EWA25 Series Slewing Drive

Slewing drives are gearboxes that can handle radial and axial loads and deliver a high rotational torque. These mechanisms generate a rotational movement along either a single axis or multiple combined axes. A finished gearbox is assembled from seals, bearings, housing, gearing, motors, and other manufactured components.Slew drives typically employ either a spur gear or a worm gear to achieve rotation. Spur Gear drives are used for high rotational speeds and quick acceleration at nominal-to-low torque loads. On the other hand, Worm gear drives are slower in speed but can magnify an input torque at much higher ratios than a typical spur gear system. Consequently, worm gear drives are used in applications requiring high torque.Slew drives can be successfully designed to operate in extremely harsh conditions such as salt spray conditions (ocean cranes), explosion-proof conditions (paint booths), mining, food and beverage, and sub-zero cold and arctic conditions. The best slew drives systems have a housing that encloses the system and provides protection from environmental factors. As a result, slew drives can be used in applications that are fully exposed to the elements without any detriment or corrosion to the inner parts. An encapsulated unit also provides for an extended work life by limiting the loss of bearing lubrication,  resulting in significantly reduced maintenance costs.

Performance Parameters

Front View	Top View

 

Output torque	Tilting moment torque	Holding torque	Axial load	Radial load	Ratio	Backlash	Weight
输出转矩	倾覆力矩	保持力矩	轴向承载力	径向承载力	速比	精度	重量
34.2 kN.m	310 kN.m	160 kN.m	2400 KN	950 KN	104:1	<= 0.1 °	200Kg
25240 Lbf.ft	229000 Lbf.ft	118000 Lbf.ft	539500 Lbf	213600 Lbf

Advantages of Slewing Drives

Fully self-contained slew drives also allow for simple integration and installation into any system, i.e., plug-and-play. They can be easily bolted into place, attached to their power source, and are ready to perform. This offers a signification advantage over the older method of designing and assembling a slewing system from components (slew ring, pinion, worm gear) and then adjusting the system for correct backlash and contact pattern. The approach is often a cost-saving solution once labor, design, purchasing, and setup time are factored in.Slew drives offer a degree of customization to meet the needs of any application. They may be powered by one or two drive motors (double the torque capacity). The driving motors can either be electric or hydraulic to accommodate a variety of power inputs or controls. Servo motors can be used for acceptable input and slew drive output control. Encoders can be added to the rotational components of a slewing drive to provide real-time feedback on variables such as angular speed and position. Various seals, greases, and coatings (paint, thick film passivation, zinc plating) are available to match corrosion protection to the application environment.

Material Selection

Material selection is essential in slew drive design. Slew drives come in a wide array of sizes and materials. Steel and cast iron are the most common materials, while synthetic materials are available depending on the application. Specifically, slew bearing and gearing constructed from stainless steel provide high strength and durability and have corrosion protection.   Bronze is employed in worm gearing for high-speed rotation, longer duty cycle times, and more excellent lubrication but dramatically reduces the load-carrying capability versus steel.

Application Case

The list of active applications for slew drives is extensive. Several industries require some form of slew drive to make their operations more efficient. Equipment for mining, construction, metalworking, and other applications that require unrelenting strength combined with faultless precision use slewing technology for safety and accuracy. Powerful devices like aerial lifts, rotating forklifts, truck-mounted cranes, cable winders, fire trucks, hydraulic machinery, and utility equipment depend on the safety and strength of slew drives.

Why Choose Our Slewing Drives?

We offer the different dimensions and construction series with straight or helical gearing, an open or closed structure, and screws and casing. We use other materials when manufacturing based on the customer's requirements and operational conditions.

Technical features
Raceway diameter	222 mm up to 640 mm (9 in up to 25 in)
Max. output torque	Up to 43,000 Nm (31,585 Ibf-ft)
Weight	Up to 250 kg (551 Ibs)
Lubrication	Grease
Temperature range	-20°C up to +40°C
Design	Enclosed housing, ball bearing
Slewing range	360°

Our slewing drives are available in a large variety of standard design sizes. We will gladly develop a slew drive tailored to your requirements if you are looking for an individual solution.Contact us – we will be happy to help you!