Multi-Parameter Monitoring

A condition monitoring method that uses various monitoring technologies to best monitor machine condition.

Mounting stud

a threaded screw used to attach a sensor to the structure.

Modulating

When the vibration signal amplitude rises and falls over time. For example, a flaw on the inner race of a bearing will rotate in and out of the load zone. When in the zone, the amplitude will be high and when it rotates out of the zone the amplitude will fall. In the frequency spectrum modulating signals will generate sideband harmonics, the spacing of the harmonics will equal the speed (CPM) of the shaft.

Misalignment

A physical condition where the shafts of two coupled units are not parallel (angular misalignment) or are not in the same vertical and horizontal planes, (offset) Misalignment will generate a spike on the frequency spectrum at twice the operating speed of the units.

Misaligned shafts

Shafts that are parallel offset, or angularly or axially misaligned or any combination thereof.

Moment simulator

An auxiliary device required to simulate the moment of the half-coupling. A moment simulator shall also be designed to serve as a solo plate.

Momentary torque limit

A torque limit that corresponds to a minimum factor of safety of 1 .O with respect to the component’s material yield strength expressed as a combination of speed, angular misalignment, and axial displacement.

Metallic diaphragm coupling

A coupling consisting of one or more metallic flexible elements in the form of thin circular plates that are attached to one part of the coupling at their outer diameter and to the other part at their inner diameter.

Metallic disc coupling

A coupling consisting of one or more metallic flexible elements that are alternately attached to the two parts of the coupling, the attachment points being at substantially the same distance from the centerline

Metallic flexible element coupling

A form of flexible element that accommodates misalignment by material deformation of a metallic member. These elements are very much like springs in that they have a free-state shape and will resist a change in shape with a reaction force. Examples of metallic flexible elements are disc, convoluted diaphragm, and contoured diaphragms.