A method of improving the efficiency of axial-piston hydraulic motors

IP Status:Provisional Patent Application Filed (app. no. 63/404,236)

Applications

  • This technology may be applied to axial piston variable displacement pump/motors in general if cam-based distributor valves are used instead of valve plates.
  • In particular, the hydraulic motor in a line of inline hydromechanical transmissions (iHMT) – known as Hondamatic, is a viable application.
  • The original Hondamatic was utilized in ATVs but similar designs are feasible in a wider range of applications, including on-road vehicles.
  • The invention may also be applied to standalone variable-displacement hydraulic motors to improve power efficiency in any existing application.

Key Benefits & Differentiators

  • Simpler
  • More precise
  • More compact
  • Significantly less expensive to implement


Technology Overview

A typical axial-piston hydraulic motor with an adjustable swashplate and fixed valve timing cannot achieve ideal precompression and decompression across a range of operating conditions. This results in a loss in energy leading to a loss in efficiency for hydraulic motors used in All Terrain Vehicles and on-road vehicles.

Researchers at the University of Minnesota have developed a method of improving the motor’s energy efficiency by rotating a valve cam for variable piston stroke. This allows, for each desired effective displacement of the hydraulic motor, a set of ideal valve timing to achieve perfect precompression and decompression so as to eliminate associated throttling losses. Efficiency improvements of as much as 10% can be achieved. This technology may be applied to axial piston variable displacement pumps/motors in general if cam-based distributor valves are used instead of valve plates. In particular, the hydraulic motor in a line of inline hydromechanical transmissions (iHMT) – known as Hondamatic, is a viable application. The Hondamatic already uses cam-based distributor valves for valve timing, The proposed method significantly improves the motor’s efficiency in the iHMT. The design has been simulated, demonstrating efficiency improvements of up to 14.4% when applied to a motor in an inline hydromechanical transmission.

Phase of Development

TRL: 3-4 Simulations of design has been completed
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Desired Partnerships

  • This technology is now available for:
  • License
  • Sponsored research
  • Co-development

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Researchers

  • Perry Y. Li Professor, Department of Mechanical Engineering

Abstract

A method of improving the energy efficiency of a hydraulic motor by rotating a valve cam for variable piston stroke

Website

https://license.umn.edu/product/a-method-of-improving-the-efficiency-of-axial-piston-hydraulic-motors

Contact Information

Name: Sandipan Banerjee

Email: baner198@umn.edu

Phone: 3023447726