Brevini Riduttori, a European leader in power transmissions, says that the increasing popularity of rotating lift platforms for a variety of applications has given a major boost to its business, since its gear units are being increasingly used on the wheels that move the platform and rotate the boom in such platforms.

“The CWD and RX series for wheeled vehicles and the CTD/CTU series for tracked vehicles are extensively used to move the machinery, while its SDU series with hydraulic motor and integrated negative brake is an effective solution for boom rotation,” says a spokesman for the Italian firm.
He adds: “Brevini gear units used to drive wheeled and tracked vehicles – especially self-propelled and utility vehicles, aerial platforms – offers them the following advantages: makes them lighter and more compact, offers an integrated hydraulic motor and the possibility of installation on chassis, wheel rim and toothed wheel.”
“Brevini wheel drives are a much more flexible engineering solution compared to axial versions because they allow the vehicle to sit higher from the ground and consequently move more easily over unlevel terrain.”
Breveni’s range covers a torque capacity from 1,000 to 38,000 Nm, with a related radial load of up to 200,000 N, which makes it suitable for a wide variety of applications and hydraulic systems, and also for pneumatic and electric power sources.
The most popular wheel drives among aerial platform manufacturers are the RX and CWD series, which offer output torques from 1,000 to 10,000 Nm, and sustained radial loads (from 6,000 to 100,000 N), thanks to the use of taper roller bearings.
“To ensure maximum configuration flexibility, RX and CWD series wheel drives - which are compatible with standard wheel rims and available in a vast range of reduction ratios - can mount orbital or axial piston hydraulic motors on their universal input flange.”
The spokesman continues: “In aerial platform design, installing a high-speed axial piston motor is an effective solution because it supplies excellent starting torque needed to overcome initial inertia. It also permits smooth and accurate control of the horizontal movement to position the vehicle.
“The combination of a planetary gear unit with a high-speed hydraulic motor is also more economical compared to large, low-speed hydraulic motors, and also offers substantial advantages in terms of operation. Therefore, if the hydraulic fluid becomes contaminated, for instance, only the motor has to be replaced, which is an operation that can be performed in just a few minutes without having to move the entire aerial platform.
“The RX and CWD models also have an optional integrated multi-disc failsafe parking brake whose release mechanism is hydraulically controlled to ensure maximum safety if the hydraulic pressure is interrupted, which is to protect the vehicles that are often operated when the platform is completely raised.”
Brevini track drives are planetary gear units with rotating casing and a transmission torque of up to 100,000 Nm, obtained thanks to the sturdiness of the parts, which undergo special thermal treatments, and to the choice in toothing geometry design.