Hydrostatic transmissions have long been favored in professional lawn equipment, but now Honda is bringing them to their HRX217HYA, HRX17HZA and HRC216HXA walk behind mowers. The Cruise Control Hydrostatic Transmission doesn’t need belts or chains to transfer power, and it makes setting and keeping a mowing speed easier than any self-propelled mower on the market.
What is a Hydrostatic Transmission?
Instead of being driven by gears, belts or chains, a hydrostatic transmission uses fluid pressure to transfer engine power to the wheels using a combination of a hydraulic pump and a hydraulic motor.
The engine is connected to a hydraulic cylinder pump. The cylinders inside the pump are connected to a swash plate, a metal disc that can change its angle. As the pump spins, the cylinders pass by the outlet of the hydraulic motor to draw in fluid, then past the inlet, where they push that fluid back into the motor. By increasing the swash plate angle, the cylinders will be farther from the outlet, pulling in more fluid, and closer to the input, pushing the fluid with more force into the motor. Need to stop? If the swash plate is at an angle parallel to the fluid connections, the cylinders will pass between the outlet and inlet at the same distance and no pumping will occur. That means there’s no need to use a clutch to disengage the drive system.
What does all that mean? Fluid pressure and thus speed is determined primarily by the angle of the swash plate. This is extremely useful in lawn mowers: the engine can be run at full speed all the time to drive the blades, while the pump output can be varied to turn the wheels at just the right speed. It’s no wonder that nearly every commercial riding lawn mower and garden tractor on the market today uses a hydrostatic transmission.
Bringing Hydrostatic Flexibility to Walk Behind Lawn Mowers
Self-propelled walk behind mowers have always been awkward to use because the drive system for the wheels uses gears or belts, making it difficult to adjust speed. This can make mowing around hilly terrain challenging and requires the operator to reset all the controls after each stop.
Honda has solved these problems with their Cruise Control Hydrostatic Transmission. It uses the same pump and motor combination used in professional riding lawn mower, but they’ve managed to package them into a unit that’s about the size as a baseball.
Easy Speed Adjustment
The orange shift lever lets you select from 9 preset maximum speeds. Once set, the speed can be varied using the clutch lever going from stopped to the preset maximum. Top speed is about 4 mph with infinite adjustment from a slow crawl along rough surfaces to full speed on even turf.
A Truly Push-Free Mow
Hate having to give a hand to your self-propelled mower when you reach a hill? There’s nothing to slip inside the Cruise Control transmission, and the steady supply of fluid pressure allows the mower to maintain the same speed at any grade.
Start Back Where You Left Off
Since the pump cuts the pressure when you release the clutch lever, you can stop to move debris or empty the bag without having to change any of the controls. Once you’re done, just squeeze the handle, and the mower will be rolling at the speed you were at when you stopped.
Less Time in the Shop
The self-contained unit doesn’t have a clutch or belt to wear out, and the quality of the case and seals is equal to any commercial equipment on the market. That means far less maintenance than traditional self-propelled drive systems.
Where to Buy Honda Mower Parts and Accessories
Want to get some accessories for your HRX mower or need parts for repairs? That’s easy, too. www.hondalawnparts.com is an authorized dealer of Honda small equipment parts, carrying anything you may need for your mower from clipping bags to complete engines. They ship anywhere in the U.S. and Canada.