Overhead Crane Wheels

Wheel is a device used to support the weight of the whole crane and make it travelling.

1、Classification

According to the form of wheel rim.

The role of the rim is to guide and prevent derailment)

A double rim

B single rim

C no rim

Normally, double rims are used for large wheels and single rims are used for small wheels. When installing, the rims are placed on the outside of the track. Rimless wheels should be fitted with a separate horizontal wheel to guide and prevent derailment.

2.Wheel tread

A Cylindrical

B Conical

C drum type

Most cranes use the first two, only in the I-beam running on the lower flange of the crane to use the latter one

For overhead travelling cranes, the tread of the active wheel of the centrally driven trolley is conical and the driven wheel is cylindrical; for individually driven trolleys, both the main and driven wheels are cylindrical; all trolley wheels are cylindrical.

For individually driven large vehicles, the main and driven wheels are cylindrical; all small vehicle wheels are cylindrical.

The wheels with conical tread must be equipped with rails with curvature in the head. Wheels with conical tread are generally only used for two driving wheels, two driven wheels on the car body.

3. Wheel set

(1) The wheels are mounted on a fixed mandrel, and the wheels are fixed to the frame with a fixed axle piece, and the wheels can rotate freely on the axle between the hub and the axle can be fitted with sliding bearings or rolling bearings.

2) Wheel mounted on a spindle or mandrel mounted on a spindle to become the active wheel, mounted on a mandrel to become the driven wheel

4.Wheel size of overhead travelling crane

Mainly based on the size of the wheel pressure to determine the wheel pressure to increase the diameter of the larger, but if too large, the equipment costs increase, while the wheel speed becomes lower so that the transmission mechanism is complex.

 Therefore, when the wheel diameter can not be increased, commonly used to increase the number of wheels to make each wheel wheel pressure reduction. In order to make each wheel pressure evenly distributed, in the number of wheels more than four, must use the articulated equalisation frame device.

5、Materials of overhead travelling crane wheels

Should be determined according to the drive mode, operating speed and crane working level and other factors.

For mechanical drive and speed greater than 30m/min, intermediate and above intermediate work type, it is recommended to use not less than ZG55 cast steel, and surface quenching (flame quenching or high frequency quenching), hardness is not less than HB320-350, quenching depth is not less than 5mm.

For human-driven or mechanically driven light work type, speed less than 30m/min, can use cast iron wheels, surface hardness HB180-240

Bridge Crane Tracks

The rails are used to withstand the concentrated pressure from the crane wheels and to guide the wheels All rails for cranes are made of standard or special rolled steel sections or rails.

Small rails - P-type railway rails

Large rails --- P or U type railway rails for cranes

Calculation of wheel and track selection

Wheel tread fatigue contact stress calculation, wheel tread contact stress and wheel diameter and track type related, according to the calculation of the maximum wheel pressure, the operating level of the operating mechanism and other factors from the standard specification of the first selected wheel diameter, and then according to the different contact conditions of the contact strength calculation.