Counterweight

A counterweight is a body of a given mass, which usually used to compensate for unidirectional forces or torques due to geometrically asymmetrical designs or weight distributions. It will usually ensure the stability of bodies or objects or facilitate mechanical applications of lifting equipment.

Ensure the steadiness

For a stand on a base object, there is a tendency to tilt or overturning when acted upon by a gravitational force in the vertical direction to a point outside of the footprint. A typical example of this tower cranes, mobile cranes or acted upon by Forklift Trucks. In such cases, a correspondingly large counterweight with a suitable arrangement to ensure or improve the static balance or steadiness. The mathematical treatment of the optimal size and the arrangement of the counterweight is derived from the law of the lever. An alternative to counterweights would be a rope guy against the ground or against the supporting structure for fixed, immovable objects.

Relief or energy savings when lifting loads

In traction elevators and bascule bridges, etc. as a counterweight can be attached to the extension of the pull cable or the flap portion about the pivot point, which is preferably the same as the hoisting load. The drive must be overcome in the best case only the mechanical friction of the lifting mechanism ( pulley or axis of rotation). Often, however, the loads are varied ( for example, by varying number of persons in lift ) and an exact match does not occur. In this case, some of the drive must also apply power for the real lifting work.

Avoid imbalance

Vehicle wheels and other rotating body ( eg crank webs of crankshafts ) can have strong, random, or design-related deviations from a rotationally symmetrical weight distribution more or less. At high speeds, or stronger, mostly design-related, weight deviations to imbalances that can have destructive effect on duration arise. In this case, ensure that the axis of rotation is as far as possible identical with the principal axis of inertia at the wheel or rotary body mounted balance weights. This process is called " balancing ".

Also on the wheels of steam locomotives counterweights were used for mass balance, in which case " balance " not only asymmetries of the wheel body but additionally also deposited on the pivot heavy dome and connecting rods with are

Using the centrifugal force

The medieval trebuchet throwing weapon had attached a limb with one in the extension behind the axis of rotation, very heavy counterweight. This imparted upon release of the locking the relatively light throwing arm a sufficiently rapid rotational motion, the centrifugal force on the finally let out fast the projectile from the open sling.

In a theoretically conceivable space elevator counterbalance for the suspension of a rope to make, can be transported to the loads into space. The counterweight causes the center of gravity of the cable is located on the geostationary orbit, so that the centrifugal force compensates for the gravitational force.

Control oscillating movement

A wind-up metronome has a movable weight is mounted on a pendulum. The pendulum is held with a spring mechanism in momentum. By the position of the weight, the speed of oscillation can be adjusted.