving.

[0058] According to another aspect of the present application, a scroll compressor is provided, comprising the rotating shaft assembly as described above.

[0059] In some embodiments,

[0060] The bearing chamber is arranged in the bracket of the scroll compressor, and the air hole 2 is connected with the exhaust chamber of the scroll compressor through a pipeline.

[0061] A bearing chamber is provided in the support of the scroll compressor, and an air hole 2 is also provided in the support, which is connected with the exhaust chamber of the scroll compressor through the air hole 2, so that the compressed high-pressure gas is used to drive the movement of the bearing.

[0062] In actual operation, the exhaust pressure is adjusted and then input into the air hole 2; when the rotating shaft 5 is vertically arranged, the bracket includes an upper and lower bracket 6, and a corresponding rotating shaft assembly can be arranged on each bracket to regulate the movement of the bearing in the bearing chamber separately, and can also be regulated in combination.

[0063] In some embodiments,

[0064] The scroll compressor also includes a frequency converter, which changes the frequency of the frequency converter to adjust the rotation speed of the rotating shaft 5.

[0065] As for the shaft dynamics of the scroll compressor, the shaft mode can also be adjusted by adjusting the rotation speed of the rotating shaft 5, mainly by changing the frequency of the motor part of the scroll compressor through a frequency converter, so as to avoid exciting resonance.

[0066] In some embodiments,

[0067] The scroll compressor further includes a temperature detection module for monitoring the temperature of the lubricating oil 4 between the sliding bearing 3 and the rotating shaft 5 .

[0068] During the operation of the scroll compressor, the viscosity of the lubricating oil 4 of the sliding bearing 3 and the rotating shaft 5 will also affect the state of the shaft system. The viscosity of the lubricating oil 4 itself is directly related to the temperature. By determining the temperature of the lubricating oil 4, combined with the rotation speed of the rotating shaft 5 and the clearance between the bearing and the bearing chamber, the state of the entire shaft system can be determined, which is convenient for adjustment to eliminate resonance.

[0069] According to another aspect of the present application, a control method for the scroll compressor as described above is provided, comprising:

[0070] Collect the real-time vibration of the scroll compressor;

[0071] If the real-time vibration exceeds the preset range, the radial movement of the sliding bearing 3 is adjusted, or / and the frequency of the frequency converter is adjusted to change the rotation speed of the rotating shaft 5 so that the real-time vibration is within the preset range.

[0072] In some embodiments,

[0073] The preset range includes the bearing stiffness range of the sliding bearing 3 , and the bearing stiffness is defined by the rotation speed of the rotating shaft 5 , the clearance distance of the sliding bearing 3 , and the temperature of the lubricating oil 4 between the sliding bearing 3 and the rotating shaft 5 .

[0074] The bearing stiffness of the sliding bearing 3 is directly related to the resonance phenomenon of the scroll compressor. The bearing stiffness has an initial bearing stiffness at the beginning of the selection and design. In addition to the influence of parameters that cannot be changed, such as the bearing material, during operation, the bearing stiffness is also related to conditions such as its unilateral clearance, rotation speed, and lubricating oil temperature. Therefore, the present application proposes that the bearing stiffness can be adjusted by adjusting these parameters, thereby changing the shaft system mode and reducing vibration.

[0075] The dynamic viscosity of lubricating oil 4 is related to the type of lubricating oil 4, temperature, whether additives are added, etc., and is difficult to control during operation. Therefore, the main control scheme adopts the control of the angular velocity of the shaft system rotation and the unilateral clearance of the bearing.

[0076] The present application controls the stiffness of the sliding bearing 3 by adjusting the radial movement of the sliding bearing 3 or / and adjusting the rotation speed of the rotating shaft 5, thereby preventing the shaft system mode from being excited and causing resonance.

[0077] By real-time monitoring and adjusting the relevant parameters that affect the stiffness of the sliding bearing 3, the scroll compressor shaft modal frequency is controlled, the resonance phenomenon that may occur during the operation of the scroll compressor is reduced, the noise and vibration level of the scroll compressor can be effectively reduced, and the operating stability and efficiency of the scroll compressor can be significantly improved. The specific effects include:

[0078] 1. Reduce noise and vibration: By dynamically adjusting the relevant parameters of the sliding bearing 3 (shaft system angular velocity, bearing unilateral clearance, etc.), the bearing stiffness is optimized, thereby adjusting the shaft system mode, which helps to reduce abnormal noise and vibration that may be generated due to changes in operating conditions during the operation of the compressor and improve user experience.

[0079] 2. Reduce resonance: By dynamically adjusting the relevant parameters of the sliding bearing 3 (shaft system angular velocity, bearing unilateral clearance, etc.), the bearing stiffness is optimized, the shaft system resonance is effectively avoided, the operating stability of the scroll compressor is increased, the damage to the scroll compressor caused by resonance is avoided, and its service life is extended.

[0080] 3. Improve energy efficiency: Reasonable bearing stiffness setting can reduce energy loss and improve the energy efficiency ratio of the scroll compressor.

[0081] In this application, the speed control of the scroll compressor is usually achieved through a frequency converter, which adjusts the motor speed by changing the power frequency supplied to the motor, thereby controlling the operating speed of the scroll compressor. This method can not only achieve accurate control of the compressor speed, but also effectively improve the energy efficiency ratio of the system, reduce energy consumption, and can adjust the operating angular velocity of the scroll compressor in real time to adapt to different working conditions and load requirements.

[0082] The unilateral clearance adjustment method of the sliding bearing 3 is mainly to dynamically adjust the unilateral clearance of the bearing through the pneumatic-spring structure to change the bearing stiffness. This structure can be used to adjust the unilateral clearance of the scroll compressor sliding bearing 3 according to demand, thereby changing the bearing stiffness to achieve the effect of adjusting the shaft system mode. It is an important measure to ensure the normal operation of the equipment and increase its service life. By adjusting the unilateral clearance, the wear of the bearing can be reduced and the operating stability and efficiency of the equipment can be improved.

[0083] The unilateral clearance adjustment of the sliding bearing 3 can also be adjusted by hydraulic adjustment, which only requires replacing the pneumatic system with the hydraulic system. An electric push rod structure can also be used for adjustment.

[0084] The present application adjusts the shaft system mode of the scroll compressor during operation by controlling the stiffness of the scroll compressor sliding bearing 3 to prevent the shaft system mode from being excited to cause resonance and generate abnormal noise and vibration.

[0085] The more specific implementation process is as follows:

[0086] 1. Collect relevant parameters such as the scroll compressor shaft system structure, material, connection relationship, and initial sliding bearing 3 stiffness, and use simulation software to simulate and calculate the shaft system modal frequency.

[0087] 2. Monitor the noise and vibration data of the scroll compressor, and capture the abnormal modal resonance signal through the sensor. If there is an abnormal signal, it will be fed back to the calculation module to calculate the appropriate speed and the single-sided clearance of the sliding bearing 3 so that the bearing stiffness meets the modal frequency of the shaft system and is not excited to resonate.

[0088] According to the calculation results of the calculation module, the speed is appropriately adjusted by the frequency converter, and the unilateral clearance of the sliding bearing 3 is adjusted synchronously. The unilateral clearance of the sliding bearing 3 is adjusted in the following way: the pneumatic adjustment module is used to introduce gas through the air hole 2, push the baffle 8, and drive the sliding bearing 3 to move to one side, so as to achieve the purpose of adjusting the unilateral clearance of the sliding bearing 3. If it is necessary to reset the sliding bearing 3, it is only necessary to stop the gas introduction, and the reset part including the spring will restore the sliding bearing 3 to its original position. And through pre-calculation, the value of the unilateral clearance adjustment of the sliding bearing 3 can also be calculated by the force of the introduced gas on the baffle 8.

[0089] Combined with the temperature monitoring module, the temperature of the lubricating oil 4 is monitored through a temperature sensor, and the real-time data of the dynamic viscosity of the lubricating oil 4 is obtained by calculation and table lookup.

[0090] This application uses the speed adjusted by the frequency converter, the unilateral clearance adjustment structure of the sliding bearing 3, the dynamic viscosity of the lubricating oil 4 calculated from the temperature obtained by the temperature monitoring module, and the bearing stiffness of the sliding bearing 3 obtained by the simulation software liquid hydrodynamic bearing rotor dynamics simulation calculation, so that the bearing stiffness meets the shaft system modal frequency and is not excited to resonate. In the same way, the stiffness of the sliding bearing 3 of the lower bracket 6 can be simulated and calculated, and the modal simulation software can be used to calculate the adjusted shaft system modal frequency to verify the results, which can also make the bearing stiffness meet the shaft system modal frequency and not be excited to resonate.

[0091] It is easy for those skilled in the art to understand that the above-mentioned implementation modes can be freely combined and superimposed without conflict.

[0092] The above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A rotating shaft assembly, characterized in that: include: A bearing chamber and a bearing arranged in the bearing chamber, wherein the bearing sleeve is provided with a rotating shaft (5); A gap is provided between the outer wall of the bearing and the inner wall of the bearing chamber, and the gap is adjustable.

2. The shaft assembly according to claim 1, characterized in that: The bearing comprises a sliding bearing (3), an annular sealed cavity is formed between the outer wall of the sliding bearing (3) and the inner wall of the bearing chamber, and at least two baffles (8) are provided in the sealed cavity, so that the sealed cavity is divided into two chambers along the circumferential direction: a first chamber (9) and a second chamber (10); the pressure difference between the first chamber (9) and the second chamber (10) is adjusted to cause the sliding bearing (3) to move in the radial direction.

3. The shaft assembly according to claim 2, characterized in that: A reset member is provided in the first chamber (9), and the two ends of the reset member abut against the outer wall of the sliding bearing (3) and the inner wall of the bearing chamber; an air hole (2) is provided on the wall of the bearing chamber, and the air hole (2) is connected to the second chamber (10); the air pressure in the second chamber (10) is adjusted through the air hole (2) to change the radial movement state of the sliding bearing (3).

4. The shaft assembly according to claim 2 or 3, characterized in that: Two baffles (8) are provided and are symmetrically arranged on both sides of the sliding bearing (3).

5. A scroll compressor, characterized in that: It comprises a rotating shaft assembly as described in any one of claims 1 to 4.

6. The scroll compressor according to claim 5, characterized in that: The bearing chamber is arranged in the support of the scroll compressor, and the air hole (2) is connected to the exhaust chamber of the scroll compressor through a pipeline.

7. The scroll compressor according to claim 6, characterized in that: The scroll compressor also includes a frequency converter, which changes the frequency of the frequency converter to adjust the rotation speed of the rotating shaft (5).

8. The scroll compressor according to any one of claims 6 or 7, characterized in that: The scroll compressor also includes a temperature detection module for monitoring the temperature of the lubricating oil (4) between the sliding bearing (3) and the rotating shaft (5).

9. A method for controlling a scroll compressor according to any one of claims 5 to 8, characterized in that: include: Collect the real-time vibration of the scroll compressor; If the real-time vibration exceeds a preset range, the radial movement of the sliding bearing (3) is adjusted, or / and the frequency of the frequency converter is adjusted to change the rotation speed of the rotating shaft (5) so that the real-time vibration is within the preset range.

10. The control method according to claim 9, characterized in that: The preset range includes a bearing stiffness range of the sliding bearing, wherein the bearing stiffness is defined by the rotational speed of the rotating shaft (5), the clearance distance of the sliding bearing (3), and the temperature of the lubricating oil (4) between the sliding bearing (3) and the rotating shaft (5).

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