# US 8,465,406 B2 · Centrifuge including a frame and a bearing device having a pair of cantilevers and a pair of spring elements located between the cantilevers and the frame > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,465,406 B2 - Document ID: US8465406B2 - Status: Granted - Kind: B2 - Application number: 12/440,389 - Filed: 2007-09-07 - Published: 2010-07-01 - Granted: 2013-06-18 - Earliest claimed: 2006-09-11 - Assignees: Westfalia Separator AG - Applicants: Martin Overberg; Stefanos Doudis; Stefan Terholsen; Helmut Figgener; Hans-Joachim Beyer - Inventors: Martin Overberg; Stefanos Doudis; Stefan Terholsen; Helmut Figgener; Hans-Joachim Beyer - Web page: https://patentgrep.com/patent/US8465406B2 ## CPC - B04B 1/20: discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl - B04B 9/12: Suspending rotary bowls {; Bearings; Packings for bearings} - B04B: CENTRIFUGES (high-speed drum mills B02C19/11; domestic spin driers D06F; analysing, measuring or monitoring physical or chemical properties of samples during centrifuging, see the relevant subclasses for these procedures, e.g. G01N) ## Abstract A screw centrifuge including a drum having a rotor, the drum having two axial ends and a horizontal axis of rotation, and a screw arranged in the drum and configured to rotate relative to the drum at a speed different from a rotation speed of the drum. Also included is a bearing device located at each axial end of the drum and configured to bear the drum. Each bearing device includes a housing and a pair of cantilevers extending in opposite directions away from the housing. Further included is a pair of spring elements associated with each bearing device and configured for sprung support of the drum. Each spring is arranged between one of the cantilevers and a frame, the spring elements being located at each axial end of the drum. ## Claims ### Claim 1 A screw centrifuge comprising: a drum including a rotor, the drum having two axial ends and a horizontal axis of rotation; a screw arranged in the drum and configured to rotate relative to the drum at a speed different from a rotation speed of the drum; a bearing device located at each axial end of the drum and configured to bear the drum; each bearing device including a housing and a pair of cantilevers extending in opposite directions away from the housing; and a pair of spring elements associated with each bearing device and configured for sprung support of the drum and each spring is arranged between one of the cantilevers and a frame, spring elements being located at each axial end of the drum. ### Claim 2 (depends on 1) The screw centrifuge of claim 1, wherein a ratio between a length of the drum to a diameter of the drum is greater than 2. ### Claim 3 (depends on 2) The screw centrifuge of claim 2, wherein the spring elements are configured as combined spring and damping elements. ### Claim 4 (depends on 3) The screw centrifuge of claim 3, wherein a damping of the separate damping elements is a function of a rotation speed such that a high damping level is produced even at low rotation speeds by driving through a rotor natural shape, while a lower damping level is provided at an operating rotation speed above a resonant frequency. ### Claim 5 (depends on 1) The screw centrifuge of claim 1, wherein the spring elements are configured as combined spring and damping elements. ### Claim 6 (depends on 1) The screw centrifuge of claim 1, further comprising at least one damping element separate from the pair of spring elements. ### Claim 7 (depends on 1) The screw centrifuge of claim 1, wherein the spring elements act as compression elements for the sprung support of the drum on the frame in a non-radial direction. ### Claim 8 (depends on 1) The screw centrifuge claim 1, wherein the spring elements include helical springs, and longitudinal axes of the helical springs are aligned at an angle of 0 to 30° from the vertical. ### Claim 9 (depends on 8) The screw centrifuge of claim 8, wherein the helical springs are aligned at an angle of 0 to 15° from the vertical. ### Claim 10 (depends on 8) The screw centrifuge of claim 8, wherein each helical spring is loaded in compression in the vertical direction and is loaded in shear in the axial direction. ### Claim 11 (depends on 1) The screw centrifuge of claim 1, wherein the spring elements have a tunable spring stiffness in at least two mutually perpendicular directions. ### Claim 12 (depends on 1) The screw centrifuge of claim 1, wherein the spring elements have a horizontal spring stiffness of 30% to 100% of a vertical spring stiffness when longitudinal axes of the spring elements are aligned vertically in an installed state. ### Claim 13 (depends on 1) The screw centrifuge of claim 1, wherein the spring elements have a horizontal spring stiffness of 50%-100% of a vertical spring stiffness when longitudinal axes of the spring elements are aligned vertically. ### Claim 14 (depends on 1) The screw centrifuge of claim 1, further comprising a pair of damping elements which are arranged physically separately from the spring elements and are configured to support the drum. ### Claim 15 (depends on 14) The screw centrifuge of claim 14, wherein a damping of the separate damping elements is a function of a rotation speed such that a high damping level is produced even at low rotation speeds by driving through a rotor natural shape, while a lower damping level is provided at an operating rotation speed above a resonant frequency. ### Claim 16 (depends on 1) The screw centrifuge of claim 1, wherein the spring elements are arranged alongside the drum. ### Claim 17 (depends on 1) The screw centrifuge of claim 1, wherein the two cantilevers are aligned in a common plane. ### Claim 18 (depends on 1) The screw centrifuge of claim 1, wherein the two cantilevers are aligned at an angle to a horizontal plane of the frame. ### Claim 19 (depends on 1) The screw centrifuge of claim 1, wherein the two cantilevers are arranged above the axis of rotation of the drum. ### Claim 20 (depends on 1) The screw centrifuge of claim 1, wherein the bearing devices each have two bearings and the spring elements are arranged on a plane at right angles to the axis of rotation, which axis of rotation is located between the bearings. ### Claim 21 (depends on 20) The screw centrifuge of claim 20, wherein a center of the spring elements in an axial direction alongside the bearings is located at a height which corresponds to a height of a center of the bearings. ### Claim 22 (depends on 20) The screw centrifuge of claim 20, wherein one of the two bearings is a grooved ball bearing and the other bearing is a cylindrical roller bearing, and the two bearings are arranged in a respective one of the bearing housings. ### Claim 23 (depends on 1) The screw centrifuge of claim 1, wherein a distance between the two bearings is at least half of an internal diameter of the bearings. ### Claim 24 (depends on 1) The screw centrifuge of claim 1, wherein a damping of the spring elements at resonance is at least 3%. ### Claim 25 (depends on 1) The screw centrifuge of claim 1, wherein a ratio between a length of the drum to a diameter of the drum is greater than 2.5. ### Claim 26 (depends on 1) The screw centrifuge of claim 1, wherein a ratio between a length of the drum to a diameter of the drum is greater than 3. ### Claim 27 (depends on 1) The screw centrifuge of claim 1, wherein a damping of the spring elements at resonance is at least between 10% and 30%.