# ISO 21940-2:2017 pdf free

**ISO 21940-2**:2017 pdf free.Mechanical vibration一Rotor balancing一Vocabulary

polar angle at which an unbalance mass (3.3.2) is located with reference to the given rotating coordinate system, fixed in a plane perpendicular to the shaft axis (3.2.7) and rotating with the rotor component of the unbalance (3.3.1) that corresponds to a parallel misalignment of the central principal axis of inertia (3.1.1) of the rotor with respect to the shaft axis (3.2.7)

Note 1 to entry: The amount of the static unbalance is equal to the product of the total mass of the rotor and the radial distance of its centre of mass from the shaft axis.

component of the unbalance (3.3.1) that corresponds to an inclined central principal axis of inertia (3.1.1) intersecting the shaft axis (3.2.7) at the centre of mass

Note 1 to entry: The dimension of a moment unbalance is mass times length squared.

Note 2 to entry: This condition can be produced by two unbalance vectors (3.3.3) with equal amounts and opposing directions, acting in two different planes perpendicular to the shaft axis, which thereby constitute a couple unbalance (3.3.8).

two unbalance vectors (3.3.3) with equal amounts and opposing directions, acting in two different planes perpendicular to the shaft axis (3.2.7)

Note 1 to entry: A couple unbalance is an alternative representation of a moment unbalance (3.3.7) with the amount of each of the two unbalance vectors calculated by dividing the amount of moment unbalance by the distance between the two planes of the couple unbalance.

state of unbalance (3.3.1) that corresponds to the central principal axis of inertia (3.1.1) having any inclined and offset position relative to the shaft axis (3.2.7)

Note 1 to entry: This condition can be produced by adding a couple unbalance (3.3.8) and a static unbalance (3.3.6) to an unbalance-free rotor.

vector sum of the moments of all the unbalance vectors (3.3.3) distributed along the rotor with respect to an arbitrarily selected plane perpendicular to the shaft axis (3.2.7)

pair of two unbalance vectors (3.3.3) of equal magnitude acting in opposite directions in two arbitrarily selected planes perpendicular to the shaft axis (3.2.7) thereby constituting a moment unbalance (3.3.7) equivalent to the resultant moment unbalance (3.3.13).ISO 21940-2 pdf free download.