For reliable turning of transmission shafting…

BHS rotor turning gears are a reliable and economical way to:

• break away and start shafts,
• turn rotors slowly so that they cool uniformly, retaining their
  dimensional stability and avoiding deposits in impeller channels, and
• align and position large shaft trains.

Depending on the design, rotor turning gears are either positioned on a free shaft end or integrated into the shafting.

Rotor turning gears from BHS are particularly resistant to wear because they use hardened straight bevel gears, so they have a long life. Compared to worm gears, they need considerably smaller motors, which reduces costs. BHS rotor turning gears are made up of simple, standard components, and spare parts are available at short notice. To facilitate fine adjustment and emergency operation, BHS supplies all rotor turning gears with handwheel and hexagon drive connections as standard. Power is provided by an electric or hydraulic motor, as required, and different types of explosion protection are available.

Rotor turning gear unit with SSS clutch

Rotor turning gear unit with swivelling pinion

For trains with a free shaft end, BHS offers fully automatic rotor turning gears. In this case, straight bevel gears drive the shaft trains via an overrun clutch that engages and disengages automatically according to the speed of the shaft.

For systems without a free shaft end, the rotor turning gear is incorporated within the shaft train by positioning it on a bearing pedestal or coupling shell. A gear rim is flange-mounted between two adjacent shaft ends, and engages with a vertically-swivelling pinion in the rotor turning gear. As the shaft accelerates, the pinion disengages automatically and is secured in a safe position.

Rotor turning gears of the swivelling pinion type can be controlled in several ways. In the standard version, the turning gear may only be engaged when the system is at a standstill. If the system is equipped with “Automatic I” control, a solenoid or pneumatic cylinder can engage the pinion remotely whenever the system is at a standstill. With the “Automatic II” version, the swivelling pinion engages automatically as soon as the shaft speed falls to match that of the rotor turning gear. The system is monitored and controlled by a speed recorder.

Rotor turning gears with an overrun clutch at the free shaft end are available for breakaway torques of up to 25,000 Nm and for turning speeds of 0.2 –300 rpm. BHS builds rotor turning gears fitted with a swivelling pinion, for integration into the shaft train, for breakaway torques up to 100,000 Nm and turning speeds of 10–400 rpm.

BHS rotor turning gears offer a high degree of safety at high turning speeds, high breakaway torques and high moments of inertia. They meet the demands of customers and OEMs for ever-increasing system availability, short lead times for original equipment and spares, and improved servicing facilities. Many well-known OEMs and engineering companies rely on BHS’s decades of know-how, with more than 1,000 references, in rotor turning gears.