Micro piezoelectric pump liquid spraying type dynamic balance control device and method

Abstract

The invention provides a micro piezoelectric pump liquid spraying type control dynamic balance device and method, which is used for regulating and controlling the dynamic balance of a rotating shaft and comprises a detection unit, a control unit and a fluid balance unit, the detection unit is arranged at one side of the rotating shaft and is used for continuously detecting the unbalance phase information of the rotating shaft and the vibration information of the rotating shaft and uploading the detection data to the control unit; the control unit is used for continuously processing and calculating the detection data and continuously controlling the fluid balancing unit to perform balancing action in a fuzzy PID (Proportion Integration Differentiation) control mode; and the fluid balancing unit is mounted at one end of the rotating shaft, is coaxial with the rotating shaft and is used for continuously changing fluid distribution in the fluid balancing unit according to an instruction of the control unit so as to regulate and control dynamic balance of the rotating shaft. The device can reduce the equipment size, is suitable for dynamic balance regulation and control of the ultra-precise micro rotating shaft, and meets the requirements for timeliness and high efficiency of dynamic balance regulation and control of the ultra-precise micro main shaft.

Description

Technical Field

[0001] The invention relates to the field of rotor dynamic balancing, and in particular to a micro piezoelectric pump liquid jet type controlled dynamic balancing device and method. Background Art

[0002] Rotor imbalance is one of the main reasons for shaft vibration and reduced rotation accuracy. As the speed continues to increase, the vibration caused by this imbalance will increase dramatically. The dynamic balancing method can reduce or eliminate the shaft imbalance, thereby achieving the purpose of suppressing vibration, improving shaft operation accuracy and processing quality. The liquid jet dynamic balancing device has the advantages of small additional mass and high balance control accuracy. In recent years, it has received much attention on ultra-precision spindles. However, the existing liquid jet dynamic balancing devices mostly use solenoid valves to control the amount of liquid sprayed. The equipment is large in size and cannot be used for dynamic balancing control of ultra-precision micro spindles.

[0003] For example, the invention patent application with application publication number CN117268631A discloses a liquid rotor online dynamic balancing device and dynamic balancing method, the device includes a central liquid storage chamber, a balancing liquid storage chamber, a fluid switch, a pipeline and a wireless sensor, the central liquid storage chamber is fixed on the rotor and pre-stored with liquid; the balancing liquid storage chamber is evenly distributed along the circumference of the rotor end surface and fixed on the rotor end surface. When the liquid rotor online dynamic balancing device is working, the centrifugal force generated by the rotation of the rotor transfers the liquid from the central liquid storage chamber to the balancing liquid storage chamber, and no additional liquid injection pump or other equipment is required to achieve liquid injection. There is no need to consider additional liquid systems during installation and maintenance, which reduces the corresponding cost. At the same time, the wireless sensor fixed on the rotor rotates synchronously with the rotor, and can collect the vibration signal of the rotor in real time, avoiding the problem that the vibration of the bearing seat and the vibration of the rotor are not synchronized, resulting in the inability to reflect the actual balance of the rotor. However, the liquid rotor online dynamic balancing device uses an external central liquid storage chamber, a balancing liquid storage chamber and a pipeline, which will cause the structure to be too large and unable to adapt to the dynamic balancing control of ultra-precision micro spindles. Furthermore, as the vibration signal detected by the wireless sensor after a certain balancing liquid storage chamber is filled with liquid, liquid is injected into the balancing liquid storage chamber in the opposite direction, which cannot achieve rapid balancing and cannot meet the needs of timely and efficient dynamic balancing control of ultra-precision micro-spindles. Summary of the invention

[0004] In order to reduce the size of the equipment, adapt to the dynamic balance control of the ultra-precision micro-spindle, and meet the timeliness and high efficiency of the dynamic balance control of the ultra-precision micro-spindle, the technical solution adopted by the present invention is: a micro piezoelectric pump liquid jet control dynamic balance device, which is used to control the dynamic balance of the spindle, including a detection unit, a control unit, and a fluid balance unit;

[0005] The detection unit is arranged beside the rotating shaft, and is used to continuously detect the phase information of the rotating shaft imbalance and the rotating shaft vibration information, and upload the detection data to the control unit;

[0006] The control unit is used to continuously process and calculate the detection data, and continuously control the fluid balancing unit to perform balancing actions through a fuzzy PID control method;

[0007] The fluid balancing unit is installed at one end of the rotating shaft and is coaxially arranged with the rotating shaft, and is used to continuously change the fluid distribution inside itself according to the instruction of the control unit to adjust the dynamic balance of the rotating shaft.

[0008] Based on the above, in order to reduce the volume, the fluid balancing unit includes a liquid-jet balancing disk, a sealing gasket, a sealing cover, and a piezoelectric pump embedded in the liquid-jet balancing disk;

[0009] The liquid-spraying balancing disk has a plurality of balancing liquid storage cavities in a circular array, and the balancing liquid storage cavities are provided with flow channel holes for bidirectional flow of fluid;

[0010] The piezoelectric pump is arranged beside the balanced liquid storage chamber and is connected to the balanced liquid storage chamber through the flow channel hole, and is used to drive the fluid to flow bidirectionally between the piezoelectric pump and the balanced liquid storage chamber by utilizing the volume change of the pump chamber;

[0011] The sealing gasket and the sealing cover are sequentially and sealingly arranged on the top of the liquid-spraying balancing disk, so as to seal the liquid-spraying balancing disk.

[0012] Based on the above, in order to facilitate adjustment, three balancing liquid storage chambers are included, and the three balancing liquid storage chambers are evenly distributed in the liquid spraying balancing disk at an angle of 120° along the end surface of the rotating shaft;

[0013] The balance liquid storage chamber is in a fan-shaped shape, and the three balance liquid storage chambers have the same specifications.

[0014] Based on the above, in order to facilitate detection, the detection unit includes a phase sensor and a vibration sensor composed of a pair of laser displacement sensors;

[0015] The vibration sensor is used to collect vibration values ​​of the rotating shaft and the liquid-injection balancing disc, and the vibration sensor is arranged beside the bearing of the rotating shaft and perpendicular to the rotation axis of the rotating shaft;

[0016] The liquid-spraying balancing disc is connected to the rotating shaft via a flat key;

[0017] The phase sensor is arranged on the outer side of the end surface of the liquid-injection balancing disk, the phase sensor is arranged parallel to the rotation axis of the rotating shaft, and the phase sensor is used to detect the phase information of the shaft imbalance.

[0018] Based on the above, in order to facilitate liquid injection and liquid discharge, three piezoelectric pumps are included, and the three piezoelectric pumps are evenly distributed in the liquid-spraying balancing disk at an angle of 120°;

[0019] The piezoelectric pump comprises, from top to bottom, a pump cover, a first sealing ring, a piezoelectric vibrator, a second sealing ring, a one-way stop valve and a lower pump body, which are sealed and connected by a connecting piece. The pump cavity of the piezoelectric pump contains fluid; an upper pump body is suspended in the lower pump body;

[0020] The piezoelectric vibrator is used to drive the valve plate inside the one-way stop valve to open and close alternately through its own deformation, and to realize the circulation of fluid in the pump chamber and the balance liquid storage chamber by changing the volume of the pump chamber.

[0021] Based on the above, the one-way stop valve includes a cantilever beam valve and a U-shaped wheel valve, and the one-way stop valve is connected to the piezoelectric vibrator through the second sealing ring;

[0022] A cylindrical cavity is provided inside the lower pump body for suspending the upper pump body, the inner wall of the cylindrical cavity is sealedly connected to the outer wall of the upper pump body, and a water inlet and a water outlet for connecting to the flow channel hole are provided at the bottom of the cylindrical cavity;

[0023] The upper pump body is provided with a cantilever beam valve disc deformation cavity and a U-shaped wheel valve hole, and the cantilever beam valve disc deformation cavity is consistent with the shape of the cantilever beam valve, the cantilever beam valve disc deformation cavity is communicated with the water outlet, and the U-shaped wheel valve hole is communicated with the water inlet;

[0024] After assembly, the water outlet, the cantilever beam valve plate deformation cavity, and the cantilever beam valve are in communication; the water inlet, the U-shaped wheel valve hole, and the U-shaped wheel valve are in communication;

[0025] The second sealing ring is respectively provided with a downward pressure vent hole and a contoured through cavity that matches the shape of the U-shaped wheel valve hole.

[0026] The present invention also provides a method for controlling dynamic balance by liquid jetting of a micro piezoelectric pump, the steps of which include:

[0027] S1: Provide a micro piezoelectric pump liquid jet controlled dynamic balancing device as described above, wherein an unbalanced amount occurs when the rotating shaft runs at a working speed; transmit the detected vibration signal and key phase signal to a control unit through a vibration sensor and a phase sensor;

[0028] S2: The control unit processes and calculates the collected vibration signals and key phase signals, and determines the balance liquid storage chambers that need to be filled and the mass of the trace liquid in each balance liquid storage chamber according to the relationship between the fluid mass and the centrifugal force in the balance liquid storage chamber and the imbalance angle information;

[0029] S3: The fuzzy PID controller in the control unit controls the piezoelectric pump to inject and discharge liquid into the corresponding balance liquid storage cavity;

[0030] S4: When liquid is injected, the piezoelectric vibrator receives the control command and bends and deforms downward, the cantilever beam valve bends and deforms downward, approaches and partially passes through the cantilever beam valve plate deformation cavity, and the cantilever beam valve plate deformation cavity is opened. At this time, the U-shaped wheel valve is close to the U-shaped wheel valve hole, and the fluid in the pump cavity is discharged from the water outlet to the balanced liquid storage cavity through the cantilever beam valve plate deformation cavity. When the piezoelectric vibrator moves downward to the limit, the water inlet and outlet are closed;

[0031] S5: When discharging liquid, the piezoelectric vibrator receives the control command and bends and deforms upward, the air pressure in the pump chamber decreases, the U-shaped wheel valve bends upward and passes through the hollow part of the second sealing ring, so that the U-shaped wheel valve is away from the U-shaped wheel valve hole, and the U-shaped wheel valve hole is opened. At this time, due to the blocking effect of the second sealing ring, the cantilever beam valve is close to the deformation cavity of the cantilever beam valve plate, and the fluid in the balanced liquid storage cavity is sucked into the pump chamber from the water inlet through the U-shaped wheel valve hole. When the piezoelectric vibrator moves upward to the limit, the water inlet and the water outlet are closed;

[0032] S6: The vibration sensor and phase sensor retransmit the detected balanced data to the control unit again. The control unit processes and calculates the data. The fuzzy PID controller determines the imbalance direction based on the transmitted data again and sends the control command to the piezoelectric pump. Steps S4 to S5 are repeated until the combined force of the centrifugal force generated by the liquid in the balanced liquid storage chamber balances the unbalanced force on the rotating shaft.

[0033] Among them, the control unit adopts fuzzy PID control, which combines fuzzy control and PID control to obtain the advantages of the two control methods to achieve better control effects. When processing vibration signals, the fuzzy PID controller uses fuzzy rules to dynamically adjust the parameters of the PID controller (proportional coefficient, integral coefficient, differential coefficient) to achieve better control effects.

[0034] When the shaft rotates, the vibration signal is collected by the two laser displacement sensors and phase sensors. By analyzing the acquired vibration signal, the vibration amplitude and phase information can be obtained. Since the direction with the largest vibration amplitude corresponds to the imbalance direction of the shaft, the imbalance direction can be determined more accurately by comparing the vibration signal phase with a reference signal phase.

[0035] Among them, the key phase signal is the signal generated by the key phase measurement. A flat key is set on the measured shaft, which is called a key phase mark. When this flat key is turned to the phase sensor position, it is equivalent to the change in the distance between the phase sensor and the measured surface, and the sensor will generate a pulse signal. Every time the shaft rotates one circle, a pulse signal will be generated, and the time of generation indicates the position of the shaft in each rotation cycle. Therefore, by counting the pulses, the rotation speed of the shaft can be measured. By comparing the pulse with the vibration signal of the shaft, the phase angle of the vibration can be determined, which is used for dynamic balancing analysis of the shaft and fault analysis and diagnosis of the equipment.

[0036] The present invention has outstanding substantive features and significant progress compared to the prior art. Specifically, the micro piezoelectric pump liquid jet control dynamic balancing device and method provided by the present invention transfers liquid from the pump cavity of the piezoelectric pump to the balancing liquid storage cavity through the fuzzy PID controller in the control unit, and liquid injection can be achieved without additional liquid injection pumps and other equipment. When dynamically balancing the rotating shaft, there is no need to consider an additional hydraulic system, and the structure is simple and the applicability is strong.

[0037] At the same time, this method uses a fuzzy PID controller to control the piezoelectric pump to perform multiple micro-injections to achieve correction of the dynamic balance of the rotating shaft. It is easy to miniaturize and lightweight, has a high allowable rotation speed and can achieve milligram-level injection volume, overcoming the problems of complex structure of traditional liquid injection dynamic balancing devices and difficulty in precise control of injection volume.

[0038] Furthermore, the online dynamic balancing device can accurately determine the imbalance direction through the laser displacement sensor and the phase sensor, and then use the fuzzy PID control piezoelectric pump to perform multiple micro-injections of liquid to the balancing liquid storage chamber in the imbalance direction, that is, it can inject liquid into a single liquid storage chamber or inject liquid into multiple liquid storage chambers at the same time to achieve rapid balancing, thus meeting the timeliness and efficiency of dynamic balancing control of ultra-precision micro-spindles.

[0039] Furthermore, since the liquid is stored in the pump chamber and the balance liquid storage chamber of the piezoelectric pump and miniaturized, the installation restrictions of using gravity to transfer liquid are eliminated, making the device and control method applicable to rotor systems of all installation methods for dynamic balancing adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the overall structure of the micro piezoelectric pump liquid jet controlled dynamic balancing device provided by the present invention.

[0041] Figure 2 It is a schematic diagram of the structure of a liquid-jet balancing disc in a micro-piezoelectric pump liquid-jet controlled dynamic balancing device provided by the present invention.

[0042] Figure 3The present invention provides a schematic diagram of the structure of a piezoelectric pump in a micro piezoelectric pump liquid jet controlled dynamic balancing device.

[0043] Figure 4 It is a schematic diagram of the structure of a piezoelectric vibrator in a micro piezoelectric pump liquid jet-controlled dynamic balancing device provided by the present invention.

[0044] Figure 5 It is a structural schematic diagram of a one-way stop valve in a micro piezoelectric pump liquid jet control dynamic balancing device provided by the present invention.

[0045] Figure 6 It is a schematic diagram of the structure of the upper pump body in the micro piezoelectric pump liquid jet control dynamic balancing device provided by the present invention.

[0046] Figure 7 It is a schematic diagram of the structure of the lower pump body in the micro piezoelectric pump liquid jet type controlled dynamic balancing device provided by the present invention.

[0047] Figure 8 It is a schematic diagram of the liquid flow direction when the piezoelectric pump in the micro piezoelectric pump liquid jet control dynamic balancing device provided by the present invention is in an upward bending state.

[0048] Fig. 9 It is a schematic diagram of the liquid flow direction when the piezoelectric pump in the micro piezoelectric pump liquid jet control dynamic balancing device provided by the present invention is in a downward bending state.

[0049] In the figure: 1. liquid-jet balancing disk; 2. piezoelectric pump; 201. pump cover; 202. first sealing ring; 203. piezoelectric vibrator; 2031. piezoelectric ceramic; 2032. metal substrate; 204. second sealing ring; 2041. contoured through cavity; 2042. downward pressure vent hole; 205. one-way stop valve; 2051. cantilever beam valve; 2052. U-wheel valve; 206. upper pump body; 2061. cantilever beam valve plate deformation cavity; 2062. U-wheel valve hole; 207. lower pump body; 2071. water outlet; 2072. water inlet; 2073. cylindrical cavity; 2074. mounting hole; 3. balanced liquid storage cavity; 301. flow channel hole; 4. flat key; 5. phase sensor; 6. sealing pad; 7. sealing cover; 8. vibration sensor; 9. rotating shaft; 10. control unit. DETAILED DESCRIPTION

[0050] The technical solution of the present invention is further described in detail below through specific implementation methods.

[0051] Example 1

[0052] This embodiment provides a micro piezoelectric pump liquid jet control dynamic balancing device, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Fig. 9 As shown, it includes a liquid-jet balancing disc 1, a piezoelectric pump 2, a balancing liquid storage chamber 3, a flat key 4, a phase sensor 5, a sealing gasket 6, a sealing cover 7, a vibration sensor 8, a rotating shaft 9, and a control unit 10.

[0053] The inner wall of the liquid-spraying balancing disc 1 is provided with a flat key 4 , which is connected to the rotating shaft 9 via the flat key. The rotating axis of the liquid-spraying balancing disc 1 coincides with the rotating axis of the rotating shaft 9 .

[0054] In this embodiment, there are three balancing liquid storage chambers 3 , which are evenly distributed in the liquid spraying balancing disk 1 at an angle of 120° along the end surface of the rotating shaft 9 , and each balancing liquid storage chamber 3 is provided with a flow channel hole 301 .

[0055] like Figure 3 As shown, the piezoelectric pump 2 includes, from top to bottom, a pump cover 201, a first sealing ring 202, a piezoelectric vibrator 203, a second sealing ring 204, a one-way stop valve 205, an upper pump body 206, and a lower pump body 207, three in number, and liquid is pre-stored in the pump chamber, which is evenly distributed in the liquid-spraying balancing disk 1 at an angle of 120° along the end face of the rotating shaft 9, one end of which is connected to the balancing liquid storage chamber 3 through the flow channel hole 301, and the other end is connected to the control unit 10.

[0056] The pump cover 201 is composed of a connection hole; the piezoelectric vibrator 203 is composed of a piezoelectric ceramic 2031 and a metal substrate 2032 bonded by a high-strength epoxy resin, and is connected to the pump cover 201 through a first sealing ring 202, and the first sealing ring 202 is a circular ring structure.

[0057] The one-way stop valve 205 is composed of a cantilever beam valve 2051 and a U-shaped wheel valve 2052. The cantilever beam valve 2051 is an outlet valve, and the U-shaped wheel valve 2052 is an inlet valve.

[0058] The one-way stop valve 205 is connected to the piezoelectric vibrator 203 through the second sealing ring 204. The second sealing ring 204 is a hollow structure, and the hollow part matches the shape of the one-way stop valve 205 structure to form a contoured through cavity 2041. The second sealing ring 204 is also provided with a downward pressure vent hole 2042, which can transmit the downward pressure to the cantilever beam valve 2051. The upper pump body 206 is provided with a cantilever beam valve plate deformation cavity 2061 and a U-shaped wheel valve hole 2062, wherein the shape of the cantilever beam valve plate deformation cavity 2061 matches the shape of the cantilever beam valve 2051. When stationary, the two are sealed and matched. When subjected to downward pressure, the cantilever beam valve 2051 can bend downward to pass through the cantilever beam valve plate deformation cavity 2061.

[0059] The cantilever beam valve plate deformation cavity 2061 is connected to the water outlet 2071. The U-shaped wheel valve hole 2062 is connected to the water inlet 2072; the lower pump body 207 is provided with a water outlet 2071, a water inlet 2072, a cylindrical cavity 2073, and a mounting hole 2074, wherein the cylindrical cavity 2073 is arranged on the side facing the upper pump body 206, and the cylindrical cavity 2073 and the cavity inside the piezoelectric pump form a pump cavity.

[0060] Specifically, Figure 8 and Fig. 9 As shown, in the initial static state, the cantilever beam valve 2051 is sealed on the cantilever beam valve plate deformation cavity 2061, and the U-shaped wheel valve 2052 is sealed on the U-shaped wheel valve hole 2062, and has a certain sealing performance.

[0061] When the piezoelectric vibrator moves downward, a downward force is applied to the cantilever beam valve plate 2051 and the U-shaped wheel valve 2052 respectively. Since the cantilever beam valve plate deformation cavity 2061 matches the shape of the cantilever beam valve 2051, this force enables the cantilever beam valve 2051 to overcome its own elastic restoring force and bend and deform downward, so that it partially passes through the cantilever beam valve plate deformation cavity 2061, thereby realizing the opening of the cantilever beam valve plate deformation cavity 2061. The U-shaped wheel valve 2052 will be blocked by the upper pump body and remain stationary. The liquid is realized to flow from the pump cavity of the piezoelectric pump to the balanced liquid storage cavity.

[0062] Similarly, when the piezoelectric vibrator moves upward, it will exert an upward force on the cantilever beam valve 2051 and the U-wheel valve 2052. Since the second sealing ring 204 is provided with a contoured through cavity 2041, the shape of which matches that of the U-wheel valve, the U-wheel valve can be bent and deformed upward through the second sealing ring 204. The cantilever beam valve will remain stationary due to the obstruction of the second sealing ring 204, so that the liquid can flow from the balance liquid storage cavity to the pump cavity of the piezoelectric pump.

[0063] Example 2

[0064] This embodiment provides a micro piezoelectric pump liquid jet controlled dynamic balancing device, which is mainly different from Embodiment 1 in that, in this embodiment, the vibration sensor 8 includes two laser displacement sensors to collect vibration values ​​of the rotating shaft 9 and the liquid jet balancing disk 1. The two laser displacement sensors are arranged at the bearing and connected to the control unit 10. The phase sensor 5 collects phase information of the unbalanced value of the rotating shaft 9, is arranged on one side of the rotating shaft 9, and is connected to the control unit 10.

[0065] Example 3

[0066] This embodiment provides a micro piezoelectric pump liquid jet control dynamic balancing device, which is mainly different from the embodiment 2 in that, in this embodiment, the shape of the balancing liquid storage chamber 3 is fan-shaped. The specifications of the three balancing liquid storage chambers 3 are the same.

[0067] Example 4

[0068] This embodiment provides a micro piezoelectric pump liquid jet controlled dynamic balancing method, using the micro piezoelectric pump liquid jet controlled dynamic balancing device provided in Example 3 to perform balancing, including the following steps:

[0069] S1: When the shaft is running at the working speed, if there is an imbalance on the shaft, the vibration signal and key phase signal detected are transmitted to the control unit through the vibration sensor and the phase sensor;

[0070] S2: The control unit processes and calculates the collected vibration signals and key phase signals, and determines the balance liquid storage chambers that need to be filled and the trace liquid mass of each balance liquid storage chamber according to the relationship between the liquid mass and the centrifugal force in the balance liquid storage chamber and the imbalance angle information;

[0071] S3: The fuzzy PID controller in the control unit controls the piezoelectric pump to perform micro-injection and drainage into the corresponding balanced liquid storage chamber;

[0072] S4: When the piezoelectric vibrator receives the control command and bends and deforms downward, the cantilever beam valve bends and deforms downward to approach and pass through the cantilever beam valve plate deformation cavity. At this time, the U-shaped wheel valve is close to the U-shaped wheel valve hole, and the liquid in the pump cavity is discharged from the water outlet to the balanced liquid storage cavity through the cantilever beam valve plate deformation cavity. When the piezoelectric vibrator moves downward to the limit, the water inlet and outlet are closed;

[0073] S5: When the piezoelectric vibrator receives the control command and bends upward, the air pressure in the pump cavity decreases, causing the U-shaped wheel valve to move away from the U-shaped wheel valve hole and pass through the second sealing ring, and the U-shaped wheel valve hole is opened; at this time, the cantilever beam valve will be closely attached to the deformation cavity of the cantilever beam valve plate due to the obstruction of the second sealing ring, so that the liquid in the balance liquid storage cavity is sucked into the pump cavity from the water inlet through the U-shaped wheel valve hole. When the piezoelectric vibrator moves upward to the limit, the water inlet and the water outlet are both closed;

[0074] S6: The vibration sensor and phase sensor retransmit the detected balanced data to the control unit again. The control unit processes and calculates the data. The fuzzy PID controller determines the imbalance direction based on the transmitted data again and sends the control command to the piezoelectric pump. Steps S4-S5 are repeated until the combined centrifugal force generated by the liquid in the three balanced liquid storage chambers balances the unbalanced force on the rotating shaft.

[0075] More specifically, for example, for an ultra-precision air-bearing electric spindle with a mass of 4.5 kg, when it runs at a speed of 200,000 rpm, the correction radius is 60 mm. To achieve a balancing accuracy of G0.064, the allowable residual unbalance is:

[0076] Known: m r =4.5kg, n=200000rpm, r c =60mm, G=0.064,

[0077] Substituting into the following formula, we can get the allowable residual unbalance:

[0078]

[0079] The allowable residual unbalance mass is:

[0080]

[0081] When the shaft rotates, the direction of rotor imbalance can be determined based on the vibration signals collected by the two arranged laser displacement sensors and phase sensors.

[0082] According to the principle of moment balance, in the equilibrium state, the moment generated by the imbalance should be equal to the reverse moment generated after the liquid is injected. Assume that the mass of the liquid injected into the liquid storage chamber A is m A , the mass of liquid injected into the liquid storage chamber B is m B , then:

[0083] U×g×d=(m A ×g×r A +m B ×g×r B ) (1)

[0084] Where g is the acceleration due to gravity; d is the displacement distance of the center of mass; r A 、r B is the distance from the balance reservoir A and B to the rotation center. The above parameters are all known.

[0085] The allowable residual unbalance mass m is known p =2.25mg, then

[0086] m A +m B =m p =2.25mg (2)

[0087] Combining equations (1) and (2), we can obtain the mass m of liquid injected into the liquid storage chamber A: A and the mass m of liquid injected into the liquid storage chamber B B The value of .

[0088] The volume of a single balanced liquid storage chamber can be obtained according to the following formula:

[0089]

[0090] Wherein: B is the thickness of the balanced liquid storage cavity, θ is the central angle of the balanced liquid storage cavity, R2 is the outer diameter of the balanced liquid storage cavity, and R1 is the inner diameter of the balanced liquid in the balanced liquid storage cavity. The above parameters are all known.

[0091] When the mass of the balancing liquid injected into a single balancing liquid storage chamber is m p =2.25 mg, the balance capacity of a single balance liquid storage chamber can be obtained according to the following formula:

[0092]

[0093] The instantaneous flow rate of the U-wheel valve when the valve disc opens can be obtained according to the following formula:

[0094]

[0095] Among them, D k is the diameter of the wheel valve disc, D s is the valve hole diameter, H2 is the vertical height of the valve disc opening, ΔP is the pressure difference between the upper and lower surfaces of the wheel valve disc, and μ is the absolute viscosity of the balancing fluid. All of the above parameters are known.

[0096] The instantaneous flow rate of the cantilever beam valve when the valve disc opens the gap can be obtained according to the following formula:

[0097]

[0098] Among them, ΔP is the pressure difference between the inside and outside of the cavity, C is the maximum flow coefficient, E is the valve plate elastic modulus of the cantilever beam valve, W is the section moment of inertia; L is the length of the cantilever beam, all of which are known.

[0099] Find m A 、m B , q, Q, according to the relationship between the volume flow rate and mass of the balancing liquid (m=ρQt, ρ is the density of the balancing liquid, Q is the volume flow rate of the balancing liquid), it is possible to calculate the time required to inject the balancing liquid into the balancing storage chamber in order to balance the rotor.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A micro piezoelectric pump liquid jet control dynamic balancing device, used to adjust the dynamic balance of a rotating shaft, characterized by: It includes a detection unit, a control unit, and a fluid balance unit; The detection unit is arranged beside the rotating shaft, and is used to continuously detect the phase information of the rotating shaft imbalance and the vibration information of the rotating shaft, and upload the detection data to the control unit; The control unit is used to continuously process and calculate the detection data, and continuously control the fluid balancing unit to perform balancing actions through a fuzzy PID control method; The fluid balancing unit is installed at one end of the rotating shaft and is coaxially arranged with the rotating shaft, and is used to continuously change the fluid distribution inside itself according to the instruction of the control unit to adjust the dynamic balance of the rotating shaft.

2. The micro piezoelectric pump liquid jet controlled dynamic balancing device according to claim 1, characterized in that: The fluid balancing unit includes a liquid-jet balancing disk, a sealing gasket, a sealing cover, and a piezoelectric pump embedded in the liquid-jet balancing disk; The liquid-spraying balancing disk has a plurality of balancing liquid storage cavities in a circular array, and the balancing liquid storage cavities are provided with flow channel holes for bidirectional flow of fluid; The piezoelectric pump is arranged beside the balanced liquid storage chamber and is connected to the balanced liquid storage chamber through the flow channel hole, and is used to drive the fluid to flow bidirectionally between the piezoelectric pump and the balanced liquid storage chamber by utilizing the volume change of the pump chamber; The sealing gasket and the sealing cover are sequentially and sealingly arranged on the top of the liquid-spraying balancing disk, so as to seal the liquid-spraying balancing disk.

3. The micro piezoelectric pump liquid jet controlled dynamic balancing device according to claim 2, characterized in that: It comprises three said balancing liquid storage chambers, and the three said balancing liquid storage chambers are evenly distributed in the said liquid spraying balancing disk at an angle of 120° along the end surface of the said rotating shaft; The balance liquid storage chamber is in a fan-shaped shape, and the three balance liquid storage chambers have the same specifications.

4. The micro piezoelectric pump liquid jet controlled dynamic balancing device according to claim 2 or 3, characterized in that: The detection unit includes a phase sensor and a vibration sensor composed of a pair of laser displacement sensors; The vibration sensor is used to collect vibration values ​​of the rotating shaft and the liquid-jet balancing disc, and the vibration sensor is arranged beside the bearing of the rotating shaft and perpendicular to the rotation axis of the rotating shaft; The liquid-spraying balancing disc is connected to the rotating shaft via a flat key; The phase sensor is arranged on the outer side of the end surface of the liquid-injection balancing disk, the phase sensor is arranged parallel to the rotation axis of the rotating shaft, and the phase sensor is used to detect the phase information of the shaft imbalance.

5. The micro piezoelectric pump liquid jet controlled dynamic balancing device according to claim 4, characterized in that: It comprises three piezoelectric pumps, and the three piezoelectric pumps are evenly distributed in the liquid-jet balancing disk at an angle of 120°; The piezoelectric pump comprises, from top to bottom, a pump cover, a first sealing ring, a piezoelectric vibrator, a second sealing ring, a one-way stop valve and a lower pump body, which are sealed and connected by a connecting piece. The pump cavity of the piezoelectric pump contains fluid; an upper pump body is suspended in the lower pump body; The piezoelectric vibrator is used to drive the valve plate inside the one-way stop valve to open and close alternately through its own deformation, and to achieve the flow of fluid between the pump chamber and the balanced liquid storage chamber by changing the volume of the pump chamber.

6. The micro piezoelectric pump liquid jet controlled dynamic balancing device according to claim 5, characterized in that: The one-way stop valve comprises a cantilever beam valve and a U-shaped wheel valve, and the one-way stop valve is connected to the piezoelectric vibrator through the second sealing ring; A cylindrical cavity is provided inside the lower pump body for suspending the upper pump body, the inner wall of the cylindrical cavity is sealedly connected to the outer wall of the upper pump body, and a water inlet and a water outlet for connecting to the flow channel hole are provided at the bottom of the cylindrical cavity; The upper pump body is provided with a cantilever beam valve disc deformation cavity and a U-shaped wheel valve hole, the cantilever beam valve disc deformation cavity has the same shape as the cantilever beam valve, the cantilever beam valve disc deformation cavity is communicated with the water outlet, and the U-shaped wheel valve hole is communicated with the water inlet; After assembly, the water outlet, the cantilever beam valve plate deformation cavity, and the cantilever beam valve are in communication; the water inlet, the U-shaped wheel valve hole, and the U-shaped wheel valve are in communication; The second sealing ring is respectively provided with a downward pressure vent hole and a contoured through cavity that matches the shape of the U-shaped wheel valve hole.

7. A method for controlling dynamic balance by liquid jetting with a micro piezoelectric pump, comprising the steps of: S1: Provide a micro piezoelectric pump liquid jet controlled dynamic balancing device as claimed in claim 6, wherein an unbalanced amount occurs when the rotating shaft runs at a working speed; transmit the detected vibration signal and key phase signal to the control unit through a vibration sensor and a phase sensor; S2: The control unit processes and calculates the collected vibration signals and key phase signals, and determines the balance liquid storage chambers that need to be filled and the mass of the trace liquid in each balance liquid storage chamber according to the relationship between the fluid mass and the centrifugal force in the balance liquid storage chamber and the imbalance angle information; S3: The fuzzy PID controller in the control unit controls the piezoelectric pump to inject and discharge liquid into the corresponding balance liquid storage cavity; S4: When liquid is injected, the piezoelectric vibrator receives the control command and bends and deforms downward, the cantilever beam valve plate bends and deforms downward, approaches and partially passes through the cantilever beam valve plate deformation cavity, and the cantilever beam valve plate deformation cavity is opened. At this time, the U-shaped wheel valve is close to the U-shaped wheel valve hole, and the fluid in the pump cavity is discharged from the water outlet to the balanced liquid storage cavity through the cantilever beam valve plate deformation cavity. When the piezoelectric vibrator moves downward to the limit, the water inlet and outlet are closed; S5: When discharging liquid, the piezoelectric vibrator receives the control command and bends and deforms upward, the air pressure in the pump chamber decreases, the U-shaped wheel valve bends upward and passes through the hollow part of the second sealing ring, so that the U-shaped wheel valve is away from the U-shaped wheel valve hole, and the U-shaped wheel valve hole is opened. At this time, due to the blocking effect of the second sealing ring, the cantilever beam valve plate is close to the cantilever beam valve plate deformation cavity, and the fluid in the balanced liquid storage cavity is sucked into the pump chamber from the water inlet through the U-shaped wheel valve hole. When the piezoelectric vibrator moves upward to the limit, the water inlet and the water outlet are closed; S6: The vibration sensor and phase sensor retransmit the detected balanced data to the control unit again. The control unit processes and calculates the data. The fuzzy PID controller determines the imbalance direction based on the transmitted data again and sends the control command to the piezoelectric pump. Steps S4 to S5 are repeated until the combined force of the centrifugal force generated by the liquid in the balanced liquid storage chamber balances the unbalanced force on the rotating shaft.

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