Power Products Technology
Hybrid Snow Blower
Engine-powered snow blowing and motor-powered propulsion make Honda’s hybrid snow blowers high performance and easy to operate
Honda’s first hybrid snow blower aiming to improve operability and ease of use was released in 2001, and has been evolving since.
In general, snow blowers consist of snow blowing and drive mechanisms, both powered by one engine. With Honda’s hybrid snow blowers, the snow blowing mechanism is powered by engine, while the drive mechanism is powered by motors.
This not only allows consistent snow blowing operation and smooth drive, but drive and engine speeds to be adjusted automatically, making snow blowing work which required experience and skill, easier and more efficient.
Hybrid system takes advantage of both engine and motor characteristics
With hybrid snow blowers, an engine provides the snow blowing mechanism with all the power it needs, while the drive mechanism requiring delicate operation is powered by two independent motors, one on each side.
Electronic control of the drive mechanism allows smooth starting, turning and stopping, and with load control that adjusts drive speed according to snow blowing load, contributes to efficient and smooth operation.
Electronic control replaces cables for the control levers and clutches, greatly reducing operation fatigue and more delicate control.
By providing separate power sources for the snow blowing and drive mechanisms, drive speed, dependent on engine speed in conventional snow blowers, can be set independently. This allows engine speed to be lowered when the snow blower mechanism is inactive, reducing noise and improving fuel consumption.
Constant engine speed is required for efficient snow blowing, as efficiency and snow discharge distance is proportional to engine torque and engine speed. Constant engine load (snow discharge amount) leads to maintaining consistent engine speed.
As snow discharge amount is proportional to drive speed, drive speed needs to be precisely adjusted according to the type of snow (height, hardness and weight) for efficient snow blower operation.
Since conditions (height, weight) of snow coverage are not consistent and need to be taken into account to maintain an optimum snow blower speed, a high level of experienced operation is required.
With hybrid snow blowers, the main ECU automatically adjusts drive speed according to snow quality, operation is easier and more efficient.
Drive control system
With hybrid snow blowers, two independent motors, one on each side, work in tandem to realize tight, smooth turning and adjustment of drive speed. The Main ECU controls speed for the left and right motors based on the main shift lever, steering lever and engine load signals.
Each of the two motors incorporates rotation sensors which feed data to the Main ECU to determine motor speeds and direction, to operate both motors together.
Work load-linked travel speed control (load control)
When the amount of snow exceeds the engine’s load capacity, snow may pile up on the snow blower, or the engine may stop.
With hybrid snow blowers, high work load causes travel speed to be reduced, which reduces the amount of snow entering the snow blower, ensuring consistent operation.
The amount of snow discharged is determined by constantly monitoring Engine ECU world load data.
The Engine ECU sends realtime work load data (such as 10%, 20%, …) to the Main ECU, which reduces travel speed before the engine load exceeds its maximum limit, reducing work load and keeping engine speed constant. Once the work load becomes lighter, travel speed is increased again, reducing work time.
When turning, the ECU controls the speed for each motor independently according to the drive speed and the amount the steering lever is gripped.
At high speeds, turning is gradual. At low speeds, extra-pivotal (on-the-spot) turning is enabled, allowing change of direction in narrow spaces.
With hybrid snow blowers which power driving by motors, electric sliders and switches are used for the various levers and clutch to allow the ECU to completely control all devices, eliminating the need for cables and greatly reducing operation load. As electric wiring is flexible, the control panel layout can be easily reconfigured, allowing often used levers to be positioned in an easily accessible configuration.
For example, the steering lever positioned on the control panel for conventional snow blowers can be moved to the handle bars, and the main shift lever (HST* + sub-transmission (2-speed)) is replaced by an electronic infinitely variable control.
- *HST: Hydrostatic Transmission
Engine speed control
A self-tuning regulator (STR) governor system controls the amount of throttle according to the varying engine work load.
Compared to conventional mechanical governors, the Engine ECU electronically controls the amount of throttle for accurate, rapid and stable engine speed control.
For effective and efficient snow blowing, subtle snow discharge direction operation (vertical and horizontal) is needed while controlling the snow discharge amount. Furthermore, performing operations at the right time according to safety, and understanding snow surface and conditions in accumulated snow, made experience in snow blowing a necessity. To reduce these loads on the operator, and to improve operability and ease of use, Honda released the first hybrid snow blower, with a drive motor that removed the need to adjust drive speed.
In 2006, the STR governor which automatically controls engine speed removed the need for throttle adjustment, and in 2018, models were announced with an accelerometer, enabling the snow blower’s attitude to be detected, automatically adjusting speed on slopes and assisting auger operation.
Honda’s snow blowers continue to evolve, furthering the hybrid system’s advantage, realizing easier to use and cleaner results, with easy operation.