According to different classification methods, speed limiter for cars can be divided into different types.
(1) According to the different triggering principles of speed limiter for cars over speed, it can be divided into two types of speed limiter, centrifugal and pendulum.
The action principle of the speed governor is that the centrifugal chunk, which is controlled by the centrifugal heavy block spring, moves away from the center of rotation with the speed of the rotation. The electrical contact is broken after reaching the contact plate of the electric switch, thus the electrical safety loop is cut off, and the elevator is stopped by the brake to stop the operation. In case of serious failure such as broken rope, the brake cannot stop the car, the speed of the car can be further accelerated, the shedding block of the speed limiter continues to open, touches the contact plate of the mechanical action of the speed limiter, and makes the clamp drop off, and can reliably clamp the wire rope under the effect of the speed limiting device and the clamp rope block, in order to make the wire rope not. The clamping force is adjusted by a compression spring.
The pendulum type speed limiter uses the cam on the traction wheel to contact the roller at the end of the pendulum in the process of rotation. The swing frequency of the pendulum is related to the speed of the rope wheel. It will increase with the speed of the rope wheel. When the swing frequency of the pendulum exceeds a certain value, the pawl of the pendulum will enter the pendulum and then touch the pendulum. The over-speed switch action of the speed limiter makes the rope wheel stop and complete the brake of the cars.
(2) According to the different functions of wire rope and rope slot, it can be divided into two types of clamping devices (or clamping rope) and friction (or traction) type speed limiter.
The car speed limiter for cars is connected to the safety rod on the two sides of the car by a wire rope. In order to ensure the speed and accuracy of the speed limiter chip, a finite speed tensioner is installed in the bottom hole of the well. When the car is running, the wire rope transforms the vertical movement of the elevator into the rotational motion of the speed limiter device.
When the speed of the car is more than 115% of the rated speed of the elevator, the speed limit of the speed limiter exceeds the limit value, the speed limiting device first makes the over speed switch cut off the power supply of the elevator control loop, and makes the electromagnetic brake out of the electric brake. If the brake fails, if the cars run, vehicle speed limiter system will clamp the wire rope, force the safety clamp to act, and force the car to stop on the guide rail. In order to prevent the traction machine from continuing to rotate, a safety clamp switch is specially set up, and the switch action is cut off when the safety clamp moves, and the control loop is cut off.