CN103982543B - Self-sensing tapered roller bearings for wind turbines - Google Patents

Abstract

The invention relates to a self-sensing tapered roller bearing for a wind power generator, and belongs to the technical field of bearings and monitoring thereof. The left end of the inner ring and the right end of the outer ring are inlaid with exciting magnets; the stepped shaft of the inner ring and the stepped hole of the outer ring are respectively equipped with a right disk and a left disk, and the right disk and the left disk are provided with stepped ring grooves and guide holes, and the right disk and the The left plate is respectively equipped with a right pressure plate and a left pressure plate, and the pressure plate is provided with a limit surface, and a piezoelectric vibrator is crimped between the left and right plates and the pressure plate, and the metal substrate on the piezoelectric vibrator is in contact with the arc limit surface ; The free end of the piezoelectric vibrator is equipped with an excited magnet, and the excited magnet is placed in the guide hole, and a circuit board and a sensor are installed in the ladder ring groove. The advantage is that it has the function of self-powered sensing and monitoring, without changing the structure of the installed equipment, and can realize real-time online monitoring in a true sense; the structure of the piezoelectric vibrator and the configuration parameters of the excitation magnet are determined reasonably, and the power generation capacity is strong; it has guide holes and limit positions measures, high reliability.

Description

Self-sensing tapered roller bearings for wind turbines

technical field

The invention belongs to the technical field of bearings and monitoring thereof, and in particular relates to a self-sensing tapered roller bearing for wind power generators.

Background technique

Bearing is a typical mechanical basic part, which is widely used in the fields of machinery, vehicles, aerospace, ships and energy; however, bearing is also one of the most vulnerable parts in rotating machines, and 30% of rotating machinery failures % is caused by bearing failure. Therefore, the state monitoring and early fault diagnosis of bearings have attracted people's attention. On-line monitoring of bearing status has gradually become an indispensable technology in the fields of large generators, ships, high-speed rail, and aircraft. The indicators to be monitored include temperature, vibration, speed, and noise. Early bearing monitoring systems were mainly plug-in. One of the disadvantages was that the distance between the sensor and the signal source was relatively long, and it was a non-contact indirect measurement, so the error was relatively large. In recent years, different forms of embedded monitoring systems have been proposed one after another. This method can solve the problem of measurement accuracy and accuracy, but it needs to change the structure or integrity of related equipment in order to install the sensor monitoring system, which is not only easy Problems such as stress concentration of equipment parts can not be realized on some equipment with complex structure or limited space; the most critical thing is that when the monitoring system needs to rotate with the inner or outer ring of the bearing, it is inconvenient to supply power through wires. And adopt battery power supply time is very short. Therefore, the current bearing monitoring systems are basically non-real-time and indirect non-contact measurements, and it is difficult to obtain the running status of the bearings in a timely and accurate manner.

Contents of the invention

The present invention provides a self-sensing tapered roller bearing for wind power generators to solve the problem that the existing bearing monitoring system is still non-real-time and indirect non-contact measurement in practical applications, and it is difficult to obtain the operation of the bearing in a timely and accurate manner. status issue.

The technical solution adopted by the present invention is: including an inner ring, a cone, a cage, and an outer ring, the right end of the inner ring is provided with a stepped shaft, the left end of the outer ring is provided with a stepped hole, the left end of the inner ring and the outer ring A group of excitation magnets are respectively inlaid on the right ends of the inner ring, and a right disk and a left disk are installed on the stepped shaft of the inner ring and the stepped hole of the outer ring respectively through interference fit, and the right disk is provided with a right stepped ring groove and a right Guide holes, the left disc is provided with a left stepped ring groove and a left guide hole, the right disc and the left disc are respectively equipped with a right pressing plate and a left pressing plate through screws, and the right pressing plate and the left pressing plate are respectively provided with equal curvature The right circular arc limit surface and the left circular arc limit surface of the radius, between the right disk and the right pressure plate, and between the left disk and the left pressure plate are respectively crimped with a group of substrates and piezoelectric sheets. The cantilever beam type piezoelectric vibrator 1 and the cantilever beam type piezoelectric vibrator 2 formed by bonding the substrate 2 and the piezoelectric sheet 2, the metal substrate on the piezoelectric vibrator 1 and the right circular arc limit of the right pressure plate Surface-to-surface contact, the upper metal substrate 2 of the piezoelectric vibrator 2 is in contact with the left circular arc limit surface of the left pressure plate, the free ends of the piezoelectric vibrator 1 and the piezoelectric vibrator 2 are respectively fixed with excited magnets by screws, and the excited magnets are respectively fixed by screws. The exciter is placed in the right guide hole or the left guide hole, the radii of the excited magnet and the exciter magnet are equal, and the circuit board 1 and circuit board 2 are respectively installed in the right step ring groove and the left step ring groove through screws, and the right step ring groove The ring groove and the left stepped ring groove are respectively provided with a sensor one and a sensor two. The sensor one and the piezoelectric vibrator are respectively connected to the circuit board one through different wire groups, and the sensor two and the piezoelectric vibrator are respectively connected through different wire groups. The lead group is connected to the circuit board two.

An embodiment of the present invention is: the axial arrangement directions of the two adjacent excitation magnet poles on the circumference of the inner ring and the outer ring are opposite, and the axial arrangement directions of the excited magnet poles on each group of piezoelectric vibrators are respectively the same, The axial configuration directions of the excited magnet poles on the two sets of piezoelectric vibrators are opposite; the number n of the excitation magnets on the inner ring and the outer ring should satisfy the following formula, namely Among them, r and R are respectively the radius of the excitation magnet and the distance from its center to the center of rotation of the inner ring; or the fixed angle ratio satisfies Wherein Q1 is the angle between two tangent lines intersecting at the center of rotation of the bearing of the excitation magnet, and Q2 is the angle between the center of two adjacent excitation magnets and the line connecting the center of rotation of the bearing.

An embodiment of the present invention is: the ratio of the thickness of the metal substrate to the total thickness of the piezoelectric vibrator is 0.7, and the minimum bending radius of the arc limit is Where: b=E _m /E _p , E _p and E _m are the Young's modulus of the piezoelectric material and the brass substrate respectively, is the electromechanical coupling coefficient of the piezoelectric material, is the allowable tensile stress of the piezoelectric material.

The advantage of the present invention is that the structure is novel, the bearing itself has the function of self-powered sensing and monitoring, and is used as an independent standard component without changing the structure of its installation equipment, which can realize real-time on-line monitoring; the structure of the piezoelectric vibrator and the excitation magnet The configuration parameters are determined reasonably, and the power generation capacity is strong; the guide hole is used to prevent the torsion of the excited magnet, and the tensile stress of the piezoelectric sheet is limited through the limiting surface, so as to improve the reliability and power generation of the piezoelectric vibrator.

Description of drawings

Fig. 1 is a structural sectional view of a preferred embodiment of the present invention;

Fig. 2 is the assembled structure of inner and outer rings and tapered rollers of the present invention;

Fig. 3 is the structural representation of right platen of the present invention;

Fig. 4 is the configuration diagram of excitation magnet of the present invention;

Fig. 5 is a structural schematic diagram of the left disc of the present invention;

Fig. 6 is the right view of Fig. 5;

Fig. 7 is the graph of the relationship between the applied force and the angle ratio of the magnet on the beam when different angle ratios are fixed in the present invention;

Fig. 8 is a graph showing the relationship between the excitation coefficient, the maximum active force and the fixed angle ratio of the present invention;

Fig. 9 is a graph showing the relationship between the power generation and the thickness ratio of the piezoelectric vibrator of the present invention.

detailed description

As shown in Figures 1 to 6, it includes an inner ring 1, a cone 2, a cage 3, and an outer ring 4. The right end of the inner ring 1 is provided with a stepped shaft 11, and the left end of the outer ring 4 is provided with a stepped hole 41. The left end of the inner ring 1 and the right end of the outer ring 4 are respectively inlaid with a group of exciting magnets C2, and the stepped shaft 11 of the inner ring 1 and the stepped hole 41 of the outer ring 4 are respectively installed with a right disk 5 through interference fit. and the left disk 5', the right disk 5 is provided with a right stepped ring groove 51 and a right guide hole 52, and the left disk 5' is provided with a left stepped ring groove 51' and a left guide hole 52', and the right The disc 5 and the left disc 5' are respectively equipped with a right pressing plate 6 and a left pressing plate 6' by screws, and the right pressing plate 6 and the left pressing plate 6' are respectively provided with a right circular arc limit surface 61 and a left circular arc with equal curvature radius. Limiting surface 61', between the right disk 5 and the right pressure plate 6, and between the left disk 5' and the left pressure plate 6', there are respectively a group of substrate-7 and piezoelectric sheet-8 bonded. Cantilever beam type piezoelectric vibrator A1 and cantilever beam type piezoelectric vibrator II A2 bonded by substrate two 7' and piezoelectric sheet two 8', the metal substrate 7 on the piezoelectric vibrator A1 and the right pressure plate The right circular arc limit surface 61 of 6 is in contact, the upper metal substrate 2 7' of the piezoelectric vibrator A2 is in contact with the left circular arc limit surface 61' of the left pressure plate 6', the piezoelectric vibrator A1 and the piezoelectric vibrator The free ends of the two electric vibrators A2 are respectively fixed with excited magnets C1 by screws, and the excited magnets C1 are placed in the right guide hole 52 or the left guide hole 52', and the radii of the excited magnets C1 and the excitation magnets C2 are equal , the right step ring groove 51 and the left step ring groove 51' are respectively equipped with a circuit board B1 and a circuit board B2 through screws, and the right step ring groove 51 and the left step ring groove 51' are respectively equipped with a sensor one S1 and The sensor 2 S2, the sensor 1 S1 and the piezoelectric vibrator 1 A1 are connected to the circuit board 1 B1 through different wire groups respectively, and the sensor 2 S2 and the piezoelectric vibrator 2 A2 are respectively connected to the circuit board 2 B2 through different wire groups.

During the working process, when the inner ring 1 and the outer ring 4 make relative rotation, the relative rotation between the excited magnet C1 and the exciting magnet C2 occurs, and the axial force between the excited magnet C1 and the exciting magnet C2 is changed, thereby The force on the first piezoelectric vibrator A1 and the second piezoelectric vibrator A2 is alternately increased and decreased, thereby converting mechanical energy into electrical energy, and the generated electrical energy is converted and processed to provide power for the sensor monitoring system. In the present invention, the maximum tensile stress on the first piezoelectric sheet 8 and the second piezoelectric sheet 8' in the piezoelectric vibrator is limited by the right circular arc limiting surface 61 and the left circular arc limiting surface 61', and the left and right guiding The holes 52' and 52 prevent the piezoelectric vibrator from torsion, so a large power generation capacity and high reliability can be obtained at the same time.

In the present invention, in order to improve the power generation capability of piezoelectric vibrator 1 and piezoelectric vibrator 2 A2, the axial arrangement directions of the magnetic poles of two adjacent excitation magnets C2 on the circumference of inner ring 1 and outer ring 4 are opposite, and each group of piezoelectric vibrator The axial arrangement directions of the magnetic poles of the excited magnet C1 on the first A1 or the piezoelectric vibrator two A2 are respectively the same, and the axial arrangement of the magnetic poles of the excited magnet C1 on the piezoelectric vibrator A1 and the piezoelectric vibrator two A2 The direction is opposite; the number n of excitation magnets C2 on the inner ring 1 and outer ring 4 should satisfy the following formula, that is Among them, r and R are respectively the radius of the excitation magnet C2 and the distance from its center to the center of rotation of the inner ring 1; or the fixed angle ratio satisfies Wherein Q1 is the angle between two tangent lines intersecting at the center of rotation of the bearing of the excitation magnet C2, and Q2 is the angle between the center of two adjacent excitation magnets C2 and the line connecting the center of rotation of the bearing.

In order to improve the power generation capacity of the first piezoelectric vibrator A1 and the second piezoelectric vibrator A2, when other conditions are determined, the deformation and the number of excitations of the first piezoelectric vibrator A1 and the second piezoelectric vibrator A2 should be increased as much as possible, that is, the excited vibration The magnitude of the force and the number of excitations make the piezoelectric vibrator A1 and the piezoelectric vibrator A2 bear the alternating excitation force of attraction and repulsion, so the configuration of the magnetic poles is: two adjacent excitations on the circumference of the inner ring 1 and the outer ring 4 The axial arrangement directions of the magnetic poles of the magnet C2 are opposite, and the axial arrangement directions of the magnetic poles of the excited magnet C1 on the first piezoelectric vibrator A1 or the second piezoelectric vibrator A2 are respectively the same, and the two sets of piezoelectric vibrator A1 and the piezoelectric vibrator The axial arrangement direction of the magnetic poles of the excited magnet C1 on the electric vibrator 2 A2 is opposite; in addition, when the inner ring 1 and the outer ring 4 of the bearing rotate one circle, the electric energy generated by a single piezoelectric vibrator A1 or piezoelectric vibrator 2 A2 Can be expressed as: Where C _f is the free capacitance of the piezoelectric vibrator A1 or A2, V _g = ηF is the open circuit voltage generated by the piezoelectric vibrator A1 or A2, η is the voltage coefficient related to the scale and material of the piezoelectric vibrator A1 or A2, h = nF ² is called the excitation coefficient, λ=C _f η ² /2 is called the structure coefficient, and n is the number of excitation magnets C2. Obviously, when other conditions are determined, the voltage and electric energy can be increased by increasing the force F, the number n of the excitation magnet C2, and the structure coefficient λ; among them, the number n of the excitation magnet C2 affects the voltage by changing the number of excitations and the magnitude of the force. Power generation characteristics of electric vibrators A1 and A2. According to the working principle of the tapered roller bearing of the present invention and the fact that the magnetic field is spatially distributed, any excited magnet C1 is simultaneously affected by a plurality of excited magnets C2, and the total force F depends on the fixed angle ratio in is the angle between the two tangent lines intersecting at the center of rotation of the bearing of the excitation magnet C2, Q2=2π/n is the angle between the center of the two adjacent excitation magnets C2 and the line connecting the center of rotation of the bearing, r and R are respectively is the radius of the excitation magnet C2 and the distance from its center to the center of rotation of the inner ring 1, thus the fixed angle ratio can be converted into a function of the number n of the excitation magnet C2, namely Further studies have shown that there are different optimal fixed angle ratios k to maximize the force, voltage and electric energy on piezoelectric vibrators A1 and A2; when k=1 to 1.5, the number of exciting magnets C2 ranges from When , the obtained electric energy and voltage are large, and the excitation coefficient is not lower than 1/2 of its maximum value.

Figure 7 shows the experimental curves of the force F on the excited magnet C1 and the angle ratio j=Q3/Q1 at different fixed angle ratios, where Q3 is the rotation of the excited magnet C1 after it completely overlaps with a certain exciting magnet C2 Therefore, the rotation angle ratio j represents the positional relationship between the excited magnet C1 and each excitation magnet C2. Figure 7 shows that when the fixed angle ratio is different, the magnitude of the force of the excited magnet C2 and the number of times of excitation on the excited magnet C1 are different. The relationship curve between the force amplitude and the excitation coefficient and the fixed angle ratio k is shown in Figure 8. Obviously, when k=1.0~1.5, the obtained voltage and electric energy are both large, and the excitation coefficient is greater than 1/2 of its maximum value .

In the present invention, in order to improve the reliability and power generation capacity of the first piezoelectric vibrator A1 and the second piezoelectric vibrator A2, the optimal ratio of the thickness of the metal substrate to the total thickness of the piezoelectric vibrator is 0.7. At this time, the minimum bending radius of the arc limit for:

Where: b=E _m /E _p , E _p and E _m are the Young's modulus of the piezoelectric material and the brass substrate respectively, is the electromechanical coupling coefficient of the piezoelectric material, is the allowable tensile stress of the piezoelectric material.

According to the working principle of the first piezoelectric vibrator A1 and the second piezoelectric vibrator A2 in the present invention, when the piezoelectric vibrator is attached to the right circular arc limit surface 61, the tensile stress and power generation of the piezoelectric sheet will be The radius of the arc limit surface decreases and increases. When the radius is too small, the piezoelectric vibrator will be damaged due to excessive tensile stress. Therefore, the actual limit radius should be smaller than its minimum value; in addition, when the total thickness of the piezoelectric vibrator When the metal substrate is too thick or too thin, the power generation will be reduced when other relevant conditions are determined. In practice, there is an optimal ratio of the substrate thickness to the total thickness to maximize the electric energy generated by the piezoelectric vibrator, and the influence of the thickness ratio on the power generation As shown in Figure 9; obviously, when the ratio of the metal substrate thickness hm to the total thickness h of the piezoelectric vibrator is th=0.7, the power generation is the largest; at this time, the minimum radius of the arc limit is: Where: b=E _m /E _p , E _p and E _m are the Young's modulus of the piezoelectric material and the brass substrate respectively, is the electromechanical coupling coefficient of the piezoelectric material, is the allowable tensile stress of the piezoelectric material.

Claims (2)

1. a kind of wind-driven generator is from taper roll bearing, including inner ring, cone, retainer, outer ring is perceived, its feature exists In：The right-hand member of the inner ring is provided with multi-diameter shaft, and the left end of outer ring is provided with shoulder hole, the left end of the inner ring and the right-hand member of outer ring point It is not inlaid with the shoulder hole of on one group of exciting magnet, the multi-diameter shaft of the inner ring and outer ring and is provided with respectively by interference fit Right disk and left disk, the right disk are provided with right ladder annular groove and right pilot hole, and the left disk is led provided with left ladder annular groove and a left side Right pressing plate and left pressing plate, the right pressing plate and left pressing plate difference are provided with by screw respectively on Xiang Kong, the right disk and left disk Right circular arc confined planes and left circular arc confined planes provided with iso-curvature radius, between the right disk and right pressing plate and left disk and a left side One group is crimped between pressing plate respectively by the cantilever beam type piezoelectric vibrator one be bonded with piezoelectric patches one of substrate one and by substrate Substrate one and the right side of right pressing plate on the two cantilever beam type piezoelectric vibrators two Nian Jie with piezoelectric patches two, the piezoelectric vibrator one Circular arc confined planes are in contact, the substrate two on piezoelectric vibrator two is in contact with the left circular arc confined planes of left pressing plate, and the piezoelectricity shakes The free end of son one and piezoelectric vibrator two is fixed with excited magnet by screw respectively, the excited magnet be placed in right pilot hole or In left pilot hole, the radius of the excited magnet and exciting magnet is equal, passes through respectively at right ladder annular groove and left ladder annular groove Screw, which is provided with circuit board one and circuit board two, right ladder annular groove and left ladder annular groove, further respectively has sensor one and sensing Device two, the sensor one and piezoelectric vibrator one are connected by different wire groups with circuit board one respectively, sensor two and pressure Electric tachometer indicator two is connected by different wire groups with circuit board two respectively, and wherein substrate one and substrate two is metal substrate；

The axial arrangement of two adjacent exciting magnet magnetic poles is in opposite direction on inner ring and outer ring circumference, being excited on every group of piezoelectric vibrator Distinguish identical, the axial arrangement direction phase of the excited magnet magnetic pole on two groups of piezoelectric vibrators in the axial arrangement direction of magnet poles Instead；The quantity n of exciting magnet on inner ring and outer ring should meet following formula, i.e.,Wherein, r And R be respectively exciting magnet radius and its center to the inner ring centre of gyration distance；Or angle is determined than satisfactionWherein Q1 is the angle between two intersecting tangent lines at the bearing centre of gyration of exciting magnet, Q2 Center for two adjacent exciting magnets and the angle between the line of the bearing centre of gyration.

2. wind-driven generator according to claim 1 perceives taper roll bearing certainly, it is characterised in that：The Metal Substrate The ratio between plate thickness and piezoelectric vibrator gross thickness h are 0.7, and now the spacing minimum bending radius of circular arc isWherein：B=E_m/E_p, E_p、E_mRespectively The Young's modulus of piezoelectric and metal substrate,For the electromechanical coupling factor of piezoelectric,For the drawing allowable of piezoelectric Stress.