Why does the elevator have a overspeed governor?

Elevator Overspeed Governor Manufacturer, Lecture on elevator parts and elevator knowledge Elevator Safety Gear & Reducer

Elevator Overspeed governorElevator OverSpeed limiter is one of the safety control components of elevator safety protection system. When the elevator in running ,no matter what the speed governor in the car or the risk of falling or other situations of safety protection devices do not work, safety gear speed governor and linkage will start to work and make the elevator car stop running, to ensure the safety of the elevator.

  1. Installation location

The speed governor is generally located in the elevator machine room. According to the requirements of the installation plan, it is generally installed on the floor of the machine room. However the speed governor also can be directly installed on the bearing beam .The specific position of the speed governor is determined according to the construction drawing and the position of the car and guide rail after adjustment.

  1. Technical requirements
  2. We should pay attention to the speed governor wheel vertical degree of deviation should not be more than 0.5 mm, speed governor wire rope should be aligned with room reserved hole center, the error is not more than 0.5 mm, governor rope groove center and tension pulley rope groove center must be in the same vertical plane. The car will be two rope to the connecting hole, two connecting holes should be on the same vertical line after the connection completed.
  3. According to the requirements of the installation plan, the position deviation of the speed governor should not be greater than 3mm.
  4. The distance between the rope and the guide rail of the speed governor device should meet the requirements of the installation plan.
  5. The tension of the tension device on each branch of the rope shall not be less than 150N.
  6. Speed governor switch and tension wheel switch shall ensure that the control loop can be cut off quickly and reliably when the rope breaks off, falls off, the rope clamp is unhooked or the speed governor is in action.
  7. Notes
  8. The action direction of the speed governor should be consistent with the descending direction of the car to ensure the safety clamp works.
  9. The wire rope of speed governor shall not be rubbed or contacted with the clamping pliers during normal operation.
  10. The steel wire rope of speed governor shall not have any dead bend and a rope sleeve shall be installed at the connection with the cage pull rod and the rope head shall be firmly fastened with a rope clamp
  11. Restrictions

The speed governor must be starting to work before the car speed exceeds 115%.

1) For instantaneous safety gear, the speed governor of 0.80m/s (except roller type).

2) For roller type instantaneous safety gear, the speed governor of 1.0 m/s.

3) for safety gear with buffer effect and for progressive safety gear with rated speed governor not exceeding 1.0 m/s, 1.5 m/s.

4) for progressive security safety gear with rated speed governor over 1.0 m/s, the speed governor of 1.25 *v+ 0.25 /v.

The speed governor is a safety device, so the manufacturer should evaluate the product in accordance with appendix Fo4 of the en81-1/2 standard before it is released. If the assessment result is positive, a type certificate will be issued and must be attached to the equipment. The CE mark is displayed simultaneously on the device.

Lecture on elevator parts and elevator knowledge Elevator Safety Gear & Reducer

Lecture on elevator parts and elevator knowledge

Lecture on elevator parts and elevator knowledge Elevator Safety Gear & Reducer

  • Elevator Safety Gear & Reducer

Elevator safety gear is a mechanical device, which stop the car (or counter-weight) from moving. Safety pliers are required for any manned car suspended by a wire rope or chain. When there is a passageway or space under the bottom pit, a safety clamp is also required for the weight. The safety clamp is set on the beam under the cage frame and ACTS in pairs on the guide rail at the same time.

A speed limiter is a device that limits the speed of a car (counter-weight), and usually installed in the machine room or at the top of the well. The tension device is placed in the bottom pit.

Safety gear and speed limiters must be combined to work.


  1. Elevator Speed limiter (Reducer)

Speed limiter can be divided into swing hammer type and centrifugal type according to its action principle.

Hem hammer speed limiter is to use the CAM on the rope wheel in contact with the roller at the end of the pendulum in the process of rotating, the frequency of the pendulum swings associated with rope wheel speed, when the vibration of the pendulum frequency exceeds a predetermined value, the pendulum of the ratchet into rope wheel stop stop claws, so that the speed limiter to stop running.

The speed limiter of centrifugal structure can be divided into vertical axis rotating type and horizontal axis rotating type. It is characterized by simple structure, high controllable ability and small space required for installation.

When designing or selecting, the following problems should be noted:

1). Speed limiter operating speed

2). Pretension force of speed limiter rope

3). Adhesion of the speed limiter rope to the rope wheel or the tension force of the speed limiter during operation

4). The response time of the limiter action should be as short as possible.


  1. Instantaneous safety gear

It features a short braking distance and a strong impact on the car.

Divided into several categories:

Wedge type instantaneous safety pliers

Eccentric block type instantaneous safety clamp

Roller type instantaneous safety pliers


  1. Progressive safety gear

It is characterized by elastic clamping of the clamping body, long stopping distance and stable car.