Types of Hydraulic Cylinders
There are various types of hydraulic cylinders designed for specific applications. Below is a brief overview of the most common cylinder types, along with some specialty cylinders available from Bailey.
The Basics
A hydraulic cylinder is an actuator that generates linear movement by converting hydraulic energy into mechanical movement. These cylinders are utilized in equipment to lift, push, pull, and press loads that demand exceptional force.
Hydraulic cylinders come in several body styles, including tie-rod, welded, and telescopic, and can be single-acting or double-acting.
Single-acting Cylinders vs. Double-acting Cylinders
Single-acting Cylinders
In a single-acting hydraulic cylinder, piston force is applied in one direction when pressurized oil extends the rod. Once the oil is depleted, gravity and the load return it to its natural position.
Double-acting Cylinders
Double-acting cylinders can exert force in two directions. The piston cylinder is divided into two pressurized chambers, allowing the rod to achieve both outward and return strokes. Pressurized oil enables the rod to move in either direction.
So how do you decide between single-acting and double-acting? Single-acting cylinders are ideal for simpler applications requiring movement in one direction. Double-acting cylinders are more complex in operation and maintenance but provide both push and pull forces, offer more precise control, and are better suited for repetitive actions.
Basic Body Styles
Tie-Rod Cylinders
Tie-rod hydraulic cylinders utilize high-strength threaded steel rods to secure the end caps to the cylinder barrel. These rods are held together by four or more threaded tie bolts running the length of the cylinder tube, which secure the baseplate and head. Typically equipped with static seals to prevent leakage, tie-rod cylinders are best suited for medium to light-duty mobile applications. Their lower cost of ownership is attributed to easier assembly, maintenance, and repair.
Standard Tie-rod Cylinder
Rephasing Tie-rod Cylinder
Rephasing tie-rod cylinders incorporate an internal bypass for synchronizing the cylinder in a series circuit, making them ideal for construction and agricultural applications requiring independent loads plumbed in series.
Welded Cylinders
In welded hydraulic cylinders, the barrel is welded to the end caps instead of using steel rods. Welded body cylinders offer numerous advantages over tie-rod cylinders, including a compact design that can withstand higher pressures, often exceeding 5,000 psi. This makes them suitable for mobile machinery where space is limited. Their robust design also makes them ideal for extreme weather and operating conditions, contributing to a much longer service life than tie-rod cylinders, as they don’t fail due to tie-rod stretch under high pressures and long strokes.
Telescopic Hydraulic Cylinders
Telescopic cylinders consist of several individual cylinders (similar to telescope sections) nested together in decreasing size. This design allows for exceptional stroke length from a compact configuration. The collapsed length of a typical telescopic cylinder can vary between 20% to 40% of its extended length. Generally, telescopic cylinders are single-acting and come in two to five stages, commonly used in construction trucks, vehicle trailers, garbage and dump trucks, and in agriculture.
Automotive Lift Repair Orlando
The Automotive Lift Repair Orlando line of cylinders serves as a durable alternative to tie-rod cylinders for lighter-duty construction and agricultural applications. Unlike tie-rods, these cylinders feature an easy snap ring on the rod-end gland for convenient field repairs.
Automotive Lift Repair Orlando
The Automotive Lift Repair Orlando line features patented designs, making it ideal for applications with restricted port adjustability and overall cylinder space.
Automotive Lift Repair Orlando
The Automotive Lift Repair Orlando cylinder features Bailey’s patented adjustable 360° rotating gland and is among the most durable cylinders available. Often referred to as a lug-end cylinder, it has a one-piece lug mount welded to both the rod and base ends. The can utilize a spherical ball or steel bushing insert to enhance wear life, making it a common choice for heavy-duty construction equipment.
Different Types of Hydraulic Cylinders
Several types of hydraulic cylinders are designed for various applications. Here are some key points to help you select the most suitable hydraulic cylinder for your needs:
– Single-acting Hydraulic Cylinders: These cylinders operate in one direction only. The plunger moves outward in a single direction, and it returns to its original position with the help of the load’s weight or a spring.
– Double-acting Automotive Lift Repair Orlando Hydraulic Cylinders: These cylinders use hydraulic pressure to both extend and retract the plunger. They require two connections: one for supplying hydraulic fluid to extend the plunger and another for retracting it.
– Low Height Hydraulic Cylinders: Also known as pancake cylinders, these have a compact profile and are specifically designed for use in tight spaces.
– Hollow Plunger Cylinders: Featuring a threaded collar for attaching various accessories, these cylinders can be utilized for both pushing and pulling applications.
– High Tonnage Cylinders: Typically designed as double-acting cylinders, these can handle significantly heavier loads, with a weight tolerance of up to 1,000 tons, making them ideal for heavy lifting tasks.
– Telescopic Hydraulic Cylinders: These cylinders can reach greater heights than standard cylinders by employing multiple plungers, referred to as stages. They can also be configured as low height or double-acting cylinders.
– Hydraulic Ram: In some regions, hydraulic cylinders may be referred to as hydraulic rams. These terms are interchangeable.
Single Acting Hydraulic Cylinders
A single acting hydraulic cylinder operates in one direction and typically has a single port. It relies on gravity or a spring to retract the plunger after use. These cylinders can be easily controlled using components like control valves to manage flow rates. They have a variety of applications and are commonly found in factory automation settings for handling packages or materials.
The term “single acting” describes the operation of the hydraulic cylinder, and these cylinders can be combined with designs such as low height, hollow plunger, or even telescopic configurations with two or three stages. While they are straightforward, single acting cylinders are reliable, easy to install, and cost-effective for many uses.
Double Acting Hydraulic Cylinders
A double acting hydraulic cylinder typically features two input ports. It uses hydraulic pressure to both push and pull the plunger, making it effective in situations that require rapid or controlled retraction in addition to extension. Although two single acting cylinders could technically achieve similar functionality, one double acting cylinder is generally more efficient and space-saving.