Rotatable torque-measuring apparatus and method

An apparatus comprising:

• a torque-measurement device that has a rotational axis, wherein the torque-measurement device includes:
• an inner tubular structure,
• an outer tubular structure, and
• a plurality of ribs coupled between the inner tubular structure and the outer tubular structure, wherein each respective one of the plurality of ribs has:
• a respective rib-length dimension in a length direction parallel to the rotational axis,
• a respective rib-width dimension in a respective width direction perpendicular to the length direction and extending in a respective plane from a respective first geometric line that is parallel to the rotational axis and that lies within the respective rib next to a minimum outside radial dimension of the inner tubular structure to a respective second geometric line that is parallel to the rotational axis and that lies within the respective rib next to a maximum inside radial dimension of the outer tubular structure, and
• a respective rib-thickness dimension in a thickness direction perpendicular to the length direction and perpendicular to the width direction,
• wherein the rib-length dimension is greater than the rib-width dimension,
• wherein a torque applied between the outer tubular structure and the inner tubular structure results in an angular displacement of the outer tubular structure relative to the inner tubular structure, and
• wherein the torque-measurement device further comprises a self-contained rotational-displacement measuring unit that includes:
• an electricity source,
• a sensor configured to sense the angular displacement of the inner tubular structure relative to the outer tubular structure,
• an electronic circuit operatively coupled to the sensor and to the electricity source, wherein the circuit generates a signal based on a magnitude of the sensed angular displacement, and
• a wireless transmitter operatively coupled to the electronic circuit and configured to wirelessly transmit the signal.

A method for making a torque-measurement device that has a rotational axis and that is arranged to make a measurement that measures only a torque force around the axis, the method comprising:

• forming a single block of metal to form an inner tubular structure, an outer tubular structure, and a plurality of ribs coupled between the inner tubular structure and the outer tubular structure, wherein each one of the plurality of ribs is connected to the inner tubular structure and to the outer tubular structure and has:
• a respective rib-length dimension in a length direction parallel to the rotational axis,
• a respective rib-width dimension in a respective width direction perpendicular to the length direction and extending in a respective plane from a respective first geometric line that is parallel to the rotational axis and that lies within the respective rib next to a minimum outside radial dimension of the inner tubular structure to a respective second geometric line that is parallel to the rotational axis and that lies within the respective rib next to a maximum inside radial dimension of the outer tubular structure, and
• a respective rib-thickness dimension in a thickness direction perpendicular to the length direction and perpendicular to the width direction, wherein the rib-length dimension is greater than the rib-width dimension, and wherein the rib-width dimension is greater than the rib-thickness dimension.

A method for measuring torque comprising:

• providing a torque-measurement device having a rotational axis and that is arranged to make a measurement that measures only a torque force around the axis, wherein the torque-measurement device includes:
• an inner tubular structure,
• an outer tubular structure, and
• a plurality of ribs coupled between the inner tubular structure and the outer tubular structure, wherein each one of the plurality of ribs is connected to the inner tubular structure and to the outer tubular structure and has:
• a respective rib-length dimension in a length direction parallel to the rotational axis,
• a respective rib-width dimension in a respective width direction perpendicular to the length direction and extending in a respective plane from a respective first geometric line that is parallel to the rotational axis and that lies within the respective rib next to a minimum outside radial dimension of the inner tubular structure to a respective second geometric line that is parallel to the rotational axis and that lies within the respective rib next to a maximum inside radial dimension of the outer tubular structure, and
• a respective rib-thickness dimension in a thickness direction perpendicular to the length direction and perpendicular to the width direction, wherein the rib-length dimension is greater than the rib-width dimension, and wherein the rib-width dimension is greater than the rib-thickness dimension;
• applying a first torque between the outer tubular structure and the inner tubular structure;
• sensing a displacement of the inner tubular structure relative to the outer tubular structure during the applying of the first torque;
• and
• determining a value of the first torque based on the sensed displacement.