Design a Gearbox for Cargo Lift | 2018

University of Moratuwa

Cargo lifter is used in airports and also in dockyards. Main purpose of this is to lift the cargo to a higher level for loading purposes like loading in to a plane etc. usually this operates in 2 ways. Hydraulically or using a motor and cable mechanism. Sometimes screw mechanism is used instead of cables. A scissor jack mechanism is used when hydraulics is used.

A main issue in hydraulic cargo lifter is the limitation of height due to the scissor mechanism used. Cost is higher when increasing the height of hydraulic lift. The weight of the cargo changes and the torque applied should also be changed accordingly. Volume and the weight of the cargo is not proportional. So sometimes though the volume is low, higher weight has to be lifted and in some occasions opposite happens. The power of the motor is kept constant and a need for a gear system occurs to change the torque applied.

Another main issue in the hydraulic system is that the all the apparatus are installed below the base plate. When loading, base plate is brought below the ground level and lifting is done. When the system fails after loading, it is very difficult to repair the system due to this.

The client wants a cargo lift with the below mentioned characteristics.

• Several torques to lift several rages of weight with different speeds.

• Easy repair in case of a failure.

• To increase the height of the lift with minimum cost

• Capacity Low range : 1 - 3 ton Medium range : 3 - 5 ton High range : 5 - 7 ton

• Machine can be moved

• Operator skill level: Low

• Machine safety: According to ISO standards

• No. of operators: 01

• Operating cost: less than Rs 500,000 per month

• Maintenance interval: Every week

• Cleaning operations: Daily

To satisfy these requirements we were designed a Gear Box.

Inside of the Gear Box

Final Design