How to calculate the static moment

To know how to calculate the static moment, let's first review the definition of the static moment: when the object has a tendency to rotate on a certain axis but does not rotate, the resulting moment is the static distance.

Static moment calculation method:

< Definition > If the distance between a particle of mass m and a rotating axis L is l, then the static moment of the particle to the rotating axis L is M(L)=m×l

From the above relationship, it can be seen that a two-dimensional plate has a static moment to a certain rotating axis, then

The mass element is dm=ρ(x,y)ds

The static distance element is dM(L)=l×ρ(l,L)ds

The static moment of a plane on a rotating axis is M(L)=∫∫[S]l×ρ(l,L)ds

Where S is the area of the two-dimensional plate, ρ(l, l) is the function of the density with respect to the position, and l is the moment departure perpendicular to the rotation axis L to the particle mi.

In the same way, the static moment of a three-dimensional body to a plane can be defined: M(L)=∫∫∫[V]l×ρ(l,L,z)dv

The above formula is the static moment of the object with respect to the L-Z plane.

In theory, we know how to calculate the static moment, but in practical application, the static moment selection needs to be determined according to the load of the motor, the load can be divided into two kinds of inertia load and friction load, a single inertia load and a single friction load does not exist. When starting directly (generally at low speed), the two loads should be considered, the inertial load should be considered when accelerating the start, and the friction load should be considered when running at constant speed. Under normal circumstances, the static moment should be between 2-3 times the friction load, and once the static moment is selected, the frame and length of the motor can be determined. If you are not sure how much static moment you need to use, or do not know how to calculate the static moment, you can contact our work colleagues, we will be guided by professional engineers.