Slewing Drive

Slewing Drive

HZPT slewing drive is a gearbox designed to handle radial or axial loads using high rotational torque. In addition, the slewing ring bearing, at the heart of the drive, enables it to withstand high overhung or moment loads. A descendant of the “worm” screw, slewing drives are present in construction machinery, manufacturing, military equipment, and many other applications that require strength and precision.

The physics of the slew drive makes it a versatile solution for many applications. In operation, the slew drive’s axial movement, or motion around its axis, interacts to create radial torque. The action occurs by meshing the grooves of the horizontal screw with the teeth of a perpendicular gear. While turning, the worm gear’s axial movement transfers magnified torque force to the radial gear. The number of threads on the horizontal screw and the number of gears that interact will determine the speed ratio of the setup.

Slew drives work best for applications in which high torque can create precision positioning and rotational accuracy. This design results in a device that works smoothly and powerfully with minimal backlash.

How Do Slewing Drive Work?

The mechanics behind it is built on the concept of a worm wheel where a slewing ring with external teeth is meshed with complementing worm gear with a predefined gear ratio. Internal components are contained and assembled inside a cast iron or aluminum housing for protection and installation.

The unique design of a slewing drive allows it to utilize two perpendicular planes transmitting high output rotational torque with a relative speed ratio to its inputs. As the worm gear rotates through a low input torque on the horizontal plane, its hardened teeth translate rotational motion onto the external slewing teeth. This force creates a rotation around the perpendicular axis of the slewing drive through the slewing outer ring.

The use of a worm-wheel design makes room for a wide range of low torque inputs to the slewing drive to transmit or hold high torque applications. Slewing drives can be found across several constructions and heavy machinery equipment. The versatility and weight allow slewing drives to act as an immediate solution to rotary-related issues.

Slewing Drive Parts

Slewing Drive Parts
Part Description Part Description
1 Enclosed housing 9 End cap O-rings
2 Large O-ring 10 Outer oil seals
3 Slewing ring 11 Taper roller bearing
4 Top plate seal 12 Inner oil seals
5 Upper positioning bolts 13 Worm shaft
6 Top plate 14 Grease nipples
7 Non-drive end cover 15 Lower positioning bolts
8 End cap & bolts 16 Drive end adaptor cap

Slewing Drive Characteristics

Slewing drives are unique on the market due to their versatility. While slewing drives are standard in size and external dimensions, custom and customer-specific requirements can be followed in the early design stages. The worm gear input can be modified to accommodate different motor input shaft sizes according to application requirements. Cast iron or aluminum end caps are bolted to both sides of the worm shaft to press the gears into place. This prevents axial play and provides better backlash control.

The standard orientation of the slewing drive is horizontal, allowing high axial loads and minimal radial loads. However, the vertical direction is widely distributed in different applications. The number of bolts and their distribution on the slewing drive surface play an essential role in the load capacity of the slewing drive. Still, custom modifications can be made to fit/replace the current models used by our customers.

Slewing Drive Applications

The slewing drive can be applied to the main machine that does circular motion, such as crane slewing table, rotating machinery, and some machinery that performs circular work. Once the product is put into production, it can be widely used in the field of construction machinery represented by aerial work vehicles and truck cranes, and in the field of new energy represented by solar photovoltaic power generation and wind power generation, as well as other fields such as automation, machine tool manufacturing, and aerospace communications. It can be said that, The market potential of slewing drives is huge.

Typical slewing drive applications include but are not limited to:

  • Solar Trackers
  • Digger Derricks
  • Wind Turbines
  • Lifts
  • Man Lifts
  • Cranes
  • Hydraulic Machinery
  • Drilling equipment
  • Telescopic Handlers
  • Military Equipment


Slewing Drive Typical Applications
Slewing Drive Typical Applications
Slewing Drive Typical Applications
Slewing Drive Typical Applications
Slewing Drive Typical Applications
Slewing Drive Typical Applications

Slewing Drive Installation

(1) clean the installation bracket, remove welding slag, galvanized residue, etc. ;Bolt the bracket to the slewing drive. The bolt head shall be provided with a flat washer and a spring washer. Slewing drive should be installed without load. Please follow the following procedures to avoid internal stress and installation problems during bolt tightening.

(2) Add thread fastening glue to thread;Pre-tightening bolts and washers shall be cross-tightened;See the following figure for tightening order of bolts;Starting from the inside or outside ring, tighten all bolts to 30% tightening torque, then repeat the diagonal tightening to 50% tightening torque, and finally to 100% tightening torque.

(3) All the mounting bolts should be mounted without missing. In case of structural restriction, the bolt hole must be sealed. If the bolt hole is filled with silicone, it will leak and dust into the slewing drive.

(4) The installation bolt should consider the thread meshing length, should not be too long, otherwise affect the rotation of the slewing support or cause interference;After the bolt is tightened, mark the bolt head and its connection with a line, so as to check whether the bolt is loose later.

(5) Refinish during slewing drive installation. Inevitably will cause surface paint bump damage, so, the system after the completion of the final assembly, it is necessary to carry out paint repair to the rotary reducer, to improve the ability of rust, corrosion prevention.

Slewing Drive Manufacturers

Our company specializes in the production of various kinds of slewing drives, which not only provide high-quality and inexpensive slewing drives but also provide professional technical guidance and considerate after-sales service. If you need slewing drive, please contact us.

Slewing Drive Suppliers
Slewing Drive Manufacturers