A Rack and Pinion Side Gate from HMA Materials Handling consists of a gate frame, blade, rack(s), pinion gear(s), pinion shaft, shaft bearings and a manual or powered shaft drive. Some larger manual drives may incorporate v-belts and/or gearboxes for mechanical advantage. Most powered rack and pinion gates incorporate some type of mechanical advantage between the driver and pinion shaft.
Rack and pinion gates from HMA Materials Handling are used generally as maintenance gates ahead of feeders and other equipment. Due to their simple construction, rack and pinion gates can be relied on to operate after months of inactivity. This is especially important in powerhouse and industrial applications.
Due to their limited actuating speed, HMA Materials Handling rack and pinion gates are rarely used to regulate flow into a process or onto a conveyor. However, they are sometimes used to discharge small hoppers that always discharge completely. For example, a rock bin that has a maximum capacity of one truckload may use a rack and pinion gate from HMA Materials Handling to shut off flow when a truck is not being loaded. Rack and pinion gates larger than 1500 mm are seldom economical due to high operating forces and the resulting expensive drive hardware.
Some typical applications include:
- 600 mm to 1200 mm rack and pinion gates from HMA Materials Handling can be used to load trucks from small coal or rock bins
- As maintenance gates ahead of coal feeders, pulverisers, crushers, and alternate process systems
- Most flow-control applications not requiring a high blade speed
- Emergency shut-off gates allow maintenance of downstream equipment without unloading the material in storage