CN117469365A - Wind turbine generator system main shaft bearing unloading system - Google Patents

Abstract

The invention relates to the technical improvement field of wind turbines, in particular to a wind turbine main shaft bearing unloading system which comprises a slewing bearing, a front bearing and a rear end cover, wherein the slewing bearing is arranged on a main shaft and is fixedly connected with the front bearing; the stepping motor is arranged on the front end cover of the rear bearing and comprises a motor shell, and a stator group is fixed in the motor shell; the rotor shaft is arranged in the stator group, bearings are arranged at the two axial ends of the rotor shaft, and an internal threaded hole which is axially communicated is formed in the rotor shaft; one end of the screw rod penetrates through the internal threaded hole, a screw rod nut matched with the internal threaded hole is arranged on the screw rod, and the end part of the screw rod, which is far away from the motor shell, is fixedly connected with the slewing bearing. The main shaft bearing unloading system can effectively share and reduce the axial force borne by the rear bearing, reduce the abrasion of the rear bearing, delay the service life of the bearing by 3-5 years, and replace a new screw after 3 years, so that the unloading system effectively works, the screw has low cost, and the replacement cost of the lower tower is avoided.

Description

Wind turbine generator system main shaft bearing unloading system

Technical Field

The invention relates to the technical field of wind turbine generator system transformation, in particular to a wind turbine generator system spindle bearing unloading system which is applied to the technical transformation of the wind turbine generator system spindle system backward movement.

Background

The wind energy resource is used as a clean renewable energy source, widely exists in the world, is rich in resources, is inexhaustible, and is environment-friendly. The wind power generation has the characteristics of safety and cleanness, and can provide long-term stable energy supply for human beings. The performance of a main shaft bearing in the wind turbine generator directly determines the running reliability of the wind turbine generator, and the design of the main shaft bearing is an important component of the design of a transmission chain. The self-aligning roller bearing has the characteristics of strong bearing capacity, simple manufacture and good assembly manufacturability, and currently, the commercial operation megawatt wind turbine generator mostly adopts a double-row spherical roller bearing mode, and the specifications of two rows of rollers are the same, however, as the wind turbine generator is a horizontal shaft unit, the thrust force born by a wind wheel is extremely large in the running process of the wind turbine generator, and the thrust load is borne by a main shaft bearing. Because the design characteristics of the double-row aligning roller bearing are that when thrust is received in the upwind direction, the roller load on the downwind side is far greater than that on the upwind side, the stress difference of the two rows of rollers is at least 3 times according to field test, the stress imbalance of the front row of rollers and the rear row of rollers and the abrasion of the roller path of the front row of rollers are serious, the problem can cause the main shaft to move backwards, and because the wind power main machine is arranged on a tower with the diameter of more than 70m, the lifting installation cost is up to more than 100 ten thousand yuan each time, the wind power generation capacity of a wind field is influenced, a large amount of manpower and material resources are consumed, the service life of a unit is seriously influenced, and the great development of the wind power industry is necessarily hindered.

The support bearing of the main transmission system of the wind driven generator is various in selection, wherein the doubly-fed wind turbine generator often uses two sets of double-row aligning roller bearings to jointly support the main shaft, and the aligning roller bearings are high in bearing capacity and can compensate coaxiality errors caused by machining, installation and deformation of a shaft or a seat, so that the doubly-fed wind turbine generator can be widely applied to a support structure of the main shaft of the wind driven generator. The bearing at one side of the gear box is a positioning end bearing, can perform axial positioning, can bear axial load and radial load at the same time, and is used for guaranteeing the stability of a transmission system. However, in the use process, the bearing of the positioning end at the side of the gear box is found to have serious unbalanced load, and single-row failure is easily caused by unbalanced load. However, under the action of certain wind load, the axial force born by the positioning end aligning roller bearing can be multiple times of the radial force, at the moment, only one row of rollers of the double-row aligning roller bearing are born, the other row of rollers are in no-load slipping, and the phenomena of uneven stress distribution, edge stress, large axial play, temperature rise, aggravation of abrasion, early fatigue peeling and the like of one row of bearing can occur, and finally, the main shaft can move backwards.

Disclosure of Invention

In order to solve the phenomenon of backward movement of a shaft system of a wind turbine generator, the application provides a wind turbine generator spindle bearing unloading system, displacement data of a spindle are monitored, and if backward movement occurs, a fixed shaft type screw rod stepping motor acts to apply force to the unloading system so as to solve the problem of reducing axial force applied to a rear bearing of the spindle system.

In order to achieve the above purpose, the invention adopts the following technical scheme: the wind turbine generator main shaft bearing unloading system comprises a slewing bearing, wherein the slewing bearing is arranged on a main shaft and is fixedly connected with a front bearing rear end cover;

a stepping motor which is arranged on the front end cover of the rear bearing,

the stepping motor comprises a motor shell, wherein a stator group is fixed in the motor shell;

the rotor shaft is arranged in the stator group, bearings are arranged at the two axial ends of the rotor shaft, and an internal threaded hole which is axially communicated is formed in the rotor shaft;

one end of the screw rod penetrates through the internal threaded hole, a screw rod nut matched with the internal threaded hole is arranged on the screw rod, and the end part of the screw rod, which is far away from the motor shell, is fixedly connected with the slewing bearing.

Further, the stepping motor is mounted on the front end cover of the rear bearing through a motor fixing bracket.

Further, a gasket and a clamp spring are arranged between the motor shell and the motor fixing support.

Further, the end of the lead screw, which is far away from the slewing bearing, is provided with a sliding bushing.

Further, one end of the screw rod, which is far away from the motor shell, penetrates through the slewing bearing and is locked with the slewing bearing through a locking nut.

Further, the motor fixing support is of a split structure.

Further, a sliding rail shell is arranged between the stator group and the rotor shaft, and one end, close to the slewing bearing, of the sliding rail shell is abutted with the bearing.

Further, the device also comprises a laser displacement sensor which is arranged on the main shaft and used for monitoring the axial displacement of the main shaft;

the signal receiver is arranged on the stepping motor;

the controller is in communication connection with the laser displacement sensor and is used for controlling the laser displacement sensor to work;

and the processor judges whether the main shaft returns to the original position or not through signals sent by the laser displacement sensor so as to determine whether to send signals for enabling the motor to continuously work and push the lead screw.

In another embodiment of the present application, the slewing bearing includes a split inner ring, a split outer ring, and rolling bodies mounted between the split inner ring and the split outer ring;

the split inner ring comprises two half inner rings which are fastened and connected through a first locking bolt;

the split outer ring comprises two half outer rings which are fastened and connected through a second locking bolt;

and an outer ring flange is arranged on the peripheral wall of the half outer ring.

Further, the half inner ring is provided with a mounting hole.

Further, one end of the screw rod is connected with the outer ring flange through a flat key.

The invention has the advantages that: the device can make corresponding adjustment in time according to the real-time backward movement amount of the main shaft. When the main shaft system of the wind turbine generator is found to have less movement (within 5 mm), the main shaft bearing unloading system is timely installed, the axial force borne by the rear bearing can be effectively shared and reduced, the abrasion of the rear bearing is reduced, the service life of the bearing is prolonged by 3-5 years, a new screw rod is replaced after 3 years, the unloading system effectively works, the screw rod is low in cost, the lower tower replacement caused by abrasion of the rear bearing of the main shaft system is avoided, and the production cost for lower tower replacement of the main shaft system is avoided.

Drawings

FIG. 1 is a schematic structural diagram of a wind turbine main shaft bearing unloading system provided by the application;

fig. 2 is a schematic structural diagram of a wind turbine main shaft bearing unloading system according to another embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a stepper motor provided in the present application;

wherein: spindle 1, front bearing rear end cap 2, stepper motor 3, rear bearing front end cap 4, motor housing 5, stator pack 6, rotor shaft 7, bearing 8, internally threaded hole 9, lead screw 10, motor fixing bracket 11, gasket 12, clamp spring 13, sliding bushing 14, lock nut 15, laser displacement sensor 16, signal receiver 17, controller 18, processor 19, half inner ring 20, half outer ring 21, first lock bolt 22, second lock bolt 23, outer ring flange 24, mounting hole 25, mounting bracket 26, lead screw nut 27, slide rail housing 28, ball roller 29, flat key 30.

Detailed Description

For the purposes, technical solutions and advantages of the present invention will become more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the present invention.

Referring to fig. 2 and 3, the present embodiment provides a wind turbine generator main shaft bearing unloading system, which includes a slewing bearing, mounted on a main shaft 1, and fixedly connected with a front bearing rear end cover 2;

three stepping motors 3 are arranged on the front end cover 4 of the rear bearing at intervals of 120 degrees,

the stepping motor 3 comprises a motor housing 5, a stator group 6 and a rotor group arranged in the stator group 6 are fixed in the motor housing 5, the stator group 6 adopts an integrally injection molding structure, a containing cavity for containing the rotor group is directly formed in the injection molding process, a pair of mounting brackets 26 are directly and integrally injection molded at two axial end parts of the stator group 8, and the containing cavity extends into the pair of mounting brackets 26;

the rotor set comprises a rotor shaft 7 suitable for rotary motion and a pair of bearings 8 respectively arranged on two shaft ends of the rotor shaft 7; in the process of assembling the rotor set and the accommodating cavity, the whole rotor set is integrally arranged in the accommodating cavity, and after the rotor set is arranged in the accommodating cavity, a pair of bearings 8 are respectively arranged in the mounting brackets 26;

the rotor shaft 7 is provided with an internal threaded hole 9 which is axially penetrated; the rotor shaft 7 in the rotor set is used to form an engagement with the threaded spindle 10 and is adapted to be converted into a linear movement of the threaded spindle 10 by a rotary movement of the rotor shaft 7. According to the use requirement of the change of the motion trail, a screw nut 27 is arranged in the internal threaded hole 9, and then the screw 10 can be fixed through the threaded fit of the screw 10 and the screw nut 27, the screw moves linearly under the rotation action of the rotor shaft 7, and the end part of the screw 10, which is far away from the motor housing 5, is fixedly connected with the slewing bearing.

The housing cavity is also provided with a sliding rail housing 28 for limiting the axial sliding of the rotor set, which comprises the sliding rail housing 28 which is suitable for being partially inserted and fixed in the housing cavity and is abutted against one bearing 8 of the rotor set, that is to say, the sliding rail housing 28 not only realizes the fixation of the sliding rail housing in the process of being assembled and fixed with the housing cavity of the stator set, but also realizes the abutting against one shaft end surface of the rotor set in the process of being fixed with the sliding rail housing 28, so that the assembly and fixation structure of one shaft end surface of the rotor set can be omitted.

In another embodiment of the present application, the stepper motor 3 is mounted on the rear bearing front end cover 4 through a motor fixing bracket 11, and the motor fixing bracket 11 is a split structure; the stepper motor 3 is fixed with the split motor fixing bracket 11 through two socket head cap screws, and meanwhile, a Babbitt metal axial sliding bushing 14 is arranged at the matching position of the split motor fixing bracket 11 and the through hole of the stepper motor and used for limiting radial movement of the wires 10. The split motor fixing bracket 11 is fixed on the rear bearing front end cover 4 through a mounting hole by bolts.

In another embodiment of the present application, one shaft end is pressed by the slide rail housing 28, and for the shaft end of the rotor set facing away from the slide rail housing 28, a limiting structure suitable for being abutted with the bearing 8 is further arranged at one end of the bearing 8 facing away from the slide rail housing in the accommodating cavity and located in the rotor set. That is, the limiting structure and the slide rail housing 28 together form a clamping and fixing for the rotor set, so that the rotor set is prevented from axial movement during use. The limit structure comprises a gasket 12 embedded on the inner wall of the accommodating cavity and abutted against the bearing 8 of the sliding rail shell in the rotor set and a clamp spring 13 abutted against the side end of the gasket 12, which is opposite to the rotor set, and the clamp spring is adopted, and the mode of matching the gasket 12 with the clamp spring 13 is convenient to install, and the overall cost is low.

In a further embodiment of the present application, the threaded spindle 10 passes through the pivoting support at the end remote from the motor housing 5 and is locked by means of a locking nut 15.

In another embodiment of the present application, referring to fig. 1, there is also a system for monitoring axial play of a spindle, comprising a laser displacement sensor 16, the laser displacement sensor 16 being mounted directly on the spindle 1 by a fixed bracket support for monitoring axial displacement of the spindle 1; the laser probe points to the front end cover 4 of the rear bearing and is used for measuring the movement of the main shaft 1 in the axial direction, the measuring precision of the laser displacement sensor 16 which is adopted by the device is 0.01mm, the measuring range is 50mm, and the working environment temperature range is-40 ℃ to +40 ℃;

a signal receiver 17 mounted on the stepping motor;

the controller 18 is in communication connection with the laser displacement sensor 16 and is used for controlling the measurement of the laser displacement sensor 16, the controller 18 is RS-232/485 digital quantity output, and the controller which is used by the device has the functions of current measured value display, original value display, calculated value display, initialization, zero point setting and key locking;

the processor 19 is positioned in a cabin control cabinet of the wind turbine generator and is connected with the controller 18 through an RS-232/485 interface, and the processor 19 is used for sending a signal to the signal receiver 17 when finding that the numerical value sent by the laser displacement sensor 16 is different from the set initial value, so that the front end of the lead screw 10 is fixed on a split type slewing bearing when the motor 3 continuously works, the split type slewing bearing is fixed with the rear end cover 2 of the front bearing, the stepping motor 3 can push the front end of the main shaft 1, the axial force of the main shaft 1 is transmitted to the front bearing seat through the lead screw 10 and the split type slewing bearing, the front bearing bears a certain axial force, and the axial force of the rear bearing is reduced;

at the same time, the processor 19 monitors the data sent by the laser displacement sensor 16 in real time until the spindle 1 is restored to the initial position, and sends a signal to the signal receiver 17 to stop the motor.

In another embodiment of the present application, a slewing bearing includes a split inner ring, a split outer ring, and rolling bodies mounted between the split inner ring and the split outer ring;

the split inner ring comprises two half inner rings 20, and the two half inner rings 20 are fixed together through four first locking bolts 22;

the split outer ring comprises two half outer rings 21, the spherical rollers 29 are assembled into the half inner rings 20, and then the two half outer rings 21 are fastened into a whole through four second locking bolts 23; forms a set of rotary support with the half inner ring 20 and the spherical roller 29,

an outer ring flange 24 is arranged on the peripheral wall of the half outer ring 21, a mounting hole 25 is arranged on the half inner ring 20, and the slewing bearing is fixed on the front bearing rear end cover 2 through the mounting hole 25.

In another embodiment of the present application, one end of the lead screw 10 is connected to the outer ring flange 24 by a flat key 30.

The assembly process is that a split type slewing bearing is fixed on a front bearing rear end cover 2 through a mounting hole 25, a lead screw 10 is screwed into a stepping motor 3, the front end of the lead screw 10 penetrates into the split type slewing bearing and then is fastened through a locking nut 15, and meanwhile, a flat key is arranged at the joint of the lead screw 10 and the split type slewing bearing and used for restraining the radial rotation of the lead screw 10; the stepping motor 3 is assembled in advance, is integrally fixed on the split motor fixing bracket 11 through two inner hexagon screws, is then mounted on the rear bearing front end cover 4 together with the split motor fixing bracket 11 through a bolt through a mounting hole, and is provided with three groups of 120-degree uniform distribution around the main shaft 1.

It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explanation of the principles of the present invention and are in no way limiting of the invention. Accordingly, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present invention should be included in the scope of the present invention. Furthermore, the appended claims are intended to cover all such changes and modifications that fall within the scope and boundary of the appended claims, or equivalents of such scope and boundary.

Claims (10)

1. The utility model provides a wind turbine generator system main shaft bearing off-load system which characterized in that: comprises a slewing bearing, which is arranged on a main shaft (1) and is fixedly connected with a front bearing rear end cover (2);

a stepping motor (3) which is arranged on a front end cover (4) of the rear bearing,

the stepping motor (3) comprises a motor shell (5), and a stator group (6) is fixed in the motor shell (5);

the rotor shaft (7) is arranged inside the stator group (6), bearings (8) are arranged at two axial ends of the rotor shaft (7), and an internal threaded hole (9) which is axially penetrated is machined in the rotor shaft (7);

one end of the screw rod (10) penetrates through the internal threaded hole (9), a screw rod nut (27) matched with the internal threaded hole (9) is arranged on the screw rod (10), and the end part of the screw rod (10) far away from the motor shell (5) is fixedly connected with the slewing bearing.

2. The wind turbine main shaft bearing unloading system of claim 1, wherein: the stepping motor (3) is arranged on the front end cover (4) of the rear bearing through a motor fixing bracket (11).

3. The wind turbine main shaft bearing unloading system of claim 2, wherein: a gasket (12) and a clamp spring (13) are arranged between the motor shell (5) and the motor fixing bracket (11).

4. The wind turbine main shaft bearing unloading system of claim 1, wherein: the end of the screw rod (10) far away from the slewing bearing is provided with a sliding bushing (14).

5. The wind turbine main shaft bearing unloading system of claim 1, wherein: one end of the screw rod (10) far away from the motor shell (5) penetrates through the slewing bearing, and the slewing bearing is locked through a locking nut (15).

6. The wind turbine main shaft bearing unloading system of claim 2, wherein: the motor fixing support (11) is of a split structure.

7. The wind turbine main shaft bearing unloading system of claim 2, wherein: a slide rail shell (28) is arranged between the stator group (6) and the rotor shaft (7), and one end, close to the slewing bearing, of the slide rail shell (28) is abutted with the bearing (8).

8. The wind turbine main shaft bearing unloading system of claim 1, wherein: the device also comprises a laser displacement sensor (16) which is arranged on the main shaft (1) and is used for monitoring the axial displacement of the main shaft;

a signal receiver (17) mounted on the stepper motor (3);

the controller (18) is in communication connection with the laser displacement sensor (16) and is used for controlling the laser displacement sensor (16) to work;

and the processor (19) sends a working signal of the stepping motor (3) through a signal sent by the laser displacement sensor (16).

9. The wind turbine main shaft bearing unloading system of claim 1, wherein: the slewing bearing comprises a split inner ring, a split outer ring and a spherical roller (29) arranged between the split inner ring and the split outer ring;

the split inner ring comprises two half inner rings (20), and the two half inner rings (20) are fixedly connected through a first locking bolt (22);

the split outer ring comprises two half outer rings (21), and the two half outer rings (21) are fixedly connected through a second locking bolt (23);

an outer ring flange (24) is arranged on the peripheral wall of the half outer ring (21).

10. The wind turbine main shaft bearing unloading system of claim 9, wherein: the half inner ring (20) is provided with a mounting hole (25); one end of the screw rod (10) is connected with the outer ring flange (24) through a flat key (30).