Richmond Wheels and Castors was recently given a design brief from a large automotive company that required 50 towable, shock absorbing and anti corrosive castors that were capable of carrying a maximum load capacity of 375kg. The spring loaded castors were to be used on high frequency trolleys transporting components to the production assembly line.
Headed by current Chairman Ray Winslow, the Richmond Engineering team applied its 50 plus years of design and manufacturing to provide a product solution that would exceed the customer’s expectation.
The first issue was to provide a hard wearing fully anti corrosive castor, this was achieved by applying a sacrificial Zinc Gold passivate to all components.
The second issue was to ensure the structural integrity of the castor whilst being towed, allowing a smooth cushioned ride for the valuable parts as they were transported along the assembly line.
Richmond’s spring loaded castors included the following special design features that helped them achieve the design brief:
- Each spring is supported by a polyurethane damper (just like a car)
- The bearing race included a twin bearing setup. One thrust bearings and one taper roller bearing, offering maximum rigidity on the swivel race
- Between each of the side plates which rotate as the springs move up and down are phosphorous bronze bushes. These space apart the brackets, eliminating rubbing between the 2 moving components. The bronze performs well as a low friction, non rusting spacer as well as removing potential squeaking from the moving parts
- Also included in the castor are twin donut profiled, polyurethane tyred 12” wheels with precision ball bearings. A twin wheel castor in towed applications is far superior to single wheeled castors. They provide lower overall rolling resistance and excellent manoeuvrability, as the wheels can turn on a dime due as the wheels rotate at different speeds, depending on the trolley’s direction or turning radius. The donut profile further reduces rolling resistance.
Shock absorbing and spring loaded castors with polyurethane wheel can be designed by Richmond to suit specific requirements.