Mounting arrangement for bearings

An arrangement for mounting two bearings supporting a shaft within a housing, each said bearing having an inner race secured to the shaft and an outer race, the arrangement comprising:

• two annular spacer membranes having a high radial stiffness and a predetermined axial flexibility, said spacer membranes having an outer edge and an inner edge;
• the inner edge of each spacer membrane being secured to the outer race of a respective bearing and the outer edge of each spacer membrane being secured within the housing, both said spacer membranes being subjected to a predetermined amount of axial deformation with respect to their unstressed condition, whereby the spacer membranes exert a precisely determined axial preload onto said outer races of said bearing;
• said two spacer membranes being located close to each other, whereby both spacer membranes are subjected to almost identical environmental conditions, the outer edges of both spacer membranes being secured within the housing in propinquity to each other, the inner edge of the first spacer membrane being secured to the outer race of a first bearing, said arrangement further comprising:
• an elongated tubular sleeve surrounding said shaft, said sleeve having a first end portion secured to the inner edge of the second spacer membrane and a second end portion secured to the outer race of the second bearing;
• and
• a centering membrane having an outer edge secured within the housing and an inner edge secured to the second end portion of the sleeve, said centering membrane having a high radial stiffness and a negligible axial stiffness.