Machine installation - part 3 - Bolt-through anti vibration mounts
After the second part of the "Machine installation" series has discussed the bolt-on variant as the solution of specific dynamic requirements, this part deals with machine installations with bolt-through anti vibration mounts.
Here, a threaded fitting is used to anchor the machine to the ground. The special feature is that the anchor bolts are guided through the wedge mount. This favours the vertical power flow of the bolted connections. In contrast to a bolted connection next to a wedge mount, the force is transferred uniformly into the wedge mount and therefore does not produce any bending moments in the machine body. This installation method is used for highly dynamic machines. The acceleration forces produced by such a machine are so high that the machine can not be maintained at its place merely with weight and friction. Machines with an eccentric or moving centre of gravity that bear a risk of overturning can also be levelled and operated safely with bolted-through wedge mounts. You must take several points into consideration if you also want to isolate a machine that is anchored to the ground. As shown in the figure above, there is a vibration insulation pad on the bottom of the wedge mount which forms an elastic bearing. To prevent the bolt from bridging the insulation and thus transferring vibrations into the ground, the bolt must be screened to the machine with anisolating washer. The tightening force of the bolt would gradually decrease with the natural flow of insulation material under pressure. To prevent this and to maintain the force, disc spring packs are installed as force accumulators between the insulation sleeve and the anchoring nut.
Machine installation series
- free-standing anti vibration mounts
- bolt-on anti vibration mounts
- bolt-through anti vibration mounts
- ridgid clamp anti vibration mounts