CN116683673A - A permanent magnet synchronous motor for torque-limiting scraper conveyor - Google Patents

Abstract

The invention discloses a permanent magnet synchronous motor for a torque-limiting scraper conveyor, and relates to the technical field of scraper conveyor drive. Including the shell, the two ends of the shell are respectively fixedly connected with the front end cover assembly and the rear end cover assembly; the inner wall of the shell is fixedly connected with the stator assembly; the rotor assembly is rotated between the front end cover assembly and the rear end cover assembly; the hollow of the rotor assembly A motor output shaft is arranged inside the output shaft; the motor output shaft is connected with the hollow output shaft of the rotor assembly through a cylindrical friction torque limiter. The invention makes full use of the functions and advantages of the permanent magnet synchronous motor, such as low speed and high torque, high efficiency and energy saving, high power density of the cylindrical friction pair, and good overload protection performance, and highly integrates the two to realize the scraper conveyor, especially the heavy-duty scraper conveyor. Ideal drive and efficient overload protection for motors.

Description

A permanent magnet synchronous motor for torque-limiting scraper conveyor

technical field

The invention relates to the technical field of driving scraper conveyors, in particular to a permanent magnet synchronous motor for a torque-limiting scraper conveyor.

Background technique

As a kind of conveying device, the scraper conveyor is the key core equipment in the fully mechanized mining face. During the operation, there are often failures such as drive system abnormality, heavy load difficult to start, chain jamming, and broken chain. Once the operation is stopped, the entire coal mining process will fall into a state of shutdown, resulting in the termination of production, which directly affects the efficiency of coal mining and the economic benefits of coal mines.

At present, the mainstream driving method of scraper conveyor is three-phase asynchronous motor, but the asynchronous motor has large starting current, small starting torque and low efficiency, and usually needs to install a reducer and other coupling devices, which has complex structure of the driving system and equipment volume. Disadvantages such as large size and high maintenance frequency.

The permanent magnet synchronous motor has the functions and advantages of low speed, high torque, high power density, high efficiency and energy saving, and small size. With the vigorous development and wide application in recent years, the permanent magnet synchronous motor is a more ideal driving device for the scraper conveyor. However, there is currently no effective mechanical torque limiting protection device for permanent magnet motor drive, which directly affects the reliability and service life of the scraper conveyor.

Due to the harsh working environment, when the scraper conveyor has a sudden load or even a chain jam, although the permanent magnet synchronous motor has traditional electrical protection, it responds slowly and cannot protect it in time; at the same time, the scraper conveyor belongs to For heavy-duty equipment, even if the power supply and power can be cut off, due to the huge inertia of the scraper conveyor and its drive system, an instantaneous stall will cause a huge inertial impact, which can easily cause accidents such as chain breakage of the scraper chain and damage to the drive system.

At present, there are many types of torque limiting protection devices for scraper conveyors, but the overload protection performance is not ideal, and the scraper conveyors and their drive systems often break down.

Underground scraper conveyors in coal mines have a harsh working environment and complex working conditions. At present, the torque-limiting overload protection device of the drive system has a complicated structure. advanced questions.

Contents of the invention

The main purpose of the present invention is to provide a permanent magnet synchronous motor for a torque-limiting scraper conveyor to solve the above problems.

In order to achieve the above purpose, the present invention provides a permanent magnet synchronous motor for a torque-limiting type scraper conveyor, including a housing, and the two ends of the housing are respectively fixedly connected with a front end cover assembly and a rear end cover assembly; the inner wall of the housing A stator assembly is fixedly connected to the top; a rotor assembly is arranged between the front end cover assembly and the rear end cover assembly; a motor output shaft is arranged in the hollow output shaft of the rotor assembly; the hollow output shaft of the motor output shaft and the rotor assembly The output shafts are connected through a cylindrical friction torque limiter.

Further, the cylindrical friction torque limiter includes an expansion piece, a tightening bolt, a friction sleeve and an inner hub connector; the expansion piece is a wedge-shaped structure, the expansion piece is in radial contact with the hollow output shaft, and the friction sleeve It is in radial contact with the wedge-shaped structure in the expansion member, and the inner hub connecting member is in radial contact with the friction sleeve; the motor output shaft and the inner hub connecting member are connected by splines.

Further, a cylindrical wet friction pair is formed between the friction sleeve and the inner hub connector, which is filled with a preset amount of lubricating oil during installation, and there are helical oil guide grooves between the friction surfaces of the friction sleeve.

Further, the rear end cover assembly is connected to the casing by bolts.

The present invention has the following beneficial effects:

(1) The present invention makes full use of the functions and advantages of permanent magnet synchronous motors such as low speed and high torque, high efficiency and energy saving, high power density of cylindrical friction pairs, and good overload protection performance, and highly integrates the two to complete a torque-limiting permanent magnet The synchronous motor scheme design realizes the ideal drive and efficient overload protection of scraper conveyors, especially heavy-duty scraper conveyors.

(2) When the scraper conveyor has a heavy load impact or a chain jam, the load torque exceeds the rated value, and the torque limiting mechanism in the permanent magnet synchronous motor dynamically separates the rotor hollow shaft from the motor output shaft, which isolates the short-term peak of the system The load and impact load have the function of "shaving peak", realizing the fast and effective protection of the motor and the drive system; after the instantaneous load, the torque limiting structure can return to the synchronous rotation state, and the motor outputs torque and power normally. The torque-limiting permanent magnet synchronous motor can improve the reliability of the equipment and prolong the service life of the whole machine.

(3) The torque-limiting permanent magnet synchronous motor is specially designed for large-scale equipment such as heavy-duty scraper conveyors. It has a high degree of integration, small size and simple structure, which is convenient for disassembly and maintenance and low maintenance cost, shortens downtime and improves production. efficiency and economic benefits.

Description of drawings

Fig. 1 is a schematic diagram of a permanent magnet synchronous motor for a torque-limiting scraper conveyor according to the present invention.

Among them, 1-stator assembly; 2-rotor assembly; 3-housing; 4-rear cover assembly; 5-hollow output shaft; 6-expansion piece; 7-tightening bolt; 8-friction sleeve; 9-inner hub connection ; 10-motor output shaft; 11-front end cover assembly.

Detailed ways

In order to achieve the above purpose and effects, the technical means and structures adopted in the present invention will be described in detail in terms of the features and functions of the preferred embodiments of the present invention in conjunction with the accompanying drawings.

As shown in Figure 1, the present invention provides a permanent magnet synchronous motor for a torque-limiting type scraper conveyor, including a housing 3, and the two ends of the housing 3 are respectively fixedly connected with a front end cover assembly 11 and a rear end cover assembly 4. A stator assembly 1 is fixedly connected to the inner wall of the housing 3; a rotor assembly 2 is arranged to rotate between the front end cover assembly 11 and the rear end cover assembly 4; the hollow output shaft 5 of the rotor assembly 2 is provided with a The motor output shaft 10; the motor output shaft 10 is connected to the hollow output shaft 5 of the rotor assembly 2 through a cylindrical friction torque limiter. The stator assembly 1 and the rotor assembly 2 of the permanent magnet synchronous motor generate torque through electromagnetic induction, and output power through the hollow output shaft 5 in the rotor assembly 2 .

The cylindrical friction torque limiter includes an expansion piece 6, a tightening bolt 7, a friction sleeve 8 and an inner hub connector 9; the expansion piece 6 is a wedge-shaped structure, and the tightening bolt 7 is connected with the expansion piece 6 for controlling The expansion member 6, the expansion member 6 is in radial contact with the hollow output shaft 5, the friction sleeve 8 is in radial contact with the wedge-shaped structure in the expansion member 6, and the inner hub connecting member 9 is in radial contact with the friction sleeve 8; The motor output shaft 10 and the inner hub connector 9 are splined, and the final power output is used to drive the scraper conveyor to work.

Compared with the traditional motor rotor, the torque-limited permanent magnet synchronous motor makes the wedge-shaped structure inside the expansion part realize the radial Squeeze to control the radial contact pressure between the friction sleeve 8 and the inner hub connector 9, and then set the friction force and slip torque between the friction sleeve 8 and the inner hub connector 9, the friction sleeve 8 and the inner hub connector 9 A cylindrical surface wet friction pair is formed between them, and a preset amount of lubricating oil is filled during installation, and there is a helical oil guide groove between the friction surfaces of the friction sleeve 8. By adjusting the different pre-tightening forces of the bolts, the adjustment of the slipping torque of the cylindrical friction pair can be flexibly realized. The torque limiter can be adjusted again when the friction coefficient of the cylindrical friction pair slips repeatedly or wears down.

Under normal working conditions, the cylindrical friction torque limiter is equivalent to a rigid coupling, which does not slip and consumes energy, and normally transmits torque. When the load of the motor output shaft 10 of the permanent magnet synchronous motor is too large or an instantaneous impact occurs, exceeding the set value of the slipping torque of the friction pair between the friction sleeve 8 and the inner hub connector 9, the friction surface slips and the permanent magnet synchronous motor is cut off. At the same time, the instantaneous impact caused by the huge moment of inertia at the output end of the permanent magnet synchronous motor and the instantaneous stall will not have a great impact on the scraper conveyor and its driving device. The scraper conveyor and the permanent magnet synchronous motor are dynamically separated and isolated. The short-term peak load and impact load are eliminated, and the overload protection of the scraper conveyor is effectively realized. When the short-term peak load disappears, the cylindrical friction pair resumes the connection and synchronous rotation state, and continues to transmit power and torque.

In another embodiment, the rear end cover assembly 4 is connected to the housing 3 by bolts. When the cylindrical friction torque limiter slips and fails or is damaged and needs to be replaced, the rear end cover assembly 4 is disassembled to carry out the cylindrical friction torque limiter. Partial replacement facilitates rapid inspection and maintenance of the torque-limiting permanent magnet synchronous motor.

The above is only a preferred embodiment of the present invention, not all embodiments, anyone should know that the structural changes made under the inspiration of the present invention, all technical solutions that are the same as or similar to the present invention belong to protection scope of the present invention.

Claims (4)

1. The permanent magnet synchronous motor for the torque-limiting scraper conveyor is characterized by comprising a shell, wherein the two ends of the shell are fixedly connected with a front end cover assembly and a rear end cover assembly respectively; the inner wall of the shell is fixedly connected with a stator assembly; a rotor assembly is rotatably arranged between the front end cover assembly and the rear end cover assembly; a motor output shaft is arranged in the hollow output shaft of the rotor assembly; the motor output shaft is connected with the hollow output shaft of the rotor assembly through a cylindrical friction torque limiter.

2. The permanent magnet synchronous motor for a torque limiting type scraper conveyor according to claim 1, wherein the cylindrical friction torque limiter comprises an expansion member, a tightening bolt, a friction sleeve and an inner hub connecting member; the expansion piece is of a wedge-shaped structure, the expansion piece is in radial contact with the hollow output shaft, the friction sleeve is in radial contact with the wedge-shaped structure in the expansion piece, and the inner hub connecting piece is in radial contact with the friction sleeve; the motor output shaft is connected with the inner hub connecting piece through a spline.

3. The permanent magnet synchronous motor for the torque-limiting scraper conveyor according to claim 2, wherein a cylindrical surface wet friction pair is formed between the friction sleeve and the inner hub connecting piece, a preset amount of lubricating oil is filled during installation, and a spiral oil guide groove is formed between friction surfaces of the friction sleeve.

4. A permanent magnet synchronous motor for a torque-limiting scraper conveyor according to claim 1, 2 or 3, wherein the rear end cap assembly is bolted to the housing.