Key points for safety inspection of electric hoist brakes
Classification:
Industry News
Author:
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Release time:
2015-11-29
The brake on an electric hoist is usually installed on the high-speed shaft of the mechanism (motor shaft or input shaft of the reducer). Some brakes are installed on the low-speed shaft or drum to prevent items from falling when the transmission system breaks. The former allows for a smaller brake size due to lower braking torque; the latter increases safety by preventing falling items due to damage to load-bearing components in the transmission system. During routine safety inspections, the following requirements must be confirmed with emphasis:
First, cranes driven by power must have brakes installed on their lifting, luffing, running, and rotating mechanisms;
Second, the brakes on the lifting and luffing mechanisms must be normally closed brakes;
Third, lifting mechanisms that handle hot metals or other hazardous materials, as well as those that could cause significant danger or loss in the event of an accident, should have two sets of supporting brakes for each independent drive unit.
Fourth, cranes driven by human power must have brakes or stops installed on their lifting and luffing mechanisms;
Fifth, the braking torque of the brakes should meet the following requirement:
Mz≥kM
Where: Mz -- braking torque of the brake;
M -- transmission torque of the shaft where the brake is located;
k -- safety factor
Safety factor for the usage condition of the mechanism
General lifting mechanism 1.50
Important 1.75
Hydraulic transmission with hydraulic brakes 1.25
Lifting mechanisms for handling hot metals or hazardous materials
when equipped with two supporting brakes, for each set of brakes 1.25
Two drive units that are rigidly connected to each other, when each unit
has two sets of supporting brakes, for each set of brakes 1.10
Non-balanced luffing mechanism 1.75
Balanced luffing mechanism in working state 1.25
In non-working state 1.15