In terms of hard ambient conditions, solid mechanic in control technology offers a competitive alternative to sensitive electronics.
Depending on application areas, symmetrical and asymmetrical systems have been established in the past. After sending us your application demands, we will advise you regarding the most qualified system.
A mechanical variable pulley Rb. mounted on the driving shaft (motor shaft) and a spring-loaded variable pulley Fb, mounted on the driven shaft* form a variable pulley set with fixed centre distance RF b. Also suitable for reversing operation.
In this system, a spring pulley which opens on both sides (Fsb) is used in conjunction with a fixed driven pulley. Speed adjustment takes place by adjusting the center distance by way of the motor carriage or tilting base.
A fixed driven pulley is required in each case for use with these single pulley drives for standard V-belts. The spring-loaded variable pulley can be opened either on one side (KM) as a plain pulley or on both sides (Fs) as an interlacing type pulley.
Asymmetrically variable speed pulleys up to 200 kW
Asymmetrical cross section
High power transmission up to 200kW
Asymmetrical V-belts have a lower belt volume and thus for higher lateral rigidity and less heating, resulting in higher load capacity and longer service life
Asymmetric output pulleys are also available with torque-dependent pressure cams, which automatically and permanently guarantees the optimum axial pressure of the V-belt and thus prevents belt slippage during peak- and overload operation or machine starts.
By taking over the asymmetric adjustable pulley technology from the company Becker Antriebe, Sinn, BERGES has significantly expanded its field of competence. BERGES is the only supplier worldwide to offer the two existing variations in design: both the symmetric and as well the asymmetric pulley-type technology.
Asymmetrical drive units FG for 0,75 – 45 kW motor ratings, comprising:
spring-loaded regulating pulley F mounted on the motor shaft
fixed-diameter driven pulley mounted on the machine or gear shaft.
The axial pressure on the V-belts is exerted by compression springs with optimally dimensioned characteristics. Speed variation is achieved by changing the centre-to-centre distance by means of a sliding motor base plate. Speed variation within ratio of 1 : 3. This system provides a high torque at a low output speed.
Asymmetrical drive units FG for 1,1 – 45 kW motor ratings, comprising:
fixed-diameter driven pulley mounted on the motor shaft
spring-loaded regulating pulley F mounted on the machine or gear shaft
The axial pressure on the V-belts is exerted by compression springs with optimally dimensioned characteristics. Speed variation is achieved by changing the centre-to-centre distance by means of a sliding motor base plate. Speed variation within ratio of 1 : 3. This system provides an almost constant output power over the complete regulating range.
Asymmetrical drive units RK, RKN for 4 – 150 kW motor ratings, comprising:
mechanically adjustable regulating pulley R with integral central adjustment a) output pulley K with automatic torque-dependent pressure device b) type KN with increased pulley diameter for lower output speeds
This driving system is characterized by high efficiency even with partial load operation. This driving system is suitable for high starting torques and provides a high degree of overload safety.
Assembly units of the type RGAE – consisting of a housing, variable pulleys and wide V-belt – are designed for mounting on motors and reduction gearboxes according to IEC standards.
RGAE assembly units are additionally equipped with step or flange bearings and two-bearing shafts (gearbox flange). They are suitable for use with any drive elements as well as for direct mounting of gearboxes with IEC connection.
These assembly units are available complete with adjustment controls, motors and reduction gearboxes if required.
Available in any combination of drive type and motor design. Let us know the job at issue and we will be happy to work out an individual solution for you.
ATEX variable speed gear motors
These variable drive motors are explosion-proofed according to directive 2014/34/EU and they classified for Device Group II in Categories 2 and 3 EX II G D c T4 135°. They are available with either reduction gear or gearbox flange.