# US 11,993,178 B2 · Method for operating a drive system for a work machine, drive system and work machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,993,178 B2 - Document ID: US11993178B2 - Status: Granted - Kind: B2 - Application number: 17/257,020 - Filed: 2019-06-28 - Published: 2021-09-09 - Granted: 2024-05-28 - Earliest claimed: 2018-07-03 - Assignees: ZF Friedrichshafen AG - Applicants: ZF Friedrichshafen AG - Inventors: Norbert Feuchtner - Web page: https://patentgrep.com/patent/US11993178B2 ## CPC - B60L 7/26: Controlling the braking effect - B60L 7/10: Dynamic electric regenerative braking (B60L7/22 takes precedence) - B60L 58/10: for monitoring or controlling batteries - E02F 9/207: {of the type electric propulsion units, e.g. electric motors or generators} - E02F 9/2095: {Control of electric, electro-mechanical or mechanical equipment not otherwise provided for, e.g. ventilators, electro-driven fans (control of hydraulic driven equipment E02F9/22)} - E02F 9/2225: {using pressure-compensating valves} - E02F 9/2278: {Hydraulic circuits} - B60L 2200/40: Working vehicles - B60L 2240/545: Temperature - B60W 2510/244: Charge state - E02F 3/283: {with a single arm pivoted directly on the chassis (linkage mechanism for it E02F3/3405)} - E02F 3/34: with bucket-arms {, i.e. a pair of arms, e.g. manufacturing processes, form, geometry, material of bucket-arms (with a single arm E02F3/283)} directly pivoted on the frames of tractors or self-propelled machines - E02F 9/2091: {Control of energy storage means for electrical energy, e.g. battery or capacitors (energy recovery arrangements in hydraulic or pneumatic drives E02F9/2217)} - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - 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 - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A method for operating a drive system for a work machine is described. A first electric motor is associated with a travel drive of the drive system and a second electric motor is associated with a work drive of the drive system. An electric energy store for operating the first and the second electric motors is associated with the travel drive and the work drive. The method includes operating the first electric motor in generator mode to produce braking power of the travel drive, electric power being produced in the generator mode. The method further includes supplying, completely or partly to the energy store and/or to the second electric motor depending on a state of the energy store, the electric power. ## Claims ### Claim 1 A method for operating a drive system for a work machine, wherein a first electric motor is associated with a travel drive of the drive system and a second electric motor is associated with a work drive of the drive system, wherein an electric energy store for operating the first and the second electric motor is associated with the travel drive and the work drive, the method comprising: operating the first electric motor in generator mode to produce braking power of the travel drive; wherein electric power is produced in the generator mode, supplying, completely or partly to the energy store and/or to the second electric motor depending on a state of the energy store, the electric power, wherein a friction brake limits the electric power that can be produced in generator mode if it exceeds the total electric power that can be received in total by the energy store and by the second electric motor. ### Claim 2 (depends on 1) The method according to claim 1, wherein the state of the energy store is a state of charge of the energy store, a temperature of the energy store, and/or a maximum charging current of the energy store. ### Claim 3 (depends on 1) The method according to claim 1, wherein the electric power is supplied to the energy store to the extent and so long as the energy store can receive electric power. ### Claim 4 (depends on 1) The method according to claim 1, wherein the second electric motor is configured to drive a hydraulic pump that produces hydraulic pressure for operating the work drive. ### Claim 5 (depends on 4) The method according to claim 4, wherein the hydraulic pressure is produced against a regulatable hydraulic resistance. ### Claim 6 (depends on 5) The method according to claim 5, wherein the hydraulic resistance is adjusted by a bypass valve. ### Claim 7 (depends on 5) The method according to claim 5, wherein the hydraulic resistance is adjusted in such a way that the total electric power can be supplied completely to the energy store and/or to the second electric motor. ### Claim 8 (depends on 1) A drive system configured to carry out a method according to claim 1. ### Claim 9 A drive system for a work machine, comprising: a travel drive having a first electric motor; a work drive having a second electric motor; a common electric energy store configured to operate the first and the second electric motors, the common electric energy store being associated with the travel drive and the work drive, wherein the first electric motor is configured to be operated in generator mode to produce braking power of the travel drive; and a friction brake, wherein electric power is produced in generator mode, wherein a controller of the drive system is configured to supply the electric power completely or partly to the common electric energy store and/or to the second electric motor depending on a state of the common electric energy store, and wherein the friction brake limits the electric power that can be produced in the generator mode if it exceeds the total electric power that can be received in total by the common electric energy store and by the second electric motor. ### Claim 10 (depends on 9) A work machine comprising a drive system according to claim 9.