Hydraulic Pumps: Piston, Gear and Vane Pumps

Fixed or Variable? The First Choice to Make

Before you compare pump types, decide how your circuit uses flow.

A fixed displacement pump moves the same volume on every turn. It is simple, tough and cheaper to buy. The catch is that any flow your machine does not use goes over the relief valve as heat.

A variable displacement pump adjusts its output to match demand. It costs more up front but uses less power and runs cooler, which pays off on machines that idle or hold pressure for long periods.

Rule of thumb: short, simple duty cycles suit fixed pumps. Long hold times and changing loads suit variable pumps.

Shop Hydraulic Pumps by Type

Each range below suits a different mix of pressure, noise, efficiency and cost.

Piston Pumps

Piston pumps are the high-pressure workhorses of hydraulics. They run at 280 to 350 bar continuously, with some designs going well past that, and they offer the best efficiency of any pump type.

• Axial piston pumps line the pistons up around the drive shaft. Swash plate designs are compact and easy to fit with pressure, flow or load sensing controls. Bent axis designs angle the whole cylinder block for higher efficiency and pressure.
• Radial piston pumps arrange the pistons like spokes on a wheel. They suit very high-pressure jobs such as presses, clamping and test rigs.

Choose piston pumps for mobile plant, presses, injection moulding and any circuit where energy costs matter.

Gear Pumps

Gear pumps are the simplest and most affordable way to make hydraulic flow. They handle dirty conditions better than most, which is why you find them on tippers, tractors, log splitters and small power packs.

• External gear pumps suit general mobile and industrial duties up to about 250 bar.
• Internal gear pumps run much quieter and smoother, so they suit indoor power units and machine tools.
• Gerotor pumps work at lower pressure for lubrication, charge and circulation duties.

Vane Pumps

Vane pumps sit between gear and piston pumps on cost, and they give you very low noise and smooth, low pulse flow. Sliding vanes ride against a cam ring and adjust for wear on their own, which keeps output steady over a long service life.

You can pick fixed displacement vane pumps for constant flow, variable displacement vane pumps that hold a set pressure, or balanced vane pumps. Balanced designs cancel the side loads on the shaft, so the bearings last longer and the pump stays quiet at higher pressure.

Servo Hydraulic

A servo hydraulic setup drives a fixed or variable pump with a servo motor and drive. The motor changes speed to deliver exactly the flow and pressure the machine asks for, then slows almost to a stop when the machine waits.

On injection moulding machines and presses, this can cut energy use sharply, reduce oil temperature and make the shop floor quieter. It also makes an existing machine a strong candidate for a retrofit.

Specialty Hydraulic Pumps

Specialty hydraulic pumps cover duties that standard ranges miss. That includes tandem and multi-section pumps that run two circuits from one drive, compact pumps for tight engine bays, and pumps built for fire-resistant or low-viscosity fluids. Tell us the duty, and we will find the right match.

Hydraulic Pump Specifications at a Glance

Use these quick profiles as a filter, then confirm the details on the datasheet.

• Gear pumps: up to about 250 bar, 80 to 90% overall efficiency, the lowest price and the best tolerance for dirt. External designs are louder, while internal gear designs are quiet. Fixed flow only.
• Vane pumps: up to about 210 bar (some designs go higher), 75 to 90% efficiency, low noise and a mid-range price. Fixed or variable flow, with fair dirt tolerance.
• Piston pumps: 280 to 450 bar, with radial designs higher still, 85 to 95% efficiency and moderate noise. Fixed or variable flow, but they need the cleanest oil and cost the most.

These figures are typical ranges across makes. Each hydraulic pump datasheet gives the exact pressure, speed, and efficiency for that model.

Size It in Two Quick Sums

Need to check a pump before you buy? These two sums get you close.

• Flow (L/min) = displacement (cc/rev) × shaft speed (rpm) ÷ 1,000. A 28 cc/rev pump at 1,450 rpm gives about 40 L/min.
• Power (kW) = flow (L/min) × pressure (bar) ÷ 600 ÷ efficiency. At 40 L/min and 200 bar, you need about 15 kW from the motor.

For new systems or tricky duty cycles, our pump selection and sizing service runs the full numbers for you.

How to Match a Replacement Hydraulic Pump

Most replacement orders stall on one missing detail. Gather these six, and we can confirm a match fast.

1. Part number: the full code from the nameplate. It tells us the series, displacement, controls, and options.
2. Displacement: in cc/rev, often shown in the part number.
3. Rotation: clockwise or anticlockwise, viewed from the shaft end.
4. Mounting flange: SAE A, B or C, or a metric ISO flange, plus the bolt count.
5. Shaft: keyed or splined, with its diameter or spline count.
6. Ports and controls: port type and size, and the control fitted, such as a pressure compensator or load sensing.

Nameplate missing or worn? Send clear photos of the flange, shaft and ports. Our engineers cross-reference part numbers from major brands such as Parker, Kawasaki, Rexroth and Danfoss every day, and we will tell you upfront whether we are offering a genuine pump or an equivalent.

Three Checks Before You Fit a New Pump

A new pump will fail just as fast as the old one if the cause is still in the system. Take five minutes for these checks.

1. Check the suction side. A blocked strainer, a kinked hose or a low tank causes cavitation, which shows up as a gravelly noise and pitted parts.
2. Check the oil. Dark, milky or gritty oil will wear a new pump quickly. Piston pumps often need oil at ISO 4406 18/16/13 or cleaner, so replace the filters at the same time.
3. Check the settings. A relief valve or compensator set too high overloads the pump and the drive.

Where Our Hydraulic Pumps Work

Our hydraulic pumps run in presses and forming lines, injection moulding and plastics plants, mining equipment, marine winches and mobile machinery worldwide. Most jobs need more than a pump, so we also supply the hydraulic motors, directional control valves and hydraulic power units that complete the circuit.

Why Buy Hydraulic Pumps From TSA Hydraulics Engineering

When a machine is down, you need a hydraulic pumps supplier that answers fast and gets the part right first time. We stock common sizes, match obsolete and foreign part numbers, and give you clear hydraulic pump prices in AUD. We also source hydraulic pump replacement parts, such as seal kits, so you can repair as well as replace. And if you are unsure, an engineer will talk it through with you before you order.