Pressure measuring device

A measuring device comprising:

• a rotative shaft for measurement of axial forces acting on a shaft,
• at least one gas-permeable body positioned on the outside of said shaft with a column standing under pressure between the outer envelope surface of the shaft and said body;
• a protruding portion protruding from said shaft extending through said body with play, said protruding portion having two axially opposing sides;
• means for supplying gas under overpressure to said body;
• and
• pressure measuring means for measurement of pressure on at least one of said two sides of said protruding portion,
• wherein the force acting on said shaft is a function of the measured pressure.

A method for measurement of radial forces acting on a shaft comprising the steps of:

• supplying the outer envelope surface of said shaft with gas under overpressure, gas pressure is built up in a space between the envelope surface and at least one gas-permeable body adjacent to the envelope surface;
• measuring a first pressure differential between said gas pressure on two radially opposing first portions of said space;
• and
• measuring a second pressure differential between gas pressure on two radially opposing second portions of said space, said first and second portions being provided perpendicularly to each other,
• wherein the resulting pressure differential is determined as the difference between said first and second pressure differentials, and the radial force acting on said shaft is determined as k*.DELTA.P, with k being a constant and .DELTA.P being the resulting pressure differential.

A method for measurement of forces comprising the steps of:

• supplying at least one of two opposing faces of a measuring plate with gas under overpressure such that gas pressure is built up between at least one of said two opposing faces and at least one gas-permeable body provided external to said opposing faces;
• and
• measuring gas pressure on at least one of said opposing faces,
• wherein the force acting on one of said faces is determined as a function of the measured gas pressure.

A measuring device for measurement of forces on a measuring plate comprising;

• said measuring plate provided with at least one body having at least one of two opposing faces of said measuring plate turned toward gas-permeable surfaces of the body;
• means for supplying gas under overpressure to said body;
• and
• pressure measuring means for measurement of gas pressure on at least one of the two faces of the measuring plate,
• wherein the force acting on the measuring plate is a function of the measured gas pressure.