# US 12,119,197 B2 · On-load tap changer with positioning device and method for assembling an on-load tap changer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,119,197 B2 - Document ID: US12119197B2 - Status: Granted - Kind: B2 - Application number: 18/560,711 - Filed: 2022-07-21 - Published: 2024-07-25 - Granted: 2024-10-15 - Earliest claimed: 2021-07-23 - Assignees: Hitachi Energy Ltd - Applicants: Hitachi Energy Ltd - Inventors: Borislav Vasilev; Todor Kokev; Angel Mihaylov; Tommy Larsson - Web page: https://patentgrep.com/patent/US12119197B2 ## CPC - H01H 9/0044: {Casings; Mountings; Disposition in transformer housing} - H01H 11/00: Apparatus or processes specially adapted for the manufacture of electric switches (processes specially adapted for manufacture of rectilinearly movable switches having a plurality of operating members associated with different sets of contacts, e.g. keyboards, H01H13/88) - H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00) ## Abstract An on-load tap changer includes a static unit including fixed contacts for connection to taps at a transformer winding, a dynamic unit including at least one movable contact for selectively contacting one of the fixed contacts during operation of the transformer, and includes a rotational positioning device for adjusting the rotational position of the dynamic unit relative to the static unit during at least one of assembly or disassembly of the tap changer. ## Claims ### Claim 1 An on-load tap changer comprising: a static unit comprising fixed contacts for connection to taps at a transformer winding, a dynamic unit comprising at least one movable contact for selectively contacting one of the fixed contacts during operation of the transformer, and comprising a rotational positioning device for adjusting the rotational position of the dynamic unit relative to the static unit during at least one of assembly or disassembly of the tap changer to engage or disengage the movable contacts to or from the fixed contacts, wherein the dynamic unit comprises first teeth and the static unit comprises a spur wheel comprising second teeth, the first teeth and the second teeth interacting with each other, wherein the rotational positioning device comprises an adjustment member operable by a user for rotating the spur wheel, wherein the rotational positioning device comprises a first stop position, in which further rotational adjustment in one rotational direction is prevented, wherein in the first stop position the movable contacts are fully engaged with the fixed contacts and wherein the rotational positioning device comprises a second stop position, in which further rotational adjustment in a second rotational direction is prevented, the second rotational direction being opposite to the first rotational direction, wherein in the second stop position the movable contacts are fully disengaged from the fixed contacts. ### Claim 2 (depends on 1) The on-load tap changer of claim 1, comprising at least one axial blocking device preventing at least one of assembling and disassembling the dynamic unit and the static unit unless the dynamic unit is in a pre-defined rotational position relative to the static unit. ### Claim 3 (depends on 2) The on-load tap changer of claim 2, wherein the at least one axial blocking device comprises a stop member and a stop surface, wherein an abutment of the stop member and the stop surface prevents an axial movement of the dynamic unit in at least one axial direction, and further comprises a slot, wherein at least one of assembly and disassembly is enabled when the stop member is aligned with the slot. ### Claim 4 (depends on 1) The on-load tap changer of claim 1, wherein the dynamic unit comprises a top plate located at a top of the dynamic unit, wherein the rotational positioning device comprises an interaction of the top plate with the static unit. ### Claim 5 (depends on 4) The on-load tap changer of claim 4, wherein the top plate carries an energy accumulating device for coordinating and driving operations during a tap change. ### Claim 6 (depends on 5) The on-load tap changer of claim 5, wherein the adjustment member comprises a bolt and wherein the spur wheel is in splined connection with the bolt. ### Claim 7 (depends on 1) A method for at least one of assembling and disassembling the on-load tap changer of claim 1, comprising the step of adjusting the relative rotational position of the dynamic unit and the static unit by actuating the rotational positioning device. ### Claim 8 (depends on 7) The method of claim 7, wherein assembling the on-load tap changer comprises positioning the dynamic unit within the static unit in a final axial position and, after that, actuating the rotational positioning device. ### Claim 9 (depends on 8) The method of claim 8, wherein disassembling the on-load tap changer comprises actuating the rotational positioning device and, after that, removing the dynamic unit from the static unit by axially displacing the dynamic unit. ### Claim 10 (depends on 7) The method of claim 7, wherein at least one of assembling and disassembling the on-load tap changer comprises the step of actuating the rotational positioning device until a stop position is reached. ### Claim 11 (depends on 10) The method of claim 10, wherein in the assembly process the stop position is a position in which the movable contacts are fully engaged with the fixed contacts and in the disassembly process the movable contacts are fully disengaged from the fixed contacts.