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Common problems in elevator speed limiter inspection

I. schindler elevator parts Speed limiter-safety gear linkage test in acceptance inspection

1. Determination of action speed
Determining the operating speed: Because the operating speed of the speed limiter has been debugged and verified, and the energy absorbed by the safety gear has passed the type test verification, the safety gear combined transport test is performed to prove the speed limit before delivery. Is the switch's operating speed before reaching the operating speed and whether the safety gear is correctly installed? Is the installation adjustment qualified? Is the connection between the safety gear and the building secure?

2. The entire process of linkage test and safety standards
In the elevator engine room, the mechanical switch of the speed limiter is manually operated to control the elevator to go down the maintenance speed, causing the speed limiter electrical safety switch to be turned off, thereby stopping the traction machine. Link the speed limiter's electrical safety switch, operate the elevator to continue the maintenance, and let the hard wire rope of the speed limiter brake and pull up to the safety gear. At this time, the electrical switch equipped with the safety gear stops the traction machine and is safe. The tongs move, clamping the guide rails, and stopping the car.
Safety standards: First, after the safety gear is activated, it should continue to be checked down. At this time, the traction wire rope will slip on the traction wheel, thus proving that the safety gear has braked the car on the guide rail. Second, to ensure the consistency of the track of the safety gear wedge on the guide rail.
According to the requirements of the "Elevator Supervision and Inspection Regulations", when the elevator performs the speed limiter-safety gear linkage test, each safety gear must be under no-load inspection of the car, and its test speed must be consistent at the leveling speed or during maintenance. Speed down.

3. Related issues
If the safety gear stops working during the linkage test, it needs to be tested from the following aspects:
①Test whether the tension of the governor wire rope is sufficient and the oil on the governor sheaves, these two factors will cause the wire rope to fail to lift the safety gear reliably;
② Test the lifting mechanism of the safety gear is not flexible, and whether there is corrosion;
③Test whether the safety gear is installed incorrectly and whether the adjustment is incorrect. Especially if the gap between the jaw and the rail is too large;
④ Is the stroke of safety gear lifting too small?
 

Second, the speed check of the speed limiter during periodic inspection

Today, XC series speed limiter testers are widely used for speed limiter calibration. After the elevator is used for a period of time, many problems such as wear, fatigue, and corrosion will occur in the safety gear and the governor. These problems will cause changes in main parameters or weakened functions and loss of functions.
  We take the XC series speed limiter tester as an example to do the following analysis.
 
1. Frequent problems in speed limiter inspection
According to the different conditions of the elevator and on-site conditions, many different problems will be encountered during the on-site verification process. The main issues are:
① The main reason for the increase in the negative force of the governor wheel rotation is the bearing damage, shaft wear, burnout, and oil shortage. Due to the long service life and lack of maintenance, the bearing is short of oil and wear. This situation can only be detected after the speed limiter wire rope is removed;
② The action mechanism is rusty and inflexible. If the pawl cannot catch the ratchet teeth, it is because the spring on the pawl and the oil and dust on the shaft make the spring insufficient.
③ The speed limiter cannot be dismantled, adjusted, and the seal is damaged because the seal is forbidden for maintenance personnel to adjust;
④ The friction of the speed limiter will reduce friction due to rust, which will cause the speed limiter to exceed its operating speed;
⑤ Due to the artificially adjusted spring of the speed limiter, the mechanical action speed exceeded the standard;
⑥ Because many units do not understand and save money, only the upper wheel of the speed limiter has been replaced without considering whether the upper and lower wheels match;
⑦If the diameter and requirements of the wire rope on the speed governor are consistent, it is easy to cause the speed governor to malfunction due to the small gap between the wire rope and the clamping block;
⑧Because of the lack of oil and rust on the transmission arm of the connecting rod, the lifting force greatly exceeds 300N;
⑨When the arm is raised, the switches cannot move at the same time because the distance between the end of the active lever and the safety gear interlock switch is too large;
⑩ When the connecting rods are pulled together, the wedges cannot catch the guide rails because of the large gap between the wedges and the work on the side of the guide rails;
⑪If there is too much oil, when the arm is released, the wedge will not be restored to its original position, which will damage the guide rail. Due to the large existence of these problems, the system becomes a decoration, and the human psychology is paralyzed If in the past, it may cause serious harm.
 
2.Solving measures for elevator speed limiter calibration problems
To prevent major accidents, regular maintenance and maintenance of the speed limiter and safety gear must be performed. Specific needs to do the following 3 points:
① Frequently check the speed limiter. Calcium-based lubricant is added to the rotating pin and tightening equipment once a week. The tension of the tensioning equipment must be uniform, the shaft should be injected once a week, and cleaned once a year. The rope should be shortened in the sealed place. To check the speed limiter's operating speed through the special congestion inspection department, it must be ensured that its operating speed is within the range prescribed by national standards.
② Add oil to the safety gear and connecting rod mechanism once a month. Be sure to ensure that the lifting force can be quickly transmitted to the lever, and not exceed 300N. Regularly adjust loose springs, screws, pins and other parts. Apply a small amount of petroleum jelly to the wedges once a month. Regularly clean and adjust the safety gear to remove the dirt inside, otherwise the forceps block cannot move flexibly.
③ When the factory maintenance personnel make adjustments to the speed limiter, they need to make seals after the adjustment is appropriate. Other non-professionals should not arbitrarily perform adjustment and maintenance work.
速 The speed limiter-safety gear has passed the calibration and is of great importance to its resetting, so this work requires qualified maintenance personnel to restore the speed limiter and related electrical switches. The most important thing is not to open the safety gear under stress, otherwise it will cause the speed limiter to fall quickly. In this way, the switch action of the tensioner and the rope of the speed limiter will hang on other devices. After the inspection is correct, the test speed and the rated speed must be divided into single-layer and multi-layer test runs from top to bottom, and from bottom to top. After confirming that there are no abnormalities, use the rated speed to perform a full test run. The abnormal noise makes the elevator can be used normally.

3. Correct the data error
When verifying the operating elevator parts speed of the speed limiter, it is possible that the actual measured value of this operating speed has just exceeded the upper limit specified in GB7588-2003, which will result in failure. At this time, the speed of the X-series instrument should be used to measure the error. The actual measured value of the speed of the speeder needs to be corrected to avoid misjudgment and avoid unnecessary losses.

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