Torsional Supporting Insulators

Abstract

In the practical utilization of torsional-mode vibration systems, they need to be attached and secured. The basic requirements on the attachment system is a minimization of the acoustic energy losses in it and of the addition of extraneous reactance, which tends to throw the system out of resonance adjustment. In general, these requirements are met by the mode of attachment in a nodal plane for the angles of twist. The position of this plane (the coordinate x| _φ=0 ) may be precisely calculated from the relations given in Table 1. This type of attachment of the vibration system has a number of indisputable advantages: relative simplicity of construction, the feasibility of calculating precisely the site of attachment, etc. In some cases, however, it may be inconvenient from the design point of view to have such a fixed attachment location. It must also be remembered that the coordinates x | _φ=0 were calculated on the condition of ideal matching or zero load (see Chapter 3). These conditions are sometimes not met in practice. Consequently, as the calculations in Chapter 3 make apparent, any change in the boundary conditions from those indicated alters the resonance length of the concentrator (for concentrators with a smoothly varying cross section) and the coordinate x| _φ=0.