Mechanical damper for air pad instability
AssigneeKoninklijke Philips Electronics N.V.
InventorWilliam C. Brunnett
Life of this patent
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Abstract
In a diagnostic imaging apparatus, a stationary gantry (24) and a rotating gantry (22) are interfaced by a plurality of air bearing elements (40). Lower air bearing elements bear the weight of the rotating gantry (22) which induce air hammering phenomena at a characteristic vibration frequency. To counteract the air hammering, a damping assembly (44) is mounted to at least one lower bearing element (40). The damping assembly (44) includes a damping mass (46) and an elastomeric connector (48) that are tuned to a frequency near the air hammer frequency to absorb the vibrational energy and damp the air hammer vibrations.
Claims18
A diagnostic scanning apparatus comprising:
- a first, rotating gantry;
- a second, stationary gantry;
- an imaging region defined by a bore in the first gantry;
- an air bearing system including a plurality of bearing elements, at least one of the elements exhibiting mechanical disturbance;
- a mechanical damper mounted adjacent at least one bearing element to dampen the mechanical disturbance, the mechanical damper being not directly connected to the stationary gantry.
A diagnostic scanning apparatus comprising:
- first and second gantries that define an imaging region;
- an air bearing system that connects the first and second gantries, the air bearing system including a plurality of bearing elements, at least one of the elements exhibiting mechanical disturbance;
- a damping mass for providing momentum opposite to momentum of the mechanical disturbance;
- and,
- an elastomeric connector that connects the damping mass to one of the air bearing elements and absorbs energy from the mechanical disturbance.
A method of diagnostic scanning comprising:
- rotating a rotating gantry about a subject in an examination region;
- supporting the rotating gantry on a plurality of bearing elements supported by a stationary gantry, at least one of which bearing elements tends to vibrate at a characteristic frequency;
- mechanically damping the vibrating bearing element by mounting mass to the at least one bearing element with a resilient connector, the mass and resilient connector being not directly connected to the stationary gantry.
A method of diagnostic scanning comprising:
- rotating a rotating gantry about a subject in an examination region;
- supporting the rotating gantry on a plurality of air bearing elements which are supported by a stationary gantry, at least one of which bearing elements tends to vibrate at a characteristic frequency;
- mechanically damping the vibrating bearing element with a damping element which is tuned to the characteristic frequency and not directly connected to the stationary gantry.
A CT scanner comprising:
- a stationary gantry;
- a plurality of air bearing pads mounted to the stationary gantry;
- a mass mounted to at least a lower one of the air bearing pads with a resilient element, the mass being not directly connected to the stationary gantry;
- a rotating gantry having an annular race supported by the air bearing pads;
- an x-ray source mounted to the rotating gantry;
- an array of x-ray detectors mounted to one of the rotating and stationary gantries for receiving x-rays from the x-ray source;
- a reconstruction processor connected with the detector array for reconstructing outputs of the detector array into an electronic image representation.
Dependencies are inferred from the claim text.