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Ball Screws Terms
- The conversion of thrust motion
back to torque motion. Backdrive can be reduced through a self-locking
mechanism.
- The movement of a screw and nut from its initial position.
Unlike creep, backlash is not caused from vibration or heavy loads.
- The movement of a screw and nut from its initial position
due to vibration, shock, or intense loads.
- When a screw is loaded in compression its limit
of flexible stability can be exceeded but may end of failing due to future
buckling or bending.
- Revolving screw shafts will develop normal frequencies
of vibration depending upon their length, size and end shape. The speed
at which this vibration occurs is predictable and is called the critical
speed.
- A measurement, expressed as a percentage, representing
the comparison of power output to power input of a screw assembly.
- This refers to the method by which the ends of the
screw are supported. There are three basic types of end fixity as follows;
free, simple and fixed.
- A condition that occurs in ball screw assemblies
involving continued screw rotation, but no linear movement.
- A screw's and nut's resistance to movement.
Different types of friction exist, including sliding friction characteristic
of Acme screws and lead screws, and rolling friction characteristic of
ball screws.
- The measurement of a nut's movement across the screw,
measured in inches per revolution (in/rev).
- The axial measurement between threads. Pitch also refers
to the number of full rotations a screw makes in order to produce one
inch of movement of the nut along the screw.
- This is reference to the minor diameter of a screw
thread or the major diameter of a nut thread.
- The rotary speed of a ball screw, represented
by the number of full rotations of a screw occurring in one minute.
- Referring to the number of independent threads found
on a screw shaft, usually found in configurations of either 1, 2, or
4.
- A characteristic of Acme screw and other types of
screws in which back drive is prevented by the disallowance of thrust
to torque conversion.
- The portion of the screw which contains the threads.
- The measurement of the pace of linear movement in ball
screw assemblies, expressed in inches per minute. Speed is calculated
through the multiplication of screw lead by RPM, or revolutions per minute.
- The measurement, expressed in inches, of a ball screw
system's linear motion or thrust.
- The raised helical rib going around the shaft of a common screw.
- Linear movement achieved by the torque produced from ball
screw assemblies.
- Rotational motion of a ball screw system that translates
into linear movement, known as thrust.
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