High-pressure motors are able to accomplish more in a smaller package compared to medium-pressure technology. When it comes to enhancing performance of both mobile and stationary hydraulic systems, high-pressure technology can be used to reduce package size, improve starting torque, and reduce system costs. At the end of the day, this means that skid steer loaders (SSL and CTL), drilling equipment, grinders and mixers, material handling and other mobile equipment can get more done, generate less emissions and use less fuel.
Switching from medium to high-pressure models is typically driven by three factors:
- Equipment size: as machines become more compact and nimble, higher pressure products allow the same capability in a smaller envelope.
- Capability gains: applications where more capable motors yield more productive or efficient machinery
- Future compatibility: supporting future upgrades and changes
Key advantages of high-pressure motors
There are many factors that impact the decision on the type of motor to select. New high-pressure motor technology is delivering benefits across a variety of aspects, making high-pressure motors the right choice for a range of hydraulic systems.
Smaller package design
High-pressure motors are more compact than medium-pressure models, upwards of 1.5 to 2-in. shorter. With improved mechanical efficiency, high-pressure motors require less cooling space. By generating less heat, high-pressure motors need less fuel over the life of the equipment.
Weighing in less than larger, lower pressure technology
Weight is an important consideration during machine design and typically impacts a range of performance parameters, including lifting capacity, ground compaction and towing requirements. Extra weight wastes fuel, requires stronger machine frames and often takes up valuable space.
High-pressure motor designs are enhanced through computational fluid dynamics (CFD) and fluid element analysis (FEA), so that material is placed where it is required and minimized elsewhere. These latest design methods are yielding motors that are stronger in more targeted and effective ways, reducing unnecessary weight in castings and reducing overall package size. Ultimately, today’s innovative motor designs are yielding lighter and smaller motors that can do more work.
With higher motor pressure capability, high-pressure motors can perform more work. High-pressure motors have been shown to deliver an 8% increase in starting torque efficiency. This means that high-pressure motors can perform more work than lower-pressure technology. Further, a high starting torque efficiency provides more power to the output shaft at start-up and reduces pressure and flow requirements to initiate rotation.
Additionally, high-pressure motors with two-speed technology can help accomplish some tasks faster and more cost-effectively. A high-speed low-torque mode (HSLT) can reduce motor displacement, which can yield a significant increase in rotation speed and reduce pressure and flow requirements to start rotation.
High-pressure motors have been shown to deliver an eight percent increase in starting torque efficiency.
Heat and friction losses increase the need for cooling and overall costs. CFD (Computational Fluid Dynamic) models are helping to reduce fluid losses through disc valves with large flow passages; this means less heat is generated as the fluid travels through the motor. With less heat, cooling system requirements are reduced and the cooling system itself can be less costly and smaller. Further, finite element analysis is driving innovation in the design of built-in motor balance rings, so they are able to maintain high volumetric efficiencies at high pressures.
High-pressure motors with a two-speed capability are optimized for reduced no-load pressure drop. This can reduce heat build-up, improving operating efficiency when traveling fast with low engine speeds when cooling is critical.
High-pressure motors can provide some additional design capabilities in terms of series circuits, speed sensing and open or closed loop capability. With a design able to handle high backpressure, HP30 high-pressure motors can be used in series circuits without limitations on duty cycle or pressure ratings. Further, high-pressure motors can sense motor speed for real-time machine control. With an HP30 Design code 003 motor, an open-loop motor configuration can be changed to a closed-loop arrangement (and a closed-loop configuration can be altered later to an open loop) quickly and easily.
Contributed by Todd Degler, product manager, Geroler Motors, Gear Products, Eaton.
Learn more about high-pressure motor technology at eaton.com/HP30.