Coupling Selection Factors

Release Date: May 1, 2017

In this installment of the Ruland Instructional Video Series we will discuss the factors you must consider before choosing your coupling.


Hi, Bobby Watkins from Ruland Manufacturing and in this segment, we're gonna talk about coupling selection factors and we'll go through a few. The geometry requirements, what are your two shaft sizes? Are they round shaft or are they d-shaped shaft? Are the shafts keyed? This is important information to have and your coupling envelope size. What is the maximum outside diameter and what is the maximum length that you have to work with the application? This information can be helpful in steering us to suggesting the correct type of coupling. So again, is the application an encoder? Is it valve actuation? Is it a linear actuator? Ball screw? Lead Screw? Again, the application basics can also help us decide what type of coupling to start looking at. So, the misalignment requirements, you know, parallel misalignment, angular, axial misalignment requirement, identifying the types of misalignment that you're trying to correct with the coupling and the amount of each, again is going to steer us to choosing and suggesting the correct coupling to handle the degree of misalignment that you've got in your system. Mechanical performance requirements, the torque required, the RPM, range speed if you will. Do you want couplings with a lot of wind-up, a lot of cushioning, a lot of dampening, or are you looking for high torque stiffness and accuracy? Those are important in choosing the proper type of coupling and environment and serviceability requirements. So what's the ambient temperature? Is it in a vacuum? Is it a corrosive environment and accessibility. Some applications, there's only a slot or an access hole to get at a coupling to tighten it down if you will and again if you've got a situation where you need the screw location on the coupling in a particular spot because of limited access, that's important information as well.

Helpful Resources for Coupling Selection

Coupling Comparison Guide -This is a chart that shows the comparison of Ruland servo coupling on critical performance characteristic.

What to look for in a Servo Coupling - Choosing the most appropriate type of coupling to use in servo applications can be confusing. This article examines the pros and cons of the various couplings.

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