Why not use spring washers for mounting bolts of slewing bearings?

The installation and operation manual of the slewing bearing tells everyone that spring washers cannot be used when installing the connecting bolts of the slewing bearing, So if use spring washers, what impact will it have on the slewing bearing? Why the spring washers are widely used in other mechanical equipment, but can not be used on slewing bearings? Let’s take a look at the reasons.

First, we must understand the role of spring washers. The spring washer has a certain degree of elasticity, which can prevent the bolts and nuts from loosening and falling off during the equipment use, which is suitable for many mechanical equipment with vibration. However, the slewing bearing generally bears a large load, so the strength of the bolt is relatively high, usually use 10.9 grade bolt and nut, the high-strength bolt connection mainly relies on the friction resistance between the bolt and the connected part to achieve locking, unlike ordinary bolts can rely on spring washers to achieve prevent loosening, the correct anti-loosening measure for high-strength bolts and nuts is to use thread fastening glue.

Second, the slewing ring does not use spring washers to prevent deformation of the slewing ring. The contact area of spring washers is not as large as flat washers, under the action of large pre-tightening force, no flat washer is reliable, the large pre-tightening force of the bolt may cause plastic deformation of the mounting surface of the slewing bearing in contact with the spring washer, as the use time increases, the deformation will become larger and larger, the pre-tightening force of the bolt will become smaller, the bolt will appear loose. The slewing ring usually bears tilting moment. The tilting moment during operation will aggravate the plastic deformation of the mounting surface of the slewing ring, may also cause the spring washer to open, causing rapid damage to the bolt and the slewing bearing.

Third, suitable flat washers can increase the contact area between the bolt and slewing bearing, prevent the workpiece with insufficient hardness from plastic deformation of the contact surface of the slewing bearing when the bolt is pre-tightened, due to the contact area increase during the slewing bearing use, the bolt connection can maintain high reliability when the slewing bearing bears tilting moment and impact load.

Through the above analysis, we come to the following conclusions, spring washers cannot be used when installing the slewing ring, but suitable flat washers can be selected, when installing the bolts, you need to tighten the bolts according to the required pre-tightening torque in the instruction manual, use thread fastening glue can prevent bolts from loosening.

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Why not use spring washers for mounting bolts of slewing bearings?

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This article introduces the reasons why spring washers cannot be used when installing slewing ring connecting bolts.

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U-TRSM

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U-TRSM

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