CN115594049B

CN115594049B - Method for detecting abrasion of spline teeth of friction disc in disc brake

Info

Publication number: CN115594049B
Application number: CN202211525211.8A
Authority: CN
Inventors: 周卫; 张志杰; 陈杰; 王志豪; 钱志超
Original assignee: Suzhou Torin Drive Equipment Co Ltd
Current assignee: Suzhou Torin Drive Equipment Co Ltd
Priority date: 2022-12-01
Filing date: 2022-12-01
Publication date: 2023-03-10
Anticipated expiration: 2042-12-01
Also published as: CN115594049A

Abstract

A method for detecting abrasion of spline teeth of a friction disc in a disc brake belongs to the technical field of traction machines. The method comprises the following steps: judging whether the elevator is in a dormant state, if so, executing the next step, and if not, ending the program; applying short-time current to the motor to enable the main shaft to rotate towards one side of the lift car, wherein the rotating angle alpha of the main shaft is measured by an encoder, and the encoder transmits a signal to the controller; the controller converts the signal input by the encoder into a tooth space gap L between the inner spline teeth of the friction disc and the outer spline teeth of the main shaft and stores the tooth space gap L; comparing the inter-tooth gap L with a specified value A, if L is larger than or equal to A, sending an early warning signal for replacing the friction disc, and ending the program; if L < A, the procedure ends. The advantages are that: the wearing and tearing condition of the spline tooth of ability effective detection friction disk prevents to take place the elevator accident because of spline tooth wearing and tearing, improves the security of elevator.

Description

Method for detecting abrasion of spline teeth of friction disc in disc brake

Technical Field

The invention belongs to the technical field of traction machines, and particularly relates to a method for detecting abrasion of spline teeth of a friction disc in a disc brake.

Background

The safety standard of the GB/T7588-2020 elevator manufacture and installation puts forward the requirements: the brake mechanics parts participating in braking the hoisting machine should be installed in at least two groups, and when one of the groups is not functioning, the other group should have sufficient braking force to brake the elevator. Therefore, there are two general types of disc brakes installed in the conventional traction machine, the first type is that two sets of brake members correspond to two friction disc structures, respectively, as shown in fig. 1, and the second type is that two sets of brake members correspond to the same friction disc structure, as shown in fig. 2.

For the first disc brake structure, the two sets of brake components include a first brake component 11 composed of a first stationary core 111 and a first movable core 112, and a second brake component 12 composed of a second stationary core 121 and a second movable core 122, the first brake component 11 corresponds to the first friction disc 130, the second brake component 12 corresponds to the second friction disc 130', the first brake component 11, the first friction disc 130, the second brake component 12 and the second friction disc 130' are sequentially mounted on a main shaft of a traction machine, and the first friction disc 130 and the second friction disc 130' are connected with the main shaft through splines. In actual use, due to the reasons of processing and adjusting precision, the braking working gaps cannot be completely consistent, the friction discs of the group of braking parts with small working gaps are stressed firstly, and the friction discs of the group of braking parts with large working gaps are stressed later and are influenced by the braking response speed, so that the friction discs are worn firstly, and the worn friction discs do not play a braking role in actual use.

For the second disc brake structure, the two sets of brake components include a first brake component 11 composed of a first stationary iron core 111 and a first movable iron core 112, and a second brake component 12 composed of a second stationary iron core 121 and a second movable iron core 122, the first brake component 11 and the second brake component 12 correspond to the same friction disc 13, and the friction disc 13 is connected with the main shaft of the traction machine through a spline. In actual use, the braking surfaces of the friction discs 13 are unevenly stressed due to the difference in response speed between the two sets of brake members. During brake actuation, the friction discs 13 are slightly inclined, which increases the wear during engagement with the external spline teeth on the spindle.

In the two disc brake structures, the friction discs are both arranged on the main shaft through splines. When the brake is off and the brake is braked, the movable iron core can clamp the friction disc on the movable iron core and the brake mounting surface due to the pushing of the brake spring. When the brake is electrified and released, the friction disc retreats to be positioned between the movable iron core and the brake mounting surface and rotate along with the main shaft. Here, if the friction disk is made of a relatively heavy material, it is not favorable for centering the disk after energization, and therefore, a relatively light material is required. In addition, the internal spline teeth of the friction disks mate with the external spline teeth on the spindle, which can be easily worn during long-term use.

Further, in long-term use, the clearance between internal spline tooth and the external spline tooth can become bigger and bigger because of wearing and tearing, reaches the certain degree after, big clearance produces the impact for the internal spline tooth of friction disc takes place disconnected tooth easily, especially to the stopper of the single friction disc structure of second kind, has the potential safety hazard, can cause the elevator accident when serious.

In view of the above-mentioned prior art, it is highly desirable to effectively detect wear of the spline teeth of a friction disc in a disc brake. The applicant has made an advantageous design for this purpose, in the context of which the solution to be described below is made.

Disclosure of Invention

The invention aims to provide a method for detecting the abrasion of spline teeth of a friction disc in a disc brake, which has simple operation process, can effectively detect the abrasion condition of the spline teeth of the friction disc and improve the safety of an elevator.

The task of the invention is accomplished by the following steps, the friction disc in the disc brake is installed on a main shaft of a traction machine through spline connection, an encoder is also installed on the main shaft, and the encoder is electrically connected with a controller for controlling the operation of an elevator, and the method for detecting the abrasion of the spline teeth of the friction disc is characterized by comprising the following steps:

s1, judging whether the elevator is in a dormant state, if so, executing the next step, and if not, ending the program;

s2, applying short-time current to the motor to enable the main shaft to rotate towards one side of the lift car;

s3, measuring the rotation angle alpha of the main shaft through an encoder, and transmitting a signal to a controller through the encoder;

s4, the controller (60) converts the signal input by the encoder (15) into a tooth space gap L between the internal spline teeth (131) of the friction disc (13) and the external spline teeth (211) of the main shaft (21) through the following formula and stores the tooth space gap L,

wherein r represents a spline pitch circle radius;

s5, comparing the inter-tooth gap L with a specified value A, if L is larger than or equal to A, sending an early warning signal for replacing a friction disc, and ending the program; if L < A, the procedure ends.

In a specific embodiment of the present invention, the controller is provided with a manual detection button, and the method for detecting the wear of the spline teeth of the friction disc comprises the following steps:

s1', pressing a manual detection button on the controller;

wherein r represents a spline pitch circle radius;

s5, comparing the inter-tooth gap L with a specified value A, if L is larger than or equal to A, sending an early warning signal for replacing the friction disc, and ending the program; if L < A, the procedure ends.

In another specific embodiment of the present invention, a detection time point is provided in the controller, and the method for detecting wear of the spline teeth of the friction disk comprises the steps of:

s2', judging whether the elevator reaches a specified detection time point, if so, executing the next step, and if not, ending the program;

wherein r represents a spline pitch radius;

In still another embodiment of the present invention, the interdental space L obtained by a plurality of times of detection is used to construct a graph of the change in the interdental space L.

Due to the adoption of the structure, the invention has the beneficial effects that: firstly, the abrasion condition of the spline teeth of the friction disc can be effectively detected, the elevator accident caused by the abrasion of the spline teeth is prevented, and the safety of the elevator is improved; secondly, regular detection can be carried out, detection data can be stored in time, and the data are accumulated and used for assisting in pre-judging the service life of the spline teeth; and thirdly, the detection method is simple and easy to operate, and manual detection and regular automatic detection can be realized.

Drawings

Fig. 1 is an exploded view of an embodiment of a prior art disc brake.

Fig. 2 is an exploded view of another embodiment of a prior art disc brake.

Fig. 3 presents a diagrammatic illustration of the structure of the elevator system according to the invention.

Fig. 4 is a schematic structural diagram of the traction machine according to the present invention.

Fig. 5 is an exploded view of a disc brake of a traction machine according to the present invention.

Fig. 6a is a schematic illustration of the mating of the female spline teeth on the friction disc and the male spline teeth on the spindle of the present invention.

FIG. 6b is another schematic illustration of the mating of the internal spline teeth on the friction disc and the external spline teeth on the spindle of the present invention.

Fig. 7 is a flowchart of an embodiment of a wear detection method of spline teeth according to the present invention.

Fig. 8 is a flowchart of another embodiment of the wear detection method for spline teeth according to the present invention.

Fig. 9 is a flowchart of another embodiment of the wear detection method for spline teeth according to the present invention.

In the figure: 10. a traction machine; 20. a guide wheel; 30. a wire rope; 40. a car; 50. counterweight; 60. a controller; 1. the brake comprises a disc brake 11, a first brake component 111, a first static iron core 112, a first movable iron core 113, a first brake spring 114, a first coil component 12, a second brake component 121, a second static iron core 122, a second movable iron core 123, a second brake spring 124, a second coil component 13, a friction disc 130, a first friction disc 130', a first friction disc 131, internal spline teeth 14, a brake mounting surface 15 and an encoder 15; 2. motor, 21, main shaft, 211, external spline teeth; 3. a traction sheave.

Detailed Description

The following detailed description of the embodiments of the present invention is provided in conjunction with the accompanying drawings, but the embodiments described by the applicant are not intended to limit the technical solutions, and any changes made in the form of the present inventive concept rather than the essential changes should be regarded as the protection scope of the present invention.

In the following description, all the concepts related to the directions or orientations of up, down, left, right, front and rear are based on the positions shown in the corresponding drawings, and thus, should not be construed as particularly limiting the technical solution provided by the present invention.

Referring to fig. 3 to 5, the present invention relates to a method for detecting wear of spline teeth of a friction disc of a disc brake, the disc brake 1 is an important safety part of an elevator system, and particularly, the disc brake 1 is mounted on a brake mounting surface 14 of a traction machine 10. The traction machine 10 further includes a motor 2 and a traction sheave 3, and the motor 2 is a driving member for driving the traction sheave 3 to rotate, and a main shaft 21 is mounted thereon. The disc brake 1 comprises a first brake component 11 and a second brake component 12, wherein the first brake component 11 and the second brake component 12 are matched with a friction disc 13 which is the same friction disc, so that the brake and the release of the traction machine 10 are realized.

As shown in fig. 4 and 5, the first brake member 11 includes a first stationary core 111, a first movable core 112, and a first brake spring 113 and a first coil assembly 114 disposed between the first stationary core 111 and the first movable core 112. The second brake unit 12 includes a second stationary core 121, a second movable core 122, and a second brake spring 123 and a second coil assembly 124 disposed between the second stationary core 121 and the second movable core 122.

The friction disc 13 and the traction sheave 3 are sleeved on the main shaft 21 and rotate synchronously with the main shaft 21, wherein the friction disc 13 is connected with the main shaft 21 through a spline. When the first coil assembly 114 and the second coil assembly 124 are both energized, a magnetic loop is formed between the air gap between the first stationary iron core 111 and the first movable iron core 112, so as to generate electromagnetic force, and the electromagnetic force overcomes the spring force of the first brake spring 113, so that the first stationary iron core 111 and the first movable iron core 112 are correspondingly attracted together. Similarly, a magnetic circuit is formed between the air gap between the second stationary iron core 121 and the second movable iron core 122, and an electromagnetic force is generated, which overcomes the spring force of the second braking spring 123, so that the second stationary iron core 121 and the second movable iron core 122 are correspondingly attracted together. The friction discs 13 now rotate as the spindle 21 rotates. When one of the first coil assembly 114 and the second coil assembly 124 is energized, the other brake component is still in a braking state, and the operating condition of the side brake component can be detected. When the first coil assembly 114 and the second coil assembly 124 are both de-energized, the first brake spring 113 and the second brake spring 123 will press on the first movable iron core 112 and the second movable iron core 122, and the first movable iron core 112 and the second movable iron core 122 cooperate to clamp the friction disc 13 in cooperation with the brake mounting surface 14, so as to generate a braking torque, so that the friction disc 13 and the main shaft 21 stop rotating, thereby performing a braking function.

As shown in fig. 3, a rope 30 is wound around the traction sheave 3 and the guide sheave 20 of the elevator system, and a car 40 is mounted on one end of the rope 30 and a counterweight 50 is mounted on the other end thereof. Operation of the elevator system is controlled by a controller 60. The main shaft 21 is also provided with an encoder 15, the encoder 15 is used for detecting the motion condition of the motor rotor or the main shaft 21 and sending the detection result to the controller 60, and the controller 60 drives the elevator to normally operate according to the received signal. By the rotation of the traction sheave 3, the car 40 and the counterweight 50 are raised or lowered.

Continuing to refer to fig. 4, in this embodiment, the friction disc 13 has internal spline teeth 131 directly machined on the friction disc 13, the main shaft 21 has external spline teeth 211 directly machined on the main shaft 21, and the internal spline teeth 131 and the external spline teeth 211 are matched with each other to realize spline connection between the friction disc 13 and the main shaft 21. During the use of the elevator, the external spline teeth 211 on the main shaft 21 and the internal spline teeth 131 on the friction disc 13 generate a certain tooth space L through friction, as shown in fig. 6a, due to the existence of the tooth space L, the main shaft 21 can rotate relative to the friction disc 13 when the disc brake 1 brakes, and when the left tooth surface of the internal spline teeth 131 is in contact with the left tooth surface of the external spline teeth 211 as shown in fig. 6b, the tooth space L can be calculated through the rotation angle α of the main shaft 21.

Continuing to refer to fig. 3, when the elevator is dormant, the disc brake 1 is in a braking state, the car 40 is an empty car, and the counterweight side is heavier than the car side, so that the inter-tooth gap L between the internal spline teeth 131 and the external spline teeth 211 is close to one side of the car 40. As shown in fig. 3 and 6a, a short-time current is applied to the motor 2, the magnitude of the short-time current is determined by specific parameters of each type of elevator, as long as the short-time current satisfies a driving torque which can enable the motor 2 to generate a static moment greater than the idle load of the main shaft 21 so as to enable the main shaft 21 to rotate, but the driving torque is smaller than the braking torque of the disc brake 1, that is, the main shaft 21 can rotate within the tooth space L, when the left tooth surface of the internal spline tooth 131 in fig. 6b is attached to the left tooth surface of the external spline tooth 211, the main shaft 21 rotates by an angle α in the arrow direction of fig. 6a, the tooth space L is eliminated, and the driving torque cannot overcome the action of the braking torque and the main shaft 21 continues to rotate. When short-time current is supplied to the motor 2, the encoder 15 sends the rotation angle of the spindle 21 to the controller 60 as a waveform signal, when the waveform signal fed back by the encoder 15 does not change in the later period, it indicates that the spindle 21 does not rotate any more after rotating to eliminate the angle alpha of the inter-tooth gap L, at this time, the motor 2 can be stopped to be powered on, and the power on of the motor 2 is determined to be stopped according to how long the waveform signal fed back by the encoder 15 does not change, or how long the power on of the motor 2 is enough to enable the spindle 21 to rotate to be incapable of continuing rotating, which is also determined after the test of various types of elevators. Therefore, the magnitude of the short-time current and the electrifying time are determined by the specific conditions of the elevators of various types, and the finally satisfied requirement is that when the short-time current is applied to the motor 2, the main shaft 21 rotates to eliminate the gap L between the teeth. Therefore, the determined magnitude of the short-time current and the electrifying time are input in advance into the controller 60 of the elevator, and during detection, the encoder 15 transmits the rotation angle condition of the main shaft 21 to the controller 60, so that the controller 60 can determine the rotation angle alpha of the main shaft 21 according to the detection condition of the encoder 15 and then calculate the magnitude of the tooth space L at the spline pitch circle through a built-in calculation formula (1), wherein the formula (1) is as follows:

where r represents the pitch radius of the spline, and the pitch radius r is input in advance to the controller 60.

After a plurality of times of detection and storage of the value of the interdental gap L, a gap data curve varying with time can be formed. When the measured tooth-to-tooth clearance L exceeds the prescribed value a, indicating that the internal spline teeth 131 of the friction disc 13 have exceeded the wear limit, there is a safety risk, the controller 60 sends an early warning signal to notify the maintenance company to replace the friction disc 13.

Specifically, as shown in fig. 7, the method for detecting wear of spline teeth of a friction disc according to the present invention includes the following steps:

s2, applying short-time current to the motor 2 to enable the main shaft 21 to rotate towards one side of the lift car 40;

s3, measuring the rotation angle alpha of the main shaft 21 through the encoder 15, and transmitting a signal to the controller 60 through the encoder 15;

s4, the controller 60 calculates and stores the inter-tooth gap L between the inner spline teeth 131 of the friction disc 13 and the outer spline teeth 211 of the main shaft 21 according to the signals input by the encoder 15;

s5, comparing the inter-tooth gap L with a specified value A, and if L is larger than or equal to A, sending an early warning signal for replacing the friction disc 13, and ending the program; if L is less than A, the procedure is ended;

in the step S2, after a short time of current flowing through the motor 2, a torque is applied to the main shaft 21, which is sufficient to rotate the main shaft 21 by a certain angle α, as shown in fig. 6b, the left tooth surface of the external spline tooth 211 is close to the left tooth surface of the internal spline tooth 131, and the pitch circle length of the rotation of the external spline tooth 211 is the inter-tooth gap L.

The detection method can realize manual detection and regular automatic detection.

In the case of manual detection, the elevator system can perform the detection process according to the above steps as long as the manual detection button is set on the controller 60 and the motor 2 is powered on by pressing the manual detection button. As shown in fig. 8, the operation flow of manual detection is as follows:

s1', pressing a manual detection button on a controller 60;

s4, the controller 60 calculates and stores the inter-tooth gap L between the inner spline teeth 131 of the friction disc 13 and the outer spline teeth 211 of the spindle 21 according to the signals of the encoder 15;

s5, comparing the inter-tooth gap L with a specified value A, and if L is larger than or equal to A, sending an early warning signal for replacing the friction disc 13, and ending the program; if L < A, the procedure ends.

In the case of automatic periodic detection, a detection time point needs to be set in the controller 60, and when the time reaches the detection time point, the motor 2 is powered on, and the system can start to execute the detection process. As shown in fig. 9, the specific process is as follows:

s4, the controller 60 calculates and stores the tooth space gap L between the inner spline tooth 131 and the outer spline tooth 211 through the signal of the encoder 15;

s5, comparing the clearance L with a specified value A, if the clearance L is larger than or equal to the specified value A, sending an early warning signal for replacing the friction disc 13, and ending the program; if L < A, the procedure ends.

Furthermore, the data detected each time are collated to form a graph of the change in the clearance L, so that the service life of the friction disc 13 can be estimated, and valuable data are left for reference in further subsequent research.

The brake structure that two brake parts correspond to the same friction disc is taken as an example, and for other disc brakes, as long as the friction disc of the brake is in spline fit with a main shaft of a traction machine, a method that an encoder detects the rotation angle of the main shaft can be adopted to detect whether the spline teeth of the friction disc are worn or not.

Claims

1. A method for detecting wear of spline teeth of a friction disc in a disc brake, wherein the friction disc (13) in the disc brake is mounted on a main shaft (21) of a traction machine through spline connection, an encoder (15) is further mounted on the main shaft (21), and the encoder (15) is electrically connected with a controller (60) for controlling the operation of an elevator, the method for detecting wear of the spline teeth of the friction disc is characterized by comprising the following steps:

s2, applying short-time current to the motor (2) to enable the main shaft (21) to rotate towards one side of the lift car (40);

s3, measuring the rotation angle alpha of the main shaft (21) through the encoder (15), and transmitting a signal to the controller (60) through the encoder (15);

wherein r represents a spline pitch circle radius;

s5, comparing the inter-tooth gap L with a specified value A, if L is larger than or equal to A, sending an early warning signal for replacing the friction disc (13), and ending the program; if L < A, the procedure ends.

2. A method of detecting wear of the spline teeth of a friction disc in a disc brake according to claim 1, wherein said controller (60) is provided with a manual detection button, said method of detecting wear of the spline teeth of a friction disc comprising the steps of:

s1', pressing a manual detection button on the controller (60);

wherein r represents a spline pitch circle radius;

3. A method of detecting wear of spline teeth of a friction disc in a disc brake according to claim 1, wherein a detection time point is provided in said controller (60), said method of detecting wear of spline teeth of a friction disc comprising the steps of:

s4, the controller (60) converts the signal of the encoder (15) into a tooth space gap L between the internal spline teeth (131) and the external spline teeth (211) through the following formula and stores the tooth space gap L,

wherein r represents a spline pitch radius;

4. A method of detecting wear of spline teeth of a friction disc in a disc brake according to any one of claims 1 to 3, wherein: the interdental space L obtained by the plurality of detections constitutes a variation graph of the interdental space L.