Abstract: A dispersion measurement apparatus includes a pulse forming unit, a correlation optical system, a beam splitter, an operation unit, an imaging unit, a spatial filter unit, and a photodetector. The pulse forming unit forms a light pulse train including light pulses having time differences and different center wavelengths. The beam splitter branches the light pulse train passed through a measurement object. The imaging unit disperses one light pulse train and images each light pulse. The spatial filter unit extracts light of a partial region of the other light pulse train. The correlation optical system outputs correlation light including a cross-correlation or an autocorrelation of the extracted light. The photodetector detects a temporal waveform of the correlation light. The operation unit estimates a wavelength dispersion amount in the measurement object based on a feature value of the temporal waveform.

Abstract: A dispersion measurement apparatus includes a pulse forming unit, a correlation optical system, a beam splitter, an operation unit, an imaging unit, a spatial filter unit, and a photodetector. The pulse forming unit forms a light pulse train including light pulses having time differences and different center wavelengths. The beam splitter branches the light pulse train passed through a measurement object. The imaging unit disperses one light pulse train and images each light pulse. The spatial filter unit extracts light of a partial region of the other light pulse train. The correlation optical system outputs correlation light including a cross-correlation or an autocorrelation of the extracted light. The photodetector detects a temporal waveform of the correlation light. The operation unit estimates a wavelength dispersion amount in the measurement object based on a feature value of the temporal waveform.

Abstract: An N-phase electric machine, N being an integer ?3, includes a housing; i×N stator windings arranged in a fixed manner in the housing, i being an integer ?2; and a rotatable rotor surrounded by the i×N stator windings in the housing. The stator windings are consecutively divided into i subgroups in a circumferential direction, each subgroup having N stator windings. The electric machine further comprises i current control modules and i temperature measurement devices, each current control module being correspondingly electrically connected to the N stator windings in one corresponding subgroup, so that when the stator windings in the i subgroups are supplied with power by the i current control modules, a rotating magnetic field is generated around the rotor. Each temperature measurement device is configured to measure the temperature of one corresponding subgroup in the i subgroups during operation of the electric machine.

Abstract: A laser welding method includes: forming a molten weld pool by emitting laser light including a main power region and a sub-power region onto a workpiece, the main power region including at least one main beam, the sub-power region including at least one sub-beam having a lower power density than power density of the main beam; and solidifying the molten weld pool. The sub-beam is emitted onto the workpiece such that a void formed inside the molten weld pool escapes to outside of the molten weld pool before the molten weld pool becomes solidified.

Abstract: A laser welding method includes: preparing a first member and a second member, the first member and the second member having a first end portion and a second end portion in a first direction, respectively; arranging the second member adjacent to the first member in a second direction intersecting with the first direction such that a distance between the first end portion and the second end portion is 0 or more along the first direction; forming a first molten pool protruding from the first end portion toward at least the second end portion, by emitting laser light to the first end portion; forming a bridging molten pool by emitting laser light to at least the first end portion after the forming of the first molten pool, the bridging molten pool bridging over the first end portion and the second portion; and solidifying the bridging molten pool.

Abstract: A laser cutting method for metal foil includes: cutting a processing target by laser by intermittently applying a pulse of laser beam to a surface of a metal foil serving as the processing target at a frequency of 1 [MHz] or less.

Abstract: A welding method includes: emitting a laser beam to a workpiece including a metal; and welding a portion of the workpiece to which the laser beam is emitted by melting. The laser beam includes a main power region and at least one auxiliary power region, power in the main power region is equal to or higher than power in each of the at least one auxiliary power region, and a power ratio of the power in the main power region and a total of the power in the at least one auxiliary power region is within a range of 144:1 to 1:1.

Abstract: An electric motor and inverter assembly (100) used in an electric vehicle or a hybrid electric vehicle to drive the vehicle's wheels to rotate is disclosed. The electric motor and inverter assembly comprises: an electric motor (300), which includes a housing including a main shell (310), an end cover (320) and a connecting cover (330), wherein a cooling passage is formed in a wall of the housing such that coolant is able to flow in the cooling passage, and an end cover (320) and a connecting cover (330) are respectively connected to opposite ends of the main shell; and an inverter, which includes a housing (210) in which a power element and/or an electrical device is received, wherein the housing of the inverter contacts the connecting cover such that an interface is defined between the connecting cover and the housing of the inverter, and the coolant flowing through the cooling passage is able to contact the interface.

Abstract: A welding method includes: irradiating a surface of a workpiece with a laser light that moves relatively to the workpiece in a sweep direction; and performing welding by melting a part of the workpiece irradiated with the laser light. The laser light includes a plurality of beams, the plurality of beams include at least one main beam and at least one sub beam smaller in power than the main beam, a main power region including the at least one main beam and a sub power region including the at least one sub beam are formed on the surface, and a minimum distance between centers of adjacent ones of the plurality of beams on the surface is 75 ?m or less.

Abstract: An electric drive system (100) used in an electric vehicle or a hybrid electric vehicle to drive the vehicle's wheels to rotate. The electric drive system (100) includes an electric motor (300). The electric motor (300) includes a housing in which a stator and a rotor are received. A transmission device (400) is operatively coupled to the electric motor (300); and an output shaft (500) is operatively coupled to the transmission device (400). The output shaft (500) extends from the transmission device (400) and is substantially parallel to the rotor's axis of the electric motor (300). The electric drive system (100) also includes an inverter (200) secured over the housing of the electric motor (300) such that the inverter is located between the output shaft (500) and the housing of the electric motor (300).

Abstract: A welding method includes: placing a workpiece including aluminum in a region to which laser light is emitted; and irradiating the laser light to the workpiece to melt an irradiated portion of the work piece to perform welding. Further, the laser light is formed of a main beam and plural auxiliary beams, and the plural auxiliary beams are positioned so as to surround a periphery of the main beam.

Abstract: An N-phase electric machine, N being an integer ?3, includes a housing; i×N stator windings arranged in a fixed manner in the housing, i being an integer ?2; and a rotatable rotor surrounded by the i×N stator windings in the housing. The stator windings are consecutively divided into i subgroups in a circumferential direction, each subgroup having N stator windings. The electric machine further comprises i current control modules and i temperature measurement devices, each current control module being correspondingly electrically connected to the N stator windings in one corresponding subgroup, so that when the stator windings in the i subgroups are supplied with power by the i current control modules, a rotating magnetic field is generated around the rotor. Each temperature measurement device is configured to measure the temperature of one corresponding subgroup in the i subgroups during operation of the electric machine.

Abstract: A welding method includes: emitting laser beam toward a workpiece including a metal to melt and weld a part of the workpiece, the part being where the laser beam has been emitted to. Further, the laser beam includes a main power region and at least one auxiliary power region, a power of the main power region is larger than a power of each of the at least one auxiliary power region, and a ratio between the power of the main power region and the total of powers of the at least one auxiliary power region is in a range of 144:1 to 1:9.

Abstract: A welding method includes a step of, while irradiating laser beam toward a workpiece, relatively moving the laser beam and the workpiece and, while sweeping the laser beam on the workpiece, melting the workpiece in an irradiated portion to perform welding. Further, the laser beam is configured by a main power region and a sub-power region, at least a part of the sub-power region is present on a sweeping direction side of the main power region, a power density of the main power region is equal to or higher than a power density of the sub-power region, and the power density of the main power region is at least power density that can generate a keyhole.

Abstract: A welding method includes: layering two or more plate materials each including a plating plate material having a preform on a surface of which a plating layer is formed to form a workpiece; disposing the workpiece in a region to be irradiated with a processing laser beam; generating the processing laser beam having a power distribution shape in which two or more power regions are disposed along a predetermined direction in a plane perpendicular to a light traveling direction; irradiating a surface of the workpiece with the processing laser beam; and moving the processing laser beam and the workpiece relatively while performing the irradiation, and melting an irradiated area of the workpiece to perform welding while sweeping the processing laser beam in the predetermined direction on the workpiece during a swing of the processing laser beam.

Abstract: A welding method includes: disposing a workpiece formed by stacking a plurality of metal foils in an area to be irradiated with laser light that contains a plurality of beams; irradiating a surface of the workpiece with the beams of the laser light by dispersing positions of the beams such that centers of the beams do not overlap with each other within a prescribed area on the surface; melting an irradiated part of the workpiece and performing welding; and setting each of the beams to have a power density with which no hole opens in the metal foils, and setting the power density of the beams and dispersing irradiating positions to be emitted so as to form a weld pool penetrating the workpiece by the beams.

Abstract: A welding method includes: arranging a workpiece containing copper in a region to be irradiated with laser light; and irradiating the workpiece with the laser light to melt and weld an irradiated portion of the workpiece. Further, the laser light is formed of a main beam and a plurality of sub beams, and a ratio of power of the main beam to total power of the plurality of sub beams is 72:1 to 3:7.

Abstract: A welding method includes: forming a workpiece by stacking plated sheet members having a plating layer formed on a surface of a base material; disposing the workpiece in an area to be irradiated with laser light; irradiating a surface of the workpiece with a plurality of beams by dispersing positions such that centers of the beams do not overlap with each other within a prescribed area on the surface; while continuing the irradiation, relatively moving the beams and the workpiece and sweeping the beams on the workpiece so as to melt an irradiated part of the workpiece for performing welding; and setting a distance between the beams to be emitted such that weld pools formed in the workpiece by irradiation of each of the beams overlap with each other.

Abstract: An electric motor and inverter assembly (100) used in an electric vehicle or a hybrid electric vehicle to drive the vehicle's wheels to rotate is disclosed. The electric motor and inverter assembly comprises: an electric motor (300), which includes a housing including a main shell (310), an end cover (320) and a connecting cover (330), wherein a cooling passage is formed in a wall of the housing such that coolant is able to flow in the cooling passage, and an end cover (320) and a connecting cover (330) are respectively connected to opposite ends of the main shell; and an inverter, which includes a housing (210) in which a power element and/or an electrical device is received, wherein the housing of the inverter contacts the connecting cover such that an interface is defined between the connecting cover and the housing of the inverter, and the coolant flowing through the cooling passage is able to contact the interface.

Abstract: An electric drive system (100) used in an electric vehicle or a hybrid electric vehicle to drive the vehicle's wheels to rotate, the electric drive system (100) comprising: an electric motor (300), said electric motor (300) including a housing in which a stator and a rotor are received; a transmission device (400) operatively coupled to the electric motor (300); and an output shaft (500) operatively coupled to the transmission device (400), wherein the output shaft (500) extends from the transmission device (400) and is substantially parallel to the rotor's axis of the electric motor (300), and wherein the electric drive system (100) also comprises an inverter (200), the inverter is secured over the housing of the electric motor (300) such that the inverter is located between the output shaft (500) and the housing of the electric motor (300), such that the system is compact in configuration and is high-integrated.