Kendro Laboratory Products Gmbh

Heraeus Instruments Gmbh

Heraeus Instruments Gmbh & Co. Kg

Michael Koch

Rudiger Uhlendorf

Sebastian Reich

Detlev Demmig

Ingo Jaeckel

Ruediger Uhlendorf

Klaus Schutz

A laboratory centrifuge has a housing which can be closed by a casing cover and having in the housing a rotor chamber which contains a motor-driven vertical-axis rotor to accept test tubes. During operation, the test tubes are warmed by friction. To cool the centrifuge, cooling air is pulled in through openings in the lower side of the housing and upward into the rotor chamber by the fan action created by the rotation of the rotor. The air is guided out of the rotor chamber through an air exit in a direction of flow tangential to the perimeter of the rotor in a manner that ensures low turbulence and, thus, low noise. In particular, a slit-like air exit opening is arranged between the casing cover and the top side of the housing. In the annular gap between the rotor and the rotor chamber, an aerodynamically shaped displacement body is provided in a position at the side of the area of the air exit opening such that it directly follows the area of the air exit opening when viewed in the direction of rotation of the rotor. The displacement body is put on a molded part for attaching to the inside surface of the casing cover of the centrifuge such that the displacement body projects from the inside surface of the casing cover into the annular gap to thereby permit the cooling air to be guided out of the centrifuge with low turbulence and low noise.

Laboratory centrifuge having a casing cover and rotor chamber adapted to

A laboratory centrifuge includes a continuous metal plate comprising an underbody base plate having a rotor drive motor mounted thereon, an angled front screen which contains operating devices and display instruments, and a bending region which extends between the base plate and the front screen. At least two reciprocally parallel rows of decoupling slots are arranged between the bending region of the metal plate and the base plate. The decoupling slots form a meandering bar connection between the front screen and the base plate, by which noise generated due to imbalance at the rotor or structural noise in the direction of the front plate is considerably reduced. A conventional table centrifuge housing having a hinged lid and rotor bowl is fitted on the underbody.

Centrifuge with reduced noise generation

A laboratory centrifuge having a housing which can be closed by a casing cover and having in the housing a rotor chamber which contains a motor-driven vertical-axis rotor to accept test tubes is disclosed. During operation, the test tubes are warmed by friction. To cool the centrifuge, cooling air is pulled in through openings in the lower side of the housing and upward into the rotor chamber by the fan action created by the rotation of the rotor. The air is guided out of the rotor chamber through an air exit in a direction of flow tangential to the perimeter of the rotor in a manner that ensures low turbulence and, thus, low noise. In particular, a slit-like air exit opening is arranged between the casing cover and the top side of the housing. In the annular gap between the rotor and the rotor chamber, an aerodynamically shaped displacement body is provided in a position at the side of the area of the air exit opening such that it directly follows the area of the air exit opening when viewed in the direction of rotation of the rotor. The displacement body is put on a molded part for attaching to the inside surface of the casing cover of the centrifuge such that the displacement body projects from the inside surface of the casing cover into the annular gap to thereby permit the cooling air to be guided out of the centrifuge with low turbulence and low noise.

In order to achieve a mechanically simple, reliable, and independent balancing device for compensation of an unbalance in a rotating body without the need for a supply of a fluid from outside the rotor nor an adjustment of nozzles to insert the fluid, the balancing device features a feed device with a fluid-containing cavity arranged stationary in or on the body of rotation, which has outlet openings emerging into the balancing chambers, which are to be closed and opened by a movable closing body depending upon the occurrence of an unbalance. Specifically, on or in the body of rotation reside at least three balancing chambers uniformly distributed in the peripheral direction, each of which is connected by an inlet opening to a feed device for a fluid with a specific gravity that is greater than that of air, and with a regulator for regulated feeding of fluid from the feed device into the balancing chambers.

Balancing device for a rotating body

In order to determine an imbalance of a rotor caused to turn by means of a driving arrangement, imbalance-produced deflections or accelerations of the driving arrangement, spring-loaded with respect to a stationary housing, are determined and relayed as an electrical signal to an evaluation device. The sensor may be, for example, a piezoelectric crystal for detection of accelerations of the drive unit caused by imbalance or a path sensor for detection of deflections of the drive unit relative to the housing as a result of imbalance. The signal is evaluated as a function of the rotary speed of the rotor by means of an adaptive band filter. The method is especially suitable for determination of imbalance during operation of laboratory centrifuges, where an imbalance can occur, for example, from breakage of test tubes.

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Osterode, Germany

Michael Koch