Anchor Frame Collar 2m For L68A1 Mast

Products Specification

Type , Model: Anchor Frame Collar 2m For L68A1 Mast

Size: 2m for 2M L type mast

Materials: Q345B

Process: Blasting derusting, 

Painting:  Under painting , Middle painting, Surface painting.

Our factory produce and supply almost all famous brand tower crane :Mast section, Anchor Frame, Fixing angle ,Adaptor and so on as good quality and price.

Anchor Frame Collar 2m For L68A1 Mast

Tower Crane Knowledge sharing：

Causes and solutions of electrification of tower crane hooks

According to above analysis, when the hook charged occur, to measure the tower crane electrical system, if the grounding resistance (including the hook of the resistance value), insulation resistance is normal, can be judged as is commonly caused by high frequency induction,

if in near a high-power radio transmitters or other source of high frequency, it can get more auxiliary certificate. Of course, it would be better to measure the frequency of the induced voltage.

Second, the shielding, short-circuit to the ground, repeated grounding method to solve the effect of high frequency induction is not good.

Anchor Frame Collar 2m For L68A1 Mast

1. Because the installation height of the tower crane and the long track of the horizontal arm are tens of meters, and the crane arm has to be rotated, the shielding method is used to solve the problem of the high frequency induction of the tower crane.

2.  Although it is feasible in theory, it is almost impossible to achieve, and there is no possibility of practical application.

Repeated grounding of the tower body of the tower crane is ineffective in eliminating or reducing high-frequency induction, because repeated grounding of the lower or upper part of the tower body or the component of the open conductor frame cannot achieve the purpose of eliminating the live hook.

3. Use soft wire to hang on the hook, so that the hook can be earthed before being touched by the cable staff, which can greatly reduce or eliminate the live phenomenon of the hook.

4. This is because when the hook touches the ground through the soft wire, it is equivalent to closing the conductor frame. The induced electromotive force caused by the alternating electromagnetic field in the frame forms a current in the closed conductor frame and consumes energy.

Besides, the resistance value of the grounded soft wire is far less than that of the human body. However, the current flowing through the lifting wire rope at this time has an impact on the service life of the wire rope, so this scheme can only be temporarily used, rather than long-term use.

To sum up, the electrification phenomenon of tower crane hooks is generally caused by high-frequency induction, and there are high-power (kw level) radio transmitters near the construction site.

Anchor Frame Collar 2m For L68A1 Mast

When this phenomenon occurs, it is an effective and simple way to deal with this phenomenon by using passive preventive measures such as replacing the hoisting hook frame pulley with nylon pulley and wearing insulating shoes and gloves by the rope rope personnel.

Preventive and improvement measures to prevent h3/36b tower crane hook from slipping

In 2007, in a construction site, h3/36b tower crane hoisted steel bar, steel bar just hoisted about 1m height, hook wire rope suddenly slipped, steel bar fall, due to the low lifting height, fortunately no personal injury accident occurred.

The tower crane manufacturer searched the data related to "the fall of the tower crane hook" and found that h3/36b and FO/23B tower cranes had such accidents for many times, which we analyzed and dealt with.

Anchor Frame Collar 2m For L68A1 Mast

I. cause of the accident

Through analyzing several same accident, after the incident are in inspection of lifting mechanism motor, reducer, found and motor gear (38 teeth), low speed gear tooth) (19 99 tooth meshing tooth plate and lock nut out of helical gear shaft, 38, 19 tooth gear tooth surface has obvious slip lines, 99 teeth of the gear shaft with spline gear disk with connecting all broken, caused the accident. The reasons are as follows.

1. The original design of the locking nut is not reliable. The original design is in the M38 lock nut back of a multi-car a phi 39 lock ring, nut tighten the lock trap embedded in the shaft end groove. This kind of structure does not use the stop washer, the structure is novel.

through the practice has proved that the locking ring after long-term use will appear the phenomenon such as crack, fracture, so this kind of structure is not reliable. Because of the axial force generated when the gear shaft is driven, the locking nut will become loose and exit in actual use.

resulting in the loose spline fit between the 99 tooth disk and the gear shaft, resulting in the loose spline fit and uneven force, thus causing the phenomenon of tooth hitting.

2. The original design of 99 tooth disk and gear shaft with spline teeth too small, strength is not enough, once loose, it is easy to spline teeth wear, break, make with failure, transmission failure, due to heavy weight caused by sliding accident.

Anchor Frame Collar 2m For L68A1 Mast

3. The maintenance is not in place. During the pre-installation maintenance of the h3/36b tower crane, the site was opened for maintenance and part of the high and low speed gears were replaced. The site was found intact after inspection. In addition.

according to the original design requirements for the maintenance of this part, it is only required to be carried out when the tower crane is removed for overhaul. However, according to the on-site situation, the mechanical installation.

maintenance personnel do not fully understand the installation of this part, especially the locking function of the locking ring of the locking nut and the inspection of the locking nut. Additional, the damage of this place, become loose gradually wear accumulates and cause, check at ordinary times maintenance is not in place also be one of reasons.

Ii. Preventive measures

I plant for the discussion of the problem, put forward the following preventive measures and maintenance system.

Anchor Frame Collar 2m For L68A1 Mast