# US 2018/0022380 A1 · Hydraulic arrangement with two drive motors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0022380 A1 - Document ID: US20180022380A1 - Status: Published application - Kind: A1 - Application number: 15/654,203 - Filed: 2017-07-19 - Published: 2018-01-25 - Earliest claimed: 2016-07-20 - Assignees: Weber-Hydraulik GmbH - Applicants: Weber-Hydraulik GmbH - Inventors: Ralf Naumann; Torsten Winkler - Web page: https://patentgrep.com/patent/US20180022380A1 ## CPC - B62D 5/064: {Pump driven independently from vehicle engine, e.g. electric driven pump (B62D5/065 takes precedence)} - B62D 3/14: hydraulic - B62D 5/046: {Controlling the motor} - B62D 5/0487: {detecting motor faults (B62D5/0496 takes precedence)} - B62D 5/065: characterised by specially adapted means for varying pressurised fluid supply based on need, e.g. on-demand, variable assist - B62D 5/30: Safety devices, e.g. alternate emergency power supply or transmission means to ensure steering upon failure of the primary steering means - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) ## Abstract A hydraulic drive arrangement (1) for the pressure supply of a hydraulic steering system (20), particularly for construction or agricultural machines, including a hydraulic pump (2) and an electric drive. It is essential that the electric drive is designed in a redundant fashion and has two separately controlled electric drive engines (3a, 3b), which are mechanically coupled via the hydraulic pump (2) in a rigid fashion, and that the separate control circuits (6a, 6b, 7a, 7b) are provided by which a variable load distribution can be specified for the electric drive engines (3a, 3b). ## Claims ### Claim 1 A hydraulic drive arrangement (1) for pressure supply of a hydraulic steering system, comprising a hydraulic pump (2), a redundant electric drive that comprises two separately controlled electric drive engines (3a, 3b) that are mechanically coupled to each other via the hydraulic pump (2) in a rigid fashion, and separate control circuits (6a, 6b, 7a, 7b) by which a variable load distribution over the electric drive engines (3a, 3b) is specified. ### Claim 2 (depends on 1) The hydraulic drive arrangement (1) according to claim 1, wherein the electric drive engines (3a, 3b) each comprise motor controllers (6a, 6b) that are embodied to control the electric drive engines (3a, 3b). ### Claim 3 (depends on 2) The hydraulic drive arrangement (1) according to claim 2, wherein the control circuits (7a, 7b) are each integrated in the motor controllers (6a, 6b), and the motor controllers (6a, 6b) each are formed with a motor control and a control logic acting as the control circuit (7a, 7b). ### Claim 4 (depends on 1) The hydraulic drive arrangement (1) according to claim 1, wherein the control circuits (6a, 6b, 7a, 7b) are embodied to monitor each other for malfunctions. ### Claim 5 (depends on 4) The hydraulic drive arrangement (1) according to claim 4, wherein in case of a detected malfunction the control circuit (6a, 6b, 7a, 7b) not affected by the malfunction is configured to adjust an output of an associated one of the electric drive engines (3a, 3b). ### Claim 6 (depends on 1) The hydraulic drive arrangement (1) according to claim 1, wherein the control circuits (6a, 6b, 7a, 7b) are embodied such that one of the control circuits (6a, 6b, 7a, 7b) operates as a master control circuit, which specifies a load distribution for the electric drive engines (3a, 3b) and specifies to the other control circuit (6a, 6b, 7a, 7b) operating as a slave control circuit an operating output for the electric drive engine (3a, 3b) controlled thereby. ### Claim 7 (depends on 6) The hydraulic drive arrangement (1) according to claim 6, wherein the control circuits (6a, 6b, 7a, 7b) are embodied to coordinate a master and slave allocation in reference to each other. ### Claim 8 (depends on 1) The hydraulic drive arrangement (1) according to claim 1, further comprising an additional control circuit as a master control circuit that controls the electric drive engines (3a, 3b) via the respective motor controller (6a, 6b). ### Claim 9 (depends on 1) The hydraulic drive arrangement (1) according claim 1, further comprising a communication network (11) for the communication between the control circuits (6a, 6b, 7a, 7b) with each other. ### Claim 10 (depends on 1) The hydraulic drive arrangement (1) according to claim 1, wherein the hydraulic pump (2) is embodied as a gear pump ### Claim 11 (depends on 10) The hydraulic drive arrangement (1) according to claim 10, wherein the gear pump has a drive at both sides. ### Claim 12 (depends on 1) The hydraulic drive arrangement (1) according to claim 1, wherein the two drive engines (3a, 3b) are mechanically coupled via a common shaft. ### Claim 13 (depends on 12) The hydraulic drive arrangement (1) according to claim 12, wherein the two drive engines (3a, 3b) and the hydraulic pump (2) are arranged on a common shaft (11), and the hydraulic pump (2) is arranged between the two drive engines (3a, 3b). ### Claim 14 (depends on 1) The hydraulic drive arrangement (1) according to claim 1, wherein the two drive engines (3a, 3b) are mechanically coupled via the hydraulic pump (2). ### Claim 15 (depends on 14) The hydraulic drive arrangement (1) according to claim 14, wherein the two drive engines (3a, 3b) are mechanically coupled via the pump gears of the hydraulic pump (2), and a rotor (4a, 4b) of the two drive engines (3a, 3b) is arranged on a common shaft (11) with at least one pump gear of the hydraulic pump (2). ### Claim 16 (depends on 1) The hydraulic drive arrangement (1) according to claim 1, wherein the two drive engines (3a, 3b) are embodied as brushless electric engines, and a rotary encoder (12a, 12b) is provided at least at one of the two drive engines (3a, 3b). ### Claim 17 (depends on 1) The hydraulic drive arrangement (1) according to claim 1, wherein common motor cooling for the two drive engines (3a, 3b) is provided via a hydraulic fluid of the hydraulic pump (2). ### Claim 18 (depends on 1) The hydraulic drive arrangement (1) according to claim 1, wherein the hydraulic drive arrangement (1) is embodied for a front axle and/or a rear axle steering system. ### Claim 19 A method for operating a hydraulic drive arrangement (1) for pressure supply to a hydraulic steering system (20) with a hydraulic pump (2) and an electric drive, wherein the electric drive comprises two separately controlled electric drive engines (3a, 3b) with separate control circuits (6a, 6b, 7a, 7b) and the method comprises driving the separately controlled drive engines via the control circuits (6a, 6b, 7a, 7b) and providing a variable load distribution to the electric drive engines (3a, 3b). ### Claim 20 (depends on 1) A steering system (20) comprising a hydraulic drive arrangement (1) according to claim 1.