The motor damper is a new type of magnetic transmission mechanism that has appeared abroad in the last ten years. It uses the principle of magnetism, AC Motor Damper the main, passive pair of magnetic pairs, through the magnetic contactless connection, the torque transmission. Adjust the size of the air gap between the magnetic pairs, you can adjust the damping torque from zero to the maximum. When the air gap distance is locked, the size of the damping torque during operation can be kept constant for a long time and does not change with the change of the relative speed of the passive pair.
Motor dampers by the two semi-semi-composed, simple structure, the process of running by magnetic connection, both without direct contact friction. Clearance adjustment (ie, torque adjustment) convenient, small installation size, long life, no fault.
It is widely used in machinery such as wire and cable, fiber optic cable, film, textile, weaving and so on, which need to provide stable transmission torque, damping torque or tension. In the cable, fiber optic cable machine, can be used as a beam machine, stranding machine, paint machine, paper charter, AC Motor Damper around the charter, drawing machine, rewinding machine, fiber covered machine, fiber optic cable belt machine Put on, retractor with tensioner. Because of its constant torque characteristics, can make in the high-speed, low speed, full disk, tray and other occasions to make tension moment unchanged. If the motor dampers are coaxial with the sizing wheels, the tension (F) of the wires and strips can be made constant by passing the sizing leads and the belt at the same time.
It is more than the industry with a rubber band tension, or silk brush block to provide lines, with tension of the way there is no comparable advantages. Compared with the mechanism of controlling the tension with the motor, AC Motor Damper the same tension quality, and its structure is much simpler. Adjust more convenient, lower prices, and no trouble, no maintenance.
The motor dampers are just a component that uses different damping effects in different places or in different working environments. Damper: for damping; Snubber: for shock, low speed allows to move, when the speed or acceleration exceeds the corresponding value of the lock, the formation of rigid support.
Various applications include: spring motor dampers, hydraulic motor dampers, pulse motor dampers, rotating motor dampers, wind turbine dampers, viscous motor dampers, damping hinges, damping slides, furniture hardware, cabinet hardware The
High-speed rotating machine vibration problem is a more prominent and difficult to solve the problem. The speed of this machine is high, all in the critical and even higher than the critical speed to run. Therefore, AC Motor Damper in order to ensure its safe operation, in addition to ensuring careful design and accurate manufacturing installation, usually also use the motor damper to reduce vibration. Squeeze film motor dampers and electromagnetic motor dampers are two commonly used motor dampers. This paper designs a new type of controllable passive electromagnetic motor damper.
Structure and working principle of controllable passive motor dampers
Figure 1 is a schematic diagram of a controllable passive electromagnetic motor damper. It has no displacement sensor. The structure is similar to the extruded oil film motor damper: the rotor (1) of the rotating machine is supported on the core (3) by means of a rolling bearing (2) or a sliding bearing. The core is further supported on the base (5) by means of a spring (4). The stiffness of the spring can be designed according to the requirements of the use, to support the main stiffness of the system. In the base around the core concentric placed four electromagnets (6). Each of the magnet coils are acting on the same size of the DC excitation voltage.
Figure 2 shows the controllable passive electromagnetic motor damper generated by the additional stiffness and damping with the frequency of the situation. It can be seen that the value of the additional stiffness over the entire frequency range is negative and the negative stiffness value decreases as the frequency increases. AC Motor Damper The stiffness value in the high frequency region is almost zero. This damping characteristic just conforms to the low frequency damping high frequency small damping required by the rotating machine. After the dimensions of the controllable passive electromagnet dampers are determined, the stiffness and damping values depend only on the static excitation current or the excitation voltage. Changing the excitation voltage can change the stiffness and damping, so this motor damper is controllable.