Types of Hydraulic Pumps Explained

Hydraulic pumps are central in a hydraulic system, converting mechanical energy into hydraulic power to drive machinery across a range of industries. From trucks and mobile equipment to industrial applications, choosing the right hydraulic pump is essential for efficiency, performance and longevity.

BSP Hydraulics specialises in supplying hydraulic pumps and motors for various applications. In this guide, we’ll explore the most common types of hydraulic pumps—including gear pumps, vane pumps, piston pumps, and the difference between fixed displacement and variable displacement pumps.

Gear Pumps

Gear pumps are a robust and reliable option for medium-pressure applications.

Gear pumps are among the most widely used types of fixed displacement hydraulic pumps, known for their durability, simple design, and cost-effectiveness. These pumps operate using cogs and gears that create a continuous flow, making them ideal for applications where a steady and reliable flow is required. There are two types of gears pumps- internal and external.

Advantages of Gear Pumps:

• High-speed operation with consistent performance
• Compact and simple design, making them easy to install
• Cost-effective and easy to maintain
• Less sensitive to contamination

Disadvantages of Gear Pumps:

• Efficiency decreases at high pressures due to leakage between gear teeth
• Can generate noise and vibrations

Vane Pumps

Vane pumps are positive displacement pumps that work with vanes sliding in and out of a rotating rotor. As the rotor spins, the force created pushes the vanes against the pump casing, which draws in hydraulic fluid and then pressurises it.

These pumps can be either fixed displacement or variable displacement, making them suitable for applications that require smooth and efficient operation. Vane pumps are commonly used in utility vehicles, mobile equipment and industrial applications requiring moderate pressure.

Advantages of vane pumps

• Provides a smooth and pulse-free flow, reducing system noise and vibration
• Compact and lightweight design, making it ideal for mobile applications
• Capable of handling moderate pressures efficiently

Disadvantages of vane pumps

• Not designed for high-pressure applications
• More sensitive to contamination and requires clean hydraulic fluid to prevent wear

If you’re looking for a reliable pump with smooth operation and excellent suction capabilities, vane pumps are a good choice.

Piston Pumps

Including radial piston pumps and fixed or bent-axis pumps, piston pumps are high-performance hydraulic pumps designed to handle higher pressures than other types. These pumps use a series of pistons moving back and forth within cylinders to pressurise the hydraulic fluid. Due to their high efficiency and ability to handle extreme operating conditions, piston pumps are widely used in demanding applications, including industrial machinery, construction equipment, and heavy-duty hydraulic systems.

Advantages of piston pumps

• Wide and high pressure range, capable of reaching extremely high pressures
• Pressure can be regulated without affecting the flow rate
• Capable of moving large volumes of gas and viscous liquids efficiently
• Highly durable and long-lasting when properly maintained

Disadvantages of piston pumps

• High upfront cost
• Require frequent maintenance
• Mechanical parts are prone to wear from high pressure if not properly lubricated
• Heavy and bulky due to robust components used

Piston pumps are a durable solution for high-pressure applications but come at a higher initial cost.

Fixed Displacement vs Variable Displacement Pumps

Another option when choosing the right hydraulic pump for your application is between fixed displacement pumps and variable displacement pumps.

Fixed Displacement Pumps

Fixed displacement pumps, such as gear pumps and some vane pumps, provide a constant flow of hydraulic fluid at a given shaft speed. These pumps are ideal for applications where you need steady pressure and flow, such as conveyor systems and hydraulic lifting mechanisms.

Advantages of fixed displacement pumps

• Simple, cost-effective design
• Reliable operation with minimal complexity
• Well-suited for applications where flow demand is consistent

Disadvantages of fixed displacement pumps

• Can be inefficient if the system doesn’t require a constant flow
• Generates excess heat and energy waste in variable load applications

Variable Displacement Pumps

Variable displacement pumps, such as axial piston pumps and variable vane pumps, adjust the flow rate based on system demand. This makes them highly energy-efficient and suitable for applications with fluctuating hydraulic needs.

Advantages of variable displacement pumps

• Improved efficiency, reducing energy waste
• More precise control over flow and pressure
• Ideal for systems with varying loads

Disadvantages of variable displacement pumps

• More complex design requiring advanced control mechanisms
• Higher initial cost compared to fixed displacement pumps

Understanding the various types of hydraulic pumps is important to find the right solution for your industry and application. Whether you need a gear pump for steady fluid movement, a vane pump for smooth and quiet operation, or a piston pump for high-pressure applications, we have a wide range of hydraulic pumps and motors to suit your needs.

If you have any questions about our range of hydraulic pumps feel free to contact us – our team of specialists are here to help.