Engines 101: Hydraulics in Action

This article, Motors 101, continues HPS's series of articles focusing on the "basics" of the major categories of hydraulic parts. If you are in the hydraulic power sales or service business and need a reputable hydraulic motor, pump or valve repair provider, HPS is ready to help.

Among the many types of liquid energy products available, actuators are defined as "actuators that release energy to do the physical work of hydraulic systems."

While the hydraulic pumps move the power and the hydraulic valves control the energy of the fluid, the hydraulic motors do the work, along with the pumps, converting the energy of the fluid into energy.

Motors work by converting fluid pressure into motion. The pressure from the pump turns the output shaft of the motor by applying pressure to the gears, pistons or rotors of the hydraulic motor. Selecting a Hydraulic Motor

The design of the complete hydraulic system will change depending on the type of motor chosen, so it is important that the selection of the motor comes first in the process, since this decision depends to a great extent on the load requirements of the system, the objectives of performance and application.

For example, an important consideration in the design and decision process is how motors are rated by displacement (the volume of fluid required to turn the output shaft once), measured in cubic inches per revolution (CIR) or cubic centimeters per revolution. revolution (RCC). .

In addition to compensation, additional operational considerations include:

Operating torque, or the torque that the motor is capable of delivering

maximum system pressure

Fluid temperature range, including minimum and maximum operating temperatures

maximum operating speed

Power limits depend on maximum volumetric flow rate through the motor

fluid viscosity

Attention to adhere to these particular limits is vital to ensure that the engine delivers the maximum amount of power.

Speed classification and types of motors. Hydraulic motors can be sorted in two ways:

Revolving speed: Defined as either a high speed, low torque (HSLT); or low speed, high torque (LSHT)

Design configuration: Three main types are gear, vane, and piston motors

In terms of revolving speed, high-speed hydraulic motors operate at 500 rpm and above, and have a low output torque (these are known as “HSLT” motors).

A low-speed motor operates at fewer than 500 rpm, and has a large displacement, size, and low revolving speed (equating again to high output torque – abbreviated as “LSHT”).

In terms of design, each type has a specific profile to meet the requirements, performance goals, and desired applications within a hydraulic system.

Hydraulic Motor Design Configurations in Detail

Gear Motors

Gear motors consist of rotating gears that move when hydraulic fluid enters the motor. They are categorized as either internal or external.

External gear drives consist of identical gears enclosed in a single casing. Internal gears can consist of a direct drive motor or rotary motor, and typically have fewer gear teeth than external gear motors vickers hydraulic pump.

Small in size and light in weight

low cost

wide speed range

wide temperature range

Wide range of viscosity

low inertia

The main features of geared motors include:

Some of the disadvantages include:

Large compression ripple and torque

Low volumetric efficiency and insertion pressure.

low starting torque

high noise level

Poor stability at low speed

Therefore, geared motors are only applicable within the High Speed Low Torque (HSLT) classification and are best suited for mechanical equipment that is not very demanding on torque uniformity.

feather motors

The vane motor uses a rectangular vane to generate power. When a pressurized fluid enters the motor, the blades in the vane cause it to rotate and produce a resultant torque.

Key features include:

low noise level

High torque at low speeds

low flow pulse

plain design

cunning

Easy vertical installation

Some of the disadvantages include:

great escape

low inlet pressure

unstable at low speed

Anti-pollution ability is not as good as geared motors

Vane motors are generally classified as HSLT units, although larger displacements will fall under the LSHT category. It meets motion sensitive requirements, so it is often used in mobile applications.

piston engines

Piston engines work by using compound pistons to generate power. They come in a variety of designs, such as radial piston and axial piston, with LSHT and HSLT ratings.

A radial piston hydraulic motor uses pistons arranged radially around a central axis, sometimes using multiple pistons interconnected in a star pattern, to generate power. They are classified as LSHT and generally perform efficiently over a long life, despite the high cost and complex design.

The axial piston hydraulic motor produces axial movement, not radial movement. It is similar to radial piston motors and also offers high efficiency and long life at a high cost. Unlike the radial design, it is not as effective at lower speeds and is classified as HSLT.

As always with hydraulics, it's all about putting the pieces together

Pumps and motors have overlapping characteristics and types (vane, gear, piston), and for good reason. Both work together to provide the power needed to operate hydraulic equipment.

The pump converts mechanical energy into fluid energy in the form of oil flow. The oil flow generated by the hydraulic pump is then directed to the engine through the system Rexroth hydraulic Motors valve.

But it is the motor that produces the output of this cohesive unit and converts the energy of the fluid into mechanical energy to perform the physical work.

Hydraulic Parts Source is Here to Help - Whether you have questions about actuators or any type of hydraulic system component, we're here to help you learn. Call (888) 477-7278 for expert hydraulic assistance.