Composition of single girder crane

Electric single girder cranes mainly include three kinds of operating mechanisms: hoisting operating mechanism, trolley operating mechanism, and crane running mechanism. The hoisting mechanism is mainly composed of an electric hoist, wire rope, pulley, hook, or spreader. The metal structure of an electric single girder overhead traveling crane mainly consists of two parts: the main girder and the end girder. The main girder structure is mostly a combination of I-beam and steel plate sections. It consists of a cover plate, web plate, and I-beam. The reinforcement plate, its safety, and its reliability directly affect the operational quality and working capacity of the crane.

Features of single girder crane steel structure production

• The materials of the main steel structure (main beam, end beam) are all -B, and the materials used have material reports and corresponding certificates of conformity.
• Manufacturing, welding, and inspection of crane steel structures are carried out following GB/T 1306-2008. Important load-bearing butt joints are welded by a double-sided bevelling process, and appearance inspection and non-destructive testing are carried out according to regulations. All welders have relevant certificates.
• The main girder of all cranes adopts the whole-plate non-butt process, which cancels the butt weld of the main girder steel plate and eliminates the hidden danger of the butt weld of the steel plate. (Butt welding of steel plate is the most important welding and also the part with hidden quality problems)
• All plates are automatically cut by a CNC cutting machine, and the main beam arch is pre-set to avoid the problem of arch deflection of the traditional fire-baked main beam.
• Steel surface by shot blasting, surface roughness reaches “before painting steel surface treatment registration rust removal grade” Sa2, 5 level, improve paint adhesion, do not peel off the paint, and single girder crane looks beautiful and long-lasting.
• The longitudinal waist weld of the main beam adopts a domestic fully automatic submerged welding special machine, a beautiful shape.
• The whole crossbeam of the wagon adopts a rectangular tube, no splicing, no weld, beautiful appearance, strong and durable.
• Wheel mounting adopts drilling-type mounting, preventing the tread surface of the wheels from leaving the same level and improving the running accuracy of the wheels.

Mechanical system performance characteristics of single girder crane

Lifting mechanism

The lifting mechanism of single girder crane is composed of two-speed electric hoist. This product has the advantages of compact structure, light weight, small volume and easy operation.

• Reducer: The reducer of electric hoist on the single girder crane adopts helical gear three-stage reduction. Gears and gear shafts made of steel or steel, heat-treated are supported by rolling bearings. The case is made of cast iron. Tight assembly, dustproof and reliable.
• Drum device: The drum is made of cast iron or seamless steel pipe, connected with the reducer through spline, and the other end is supported by the rolling bearing at the front end of the conical motor. The drum shell is made of steel plate.
• Hook device: The hook is made of 20 steel die forging, thrust ball bearings are connected with the shell through the hook beam to make the hook run freely.
• Coupling: The torque of motor is transferred to the reducer through claw type flexible coupling, which can absorb the shock of load and get smooth start.
• Slow speed drive device: The slow speed drive device consists of drive box, box cover and small motor. The small motor drives the main motor through the slow speed device.
• Limiter: In order to prevent the hook from rising and falling beyond the limit position and causing failure, the hoist is fitted with a limiter. When the hook reaches the limit position, the rope guide on the single girder crane reel device drives the limiter action, automatically cuts off the power supply and stops the hoist. All electric hoist are equipped with lifting capacity limiter.
• Motor: The lifting motor adopts conical brake motor, which has greater starting torque and is suitable for frequent direct starting when the product runs intermittently. The torque is 2.4~3 times of the rated torque.
• Electric control system: mainly consists of control box and operation button box of single girder crane, with protection or alarm functions such as loss of pressure, interlocking, overload and overload alarm.

Trolley operating mechanism

The operating mechanism of single girder crane electric hoist is electric trolley type. The speed reducer is forged, tempered and installed in a closed speed reducer box. All supported by rolling bearings. The wall plate is made of steel plate, which is flexible in operation, easy to use and has a long service life.

The trolley operating mechanism is equipped with frequency converter, stepless speed regulation, smooth running, accurate positioning and comfortable operation.

Crane trolley running mechanism

Single girder crane trolley running structure consists of motor, reducer, wheel set. The wheels are 45# forgings. The hardness after heat treatment is HB≥~ for the tread and HB≥ for the deep part. Shaft and gear material is 45# or after tempering. The trolley drive is a new type of LDA drive device with the advantages of simple structure, small size, large starting torque, frequent start-up, stable running speed, low noise, easy installation and maintenance, and beautiful appearance.

Single girder crane trolley running mechanism adopts frequency converter, stepless speed regulation, smooth running, accurate positioning, comfortable operation.