EP0109410A1 - Palier stabilisateur pour centrifugeuse - Google Patents

Palier stabilisateur pour centrifugeuse

Info

Publication number
EP0109410A1
EP0109410A1 EP19830901498 EP83901498A EP0109410A1 EP 0109410 A1 EP0109410 A1 EP 0109410A1 EP 19830901498 EP19830901498 EP 19830901498 EP 83901498 A EP83901498 A EP 83901498A EP 0109410 A1 EP0109410 A1 EP 0109410A1
Authority
EP
European Patent Office
Prior art keywords
shaft
bearing
rotor
terized
charac
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP19830901498
Other languages
German (de)
English (en)
Inventor
Kenneth E. Jacobson
Kenneth K. Inouye
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beckman Coulter Inc
Original Assignee
Beckman Instruments Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beckman Instruments Inc filed Critical Beckman Instruments Inc
Publication of EP0109410A1 publication Critical patent/EP0109410A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04B—CENTRIFUGES
    • B04B9/00—Drives specially designed for centrifuges; Arrangement or disposition of transmission gearing; Suspending or balancing rotary bowls
    • B04B9/12—Suspending rotary bowls ; Bearings; Packings for bearings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04B—CENTRIFUGES
    • B04B9/00—Drives specially designed for centrifuges; Arrangement or disposition of transmission gearing; Suspending or balancing rotary bowls
    • B04B9/14—Balancing rotary bowls ; Schrappers

Definitions

  • the present invention is directed, to ultra- centrifuges and, more specifically, is directed to a stabilizing bearing for use on an ultracentrifuge thin drive shaft.
  • the spindle is made relatively thin in order that it have the requisite flexibility for successful operation.
  • the oper ⁇ ator does not achieve the correct balance and there will be slight imbalance in the samples within the rotor which will cause a slight unbalanced condition in the operation of the rotor.
  • a slight flexing of the drive spindle can accommodate this imbalance and relieve stress on the high speed bearings.
  • the second reason for flexibility in the drive spindle relates to slight geometric limitations in the machining for the making of the rotor drive shaft and the driving mechanism. It is not possible, due to restric ⁇ tions in machining capabilities, to make an ideal, exact ⁇ ly perfect geometrically aligned rotor drive shaft and driving mechanism. Although nearly perfect, the arrange ⁇ ment for the ultracentrifuge is such that even the slightest geometric imperfection caused by limitation in the machining will become apparent with respect to ultra ⁇ centrifuge operation. Therefore, a flexible shaft is necessary in order to relieve some of the stress which would occur, especially in the bearing area of the machine as a result of rotor unbalance or slight geomet ⁇ ric imperfections. Therefore, the drive shaft is made relatively thin in order to accomplish the desired flexi ⁇ bility.
  • a thin drive shaft has a natural fre ⁇ quency or critical speed which occurs at a relatively low speed. At this point the drive shaft will experience vibration. When possible unbalanced conditions or slight geometric imperfections combine with the shaft's critical frequency, the vibration is accentuated to cause possible detrimental deflection and bending in the shaft. Conse ⁇ quently, it is important during this critical speed of the shaft to stabilize the shaft so that this frequency does not cause deflection of the shaft. Otherwise, the shaft would continue to deflect or oscillate in such a manner that it may result in damage to the entire centri ⁇ fuge.
  • the present invention is directed to a movable stabilizing bearing mounted adjacent the drive shaft to provide selective support to the drive shaft during cer ⁇ tain phases in the operation of the centrifuge.
  • the preferable arrangement of the present invention utilizes a bushing surmounted on the shaft which is activated by a solenoid to move it into and out of bearing engagement with the shaft to provide lateral support to that shaft.
  • the operation of the solenoid or any other type of activating device is in response to a specific speed of the rotor shaft.
  • the stabilizing bearing By utilizing the stabilizing bearing for en ⁇ gagement with the shaft at its critical speed, the nat ⁇ ural or critical frequency of the shaft is raised. Therefore, no vibration will occur in the shaft during the time frame and speeds that the stabilizing bearing is supporting the shaft. However, once the speed of the shaft is above its natural critical speed, the removal of the stabilizing bearing will result in no vibration oc ⁇ curring, because the shaft will be operating higher than its natural critical frequency.
  • the rotor goes from zero to its operational speed; however, at some point it will reach its natural critical frequency where vibration may occur.
  • a thin diameter shaft it may be a range of, for example, approx ⁇ imately 700 RPM's. Consequently, in the design of an embodiment of the present invention the stabilizing bear ⁇ ing will automatically be engaged with the drive shaft from zero up to a speed of approximately 1,000 RPM.
  • the stabilizer bearing will provide a stiffening effect which in essence gives the shaft an artificially higher natural frequency to prevent vibration at these lower speeds.
  • the solenoid operated stabil ⁇ izing bearing will disengage, allowing the shaft to oper ⁇ ate at higher speeds and at that point the shaft will be above its natural frequency and no vibration will oc ⁇ cur.
  • the stabilizing bearinq will automatically be activated when the speed is reduced to 1,000 RPM's until the rotor completely stops.
  • Figure 1 shows a vertical sectional view of a centrifuge drive assembly incorporating the stabilizing bearing of the present invention with the stabilizing bearing in the disengaged position;
  • Figure 2 shows a partial vertical sectional view of the drive assembly with the stabilizing bearing of the present invention in the engaged position.
  • FIG. 1 shows a centrifuge 10 having a drive spindle assembly 12 with a hub assembly 14 which projects into a rotor chamber 16.
  • the hub assembly 14 is designed to receive a rotor (not shown) .
  • the drive spindle 18 extends downward from the hub assembly for connection with an induction motor assembly 20.
  • an armature shaft 22 Located in the induction motor is an armature shaft 22 which engages an upper high speed bearing 24 and a lower high speed bear ⁇ ing 26.
  • Surmounted on the armature shaft 22 Surmounted on the armature shaft 22 is the arma ⁇ ture 28 of the induction motor 20.
  • the induction motor 20 has a housing 30 which is mounted below the drive mount plate 32. Both the drive mount plate 32 and the induction motor housing 30 are located below the bottom 34 of the rotor chamber 16.
  • the shaft 18 in the present invention is pref ⁇ erably a very small diameter drive shaft which is for some centrifuge assemblies as small as approximately .078 inches. This shaft is used to drive a relatively small ultracentrifuge rotor having a diameter as small as ap ⁇ proximately four inches. Consequently, the drive shaft 18 is susceptible to flexing due to its function as a coupling between the rotor and the bearings 24 and 26. Also, the shaft may be subjected to flexing caused by rotor imbalance and geometric limitations in the manufac ⁇ turing methods of the centrifuge.
  • the sta ⁇ bilizing bearing assembly 36 comprising a solenoid coil 38 and a bushing 40 which is slidably mounted on the drive shaft 18.
  • a collar or sleeve 42 which is designed for bearing engagement with the bushing 40 when it is activated to move up toward the cap 44 of the drive spindle assembly 12.
  • the bushing 40 has an interior diameter which is slightly greater than the exterior diameter of the drive shaft 18, so that the bushing is freely movable longitudinally along the drive shaft 18. When the bushing 40 is moved into bearing engagement with the collar 42, the top 41 of the bushing will contact the bottom 43 of the cap 44.
  • the upper portion of the bushing 40 has a tapered opening 46 to provide guidance over the collar 42 when the bushing is moved toward the cap 44.
  • a lower housing assembly 50 which is designed to secure the induction motor arma ⁇ ture shaft 22 in place with the high speed bearings 24 and 26. This proper alignment is maintained by the use of the spring 52 in this cap arrangement 50.
  • a rotor containing fluid samples for centrifugation is placed on the hub assembly 14.
  • the drive shaft 18 is connected through the armature shaft 22 to the induction motor 20 which provides the driving mechanism for rota ⁇ tion of the shaft 18 which, in turn, operates the ro ⁇ tor.
  • the rotor will tend to spin about its own geometric center which may be slightly out of alignment with the armature shaft 22. Also, the rotor may be slightly unbalanced if the operator was not care ⁇ ful in loading the samples into the rotor. Consequently, the drive shaft 18 will flex in order to accommodate these inconsistencies.
  • the drive shaft 18 is very thin and too much flexing may cause some problem with respect to the integrity of the shaft. This problem is accentuated at the critical speed of the shaft where natural vibration will occur. In rotor operation it is necessary to avoid the generation of detrimental vibra ⁇ tions on the rotor which could disturb the separated constituents in the rotor and in severe situations may cause damage to the centrifuge. It has been found that the critical speed for a very thin shaft normally occurs at a relatively low speed while the rotor is either going from zero speed to its operational speed or decelerating from its speed at operation to its stationary position. By way of example, it has been found that a rotor shaft of the diameter of approximately .078 inches will vibrate at a critical point during its acceleration or decelera ⁇ tion at some point between zero and 1,000 RPM.
  • the solenoid 38 is automatically activated to move the bushing 40 of the stabilizing bearing into position around the collar 42.
  • the stabilizing bearing 36 with its bushing 40 pro ⁇ vides support to the rotor shaft 18 and will prevent the occurrence of any vibration as the shaft goes through its critical or unstable speed.
  • the stabilizing, bearing provides support by absorbing energy transmitted from the shaft similar to the operation of a damper bearing or a bumper bearing.
  • the control system for the solenoid 38 operates automatically in response to the speed of the shaft 18. In most cases, once the rotor and the shaft exceed 1,000 RPM's, the stabilizing bearing will be automatically deactivated, since at that point the shaft will be above its vibrational frequency range and will provide a smooth rotative motion. After the deactivation of the solenoid 38 vibration in the shaft and the force of gravity will cause the freed bushing 40 to move away from the cap 44 and disengage from the collar 42 as shown in Figure 1.
  • the rotor When the centrifuge run has been completed, the rotor will decelerate and, when it reaches the speed of 1,000 RPM's, the stabilizing bearing will again automatically be activated by the solenoid to move the bushing 40 up around the collar 42 to create the necessary stiffening of the shaft 18 as it again passes through its critical vibrating or frequency point below 1,000 RPM's.
  • An alternate embodiment of the present inven ⁇ tion would incorporate the use of a ball bearing arrange ⁇ ment which would move into and out of engagement with the collar 42.
  • the ball bearing would provide in some in ⁇ stances a better bearing for the shaft than the use of the bushing 40. It is envisioned that any type of bear ⁇ ing arrangement could be used in conjunction with the present invention of selectively engaging the bearing with the shaft for added support at critical speeds.

Landscapes

  • Centrifugal Separators (AREA)

Abstract

Palier stabilisateur destiné à fonctionner sélectivement pour obtenir le support latéral d'un arbre d'entraînement de petit diamètre (18) utilisé dans une ultra-centrifugeuse de dimension réduite. Le palier stabilisateur (40, 42) est actionné de préférence par un solénoïde (38) qui met le palier (40) en place pour permettre le support latéral de l'arbre mince d'entraînement (18) lorsqu'il pourrait subir des flexions à faible vitesse, provoquant des vibrations et d'éventuels effets nocifs sur la séparation centrifuge désirée de l'échantillon de fluide dans le rotor. L'actionnement du palier stabilisateur a lieu automatiquement en réponse à un paramètre spécifié de la vitesse de l'arbre d'entraînement.
EP19830901498 1982-05-19 1983-03-21 Palier stabilisateur pour centrifugeuse Withdrawn EP0109410A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US37967282A 1982-05-19 1982-05-19
US379672 1982-05-19

Publications (1)

Publication Number Publication Date
EP0109410A1 true EP0109410A1 (fr) 1984-05-30

Family

ID=23498197

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19830901498 Withdrawn EP0109410A1 (fr) 1982-05-19 1983-03-21 Palier stabilisateur pour centrifugeuse

Country Status (3)

Country Link
EP (1) EP0109410A1 (fr)
JP (1) JPS59500006U (fr)
WO (1) WO1983003985A1 (fr)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5026341A (en) * 1987-05-22 1991-06-25 Robert Giebeler Low speed disengageable damper
SU1704839A1 (ru) * 1988-07-18 1992-01-15 Московское научно-производственное объединение "Биофизприбор" Привод ультрацентрифуги
DE69710166T2 (de) * 1996-04-30 2002-09-26 Dade Behring Inc., Deerfield Vorrichtung und verfahren zur stabilisierung eines zentrifugenrotors
US6722214B1 (en) * 1998-09-05 2004-04-20 Genevac Limited Control of weight during evaporation of samples
GB9824702D0 (en) * 1998-11-12 1999-01-06 Cole Michael Devices for controlling amplitude vibration in rotary systems
US6354988B1 (en) 1999-06-17 2002-03-12 Kendro Laboratory Products, Llp Centrifuge gyro diaphragm capable of maintaining motor shaft concentricity
WO2002085526A1 (fr) * 2001-04-20 2002-10-31 Hitachi Koki Co., Ltd. Machine centrifuge
DE102009009958A1 (de) * 2009-02-23 2010-09-02 Hanning Elektro-Werke Gmbh & Co. Kg Zentrifuge
IL286751A (en) * 2021-09-28 2023-04-01 Pappirov Eduard A device for measuring the viscosity of body fluid

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2524678A (en) * 1947-08-15 1950-10-03 Charles A Olcott Suspended gyratory centrifugal
US3430852A (en) * 1967-06-08 1969-03-04 Beckman Instruments Inc Rotor stabilizer
GB1210038A (en) * 1969-09-18 1970-10-28 Heinz Janetzki Kg Maschb High speed laboratory centrifuge
DE2632586C2 (de) * 1976-07-20 1983-05-19 Gesellschaft für Kernverfahrenstechnik mbH, 5170 Jülich Verfahren und Vorrichtung zum Durchlaufen kritischer Drehzahlen langgestreckter Rotoren

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8303985A1 *

Also Published As

Publication number Publication date
WO1983003985A1 (fr) 1983-11-24
JPS59500006U (fr) 1984-05-17

Similar Documents

Publication Publication Date Title
EP0848649B1 (fr) Appareil et procede de stabilisation d'un rotor de centrifugeuse
US2827229A (en) Centrifuge mounting means
US3747998A (en) High speed magnetic shaft bearing
CA1087874A (fr) Methode et dispositif permettant de passer par les vitesses critiques de rotors allonges
JPS5817858A (ja) 流体を処理する遠心分離機
EP0109410A1 (fr) Palier stabilisateur pour centrifugeuse
JPS6250189B2 (fr)
US5026341A (en) Low speed disengageable damper
US4337981A (en) Drive and support arrangement for a disc-shaped rotor
US2285681A (en) Rotating assembly
US6183408B1 (en) Rotor shaft assembly having non-linear stiffness
US1743753A (en) Centrifugal machine
US2942494A (en) Centrifuge drive
JPH05146719A (ja) イナーシアスラブにより支持された回転機械
US4098457A (en) Friction producing stator pad for an air driven centrifuge
JP3860342B2 (ja) ヘリコプター用制振装置
US2838954A (en) Precession control means for upright centrifugal spinner
JPS6341076Y2 (fr)
JPS5824367A (ja) 遠心分離装置用コンテナ
JP2006050738A (ja) モータ
JP3559111B2 (ja) 高速回転シャフト用ダンピング機構
RU2220782C2 (ru) Центробежная установка с газостатической опорой
SU1483321A1 (ru) Устройство дл креплени колеса лопаточной машины
JPH03127645A (ja) 遠心機
RU1771893C (ru) Фреза

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19840113

AK Designated contracting states

Designated state(s): CH DE GB LI

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19850601

RIN1 Information on inventor provided before grant (corrected)

Inventor name: JACOBSON, KENNETH E.

Inventor name: INOUYE, KENNETH K.