The drivetrain in our Rollair V range of compressors is an incredible feat of engineering. A drivetrain consists of 3 key parts, and we made improvements on every one of them. It features an oil-cooled interior permanent magnet motor, an integrated direct drive transmission, and our new screw element. These three innovations have a major impact on the compressor's overall efficiency, reliability, and productivity. Let's take a closer look at how they are improved.
• In-house designed iPM motor (1) with IE4 Super Premium Efficiency • New generation in-house designed screw elements (2) with improved efficiency • Integrated direct drive transmission (3) for minimal losses • Smart inlet valve (5) optimizes the inlet flow and improves efficiency
• iPM motor (1) rated IP66, protected against dust and water ingress • Globally renowned screw elements (2), proven in thousands of installations • Optimal cooling at all speeds and conditions thanks to the oil-cooling principle (4) of the iPM motor (1)
• No greasing of the motor (1) bearing needed • Coupling-free direct drive design (3), no maintenance needed • Smart inlet valve (5), no maintenance needed
The iPM motor is located on the right side of the compressor drivetrain.
In a conventional induction motor, an electric current flowing in the stator windings in a rotating motion will, thanks to electromagnetism, create a rotating magnetic field (RMF) in the stator. The RMF rotates at synchronous speed. Through electromagnetic induction, the RMF also induces an electric current and a magnetic field in the rotor. This magnetic field in the rotor will try to catch up to with the RMF of the stator but will always be behind in speed. In other words, the rotor rotates at asynchronous speed. The differences between synchronous and asynchronous speed are called slip losses and reduce the efficiency of the motor. Because current is induced in the rotor to create the rotor's magnetic field, the heat losses are rather high which further reduces the efficiency of the motor. In our iPM motor, permanent magnets are housed inside the rotor. When the electric current is flowing in the stator windings they create a rotating magnetic field (RMF). As a result, the permanent magnets inside of the rotor will be attracted by, and start rotating with the RMF of the stator. The rotor will rotate at the same exact speed as the RMF of the stator at synchronous speed, meaning there are no slip losses. The heat losses are also lower than those in conventional induction motors since no current needs to be induced in the rotor (the magnetic field of the rotor is created by the permanent magnets inside of the rotor).
The third improvement comes in the form of an integrated direct drive transmission, which means that the motor and screw element rotate together as one functional unit, resulting in zero transmission losses. Unlike conventional direct drive transmissions, this design is coupling-free, keeping transmission losses and service costs to a minimum.
The cool oil runs through the housing, cooling the motor evenly.