# US 10,766,346 B2 · Liquid-cooled electric drive system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,766,346 B2 - Document ID: US10766346B2 - Status: Granted - Kind: B2 - Application number: 16/374,921 - Filed: 2019-04-04 - Published: 2019-11-07 - Granted: 2020-09-08 - Earliest claimed: 2018-05-07 - Assignees: Audi AG - Applicants: Audi AG - Inventors: Martin Hüttl; Stefan Till - Web page: https://patentgrep.com/patent/US10766346B2 ## CPC - B60K 1/02: comprising more than one electric motor - B60L 3/0023: {Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train} - B60L 3/0061: {relating to electrical machines} - B60L 15/20: for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed - H02P 29/60: Controlling or determining the temperature of the motor or of the drive (H02P29/02 takes precedence) - B60L 2220/40: Electrical machine applications - B60L 2240/425: Temperature - B60L 2240/525: Temperature of converter or components thereof - B60L 2260/26: Transition between different drive modes - B60L 2260/28: Four wheel or all wheel drive - H02M 1/327: {against abnormal temperatures} - Y02T 10/64: Electric machine technologies in electromobility - Y02T 10/72: Electric energy management in electromobility - B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A liquid-cooled electric drive system for a motor vehicle and a method of operating the drive system. ## Claims ### Claim 1 A liquid-cooled electric drive system for a motor vehicle, comprising: at least two drive units, each drive unit having components including an electric machine and associated power electronics which are connected to a coolant circuit of the motor vehicle, and a drive control unit which is set up to distribute the drive power produced by the drive system between the drive units depending on the temperature of the components of the drive units, wherein the drive control unit is adapted to reduce the drive power provided to the drive unit whose components have the higher temperature and to increase the drive power provided to the drive unit whose components have the lower temperature. ### Claim 2 (depends on 1) The liquid-cooled electric drive system of claim 1, wherein the coolant circuit has no coolant pump other than the electric machines. ### Claim 3 (depends on 2) The liquid-cooled electric drive system of claim 2, wherein the coolant is conveyed through the coolant circuit by centrifugal forces occurring in the electric machines. ### Claim 4 (depends on 2) The liquid-cooled electric drive system of claim 2, wherein each wheel is individually driven by an associated drive unit. ### Claim 5 (depends on 1) The liquid-cooled electric drive system of claim 1, wherein the coolant is conveyed through the coolant circuit by centrifugal forces occurring in the electric machines. ### Claim 6 (depends on 5) The liquid-cooled electric drive system of claim 5, wherein each wheel is individually driven by an associated drive unit. ### Claim 7 (depends on 1) The liquid-cooled electric drive system of claim 1, wherein each wheel is individually driven by an associated drive unit. ### Claim 8 (depends on 1) The liquid-cooled electric drive system of claim 1, wherein the coolant circuit has no coolant pump other than the electric machines. ### Claim 9 (depends on 1) The liquid-cooled electric drive system of claim 1, wherein the coolant is conveyed through the coolant circuit by centrifugal forces occurring in the electric machines. ### Claim 10 (depends on 1) The liquid-cooled electric drive system of claim 1, wherein each wheel is individually driven by an associated drive unit. ### Claim 11 A method for operating a liquid-cooled electric drive system for a motor vehicle, comprising: at least two drive units each having components including an electric machine and power electronics assigned to it, wherein the drive power produced by the drive system is divided between the drive units depending on the temperature of the components of the drive units, wherein the drive power provided to the drive unit whose components have the higher temperature is reduced, and the drive power provided to the drive unit whose components have the lower temperature is increased. ### Claim 12 (depends on 11) The method of claim 11, in which the electric machines are operated at a speed at which the coolant is conveyed through the coolant circuit by centrifugal forces occurring in the electric machines. ### Claim 13 (depends on 11) The method of claim 11, in which the electric machines are operated at a speed at which the coolant is conveyed through the coolant circuit by centrifugal forces occurring in the electric machines.