# US 10,119,431 B2 · Camshaft phaser systems and method of commutating an electric motor for the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,119,431 B2 - Document ID: US10119431B2 - Status: Granted - Kind: B2 - Application number: 15/318,411 - Filed: 2015-06-18 - Published: 2017-05-04 - Granted: 2018-11-06 - Earliest claimed: 2014-06-25 - Assignees: BorgWarner Inc. - Applicants: BorgWarner Inc. - Inventors: Daniel Brown - Web page: https://patentgrep.com/patent/US10119431B2 ## CPC - F01L 1/344: changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear - F01L 1/02: Valve drive (transmitting-gear between valve drive and valve F01L1/12) - F01L 1/024: {Belt drive} - F01L 1/047: Camshafts - F01L 1/352: using bevel or epicyclic gear - F01L 9/20: by electric means - H02P 6/18: without separate position detecting elements - H02P 25/03: with brushless excitation - F01L 9/26: Driving circuits therefor - F01L 2001/0537: {Double overhead camshafts [DOHC]} - F01L 2001/3522: {with electromagnetic brake} - F01L 2009/2103: {comprising one coil} - F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract A system (42) including a phaser (28), a motor (38), and a controller (40) for controlling the phase between a camshaft (18) and a crankshaft (16) of an engine (10). The phaser (28) is attached to the camshaft (18), is in communication with the crankshaft (16), and is configured to adjust the phase of the camshaft (18). The motor (38) actuates the phaser (28) and is operatively attached to and in communication with the phaser (28) such that rotation of the crankshaft (16) back-drives the motor (38) to subsequently generate a signal. The controller (40) is in electrical communication with the motor (38), is responsive to the signal, and uses the signal to determine the rotational speed of the motor (38) to thereby commutate the motor (38) and subsequently drive the motor (38) so as to actuate the phaser (28) and control the phase of the camshaft (18). ## Claims ### Claim 1 A camshaft (18) phaser (28) system (42) for use in controlling the phase between a camshaft (18) and a crankshaft (16) of an internal combustion engine (10), said system comprising: a phaser (28) operatively attached to the camshaft (18) and in rotational communication with the crankshaft (16) for adjusting the phase of the camshaft (18) with respect to the crankshaft (16); an electric motor (38) that actuates said phaser (28), said electric motor (38) operatively attached to and in rotational communication with said phaser (28) such that rotation of the crankshaft (16) back-drives said electric motor (38) and said electric motor (38) generates a signal; and a controller (40) in electrical communication with said electric motor (38), said controller (40) being responsive to said signal to thereby commutate said electric motor (38) and subsequently drive said electric motor (38) so as to actuate said phaser (28) and control the phase of the camshaft (18). ### Claim 2 (depends on 1) The system (42) as set forth in claim 1; wherein said electric motor (38) includes a plurality of coils (48) with each of said coils (48) being in electrical communication with said controller (40), and wherein said signal is further defined as a plurality of signals each generated by one of each of said coils (48) when said electric motor (38) is back-driven. ### Claim 3 (depends on 2) The system (42) as set forth in claim 2, wherein each of said signals is further defined as an oscillating voltage. ### Claim 4 (depends on 1) The system (42) as set forth in claim 1, wherein said phaser (28) includes at least one end stop (50) defining a phase limit between the camshaft (18) and the crankshaft (16), said phaser (28) being movable to said at least one end stop (50) in response to a predetermined rotational speed differential between the crankshaft (16) and said electric motor (38). ### Claim 5 (depends on 4) The system (42) as set forth in claim 4, wherein said phaser (28) back-drives said electric motor (38) when said phaser (28) moves to said end stop (50). ### Claim 6 (depends on 5) The system (42) as set forth in claim 5, wherein rotation of the crankshaft (16) causes said phaser (28) to move to said end stop (50). ### Claim 7 (depends on 4) The system (42) as set forth in claim 4, wherein said controller (40) sends a predetermined sequence of commutation states to said electric motor (38) such that said electric motor (38) moves said phaser (28) to said at least one end stop (50), and wherein subsequent rotation of the crankshaft (16) causes said phaser (28) to back-drive said electric motor (38). ### Claim 8 (depends on 7) The system (42) as set forth in claim 7, further including at least one camshaft position sensor (62) in electrical communication with said controller (40) and adapted to provide a rotational position signal thereto; and wherein said controller (40) uses said rotational position signal to determine said sequence of commutation states. ### Claim 9 (depends on 1) The system (42) as set forth in claim 1, wherein said phaser (28) includes a locking mechanism (56) having an unlocked position (56A) wherein said electric motor (38) can control the phase of the camshaft (18), and a locked position (56B) wherein said phaser (28) is fixed at a predetermined phase between the camshaft (18) and the crankshaft (16), said locking mechanism (56) being selectively movable between said unlocked position (56A) and said locked position (56B). ### Claim 10 (depends on 9) The system (42) as set forth in claim 9, wherein said phaser (28) back-drives said electric motor (38) when said locking mechanism (56) is in said locked position (56B). ### Claim 11 A method of commutating a synchronous electric motor (38) for use in actuating a phaser (28) used to control the phase between a camshaft (18) and a crankshaft (16) of an internal combustion engine (10), said method comprising the steps of: providing a phaser (28) operatively attached to the camshaft (18) and in rotational communication with the crankshaft (16); providing an electric motor (38) operatively attached to and in rotational communication with said phaser (28); providing a controller (40) in electrical communication with said electric motor (38); rotating the crankshaft (16) at a predetermined speed such that said phaser (28) back-drives said electric motor (38); generating a signal with said electric motor (38) in response to being back-driven; detecting said signal using said controller (40); determining a back-drive speed of said electric motor (38) based on said signal using said controller (40); commutating said electric motor (38) based on said signal using said controller (40); and driving said electric motor (38) using said controller (40) so as to actuate said phaser (28) and control the phase of the camshaft (18). ### Claim 12 (depends on 11) The method as set forth in claim 11, wherein the step of detecting said signal using said controller (40) further includes the step of detecting oscillating voltage generated by coils (48) of said electric motor (38) using said controller (40); and the step of determining a back-drive speed of said electric motor (38) based on said signal using said controller (40) further includes the step of determining a back-drive speed of said electric motor (38) based on said oscillating voltages using said controller (40). ### Claim 13 (depends on 11) The method as set forth in claim 11, wherein the step of rotating the crankshaft (16) at a predetermined speed such that said phaser (28) back-drives said electric motor (38) further includes the step of rotating the crankshaft (16) at a predetermined speed such that said phaser (28) moves to an end stop (50) and subsequently back-drives said electric motor (38). ### Claim 14 (depends on 11) The method as set forth in claim 11, further including the step of sending a predetermined sequence of commutation states to said electric motor (38) using said controller (40) such that said electric motor (38) moves said phaser (28) to an end stop (50) prior rotation of the crankshaft (16).