Automation & Linear Motion

Rigid couplings are manufactured from a single piece of material with no flexing elements giving them the greatest torque and torsional stiffness capabilities of any coupling Ruland offers. They are ideal for applications that require the highest degree of accuracy and repeatability. Automation and linear system designers prefer to use clamp as opposed to set screw type rigid couplings because they have increased holding power, will not mar the shaft, and have standard aluminum options for lightweight and low inertia.

Ruland manufactures rigid couplings with precision honed bores on straight bore couplings to ensure collinearity for a precise fit and greater torque transmission capability. Collinear bores prevent the coupling from introducing  misalignment into systems where it would not otherwise be present allowing for reduced wear on joined components and increased system efficiency. Ruland manufactures rigid couplings in set screw and one- and two-piece clamp styles in 1215 lead-free steel with a black oxide finish for the highest holding power, lightweight 2024 aluminum for low inertia, and 303 stainless steel for corrosion resistance. Bores are available in sizes from 1/8” to 2” and 3mm to 50mm.

Ruland beam couplings are machined from a single piece of aluminum or stainless steel with multiple spiral (helical) cuts allowing for greater torque, torsional stiffness, and parallel misalignment capabilities than commodity style single beam couplings. Ruland manufactures 4- and 6-beam couplings. The 4-beam style (P- and MW-Series) has two sets of two beams allowing for greater flexibility and more compact lengths than 6-beam couplings. They are ideally suited for encoders or other positioning sensors commonly found connected to a servo motor in automation and linear systems. The 6-beam style (F-series) has two sets of three beams for higher torque and torsional stiffness capabilities. They can also be used in encoders where a longer length is needed as well as for light duty power transmission applications such as connecting a stepper motor to a lead screw. It is common to use a 6-beam coupling in an application with low to moderate acceleration/deceleration curves such as an inspection system due to their dampening capabilities.

Designers of linear and automation systems typically prefer aluminum beam couplings for their cost effectiveness and low inertia. Stainless steel beam couplings have higher torque capacity, but significantly increased inertia than aluminum types. Ruland manufactures beam couplings with a zero-backlash balanced design for smooth operation up to 6,000 RPM. They are available with clamp or set screw attachments in bore sizes ranging from 3/32” to 3/4” and 3mm to 20mm.

Ruland bellows couplings are made of two lightweight anodized aluminum hubs joined by a flexible stainless steel bellows. The thin walls of the bellows allow the coupling to flex under misalignment while remaining rigid under torsional loads. Engineers designing precision linear systems often prefer to use bellows couplings because they are lightweight, accommodate all forms of misalignment, and have the greatest size-for-size torque and torsional stiffness of any Ruland flexible coupling.

Ruland manufactures bellows couplings with a low inertia, zero-backlash design, making them a suitable option for high torque applications where a rigid coupling is not feasible due to weight or misalignment requirements. They are available in clamp and set screw hubs with or without keyways in bore sizes ranging from 1/8” to 1” and 3mm to 25mm.

Ruland disc couplings are zero-backlash and have high torque, high torsional stiffness, and a balanced design making them an ideal fit for a variety of automation and linear systems. They are manufactured in single and double disc styles. Single disc couplings are comprised of anodized aluminum hubs and stainless steel disc springs. They are ideal for space constrained applications, however designers must be careful when using them as they cannot accommodate parallel misalignment. Double disc couplings are made of anodized aluminum hubs, an anodized aluminum or acetal spacer (for electrical isolation), and stainless steel disc springs. The double disc style can accommodate greater amounts of all types of misalignment than single disc types, including parallel misalignment.

Disc couplings have similar performance characteristics to bellows couplings with slightly less torque in exchange for better misalignment capabilities. They are well-suited for linear and automated systems that require high torsional rigidity and speed up to 10,000 RPM, such as those found in precision handling applications and factory automation. They are available in clamp and set screw hubs with or without keyways in bore sizes ranging from 1/8” to 1-1/4” and 3mm to 32mm.

Ruland zero-backlash jaw couplings consist of two lightweight aluminum hubs and a center elastomeric element called the spider. Hubs are machined with a proprietary machining process to produce a curved jaw profile that press fits with the spider to achieve consistent zero-backlash operation. The spider dampens impulse loads, minimizing shock to the motor and other sensitive system components such as bearings. This is particularly useful in linear systems with high acceleration/deceleration curves often found in optical inspection and measurement equipment. The spider is available in three durometers allowing the designer to balance dampening capabilities with torque, misalignment and torsional stiffness based on system requirements.

Zero-backlash jaw couplings are considered fail safe because the spider serves as the wear element – if it fails the jaws of the two hubs interlock for direct power transmission. This allows for the application to be safely shut down for maintenance rather than stopping suddenly. Spiders can be replaced to restore the original performance characteristics of the coupling leading to reduced maintenance costs when compared to other coupling styles that require complete replacement at the end of their usable life.  Bores are available in sizes from 1/8” to 1-1/4” and 3mm to 32mm.  The three piece design allows the user to mix and match clamp or set screw hubs with inch, metric, or keyless bores making it easier to tailor the coupling to specific system requirements.

Ruland oldham couplings are a three-piece assembly with a balanced design comprised of two anodized aluminum or stainless steel hubs and a center disk. Oldham couplings are manufactured with a proprietary machining process for smooth interaction between the hub tenons and disk allowing for the longest service life in the industry. Oldham couplings accommodate far more parallel misalignment (up to 10% of the outer diameter) than any other servo coupling offered by Ruland.

Oldham couplings are highly versatile because of the variety of hub and insert materials available. Designers can choose between acetal, Nylon, and PEEK disks to balance torsional rigidity, torque, environmental compliance, and misalignment capabilities. Aluminum oldham couplings are lightweight, cost effective, and offer low bearing loads. These properties make them useful in stop-and-go systems or scanning applications that prioritize rigidity. Stainless steel oldham couplings can be used in corrosive, cleanroom, and vacuum environments when paired with a PEEK disk. This combination is useful for automation or linear systems in food processing applications. In the event of coupling failure, the center disk will act as a torque limiter by breaking cleanly and ceasing power transmission, protecting expensive machine components.

Bore sizes are available from 1/8” to 1-1/8” and 3mm to 30mm. Oldham coupling hubs are available in clamp and set screw styles with or without keyways, allowing designers to mix and match hubs to fit different shaft types.

Controlflex couplings are a multi-piece assembly comprised of two lightweight aluminum hubs joined by one or two center inserts called frogs. They have a balanced design that allows for speeds up to 25,000 RPM, accommodate all forms of misalignment, and operate with low bearing loads to protect small, sensitive system components such as bearings. Controlflex couplings are well suited to encoder applications across a variety of automation and linear systems. They can accommodate large steps in shaft sizes, up to a 3.5 to 1 ratio, which is common in encoders that have a large motor shaft connected to a small encoder shaft.

The single insert style has high all-around misalignment capabilities and fits in space restricted applications while double insert controlflex couplings offer higher torque and torsional stiffness capabilities. The unique design of the frog inserts allows controlflex couplings to remain rigid while flexing under misalignment conditions for high performance in light duty applications with one or more types of shaft misalignment present.

Controlflex couplings are zero-backlash and electrically isolating. They are available in bore sizes from 1/8” to 1-1/2” and 3mm to 40mm. Controlflex couplings are manufactured by Schmidt Kupplung and stocked or bored to size by Ruland.

Slit couplings are zero-backlash and manufactured from a single piece of aluminum with intermittent slit cuts allowing for high torque and torsional stiffness capabilities, low inertia, and a long-life. The proprietary slit pattern with radiused edges reduces stresses that build up during misalignment conditions and torque load allowing for reduced wear and stress on the coupling.

Slit couplings have a high-performance design that balances torque, misalignment, and torsional stiffness capabilities. The have a torque capacity comparable to that of a single disc coupling, torsional stiffness similar to a stainless steel beam coupling, and accommodate misalignment like an aluminum beam coupling. This combination makes for a well balanced coupling that can be used in demanding applications where high misalignment is present.

Ruland offers slit couplings in RL- and RS-series. RL-series couplings have longer lengths allowing for greater parallel misalignment capabilities and increased torsional stiffness. RS-series couplings are designed to fit in compact spaces and offer parallel misalignment capabilities, differentiating them from single disc couplings. Both series can accommodate all forms of misalignment with low bearing loads and have a balanced design for speeds up to 70,000 RPM.

Slit couplings are available in clamp screw and set screw designs with inch, metric, and inch to metric bore sizes ranging from 1/8” to 3/8” and 1.5mm to 12mm. They are manufactured by Reliance Precision Ltd. in their Cork, Ireland factory and stocked or bored to size in Ruland’s Marlborough, MA location.