Oldham couplings are a three piece design comprised of two aluminum hubs press fit onto a center disk. Torque transmission is accomplished by mating the slots on the center disk to the drive tenons on the hubs. During operation the center disk slides on the tenons of each hub (which are orientated 90° apart) to transmit torque. While the couplings accommodate a small amount of angular and axial misalignment, they are especially useful in applications with parallel misalignment.
Ruland offers oldham couplings in set screw or clamp styles with bores ranging from 1/8" (3mm) to 1-1/8" (30mm). Inch and metric hubs (set screw, clamp style, keyed, or keyless) are interchangeable and can be combined into a single coupling as long as they have the same outside diameter. Oldham coupling hubs are standard in black anodized aluminum for improved lubricity, increased life, and low inertia. Hubs are also available in stainless steel upon request for increased corrosion resistance.
The replaceable center disk is available in acetal for high torsional stiffness and zero backlash, or nylon for shock absorption and noise reduction. The slots of the disk mate onto the tenons of the hub with a slight press fit to allow the coupling to operate with zero backlash. In the event of disk wear or failure, the disk can be easily replaced and the oldham coupling's original performance restored. Disks with a center hole are available upon request to allow full shaft penetration.
Ideal for many light duty industrial and motion control applications, oldham couplings have the ability to protect more expensive machinery components. For example the oldham coupling acts as a torque limiter during overload. When the disk fails, it breaks cleanly and does not allow any transmission of power. Oldham couplings also have the advantage of electrical isolation due to the non-conductive nature of the center disk. This prevents electrical currents from being passed to delicate instruments which can cause inaccurate data readings or damage.
As a service to our customers, we offer our vast machining experience and talents to meet special needs with custom parts. Our shop is equipped with the machines and skilled people necessary to fill all of your special requirements. If you don't see what you are looking for in our standard line, please inquire about our custom fabrication service.
Selecting a coupling for a servo application can be a complex process. It involves many different performance factors, including: torque, shaft misalignment, stiffness, rpm, space requirements, and others, that all must be satisfied for the coupling to work properly. Before selecting a coupling, it is helpful to know the specifics of these issues for the application for which the coupling is to be used. Many different types of servo couplings exist with their own individual strong and weak points. This article is designed to introduce end users to the different types of couplings available for servo applications. It also helps the user select the proper coupling for their application by highlighting the factors that should be considered in the decision making process and how they relate to the different product offerings available.
Ruland manufactures a diverse line of servo couplings to provide solutions for applications such as stepper/servo systems, linear actuators, ball screws, lead screws, encoders, and valve actuation. Industries including medical, printing, packaging, machine tools, linear motion, semiconductor, and solar benefit from having a variety of couplings to choose from. Each application has performance requirements that must be met for the system to function properly. Understanding the different characteristics of each coupling is critical when making a selection.
Oldham couplings from Ruland Manufacturing Co., Inc. are typically used in motion control applications where zero backlash performance is required. However, these couplings are increasingly used as an alternative to straight jaw couplings on general industrial equipment.
For high technology applications such as test and measurement, inspection, semi-conductor, solar panel production equipment as well as medical devices, Ruland manufactures a variety of components including oldham couplings and beam couplings.