Power transmission components supplier BMG has launched pin gear drive units that replace conventional rack systems.

“The new Tsubaki standard series, which is made from steel, and the S-series, which comprises stainless steel pin gear drive units, are a combination of a pin structure wheel/rack and a socket, with a special high-strength tooth profile that engages continually and smoothly with the rollers. This feature enables greater freedom when designing rotating or linear drive units. Another advantage is the high pin-wheel balance, which offers greater transmission torque,” says BMG chain division GM Scott Larson.

He adds that these units, which have a separable segment design to ensure easy installation, can be used in large-scale equipment by increasing the number of segments required for each application. In a rotational drive, the pin-wheel diameter is extended by increasing the number of pins, while in a linear drive, the pin rack length is determined by the number of pins used.

“Typical applications of these pin gear drive units include environmental sanitation equipment, railroad turntables, welding roll-overs and revolving door mechanisms. These units are also used in casting lines, rotary kilns, drives for large transporters, handling robots and pallet changers of machine tools,” says Larson.

“These units can also be surface coated for additional protection, while teeth are hardened to improve strength and wear resistance. Blackening these units enhances their appearance and offers protection against corrosion. “Electroless nickel plating offers corrosion and wear resistance and Tsubaki NEP treatment has rust- and weather-resistant characteristics,” he explains.

In the standard series, the lock-type pin gears have a friction- fastening mechanism for easy phase adjustment. “Units, with only two-thirds, or half the standard amount of backlash, are also available. This feature improves stopping accuracy where necessary,” Larson highlights.

BMG has published an easy-to-follow Tsubaki procedure guide to ensure the correct preselection of the pitch-circle diameter of the pin gear drive unit. This guide offers critical information on calculating applied loads (Fw) and tangential loads (Ft) and selecting the correct frame number of the unit required. This guide also includes correct installation procedures.

Larson highlights that the pin gear units have been designed for easy installation – even with rough installation precision. The projections on the pin-wheel frame share the same centres as the roller-mounting holes, so projections can be used as a reference surface for centring when fitting the pin wheel into the pilot section on the equipment.

“In pin racks, it is critical to ensure that the parallelism of the equipment-side mounting reference surface and pin gear centre is equal to, or less than, the indicated value of the gear centre parallelism, as set out in the Tsubaki guide. This is achieved by ensuring the machine is correctly aligned.”

With the complete range of Tsubaki power transmission components available from BMG’s national branch network, Larson says, the company also offers a technical advisory and 24-hour support service to ensure that clients have access to technicians should they need assistance in using the components.