Power Transmission Engineering Magazine
www.powertransmission.com/articles/4448

Ruland Offers Diverse Servo Couplings Line

December 10, 2012
Ruland Manufacturing Co., Inc. manufactures a diverse line of servo couplings to provide solutions for applications such as stepper and 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.

Rigid couplings have high torque capacity, torsional stiffness, and are zero backlash. Ruland straight bore rigid couplings have precision honed bores for proper fit and alignment. Proprietary Nypatch coating is used on hardware to resist vibration and maintain holding power. Two-piece styles feature opposing screws for balancing, reducing vibration at higher speeds. Ruland rigid couplings are available in carbon steel for highest torque capabilities, aluminum for low inertia, and stainless steel for corrosion resistance. Inch, metric, and inch to metric sizes are available with or without keyways from 1/8 in. to 2 in. and 3 mm to 50 mm.
    
Beam couplings accommodate all types of misalignment, are balanced, and operate with zero backlash. Four-beam couplings are suited for light duty applications such as encoders or tachometers while six beam couplings can be used in more heavy duty applications like connecting a lead screw to a servo motor. Ruland beam couplings are available in aluminum for increased flexibility and low inertia or stainless steel for higher torque transmission capabilities and corrosion resistance. Sizes in inch, metric, and inch to metric range from 3/32 in. to 3/4 in. and 3 mm to 19 mm. Custom cut patterns, anodizing, and other custom design features are available.

Oldham couplings are a three-piece assembly well suited to handle large amounts of parallel misalignment with light bearing loads. Aluminum hubs are used for low inertia and discs are available in acetal for high torsional stiffness and zero backlash or nylon for shock absorption and noise reduction. Ruland oldham couplings are also balanced and electrically isolating. They are highly customizable and hub styles such as clamp, set screw, keyed, keyless, inch, and metric can all be easily combined. Bore sizes range from 1/8 in. to 1-1/8 in. and 3 mm to 30 mm. Stainless steel hubs, discs with through holes, and other custom design features are also available.

Jaw couplings are a balanced three piece assembly with an elastomer spider to dampen impulse loads and are well suited for rapid start-stop applications. Spiders are available in three durometers for different torsional stiffness, misalignment, and dampening requirements. Hubs are available in aluminum for low inertia and are available in a variety of styles including clamp, set screw, keyed, keyless, inch, and metric for ease of customization. Bore sizes range from 1/8 in. to 1-1/4 in. and 3 mm to 30 mm. Stainless steel hubs, custom dimensions and other specialized design features are also available.

Disc couplings have high speed capabilities, high torsional stiffness, and low inertia for highly responsive systems. They perform with zero backlash, are balanced, can be electrically isolating and have a long life. Disc couplings are available in single disc style for compact installations or double disc style for increased misalignment capabilities. Sizes in inch, metric, and inch to metric range from 1/8 in. to 1-1/4 in. and 3 mm to 32 mm. Stainless steel hubs, keyways, and other custom designs are available by special order.
    
Bellows couplings are balanced and offer the highest degree of torsional stiffness making them ideal for applications that require accuracy and repeatability. The combination of aluminum hubs and stainless steel bellows creates a lightweight, low inertia coupling suitable for speeds of up to 10,000 rpm with no allowance for dampening. Inch, metric, and inch to metric sizes are available ranging from 1/8 in. to 1 in. and 3 mm to 25 mm. Stainless steel hubs, keyways, and other custom designs are available by special order.