# US 11,121,603 B2 · Drive unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,121,603 B2 - Document ID: US11121603B2 - Status: Granted - Kind: B2 - Application number: 16/030,921 - Filed: 2018-07-10 - Published: 2019-01-17 - Granted: 2021-09-14 - Earliest claimed: 2017-07-13 - Assignees: Honda Motor Co., Ltd.; Mitsubishi Electric Corporation - Applicants: Honda Motor Co., Ltd.; Mitsubishi Electric Corporation - Inventors: Ryoji Tomokage; Masahiro Shimada; Seiichi Goto; Naoki Honishi; Takashi Omura - Web page: https://patentgrep.com/patent/US11121603B2 ## CPC - H02K 5/24: specially adapted for suppression or reduction of noise or vibrations - H02K 5/04: Casings or enclosures characterised by the shape, form or construction thereof - H02K 7/006: {Structural association of a motor or generator with the drive train of a motor vehicle} - H02K 9/227: {Heat sinks} - H02K 11/33: Drive circuits, e.g. power electronics (H02K11/38 takes precedence) - B60K 1/00: Arrangement or mounting of electrical propulsion units (B60K7/00 takes precedence; arrangement or mounting of plural diverse prime-movers for mutual or common propulsion B60K6/00) - H02K 2213/03: Machines characterised by numerical values, ranges, mathematical expressions or similar information - H02K 2213/09: Machines characterised by the presence of elements which are subject to variation, e.g. adjustable bearings, reconfigurable windings, variable pitch ventilators - H02P 27/06: using DC to AC converters or inverters (H02P27/05 takes precedence) - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - 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 - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract A circuit unit of a drive unit includes a plate-shaped heat sink that extends in a direction perpendicular to an axis of rotation of a motor, and a lower case arranged on a lower side of the heat sink. In the drive unit, a fastening member, which is formed on the lower case, is fastened to a housing, and a height of a fastening surface, which is located on an upper end of the fastening member, is positioned within a height range that spans from a lower surface to an upper surface of the heat sink. ## Claims ### Claim 1 A drive unit having a motor, and a circuit unit accommodating a drive circuit configured to supply to the motor electrical power input from a power source, the circuit unit being fixed to an upper side of a housing of the motor; the circuit unit comprising: a plate-shaped heat sink that extends in a direction perpendicular to an axis of rotation of the motor; and a lower case arranged on a lower side of the heat sink; wherein a fastening member, which is formed on the lower case, is fastened to the housing; a height of a fastening surface, which is located on an upper end of the fastening member, is positioned within a height range that spans from a lower surface to an upper surface of the heat sink; and the heat sink comprises a coolant flow path formed between an upper surface of the heat sink and a lower surface of the heat sink. ### Claim 2 (depends on 1) The drive unit according to claim 1, wherein a height of a center of gravity of the circuit unit is positioned within the height range that spans from the lower surface to the upper surface of the heat sink. ### Claim 3 (depends on 1) The drive unit according to claim 1, wherein the fastening surface is positioned at a height of the lower surface of the heat sink. ### Claim 4 (depends on 1) The drive unit according to claim 1, wherein: a bolt hole is formed in an outer surface of the housing, and in a state in which a threaded portion of a bolt is fitted into the bolt hole, a head of the bolt presses the upper end of the fastening member against a side of the housing, whereby the fastening member and the housing are fastened to each other; and the fastening surface is a plane including the upper end of the fastening member. ### Claim 5 A drive unit having a motor, and a circuit unit accommodating a drive circuit configured to supply to the motor electrical power input from a power source, the circuit unit being fixed to an upper side of a housing of the motor; the circuit unit comprising: a plate-shaped heat sink on which components of the drive circuit are fixed on an upper surface and a lower surface thereof; and a lower case arranged on a lower side of the heat sink; wherein a fastening member, which is formed on the lower case, is fastened to the housing; a height of a fastening surface, which is located on an upper end of the fastening member, is positioned within a height range that spans from the lower surface to the upper surface of the heat sink; and the heat sink comprises a coolant flow path formed between an upper surface of the heat sink and a lower surface of the heat sink. ### Claim 6 (depends on 5) The drive unit according to claim 5, wherein: a bolt hole is formed in an outer surface of the housing, and in a state in which a threaded portion of a bolt is fitted into the bolt hole, a head of the bolt presses the upper end of the fastening member against a side of the housing, whereby the fastening member and the housing are fastened to each other; and the fastening surface is a plane including the upper end of the fastening member.