Stress-bearing umbilicus for a compact centrifuge

An umbilicus for conveying fluid between a stationary body and a rotating body, the umbilicus comprising

• an elongated body,
• a thrust bearing member on the umbilicus body comprising
• an inner annular body including a hub through which the umbilicus body passes,
• an outer annular body about the inner annular body, and an array of ball bearings between the inner and outer annular bodies that support the inner annular body for rotation relative to the outer annular body.

An umbilicus for conveying fluid between a stationary body and a rotating body, the umbilicus comprising

• a body including a proximal end, a distal end, and a middle region between the proximal and distal ends,
• a first support block with a strain relief sleeve attached to the proximal end,
• a second support block attached to the distal end, the second support block being free of a strain relief sleeve,
• a thrust bearing member in the middle region spaced apart from the strain relief sleeve and the second support block, the thrust bearing comprising
• an inner annular body including a hub through which the umbilicus body passes,
• an outer annular body about the inner annular body, and
• an array of ball bearings between the inner and outer annular bodies that support the inner annular body for rotation relative to the outer annular body.

A centrifuge comprising

• a yoke element,
• means for rotating the yoke element about a rotational axis,
• a processing chamber mounted for rotation about a second axis aligned with the rotational axis,
• an umbilicus that conveys fluid to or from the processing chamber, the umbilicus having a body including a proximal end, a distal end, and a middle region between the proximal and distal ends, a first support block with a strain relief sleeve attached to the proximal end, a second support block attached to the distal end, the second support block being free of a strain relief sleeve, and a thrust bearing member in the middle region spaced from the first and second support blocks,
• a first holder located above the yoke assembly in alignment with the rotational axis, the first holder including means for holding the first support block and strain relief sleeve stationary during rotation of the yoke assembly,
• a second holder on the rotating yoke assembly, the second holder including means for holding the thrust bearing member for rotation about the middle umbilicus region during rotation of the yoke assembly,
• a third holder on the processing chamber, the third holder including means for holding the second support block for rotation about the second axis during rotation of the yoke assembly, and
• the length of the umbilicus body and the distance between the thrust bearing member and the strain relief sleeve of the second support member being selected such that the maximum radial spacing between the rotational axis and the centerline of the umbilicus body during rotation of the yoke assembly does not exceed about 5.5 inches and the maximum axial spacing between the centerline of the umbilicus body and the bottom of the processing chamber is at least about 0.25 inch.

A centrifuge comprising

• a yoke element,
• a motor for rotating the yoke element about a rotational axis,
• a processing chamber mounted for rotation about a second axis aligned with the rotational axis, the processing chamber being free of a motor for rotating it,
• an umbilicus that conveys fluid to or from the processing chamber, the umbilicus having a body including a proximal end, a distal end, and a middle region between the proximal and distal ends, a first support block with a strain relief sleeve attached to the proximal end, a second support block attached to the distal end, the second support block being free of a strain relief sleeve, and a thrust bearing member in the middle region spaced from the first and second support blocks,
• a first holder located above the yoke assembly in alignment with the rotational axis, the first holder including means for holding the first support block and strain relief sleeve stationary during rotation of the yoke assembly,
• a second holder on the rotating yoke assembly, the second holder including means for holding the thrust bearing member for rotation about the middle umbilicus region during rotation of the yoke assembly, and
• a third holder on the processing chamber, the third holder including means for holding the second support block for rotation about the second axis during rotation of the yoke assembly, the umbilicus body rolling one rotation about its axis for each revolution of the yoke assembly to impart rotation to the processing chamber that is twice the rate of rotation of the yoke assembly.