Elmira, NY óSimple and easy to use has long been the target for engineers in the consumer products industry. Acronyms like K.I.S.S. (Keep It Simple Stupid) are used to help the designer stay focused. That is the theory behind the latest patent-pending wheel clutch developed by the design team at The Hilliard Corp.'s Motion Control Div. Lawn and garden equipment manufacturers are using the wheel clutch design for their next generation models. The system is also being promoted as an after-market device to convert non-powered equipment into self-propelled units with few modifications.
This simple and economical drive system allows two-wheel positive drive for applications such as mowers, golf-bags, blowers, and snowblowers. Other drive systems have multiple components and use more expensive and complex sprocket and chain or belt-drive technologies. The older system designs can be tedious to maintain and are usually large external drive systems. "This system is the simplest and easiest to install," says Scott Austin, director of motion control products at Hilliard.
Installing this simple clutch on a wheel shaft
converts it to a drive shaft. The leaf springs preload the needle bearing
rollers, producing automatic engagement when 'forward motion' is
The new clutch system design allows users to convert manual "push type" equipment into a self-propelled drive system by changing the wheel mounting shaft into a drive shaft. The clutch is installed inside the open hub of standard plastic wheels commonly used for lawn and garden equipment. Installation is fast and simple: remove one of the two wheel bearings, and press the powdered metal housing into the hollow opening of the wheel. The clutch is held in place by the serrated edge on the outside diameter of the housing and by replacing the bearing. The axle that joins the two wheels is then pressed into the clutch, and held by the rollers, which changes its function into a drive shaft. An internal leaf spring preloads the needle bearing rollers and allows for automatic engagement when forward motion from the operator is applied.
No additional assembly materials or machining are required for installation of the clutch system. Several methods to transmit power to the drive axle, or engage/disengage the clutch system may be used for motor-driven equipment. An idler pulley can be installed to work in conjunction with a belt drive to direct power to the wheels, creating forward motion. Since the rollers are always preloaded against the axle, the clutch engages automatically, eliminating jerky starts or hesitation.
What makes this clutch system economical? A powdered metal housing, standard off-the-shelf needle bearing rollers, and leaf spring. Customers may choose from various sizes for their application. The smallest unit is designed for use with a 0.5-inch diameter shaft. Clutch system package sizes start at 1.125 inches in diameter, 1.5 inches in length, and create 32 ft-lbs of torque.