A hydraulic drive system uses pressurized working fluid to deliver power to machinery. Every system has many common aspects. Here we will focus on the hydraulic pump. Its purpose is to pressurize the hydraulic fluid that will be used to drive a machine.
The pump can be used to pressurize fresh liquid in what would be called an open-loop system, or to re-pressurize fluid after it has driven a motor, known as a closed-loop system. In both cases, pump types are matched to certain applications and have different specifications to fit into any process design scheme. To check out various types of hydraluic pumps, one can visit this website www.schurcoslurry.com/hydraulic-pump-manufacturer.
Let us take a look at the different types available to engineers and industry.
A fixed displacement hydraulic pump has a set flow through depending on the design parameters. These pump types are more simple, less expensive, and easier to maintain. These benefits come at the expense of the flexibility to change the operating parameters to meet process needs.
The basic type is the gear pump. Pressure is created by pushing the working liquid through a pair of gears toward the outlet. These gears can be run in a line or nested within each other to improve performance and reduce noise levels.
This pump type offers a variable drive, meaning that the flow rate and outlet pressure can be regulated and changed. These pumps are typically more complex and expensive as a result.
Rotary vane hydraulic pumps are a higher efficiency model than a gear pump and are suited for the middle-pressure range (roughly 180 bar). Concentric, offset vanes are run in these pumps, creating areas where the working fluid is forced into a smaller volume thereby increasing its pressure.
The ultimate pump in terms of efficiency and high output is the bent-axis piston and cylinder design. Think of a car engine's piston and cylinder. This pump is built the same way. The bent axis refers to the alignment of the cylinders that provide maximum efficiency and run at high pressures. A double-action model can increase the throughput by using two cylinders per piston. These pumps are the most expensive but are highly responsive.