Wet friction braking permanent magnet motor

Abstract

A wet friction brake permanent magnet motor comprises a permanent magnet motor, a brake mechanism, a hydraulic system monitoring device and a brake torque monitoring device, the outer tooth hollow shaft sleeve of the brake mechanism is connected to the fixed shaft and rotates and moves axially with the permanent magnet motor shaft; the motor end cover of the permanent magnet motor is used as an end cover of the brake mechanism and is directly fixedly connected with the shell-inner tooth ring, the shell-oil cylinder and the brake mechanism end cover of the brake mechanism; the inner tooth friction plate group is embedded on the outer tooth of the outer tooth hollow shaft, and the outer tooth friction plate group is embedded on the inner tooth of the shell-inner tooth ring. The application realizes intelligent control of the wet friction brake permanent magnet motor drive belt conveyor for long time operation and safe braking. The state monitoring and fault diagnosis functions are improved, so that the belt conveyor system operation is more reliable, more intelligent, more easy to manage and maintain.

Description

Technical Field

[0001] This invention relates to an integrated drive and braking device for a belt conveyor, specifically a wet friction brake permanent magnet motor. Background Technology

[0002] Belt conveyors are widely used in bulk material conveying fields such as coal, cement, and power generation, featuring continuous conveying, high efficiency, energy saving, and environmental friendliness. The braking system is a core component of belt conveyors. For horizontal or upward-moving belt conveyors, push rod brakes are typically installed on the high-speed shaft, while for downward-moving belt conveyors, disc brakes are generally installed on the low-speed shaft of the reducer or on the shaft extension of the drum. For example, invention patent CN201510143388.5 has a multi-disc braking device built into the rear of its rotor. The multi-disc braking device includes a rotating cylinder, a brake cylinder, a brake disc assembly, a spring device, and a power device. The moving brake disc and the stationary brake disc in the brake disc assembly are staggered. The moving brake disc is axially movably connected to the rotating cylinder, and the stationary brake disc is axially movable to the brake cylinder. The spring device is located on the rear side of the brake disc assembly and is provided with a spring / spring assembly that applies a forward pushing force to the brake disc located on the rearmost side. The rotating cylinder is fixedly installed on the inner wall of the cylindrical section at the rear of the rotor or directly uses the cylindrical section at the rear of the rotor. The rear end of the power device base is fixedly connected to the rear end cover.

[0003] The traditional methods described above have the following problems: 1. Long-term continuous braking of the conveyor results in high temperature rise, low efficiency of the braking device after overheating, poor safety and controllability, and a high risk of runaway accidents. To prevent sparks, the braking device uses materials such as asbestos, which leads to environmental pollution, rapid brake shoe wear, and the need for frequent adjustment and replacement. 2. There is a lack of effective monitoring of key parameters such as system braking torque and brake shoe wear, poor fault diagnosis capabilities, and low level of intelligence. 3. The system is assembled from independent products or components, resulting in system complexity, dispersed layout, and large footprint, limiting its installation and use in confined spaces such as underground coal mines. Assembling these components on-site results in low assembly precision, causing high system vibration and noise, and affecting equipment lifespan. Low system integration and lack of efficient fusion between components lead to high failure rates and low system reliability. Summary of the Invention

[0004] The purpose of this invention is to provide a wet friction brake permanent magnet motor. By integrating the drive motor and brake into a single design, it saves installation space, improves assembly accuracy, and reduces on-site installation workload. Furthermore, through a unique wet friction brake design and comprehensive operation status monitoring and fault diagnosis, it provides big data support for intelligent operation control, making the system more reliable, intelligent, and easier to manage and maintain.

[0005] The objective of this invention is achieved as follows: A wet friction braking permanent magnet motor, comprising a permanent magnet motor, a braking mechanism, a hydraulic system, a monitoring device thereof, and a braking torque monitoring device, characterized in that: the permanent magnet motor and the braking mechanism share a fixed shaft directly connected to the braking mechanism; the external toothed hollow shaft of the braking mechanism is sleeved on the fixed shaft and rotates and moves axially with the permanent magnet motor shaft; the motor end cover of the permanent magnet motor serves as an end cover of the braking mechanism and is directly and fixedly connected to the housing-internal gear ring, housing-cylinder, and braking mechanism end cover of the braking mechanism; an internal toothed friction plate assembly is embedded on the external teeth of the external toothed hollow shaft, and an external toothed friction plate assembly is embedded on the internal teeth of the housing-internal gear ring, the internal toothed friction plate assembly and the external toothed friction plate assembly... The friction plates are interlocked to form a static and dynamic friction pair. The static and dynamic friction pair composed of the internal and external tooth friction plates is located in the braking cavity formed by the motor end cover, the housing-internal gear ring, and the piston outer ring end face. The piston is installed in the housing-cylinder. The piston end face is formed by the outer ring end face, the inner ring end face, and the groove between them. The groove is inserted into the middle partition wall of the cylinder. The piston inner ring end face extends into the cylinder cavity and drives the entire piston to move under the pressure of the oil. Multiple blind holes are opened on the end face of the piston opposite to the brake mechanism end cover. Disc springs are built into the blind holes. A guide rod is installed in the middle hole of the disc spring. The outer end of the guide rod abuts against the adjusting screw mounted on the brake mechanism end cover. The adjusting screw is locked by an external adjusting nut.

[0006] The objective of this invention can also be achieved as follows: the hydraulic system includes a hydraulic station, a cooling oil system, and a pressure oil system; the cooling oil system, through the hydraulic station, supplies cooling oil from the cooling oil inlet of the brake into the gap between the friction pads in the brake chamber, thereby cooling the friction pads, and returns the cooling oil to the hydraulic station through the cooling oil outlet, preventing the friction pads from overheating and generating sparks during braking.

[0007] The pressure oil system, through the hydraulic station, fills the cylinder cavity with pressure oil via the oil circuit of the pressure oil system. Driven by the pressure oil, the piston reciprocates, realizing the pressing and releasing separation between the inner and outer friction plates of the braking mechanism.

[0008] The hydraulic system monitoring device includes a cooling oil temperature sensor installed on the cooling oil inlet or return channel to monitor the temperature of the cooling oil entering the brake chamber and adjust the oil supply flow rate in a timely manner according to the oil temperature change to ensure the cooling effect; and a pressure oil sensor installed on the pressure oil inlet channel to monitor the oil pressure change of the pressure oil entering the cylinder chamber and adjust the oil supply pressure in a timely manner according to the oil pressure change to ensure the braking effect.

[0009] The braking torque monitoring device includes a disc spring pressure sensor mounted on the outer end of the guide rod for real-time monitoring of changes in disc spring pressure. This sensor converts electrical signals into digital signals and displays the pressure values, calculating the braking torque value from the measured disc spring pressure. Based on this braking torque value, the setting torque of the assembly torque wrench is determined during the manufacturing and assembly of the braking mechanism. Furthermore, during operation, the disc spring pressure sensor monitors and analyzes the wear degree of the friction plates, predicting their remaining service life. When excessive wear of the friction plates leads to a significant drop in braking torque, the pressure value of the disc spring is adjusted and calibrated using an adjusting screw to ensure the necessary braking torque value.

[0010] This invention offers the following advantages: By real-time monitoring of cooling oil temperature and pressure, as well as changes in disc spring pressure, it achieves intelligent control of wet friction brake permanent magnet motor-driven belt conveyors, especially for long-term operation and safe braking in explosion-proof environments like coal mines. It avoids overheating and sparking during braking. Through the design and calculation of the cooling system's oil volume, it enables long-term, continuous, controllable, and safe braking of high-power belt conveyors, with braking times reaching and exceeding 180 seconds, representing a breakthrough and significant technological advancement in this field. Furthermore, the integrated design of the drive, braking, and intermediate connecting components saves installation space, improves assembly accuracy, and reduces installation workload. It also enhances condition monitoring and fault diagnosis functions, making the belt conveyor system more reliable, intelligent, and easier to manage and maintain. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of a wet friction braking permanent magnet motor according to the present invention;

[0012] Figure 2 This is a structural diagram of the disc spring, guide rod, and adjusting screw.

[0013] Figure 3 This is a schematic diagram showing the connection relationship between the permanent magnet motor part and the braking mechanism part of the present invention;

[0014] Figure 4 yes Figure 3 The right view. Detailed Implementation

[0015] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as a result. However, these embodiments are merely exemplary and do not constitute any limitation on the scope of protection of the present invention. Those skilled in the art should understand that modifications or substitutions to the details and form of the technical solutions of the present invention can be made without departing from the scope of disclosure of the present invention, but such modifications and substitutions all fall within the scope of protection of the present invention.

[0016] The wet friction brake permanent magnet motor of this invention, as shown in the figure, includes: a support 1; a pressure oil connector 2; a cooling oil inlet 3; an adjusting screw 4; a cooling oil outlet 5; a disc spring sensor 6; a brake mechanism end cover 7; a housing-internal gear ring 8; a motor housing 9; a motor end cover 10; an external gear hollow shaft 11; a fixed shaft 12; a guide rod 13; a piston 14; a housing-cylinder 15; a disc spring 16; an internal gear friction plate assembly 17; an external gear friction plate assembly 18; a motor stator 19; a motor rotor 20; and an adjusting nut 21. Note: the hydraulic station, cooling oil inlet and return channels, pressure oil inlet channel, cooling oil temperature sensor, and pressure oil pressure sensor are not shown in the figure.

[0017] A wet friction brake permanent magnet motor includes a permanent magnet motor, a braking mechanism, a hydraulic system, a monitoring device, and a braking torque monitoring device. The braking mechanism operates in a normally closed manner. The external toothed hollow shaft 11 of the braking mechanism is mounted on the fixed shaft 12 of the permanent magnet motor and rotates with the permanent magnet motor. The braking mechanism end cover 7 is connected and fixed to the stationary motor end cover 10. The internal toothed friction plate assembly 17 and the external toothed friction plate assembly 18 are staggered on the external toothed hollow shaft 11. The internal toothed friction plate assembly 17 is embedded in the external toothed hollow shaft 11, and the external toothed friction plate 18 is embedded in the housing-internal toothed ring 8. One end of the braking mechanism is the braking mechanism end cover 7, and the other end is the motor end cover 10, both supported and fixed by bearings. The frictional force between the internal toothed friction plate 17 and the external toothed friction plate 18 is set and adjusted by the disc spring pressure, forming a compact integrated structure of the braking mechanism and the permanent magnet motor drive.

[0018] The internal and external tooth friction plates are pressed together and released by a piston. Part of the piston is inserted into the cylinder cavity, and the other part is inserted into the annular channel connecting the brake cavity to push the internal and external tooth friction plates to press together and release. The piston end face shape inside the housing-cylinder 15 is formed by an outer ring end face, an inner ring end face, and a groove between them. The groove is inserted into the middle partition wall of the housing-cylinder. The inner ring end face of the piston extends into the cylinder cavity and drives the entire piston to move under the pressure of the oil. Twenty blind holes are opened on the end face of the piston opposite to the brake mechanism end cover 7. A disc spring 16 is built into each blind hole. A guide rod 13 is installed in the middle hole of the disc spring. The outer end of the guide rod abuts against the adjusting screw 4 mounted on the brake mechanism end cover 7. The adjusting screw 4 is locked by an external adjusting nut 21. Only one of the guide rods 13 needs to be equipped with a pressure sensor to monitor the pressure change of the disc spring in real time. The pressure sensor converts the electrical signal into a digital signal and displays the pressure value, and converts the measured disc spring pressure value into the braking torque value. Based on this braking torque value, on the one hand, the set torque of the assembly torque wrench is determined during the manufacturing and assembly of the braking mechanism. On the other hand, during operation, the wear degree of the friction plates is monitored and analyzed by a pressure sensor to predict the remaining service life of the friction plates. When the friction plates wear excessively and the braking torque drops significantly, the pressure value of the disc spring is adjusted and calibrated uniformly by adjusting the adjusting screw to ensure the necessary braking torque value. Other adjustments can be made using a torque wrench to maintain consistency.

[0019] When the conveyor is in a stationary braking state, the pressure oil is released and returned to the oil. Under the action of the disc spring, the piston 14 causes the inner tooth friction plate group 17 and the outer tooth friction plate group 18 to quickly press together. Since the outer tooth friction plate 18 is embedded in the housing-inner tooth ring 8, and the housing-inner tooth ring 8 is fixed together with the brake mechanism end cover 7 and the motor end cover 10 by screws, the inner and outer tooth friction plates of the brake mechanism are in a pressed state, realizing the parking brake of the conveyor.

[0020] Before startup, cooling oil is introduced, and during operation, overheating is monitored in real time: Cooling oil from the hydraulic station and cooling oil system is introduced into the gap between the inner and outer tooth friction plates in the brake chamber of the braking mechanism through the cooling oil inlet 3 to cool the friction plates. The cooling oil returns to the hydraulic station through the cooling oil outlet 5. Then, the pressure of the controlled pressure oil is slowly increased, the piston 14 compresses the disc spring 16, and the positive pressure between the inner and outer tooth friction plates 17 and 18 slowly decreases, gradually increasing the gap between the inner and outer tooth friction plates 17 and 18 until they are completely separated. The braking mechanism is released, and then the permanent magnet motor starts to rotate in the forward direction under electrical control, and the equipment operates normally. The cooling oil temperature is monitored in real time by a cooling oil temperature sensor, the oil volume of the cooling system is calculated, and the cooling oil pressure and flow rate are intelligently adjusted to ensure that the inner and outer tooth friction plate assembly does not overheat, achieving long-term continuous and controllable safe braking. The braking time can reach and exceed 180 seconds, avoiding overheating and spark generation.

[0021] During normal shutdown, the permanent magnet motor gradually decreases in speed under electrical control until it approaches zero. This reduces the pressure of the hydraulic oil controlling the braking mechanism to zero, causing the disc spring to extend and push the piston to press against the friction pads of the braking mechanism, thus achieving parking brake operation. During this period, the power loss due to slippage is converted into heat, which is carried away by the circulating cooling oil between the friction pads.

[0022] When the machine decelerates and stops, the pressure oil of the control braking mechanism is released and returned to the oil. Under the action of the disc spring, the piston 14 reduces the gap between the internal tooth friction plate 17 and the external tooth friction plate 18 until it is zero. Since the external tooth friction plate 18 is embedded in the housing-internal tooth ring 8, and the housing-internal tooth ring 8 is fixed as a whole with the brake mechanism end cover 7 and the motor end cover 10, the braking force gradually increases and the speed of the permanent magnet motor gradually decreases, realizing intelligent and controllable braking.

[0023] The hydraulic station includes a cooling oil temperature sensor and a control oil pressure sensor. The cooling oil temperature sensor is installed on the cooling oil inlet or return channel to monitor the temperature of the cooling oil entering the wet brake. The control oil pressure sensor is installed on the control oil inlet channel to monitor the pressure changes of the brake pressure adjustment mechanism.

[0024] The outer end of the guide rod 13 connected to the disc spring 16 of the braking mechanism is equipped with a disc spring pressure sensor 6 for real-time monitoring of changes in the pressure of the disc spring. This disc spring pressure sensor can convert electrical signals into digital signals and display the pressure values, measuring the pressure of the disc spring 16 and calculating the braking torque value. On the one hand, this can be used to determine the set torque of the assembly torque wrench during brake manufacturing and assembly. On the other hand, when the friction pads wear excessively after long-term use, resulting in a decrease in braking torque, the braking torque can be accurately calibrated by adjusting the screw 4 and then detecting it through the disc spring pressure sensor 6. This allows for analysis and judgment of the wear degree of the friction pads and prediction of their remaining service life.

Claims

1. A wet friction braking permanent magnet motor, comprising a permanent magnet motor, a braking mechanism, a hydraulic system and its monitoring device and a braking torque monitoring device, characterized in that: The permanent magnet motor and the braking mechanism share a fixed shaft directly connected to the braking mechanism. The external toothed hollow shaft of the braking mechanism is sleeved on the fixed shaft and rotates and moves axially with the permanent magnet motor shaft. The motor end cover of the permanent magnet motor serves as an end cover for the braking mechanism and is directly and fixedly connected to the housing-internal gear ring, housing-cylinder, and braking mechanism end cover of the braking mechanism. Internal toothed friction plates are embedded in the external teeth of the external toothed hollow shaft, and external toothed friction plates are embedded in the internal teeth of the housing-internal gear ring. The internal and external toothed friction plates are interlocked to form a static and dynamic friction pair. This internal and external toothed friction plate pair constitutes... The static and dynamic friction pair is located in the braking chamber formed by the motor end cover, the housing-internal gear ring, and the piston outer ring end face; the piston is installed in the housing-cylinder, and the piston end face shape is formed by the outer ring end face, the inner ring end face, and the groove between them. The groove is inserted into the middle partition wall of the cylinder. The piston inner ring end face extends into the cylinder cavity and drives the entire piston to move under the pressure of the oil. Multiple blind holes are opened on the end face of the piston opposite to the brake mechanism end cover. Disc springs are built into the blind holes. A guide rod is installed in the middle hole of the disc spring. The outer end of the guide rod abuts against the adjusting screw mounted on the brake mechanism end cover. The adjusting screw is locked by an external adjusting nut. The hydraulic system monitoring device includes a cooling oil temperature sensor installed on the cooling oil inlet or return channel to monitor the temperature of the cooling oil entering the brake chamber and adjust the oil supply flow rate in a timely manner according to the oil temperature change to ensure the cooling effect; and a pressure oil sensor installed on the pressure oil inlet channel to monitor the oil pressure change of the pressure oil entering the cylinder chamber and adjust the oil supply pressure in a timely manner according to the oil pressure change to ensure the braking effect. The braking torque monitoring device includes a disc spring pressure sensor mounted on the outer end of the guide rod for real-time monitoring of changes in disc spring pressure. This sensor converts electrical signals into digital signals and displays the pressure values, calculating the braking torque value from the measured disc spring pressure. Based on this braking torque value, the setting torque of the assembly torque wrench is determined during the manufacturing and assembly of the braking mechanism. Furthermore, during operation, the disc spring pressure sensor monitors and analyzes the wear degree of the friction plates, predicting their remaining service life. When excessive wear of the friction plates leads to a significant drop in braking torque, the pressure value of the disc spring is adjusted and calibrated using an adjusting screw to ensure the necessary braking torque value.

2. The wet friction braking permanent magnet motor according to claim 1, characterized in that, The hydraulic system includes a hydraulic station, a cooling oil system, and a pressure oil system. The cooling oil system, through the hydraulic station, supplies cooling oil from the cooling oil inlet of the brake to the gap between the friction pads in the brake chamber, thereby cooling the friction pads. The oil is then returned to the hydraulic station through the cooling oil outlet to prevent the friction pads from overheating and generating sparks during braking.

3. A wet friction braking permanent magnet motor according to claim 2, characterized in that, The pressure oil system, through the hydraulic station, fills the cylinder cavity with pressure oil via the oil circuit of the pressure oil system. Driven by the pressure oil, the piston reciprocates, realizing the pressing and releasing separation between the inner and outer friction plates of the braking mechanism.

Images