Druckmittelsonde

摘要

A hydraulic expansion device particularly suitable for the production of a hollow camshaft wherein individual camshaft elements are secured about the shaft at axially spaced apart radially outwardly expanded wall portions thereof, comprises a plurality of axially spaced apart hydraulic expansion elements 10, 12 interconnected by flexible hydraulic fluid conduit elements 14, 16, 18, 20. The conduit elements are connected to a pressurised hydraulic fluid source 22 whereby hydraulic fluid may be applied to axially spaced apart locations of the shaft by the expansion elements through a radially extending bore 40 in each element communicating at its radially inner end with an axial bore 28, communicating with a conduit element, and at its radially outer end with the radially outer surface of the expansion element intermediate a pair of sealing rings in recesses 36, 38. The flexibility of the interconnecting conduit elements enables the device to be used, whilst still permitting efficient sealing of each expansion element to the interior shaft wall, in shafts which have irregularities in their linearity. The expansion elements include pressure relief bores 42, 44. <IMAGE>