What is the definition of "eccentric loading"?
Pressure directed anywhere on a component other than where the component is designed to accept the force. If a driveshaft is designed to accept pressure through its axis, eccentric loading occurs anywhere but through the axis of the shaft.

Learn more about eccentric loading in the class Actuator Applications 240 below.


Hydraulics and Pneumatics Training


Class Information
Tooling U-SME classes are offered at the beginner, intermediate, and advanced levels. The typical class consists of 12 to 25 lessons and will take approximately one hour to complete.
Class Name:Actuator Applications 240
Description:This class provides an overview of actuators for fluid power systems, including cylinders, rotary actuators, and fluid motors. Includes an Interactive Lab.
Prerequisites: 570110  570120  570125 
Difficulty:Intermediate
Number of Lessons:16
Language:English, Spanish
 
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Class Outline
  • Objectives
  • What Are Fluid Power Actuators?
  • Linear Actuators
  • Uses of Cylinders
  • Rotary Actuators with Limited Rotation
  • Uses of Rotary Actuators with Limited Rotation
  • Piston Motors
  • Uses of Piston Motors
  • Vane Motors
  • Uses of Vane Motors
  • Gear Motors
  • Uses of Gear Motors
  • Fluid Motor Performance
  • Torque Variables
  • Troubleshooting Common Problems
  • Summary
  
Class Objectives
  • Describe an actuator.
  • Identify the parts and areas of a cylinder.
  • Describe common uses of cylinders.
  • Describe rotary actuators with limited rotation.
  • Describe uses of rotary actuators with limited rotation.
  • Describe the types of piston motors.
  • Describe the uses of a piston motor.
  • Describe a vane motor.
  • Describe the variables associated with the use of vane motors.
  • Identify various gear motors.
  • Describe the variables associated with the use of gear motors.
  • Describe fluid motor performance.
  • Identify variables associated with torque.
  • Describe troubleshooting common problems associated with actuators.

Class Vocabulary

Vocabulary TermDefinition
actuator The components such as cylinders, motors, and rotary actuators that directly help convert fluid energy into mechanical energy.
air tool Any number of tools powered by a central pneumatic power source, usually in a shop setting.
air turbine motor A high speed, low torque motor commonly used in tools like high speed grinders.
barrel The housing body of a cylinder. The inside of the barrel and the piston form a seal that enables fluid pressure to extend and retract the rod.
bent-axis piston motor A piston-type actuator with pistons that are placed at an angle against the shaft flange.
blind end The side of the piston that is opposite the rod. The blind end is also called the cap end.
breakaway torque The amount of rotational force needed to initially move a load.
cap end The side of the piston that is opposite the rod. The cap end is also called the blind end.
continuous rotation Characterized by having a range of motion that is unlimited. Continuous rotation is also called infinite rotation.
crankshaft The component of a piston motor that is turned by the pistons. The linear motion of each piston causes the crankshaft to rotate.
cylinder A type of linear actuator that uses a piston to produce motion in a straight line. A cylinder is also known as a piston actuator.
cylinder block The cylindrical piston housing that is angled on a bent-axis piston motor. On an in-line piston motor, the cylinder block is parallel to the crankshaft.
displacement A fluid power variable that indicates how much fluid is moved by a hydraulic pump in one cycle. Displacement is measured in cubic inches per revolution or cubic centimeters per revolution.
double-acting cylinder A fluid power actuator that directs energy in two directions.
double-vane actuator A rotary actuator that directs energy in a circular motion through the use of two arm-like mechanisms, or vanes. Double-vane actuators commonly have a range of motion under 180 degrees.
eccentric loading Pressure directed anywhere on a component other than where the component is designed to accept the force. If a driveshaft is designed to accept pressure through its axis, eccentric loading occurs anywhere but through the axis of the shaft.
extension The movement of a single-acting cylinder characterized by air pushing on the piston and moving the rod outside of the cylinder housing. In a double-acting cylinder, extension occurs on each stroke and alternates between ends of the cylinder.
external gear motor An actuator consisting of two externally toothed and interlocked gears.
finite rotation Characterized by having a range of motion that is fixed or limited to partial rotation or a finite number of rotations. Finite rotation is also called limited rotation.
fixed displacement Characterized by a fluid capacity that is not changeable.
flow rate A fluid power variable that describes how much fluid is being moved and how much work is being performed. Flow rate is usually measured in gallons per minute (gpm) or liters per minute (lpm).
foot-pound In the English system, the unit used to measure power. Some sources use foot-pounds interchangeably with pound-feet to express torque.
gerotor A gear-within-gear pump that consists of an inner gear with one less tooth than the outer gear.
helical piston actuator A type of rotary actuator, consisting of a piston with a helical groove that rotates when fluid passes through. Also called a helical-spline, piston and helix, and sliding spline.
helical-spline The primary mechanism of a type of rotary actuator, consisting of a piston with a helical groove that rotates when fluid passes through it. Also called a helical piston, piston and helix, and sliding spline.
high speed, low torque motor A fluid motor that performs work with low torque and high speeds. A high speed grinder is a type of HSLT motor.
indexing The act of moving a part or machine component to another location.
infinite rotation Characterized by having a range of motion that is unlimited. Infinite rotation is also called continuous rotation.
in-line piston motor A piston-type actuator with pistons that are located parallel to the length of the crankshaft. An in-line piston motor involves a crankshaft that is attached to an angled swash plate.
internal gear motor An actuator consisting of two interlocking gears. One gear with external teeth is housed within a gear with internal teeth.
internal leakage The unintentional movement of fluid from one component to another within the system.
limited rotation Characterized by having a range of motion that is fixed or limited to partial rotation or a finite number of rotations. Limited rotation is also called finite rotation.
linear actuator An actuator that directs force in a straight line. A cylinder is a linear actuator.
low speed, high torque motor A fluid motor that performs work with high torque and low speeds. Various types of heavy industrial equipment use LSHT motors.
mechanical efficiency The theoretical operating horsepower compared to the operating horsepower. Mechanical horsepower describes the amount of energy loss in a hydraulic component.
motor A fluid actuator capable of infinite or continuous rotation.
overhung load A type of eccentric loading in which a force is applied to the shaft perpendicular to the shaft's axis beyond a support point. Overhung load is also called side loading.
piston The circular component of a cylinder that is moved by fluid pressure.
piston and helix The primary mechanism of a type of rotary actuator, consisting of a piston with a helical groove that rotates when fluid passes through it. Also called a helical spline, helical piston, and sliding spline.
piston motor An actuator that uses a series of pistons driven by pressurized fluid to turn a crankshaft.
pivot mount A hinged mount that is designed to move with a pivoting cylinder.
positioning The act of accurately placing a machine tool or a workpiece in a certain location.
pressure The exertion of force upon a fluid. Pressure can cause changes to the properties of a gas.
preventive maintenance Maintenance performed while a component is in working order to keep it from breaking down. Preventive maintenance includes lubricating, tightening, and replacing worn parts.
rack and pinion actuator A fluid actuator that converts the linear motion of a flat, toothed bar, or rack, into circular motion of a toothed gear, or pinion.
radial piston motor A piston motor with the pistons arranged perpendicular to the axis of the crankshaft. The crankshaft rotates as the pistons are moved linearly by fluid pressure.
retraction The movement of a single-acting cylinder characterized by air exiting the cylinder and the rod moving into the cylinder housing. In a double-acting cylinder, retraction occurs on each stroke and alternates between ends of the cylinder.
rod The cylindrical component housed parallel inside a cylinder and attached perpendicularly to the piston.
rod end The side of the piston that is attached to the rod.
rotary actuator A fluid component that performs work by directing force in a circular motion.
rotor The rotating part of a motor.
running torque The amount of rotational force needed to keep a load moving.
screw motor A motor consisting of two interlocking threaded cylinders. The male-female thread interaction traps fluid and causes rotation.
shaft flange The end portion of the crankshaft on a bent-axis piston motor that contacts the pistons.
side loading A type of eccentric loading in which a force is applied to the shaft perpendicular to the shaft's axis beyond a support point. Side loading is also called overhung load.
single-acting cylinder A fluid power actuator that directs energy in one direction.
single-vane actuator A rotary actuator that directs energy in a circular motion through the use of one arm-like mechanism, or vane. Single-vane actuators commonly have a range of motion under 360 degrees.
sliding spline The primary mechanism of a type of rotary actuator, consisting of a piston with a helical groove that rotates when fluid passes through it. Also called a helical spline, piston and helix, and helical piston.
speed The rate at which an object travels. Speed is calculated by dividing the distance traveled by the time elapsed.
stall torque A motor's maximum torque. If high torque occurs at low speeds, then theoretically a system's stall torque occurs when the machine is at rest.
starting torque The theoretical amount of torque that a motor can produce to move a load. Starting torque is a theoretical value or rating that does not change.
stationary barrier The component of a vane actuator that limits rotation.
swash plate A flat, angled component of a piston motor that is fixed to the crankshaft and rotates as the pistons push against it.
thrust A force that occurs when an object is accelerated in one linear direction.
torque A force causing rotation.
torque output The amount of rotational force applied by the motor measured in foot-pounds.
torque ripple The amount of torque measured by subtracting the minimum torque during one revolution from the maximum torque from the same motor revolution.
torque uniformity A measure of how well the forces of rotation are dispersed on the periphery of the crankshaft. On a vane motor, torque uniformity increases with the number of vanes.
vane The arm-like component that is moved by fluid pressure and causes rotation within a vane actuator.
variable displacement Characterized by a fluid capacity that is adjustable.