CN102801358B - Bi-directionally magnetically coupled and axially excited and limited rotating-shaft piezoelectric generator - Google Patents

Abstract

The invention relates to a two-way magnetic force coupling axially excited and limited rotating shaft piezoelectric generator, which belongs to the field of piezoelectric power generation. A cylinder is fixed between the two bearing seats with screws, and multiple sets of fixed magnets 1 and 2 are alternately inlaid on different cross-sections of the inner wall of the cylinder; bearings and magnetic rings are inlaid on both bearing seats, and the main shaft passes through the bearings. Installed on the bearing seat, the spline of the main shaft is covered with multiple sets of piezoelectric transducers; a pair of moving magnets with opposite magnetic poles are installed on the free ends of the piezoelectric transducers through screws. The advantage is that there is no contact impact and noise, high reliability, and it is convenient to provide electric energy to the monitoring system that rotates with the rotating shaft, and it can generate electricity at a constant speed and at a high speed.

Description

Two-way Magnetic Coupling Axially Excited and Position-limited Rotating Shaft Piezoelectric Generator

technical field

The invention belongs to the field of piezoelectric power generation, and in particular relates to a shaft-type piezoelectric generator with two-way magnetic coupling axial excitation and position limitation, which is used for power supply of a rotating machinery health monitoring system.

Background technique

The research on constructing micro-scale piezoelectric generators by using sheet-type piezoelectric vibrators has become a hot spot both at home and abroad for many years. According to the different sources of motive power and application purposes of generators, cantilever beam piezoelectric generators with various structural forms have been proposed at home and abroad, mainly including vibration type and rotary type. Among them, the rotary piezoelectric generator was originally proposed to solve the self-powered sensor monitoring of rotating machinery such as helicopter propellers, automobile tire pressure, aeroengines/high-speed trains/oil and gas drill spindles. In terms of power generation/power supply capacity, the rotary electromagnetic generator is very mature and has been widely used, but because it requires relative movement between the mover and the stator, and the size of the mover/stator is equal, the structure is complex and the volume is large, and it cannot Or it is inconvenient to be used in some tiny and remote control systems that need to integrate the generator with the rotating body. In contrast, the sheet-type piezoelectric vibrator is considered to be an effective method for constructing a micro-rotating generator because of its simple structure, small size, and integration with the rotating body.

According to the different excitation methods, the existing rotary shaft piezoelectric generators that rotate with the rotating body can be divided into three categories: ① Inertial excitation type, which uses the change of the force direction of the piezoelectric vibrator during the rotation of the shaft to make it rotate along the direction of rotation. Bending deformation, this method is simple in structure, but it is only suitable for low speed, high speed, especially when rotating at a uniform high speed, it is impossible to produce alternating bidirectional deformation due to excessive centrifugal force, and the sudden change of rotation state will cause the piezoelectric vibrator to be deformed due to excessive force/deformation. Large and damaged; ② Toggle type, using fixed teeth to toggle the rotating piezoelectric vibrator to make it bend and deform in the direction of rotation. The vibrator is damaged due to excessive denaturation; ③ impact type, using a rotating and falling steel ball to hit the piezoelectric vibrator. The vibrator is damaged by contact shock.

The common feature of the above three types of rotating shaft piezoelectric generators that rotate with the rotating body is that the piezoelectric vibrator deforms along the rotating direction of the rotating body, and the amount of deformation and power generation depends entirely on the rotating speed and rotation state of the rotating body. The disadvantages are: ①The deformation of the piezoelectric vibrator is uncontrollable, and excessive deformation will cause the piezoelectric vibrator to break, so the reliability is low; ②At high speed, uniform speed, especially uniform-high speed, the piezoelectric vibrator will not be damaged. Effective excitation, limited environmental adaptability and bandwidth. It can be seen that the existing rotary piezoelectric generators are not suitable for high-speed, uniform-speed or restricted space/structure applications such as helicopter propellers, aeroengines/high-speed trains/oil and gas drill spindles. Therefore, a new rotary shaft piezoelectric generator with simple structure, high reliability, wide frequency band, no impact/noise, and suitable for constant speed/high speed, especially uniform-high speed rotation is still urgently needed in many fields.

Contents of the invention

The present invention provides a two-way magnetic coupling axially excited and position-limited rotating shaft piezoelectric generator. In order to meet the real-time and sufficient power demand required by the rotating machinery health monitoring system, the generator must have the following characteristics: ① With the rotation body rotation, ② has sufficient power generation capacity, ③ can generate electricity at both constant speed and high speed, and has high reliability.

The technical solution adopted by the present invention is: the two bearing seats 1 and 2 are connected to the cylinder with screws, and multiple groups of fixed magnets 1 and 2 are alternately embedded on different cross-sections of the inner wall of the cylinder. The magnetic poles of the fixed magnet 1 and the fixed magnet 2 are installed along the radial direction of the cylinder, and the directions of the magnetic poles are opposite; the bearing housing 1 and the bearing housing 2 are respectively inlaid with bearings and magnetic rings, and the The magnetic pole polarity of the magnetic ring on the bearing housing 1 and the bearing housing 2 pointing to the cylinder is the same as the magnetic pole polarity of the adjacent moving magnet 1 or moving magnet 2 pointing to the cylinder; the main shaft is installed through the two bearings On the two bearing seats and above, piezoelectric transducers are sleeved on the splines of the main shaft, and each set of piezoelectric transducers consists of a pair of stepped retaining rings, a pair of short retaining rings and each The long retaining ring is crimped between the two bearings; each group of piezoelectric transducers is bonded by a cantilever beam on a metal substrate and a piezoelectric chip, and the piezoelectric transducers The center of the metal substrate is provided with a spline hole; a pair of moving magnet one and moving magnet two opposite magnetic poles are installed on the free end of the piezoelectric transducer through screws, and the same group of piezoelectric transducers The axial arrangement directions of the first moving magnet and the second moving magnet poles are the same, and the axial arrangement directions of the first moving magnet and the second moving magnet poles on the two adjacent piezoelectric transducers are opposite; the first moving magnet adjacent to the magnetic ring Or the polarity of the magnetic poles of the second moving magnet is the same as that of the magnetic poles on the magnetic ring pointing to the inside of the cylinder.

The rotary shaft type piezoelectric generator with two-way magnetic force coupling, axial excitation and position limitation of the present invention can be used for a moving rotating main shaft or a fixedly installed rotating main shaft. For example, the main shaft of the propeller of the aircraft and ship rotates around its center of rotation and also moves with the aircraft or ship. When the aircraft or ship accelerates or decelerates, the piezoelectric transducer acts on itself and the inertial force of the moving magnet. There will also be bending deformation along the axis of the spindle; for the spindle of a fixed machine tool, etc., there is also the possibility of large deformation of the piezoelectric transducer during transportation and assembly. Therefore, the present invention inlays the magnetic ring on the bearing seat, and at the same time makes the same-sex magnetic poles between the moving magnets on two groups of adjacent piezoelectric transducers relatively installed, so that the magnetic ring and the adjacent moving magnets , and the repulsive force is generated between the moving magnets on two groups of adjacent piezoelectric transducers, so as to prevent the piezoelectric transducers from being damaged due to excessive deformation.

In the present invention, the magnetic ring on the bearing seat and the fixed magnet one and the second fixed magnet on the cylinder are fixed relative to the rotation center of the main shaft, and the piezoelectric transducer and the moving magnet placed at the free end of the piezoelectric transducer Rotate with the spindle. The function of the magnetic ring located on the bearing seat is to apply a repulsive force to the piezoelectric transducer close to it, and this repulsive force moves along the axial direction through the repulsive effect of the same-sex magnetic poles of the moving magnets on two adjacent piezoelectric transducers. transmission, so as to avoid excessive axial deformation of the piezoelectric transducer; the function of the moving magnet 1 and the moving magnet 2 located on the cylinder is to apply alternate thrusts to the rotating moving magnet, so that the piezoelectric transducer moves along the main axis The axial bending vibration of the piezoelectric transducer converts mechanical energy into electrical energy; because the piezoelectric transducer is fixed on the main shaft and rotates with it, it is convenient to directly supply the generated electrical energy to the sensor monitoring system that rotates with the main shaft.

The feature of the present invention is that: the axial excitation and deformation control of the piezoelectric transducer are simultaneously completed by using two-way magnetic coupling, and the reliability is high; the bending deformation and power generation of the piezoelectric vibrator are mainly determined by the magnetic field strength between the magnetic poles, The state changes such as speed up, deceleration, and speed of the rotating shaft have no direct impact on it, so it has a strong adaptability to the speed and has a strong power generation capacity in various rotating states.

The advantages of the present invention are: ①The piezoelectric transducer rotates with the main shaft, and realizes non-contact axial excitation and deformation protection through bidirectional magnetic coupling, no contact impact and noise, high reliability, and it is convenient to provide electric energy to the rotating shaft Rotational monitoring system; ② The piezoelectric transducer bends and deforms along the axis of the main shaft, and the deformation and power generation are not affected by the rotation state of the rotating shaft, and can generate electricity at a constant speed or at a high speed.

Description of drawings

Fig. 1 is a schematic diagram of the structural principle of the generator in a preferred embodiment of the present invention;

Fig. 2 is the A-A view of Fig. 1;

Fig. 3 is a schematic structural view of a piezoelectric transducer in a preferred embodiment of the present invention;

Fig. 4 is the B-B sectional view of Fig. 3;

Fig. 5 is an enlarged view of part I of Fig. 1;

Fig. 6 is an enlarged view of part II of Fig. 1;

Detailed ways

The two-way magnetic coupling axial excitation and position-limiting rotating shaft piezoelectric generator proposed by the present invention can be used in various types of rotating components, such as helicopter propellers, aircraft engines, high-speed trains, oil and gas drilling spindles, and the like. For different application occasions, there may be some differences in the specific structure of the rotating components, but this does not affect the novelty and creativity of the present invention. Taking the application of the propeller main shaft as an example, the embodiment of the present invention is described in detail:

The cylinder 2 is fixedly connected by screws between the two bearing seats 1 and 2 1', and multiple sets of fixed magnets 4 and 2 4' are alternately inlaid on different cross-sections of the inner wall of the cylinder 2. The magnetic poles of the first fixed magnet 4 and the second fixed magnet 4' are installed along the radial direction of the cylinder 2, and the directions of the magnetic poles are opposite; 5 and magnetic ring 12, and the magnetic ring 12 on the bearing seat 1 and bearing seat 2 1' points to the magnetic pole polarity in the cylinder 2 and the adjacent moving magnet 4 or moving magnet 2 4' points to the circle The magnetic poles in the cylinder 2 have the same polarity; the main shaft 6 is installed on the two bearing seats 1 and 1' through the two bearings 5, and the spline 601 of the main shaft 6 is covered with a piezoelectric transducer device 7, each group of piezoelectric transducers 7 is crimped between the two bearings 5 by a pair of stepped retaining rings 8, a pair of short retaining rings 9 and each long retaining ring 10; A group of piezoelectric transducers 7 is formed by bonding a cantilever beam 7011 and a piezoelectric wafer 702 on a metal substrate 701, and a spline hole 703 is provided at the center of the metal substrate of the piezoelectric transducer 7; The first moving magnet 11 and the second moving magnet 11' opposite magnetic poles are installed on the free end of the piezoelectric transducer 7 by screws, and the first moving magnet 11 and the second moving magnet on the same group of piezoelectric transducers 7 11' The axial configuration directions of the magnetic poles are the same, and the axial configuration directions of the moving magnet one 11 and the moving magnet two 11' magnetic poles on the adjacent two groups of piezoelectric transducers 7 are opposite; the moving magnet one adjacent to the magnetic ring 12 11 or the magnetic poles of the second moving magnet 11 ′ have the same polarity as the magnetic poles on the magnetic ring 12 pointing to the inside of the cylinder 2 .

The rotary shaft type piezoelectric generator with two-way magnetic force coupling, axial excitation and position limitation of the present invention can be used for a moving rotating main shaft or a fixedly installed rotating main shaft. For example, the main shaft 6 of an airplane and a ship's propeller etc. rotates around its center of rotation and also moves with the airplane or ship. Under the action of the inertial force of the moving magnet 2 11', the bending deformation along the axis direction of the main shaft 6 will also occur; for the main shaft 6 of a fixed machine tool, etc., there will also be a relatively large piezoelectric transducer 7 in the process of transportation and assembly. Potential for large deformations. Therefore, the present invention inlays the magnetic ring 12 on the bearing seat 1 and the bearing seat 2 1 ', and also makes the moving magnet 11 on the two groups of adjacent piezoelectric transducers 7 and the moving magnet 2 11 ' between The magnetic poles of the same sex are relatively installed, so that between the magnetic ring 12 and its adjacent moving magnet one 11 or moving magnet two 11 ', and between the two groups of adjacent piezoelectric transducers 7, the moving magnet one 11 and the moving magnet two 11' generates a repulsive force to prevent the piezoelectric transducer 7 from being damaged due to excessive deformation.

In the present invention, the magnetic ring 12 located on the first bearing seat 1 and the second bearing seat 1' and the fixed magnet one 4 and the second fixed magnet 4' located on the cylinder 2 are fixed relative to the rotation center of the main shaft 6, and the piezoelectric transducer The transducer 7 and the moving magnet one 11 and the moving magnet two 11' placed at the free end of the piezoelectric transducer 7 rotate with the main shaft 6. The function of the magnetic ring 12 located on the first bearing seat 1 and the second bearing seat 1' is to apply a repulsive force to the adjacent piezoelectric transducers 7, and this repulsive force passes through two groups of adjacent piezoelectric transducers 7. The repulsive effect of the same-sex magnetic poles of the moving magnet one 11 and the moving magnet two 11' is transmitted along the axial direction, thereby avoiding excessive axial deformation of the piezoelectric transducer 7; the moving magnet one 4 and the moving magnet on the cylinder 2 The function of 24' is to apply alternating thrust to the rotating moving magnet 11 or moving magnet 11', so that the piezoelectric transducer 7 bends and vibrates along the axial direction of the main shaft 6, and converts mechanical energy into electrical energy; The device 7 is fixed on the main shaft 6 and rotates with it, so that the generated electric energy can be directly supplied to the sensor monitoring system which rotates with the main shaft 6.

In the present invention, the magnetic field force excites the axial bending deformation of the piezoelectric transducer and limits its deformation as follows:

When the main shaft 6 rotates so that the first, third and fifth piezoelectric transducers 7 from left to right bend to the right, The second, fourth and sixth piezoelectric transducers 7 bend to the left, so the moving magnets on the adjacent first and second, third and fourth, fifth and sixth piezoelectric transducers 7 11 and the N poles of the moving magnet 11' are close to each other to generate a gradually increasing repulsive force, thereby suppressing the deformation of the piezoelectric transducer 7 due to the action of the fixed magnet 4; when the main shaft 6 rotates, the moving magnet 11 When the moving magnet 2 11' turns upward and approaches the moving magnet 2 4', the first, third, and fifth piezoelectric rings from left to right can be bent to the left, and the second, fourth, and sixth piezoelectric rings can be bent to the left. The electric ring energy 7 bends to the right, and the S poles of the moving magnet one 11 and the moving magnet two 11' on the adjacent second and third, fourth and fifth piezoelectric transducers 7 are close to each other, and the first and third poles are close to each other. The S pole of the moving magnet 11 or the moving magnet 2 11' on the sixth piezoelectric vibrator is close to the S pole of the adjacent magnetic ring 12, which generates a gradually increasing repulsive force, thereby inhibiting the piezoelectric transducer 7 from being fixed. The amount of deformation produced by the action of magnet 2 4'.

In the working process of the piezoelectric generator of the present invention, the repulsive force produced when the same-sex magnetic poles are close between the first moving magnet 11 and the second moving magnet 11' and the first fixed magnet 4 or the second moving magnet 4' is used to excite the axial direction of the piezoelectric vibrator. deformation; at the same time, also utilize the repulsive force between the moving magnet one 11 and the moving magnet two 11' on the adjacent two piezoelectric transducers 7, and the dynamic force on the piezoelectric transducer 7 adjacent to the magnetic ring 12 The repulsive force between the first magnet 11 or the second moving magnet 11 ′ and the magnetic poles of the same sex of the magnetic ring 12 limits the deformation of the piezoelectric transducer, thereby avoiding damage due to excessive deformation.

Claims (1)

1. bidirectional magnetic force coupling axial excitation spacing rotary shaft piezoelectric generator, it is characterized in that: between two bearing pedestals one and bearing pedestal two, be screwed connection cylinder, the varying cross-section of described cylinder inner wall is alternately inlayed many group fixed magnets one and fixed magnet two, and the magnetic pole of described fixed magnet one and fixed magnet two to be installed and pole orientation is contrary along the radial direction of described cylinder; Described bearing pedestal one and bearing pedestal two are inlaid with bearing and magnet ring respectively, and the pole polarity that described bearing pedestal one and the magnet ring on bearing pedestal two point in cylinder is identical with the pole polarity that the moving magnet one be adjacent or moving magnet two point in cylinder; Main shaft is arranged on two described bearing pedestals by described two bearings, has PZT (piezoelectric transducer) at the spline upper sleeve of described main shaft, and described PZT (piezoelectric transducer) is crimped between two described bearings by a pair ladder back-up ring, short a pair back-up ring and each long back-up ring; Described PZT (piezoelectric transducer) is by the cantilever beam on metal substrate and piezoelectric chip is bonding forms, and is provided with splined hole in the center of the metal substrate of described PZT (piezoelectric transducer); A pair moving magnet one and moving magnet two opposite pole are relatively arranged on the free end of described PZT (piezoelectric transducer) by screw, the moving magnet one on described PZT (piezoelectric transducer) is identical with the axial arrangement direction of moving magnet two magnetic pole, the axial arrangement direction of moving magnet one on two adjacent groups PZT (piezoelectric transducer) and moving magnet two magnetic pole is contrary; The polarity of the moving magnet one adjacent with magnet ring or the magnetic pole of moving magnet two is identical with the pole polarity that described magnet ring points to inside cylinder.