Slewing drive installation process

Slewing drive applications in municipal vehicles


 Cleaning the slewing drive and the mounting structure:

• Remove extraneous material from supporting surfaces (including paint residues, welding beads, burr formation). Clear corrosion protection coating from supporting surfaces of the slewing drive. Cleaning material does not penetrate into the slewing drive. Cleaning material that attacks the sealing material is not used. Applicable cleaning materials: Cold solvents (e.g. white spirit, diesel oil, Kaltryl KEV).


Lubricating the slewing drive:

• slewing drive are supplied fully lubricated. They shall be greased again prior to initial operation. It is essential to use the greases specified on the delivery drawing.

Choice of mounting bolts:

Prescribed sizes, number and quality grades shall be used.

• Grip ratio (grip length to diameter of bolt) shall be observed from minimum ≥5 to maximum ≤10.

• Bolts with a fully threaded shaft are not permissible.

• The function and lifespan as well as the durability of the bolt connection are affected in the case of noncompliance.

• If the permissible interfacial pressure is exceeded, use suitable washers of appropriate size and strength.

• Do not reuse bolts, nuts and washers.


Choice of tightening torques:

Mounting bolts are in normal cases adequately secured by correct preloading.

• Mounting bolts can be secured by Loctite. Nord- Lock bolt lock washers may be necessary in case of shock or vibration.

• Use of split rings, split washers etc. is not permissible.

• If washers are used ensure that they are of the correct strength class.

• Tightening torques and bolt tension forces for regular metric threads according to DIN13.


Positioning the slewing drive:

• Mounting bolts can be secured by Loctite. Nord- Lock bolt lock washers may be necessary in case of shock or vibration.

• Use of split rings, split washers etc. is not permissible.

• If washers are used ensure that they are of the correct strength class.

• Tightening torques and bolt tension forces for regular metric threads according to DIN13.


Securing the slewing drive with bolts:

• Lightly lubricate bolt threads in order to ensure uniform frictional resistance (does not apply to bolt locking devices with adhesive).

• Preload the bolts, including washers, if required, crosswise in 3 steps with 30%, 80%, 100% of the tightening torque or the hydraulically applied pretension force.

• Thereby rotate the unbolted ring several times. Repeat the procedure for the bearing ring which has not yet been bolted.

When applying a hydraulic fastening device, the tightening forces for preloading shall not exceed 90% of yield stress. The values given in DIN 13 correspond with 85% of yield stress.


Determining the existing tilting clearance and backlash worm gear:

• The tilting clearance increases with raceway wear. To determine the increase in tilting clearance, it is necessary to take basic measurements after installation prior to putting the slewing drive into operation for the first time. The permissible increase in the tilting clearance may be 1,5 to 2 mm.

• The signal of the gear wear is an increased backlash. The permissible magnitude of the backlash depends on the swing drive type applied.

• Permanently designate the measuring point in the main load direction.

• Record all measured values.

All measurements are performed at the same measuring point, with the same loads, at the same position of the bearing rings relative to one another and in the same sequence. All the measured values are to be recorded. For purely axial or radial loads, tilting clearance is inspected by pplying an additional tilting load.


Operating test:

If the mounting bolts are properly tightened, then the slewing drive shall rotate uniformly. Deviations of the mounting structure and the effect of external loads can strongly impact the friction torque.

• Rotate the mounted slewing drive several times.

• Check whether the slewing drive runs smoothly without jumping.

• Perform further test runs under full load.

After the operating test, recheck the tightening torques of the mounting bolts.


View more about slewing drive: https://en.u-transmission.com

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