# US 7,608,949 B2 · Sliding door comprising a magnetic support and/or drive system comprising a row of magnets > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,949 B2 - Document ID: US7608949B2 - Status: Granted - Kind: B2 - Application number: 11/665,618 - Filed: 2005-10-08 - Published: 2008-05-01 - Granted: 2009-10-27 - Earliest claimed: 2004-10-17 - Assignees: Dorma GmbH + Co. KG - Inventors: Sven Busch - Web page: https://patentgrep.com/patent/US7608949B2 ## CPC - E05F 15/60: using electrical actuators - E05D 15/06: for wings sliding horizontally more or less in their own plane - E05Y 2900/132: Doors - E05F: DEVICES FOR MOVING WINGS INTO OPEN OR CLOSED POSITION; CHECKS FOR WINGS; WING FITTINGS NOT OTHERWISE PROVIDED FOR, CONCERNED WITH THE FUNCTIONING OF THE WING - E05D: HINGES OR SUSPENSION DEVICES FOR DOORS, WINDOWS OR WINGS (pivotal connections in general F16C11/00) - E05Y: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES E05D AND E05F, RELATING TO CONSTRUCTION ELEMENTS, ELECTRIC CONTROL, POWER SUPPLY, POWER SIGNAL OR TRANSMISSION, USER INTERFACES, MOUNTING OR COUPLING, DETAILS, ACCESSORIES, AUXILIARY OPERATIONS NOT OTHERWISE PROVIDED FOR, APPLICATION THEREOF ## Abstract A magnetic drive system for driving a door leaf in a driving direction is disclosed. The drive system includes a row of magnets disposed in the driving direction and having a longitudinal direction, the magnets being arranged so that magnetizations of the magnets reverse in accordance with a predetermined pattern; and a coil arrangement comprising a plurality of coil cores and a plurality of coils, the coils being wound around respective coil cores and spaced apart from each other in the longitudinal direction of the row of magnets. When energized, the coils interact with the magnets to generate a thrust force for driving the door leaf in the driving direction. The magnets in the row of magnets are disposed relative to the coil cores so that a total magnetization of the magnets has no abrupt polarity reversal in the driving direction with respect to the coil cores. ## Claims ### Claim 1 A magnetic drive system for driving a door leaf in a driving direction, comprising: a first row of magnets disposed in the driving direction and having a longitudinal direction, the magnets being arranged so that magnetization polarity of the magnets reverses at predetermined intervals in the longitudinal direction; and a coil arrangement comprising a plurality of coil cores and a plurality of coils, the coils being wound around respective coil cores and spaced apart from each other in the longitudinal direction of the row of magnets, the coil cores respective shoes, wherein when energized, the coils interact with the magnets to generate a thrust force for driving the door leaf in the driving direction, and wherein at least one of the pole shoes and the magnets are formed so that cogging force of the drive system is reduced. ### Claim 2 (depends on 1) The magnetic drive system of claim 1, wherein each magnet in the row of magnets comprises a hard magnetic element, a permanent magnet, or a high energy magnet. ### Claim 3 (depends on 1) The magnetic drive system of claim 1, further comprising: at least one of a magnetic carrying element carrying the row of magnets; and a guiding element for maintaining a predetermined distance between the magnets and at least one of the magnetic carrying element and the coil arrangement, wherein the magnetic carrying element and the magnets interact to generate a magnetic supporting force for the door leaf. ### Claim 4 (depends on 1) The drive system of claim 1, wherein the cogging force is reduced in that each magnet in the row of magnets has one of a chamfer, an arched surface and a skew. ### Claim 5 (depends on 1) The drive system of claim 1, wherein the cogging force is reduced in that each magnet in the row of magnets has edges and an irregular magnetization which weakens toward the edges. ### Claim 6 (depends on 1) The drive system of claim 1, the cogging force is reduced in that the drive system further comprises a second row of magnets disposed in the driving direction, wherein the two rows of magnets are offset relative to each other in the driving direction. ### Claim 7 (depends on 1) The drive system of claim 1, wherein the cogging force is reduced in that the magnets in the row of magnets are spaced apart from each other so that a distance between every two adjacent magnets is not constant. ### Claim 8 (depends on 1) The drive system of claim 1, wherein the cogging force is reduced in that each coil has a lateral pole shoe for conducting an electromagnetic field generated by said each coil to the magnets, each lateral pole shoe having a face which faces the magnets and is arched or has a chamfer, the faces being disposed in one row. ### Claim 9 (depends on 1) The drive system of claim 1, wherein the cogging force is reduced in that each coil core has a surface which faces the magnets and is arched or has a chamfer, the surfaces being disposed in one row. ### Claim 10 (depends on 1) The drive system of claim 1, wherein the cogging force is reduced in that each coil core has a surface which faces the magnets, the surfaces being disposed in one row, the coil arrangement further comprises a plurality of flux conducting elements which are mounted on the respective surfaces of the coil cores each said flux conducting element overlapping two adjacent said coils. ### Claim 11 (depends on 10) The drive system of claim 10, wherein the cogging force is reduced in that each said flux conducting element is skewed, rounded, arched or has a chamfer. ### Claim 12 (depends on 1) The drive system of claim 1, wherein the cogging force is reduced in that the coil arrangement comprises “x ”coils which are energized by a rotary current with “n ” electrical phases, the row of magnets comprising “y ”magnets which are regularly distributed and have “p ” magnetic poles, wherein n=x=3, and p=y=4, or n=x=5, and p=y=4, or n=x=5, and p=y=6, or n=x=5, and p=y=8, or n=x=6, and p=y=4, or n=x=8, and p=y=10. ### Claim 13 (depends on 1) The drive system of claim 1, wherein the cogging force is reduced in that each coil core has a round shaped cross section having a diameter which is greater than a height of each magnet. ### Claim 14 (depends on 1) The drive system of claim 1, wherein the cogging force is reduced in that each coil core has a rectangular shaped or square shaped cross section. ### Claim 15 (depends on 14) The drive system of claim 14, wherein the cogging force is reduced in that each coil core has edges which are provided with a rounding or a chamfer. ### Claim 16 (depends on 1) The drive system of claim 1, wherein the cogging force is reduced in that each coil core has a cross section composed of a rectangular section and two semicircle sections extending outward from respective sides of the rectangular section. ### Claim 17 (depends on 1) The sliding door of claim 1, wherein the cogging force is reduced in that each coil core has an oval shaped cross section. ### Claim 18 (depends on 1) The drive system of claim 1, wherein each magnet in the row of magnets is magnetized perpendicularly to the driving direction. ### Claim 19 (depends on 3) The drive system of claim 3, wherein the magnets are arranged so that magnetization polarity of the magnets reverses at predetermined intervals in the longitudinal direction. ### Claim 20 The drive system of claim3, wherein the magnetic carrying element is formed by a row of spaced, soft magnetic elements. ### Claim 21 (depends on 3) The drive system of claim 3, wherein the magnetic carrying element comprises two magnetic carrying rails disposed on respective sides of the row of magnets. ### Claim 22 (depends on 3) The drive system of claim 3, wherein the magnetic carrying element comprises a U-shaped carrying rail having two lateral sections and a bottom section connecting the two lateral sections, the row of magnets being at least partially guided in the U-shaped carrying rail so that an inner surface of one of the lateral sections is spaced from a first side of the row of magnets with an inner surface of the other of the lateral sections being spaced from an opposite, second side of the row of magnets. ### Claim 23 (depends on 3) The drive system of claim 3, wherein the magnetic carrying element is stationary and the row of magnets is non-stationary. ### Claim 24 (depends on 3) The drive system of claim 3, wherein the magnetic carrying element comprises a soft magnetic element. ### Claim 25 (depends on 3) The drive system of claim 3, wherein the guiding element comprises a sliding member. ### Claim 26 (depends on 2) The drive system of claim 2, wherein the coil arrangement is stationary and the row of magnets is non-stationary. ### Claim 27 (depends on 2) The drive system of claim 2, wherein the magnetization polarity of the magnets reverses so that every two adjacent magnets have different polarities facing the coil arrangement. ### Claim 28 (depends on 2) The drive system of claim 2, wherein the magnetization polarity of the magnets reverses irregularly in the driving direction, the coils being spaced apart from each other so that a distance between every two adjacent coils is constant. ### Claim 29 (depends on 2) The drive system of claim 2, wherein each magnet in the row of magnets has a skewed shape or is mounted skewedly with respect to the driving direction. ### Claim 30 (depends on 6) The drive system of claim 6, wherein magnetization polarities of the two rows of magnets, magnetization polarities of two adjacent groups of adjacent magnets of one of the two rows of magnets, or magnetization polarities of two adjacent magnets of one of the two rows of magnets are offset with each other with respect to the coils. ### Claim 31 (depends on 30) The drive system of claim 30, wherein the magnetization polarities of the two rows of magnets are offset by ½ “l” with respect to the coils, wherein “l” is one wavelength of a cogging force arising of one of the two rows of magnets in the driving direction. ### Claim 32 (depends on 30) The drive system of claim 30, wherein the magnetization polarities of two adjacent groups of magnets of one of the two rows of magnets are offset with each other by ½ “l ” with respect to the coils, wherein “l ” is one wavelength of a cogging force arising of one of the two adjacent groups in the driving direction. ### Claim 33 (depends on 30) The drive system of claim 30, wherein the magnets in the row of magnets are alternatingly polarized in the driving direction, two adjacent magnets or two adjacent groups of at least two adjacent magnets being offset with each other with respect to the coils, a maximum of the offset being “l”, wherein “l” is one wavelength of a cogging force which is generated when the two adjacent magnets or the two adjacent groups of at least two adjacent magnets are not offset with each other. ### Claim 34 A sliding door system comprising: a housing; a door leaf guided in the housing and movable in a driving direction; a row of magnets supported by one of the door leaf and the housing, the row of magnets being disposed in the driving direction and having a longitudinal direction, the magnets being arranged so that magnetization polarity of the magnets reverses at predetermined intervals in the longitudinal direction; and a coil arrangement supported by the other of the door leaf and the housing, the coil arrangement comprising a plurality of coil cores and a plurality of coils, the coils being wound around respective coil cores and spaced apart from each other in the longitudinal direction of the row of magnets, the coil cores having respective pole shoes. wherein when energized, the coils interact with the magnets to generate a thrust force for driving the door leaf in the driving direction, wherein at least one of the pole shoes and the magnets are formed so that cogging force of the drive system is reduced, and wherein the sliding door is formed as an arched sliding door or as a horizontal sliding wall. ### Claim 35 A magnetic drive system for driving a door leaf in a driving direction, comprising: a plurality “y” of magnets with “p” magnetic poles disposed in the driving direction in at least one row having a longitudinal direction, the magnets being arranged so that magnetization polarity of the magnets reverses at predetermined intervals in the longitudinal direction; and a coil arrangement comprising a plurality of coil cores and a plurality “x ” of coils which are energized by a rotary current with “n” electrical phases, the coils being wound around respective coil cores and spaced apart from each other in the longitudinal direction of the row of magnets, wherein, when energized, the coils interact with the magnets to generate a thrust force for driving the door leaf in the driving direction, and wherein the magnets in the row of magnets are disposed relative to the coil cores so that the magnets as a whole have no abrupt polarity reversals in the driving direction with respect to the coil cores, and wherein n=x=3, and p=y=4, or n=x=5, and p=y=4, or n=x=5, and p=y=6, or n=x=5, and p=y=8, or n=x=6, and p=y=4, or n=x=8, and p=y=10.