A dual motor system includes a first motor providing a lower speed range and a second motor providing a higher speed range, wherein the motors are coaxially arranged and aligned on and drive a common shaft, and a motor control system controlling the speed of the first motor and engaging the second motor as needed. The first motor is a variable speed motor providing a lower two-thirds of a full speed range, and the second motor is an induction motor providing the upper one-third in the form of one or more discrete fixed speeds. The system may include a transformer including a first winding tap which provides a first higher speed, and a second winding tap which provides a second higher speed. The system may also include a flow control system for automatically controlling the speed of the motors for particular applications, such as flow control in a pool.

A dual motor system includes a first motor providing a lower speed range and a second motor providing a higher speed range, wherein the motors are coaxially arranged and aligned on and drive a common shaft, and a motor control system controlling the speed of the first motor and engaging the second motor as needed. The first motor is a variable speed motor providing a lower two-thirds of a full speed range, and the second motor is an induction motor providing the upper one-third in the form of one or more discrete fixed speeds. The system may include a transformer including a first winding tap which provides a first higher speed, and a second winding tap which provides a second higher speed. The system may also include a flow control system for automatically controlling the speed of the motors for particular applications, such as flow control in a pool.

Abstract: A vibratory hammer (1) for driving or retracting sheet piles, pipes or other elements into or from the soil, comprises a vibration case (2). A clamp (17) is attached to the vibration case (2). The clamp (17) comprises gripping jaws (18) for gripping the sheet piles or other elements. A yoke (3) is connected to the vibration case (2) via one or more vibration damping elements for suspending the vibratory hammer (1) from a hoist cable or the like. In the vibration case (2) an even number of pairwise arranged eccenter weights are rotationally mounted. The vibratory hammer comprises at least one synchronous electric motor (13A) for driving the rotation of the eccenter weights.

Abstract: A vibratory hammer (1) for driving or retracting sheet piles, pipes or other elements into or from the soil, comprises a vibration case (2). A clamp (17) is attached to the vibration case (2). The clamp (17) comprises gripping jaws (18) for gripping the sheet piles or other elements. A yoke (3) is connected to the vibration case (2) via one or more vibration damping elements for suspending the vibratory hammer (1) from a hoist cable or the like. In the vibration case (2) an even number of pairwise arranged eccenter weights are rotationally mounted. The vibratory hammer comprises at least one synchronous electric motor (13A) for driving the rotation of the eccenter weights.

The present invention relates to an electrical machine comprising a rotor (10) and a stator, rotor (10) being formed by assembling a rotor body (4) and a rotor shaft (1). According to the invention, rotor shaft (1) is knurled and the outside diameter of rotor shaft (1) is greater than the inside diameter of rotor body (4), by a value ranging between 0.05 mm and 0.3 mm. The present invention further relates to a method of manufacturing such an electrical machine.

The present invention relates to an electrical machine comprising a rotor (10) and a stator, rotor (10) being formed by assembling a rotor body (4) and a rotor shaft (1). According to the invention, rotor shaft (1) is knurled and the outside diameter of rotor shaft (1) is greater than the inside diameter of rotor body (4), by a value ranging between 0.05 mm and 0.3 mm. The present invention further relates to a method of manufacturing such an electrical machine.

A drone for triggering naval mines, which drone includes a drive having an electric motor for locomotion in the water, wherein the electric motor can be used additionally to trigger the naval mines during operation of the drone, by an external magnetic field formed by the operation of the electric motor. The electric motor includes a stationary stator and a rotor, which is mounted for rotation relative to the stator. The stator includes at least one magnetic and/or electromagnetic element for forming an excitation field. The rotor includes at least one armature winding, which electromagnetically interacts with the excitation field during operation of the electric motor, whereby a superordinate magnetic field is formed. The external magnetic field formed outside of the electric motor during operation is in the form of a constant magnetic field.

A drone for triggering naval mines, which drone includes a drive having an electric motor for locomotion in the water, wherein the electric motor can be used additionally to trigger the naval mines during operation of the drone, by an external magnetic field formed by the operation of the electric motor. The electric motor includes a stationary stator and a rotor, which is mounted for rotation relative to the stator. The stator includes at least one magnetic and/or electromagnetic element for forming an excitation field. The rotor includes at least one armature winding, which electromagnetically interacts with the excitation field during operation of the electric motor, whereby a superordinate magnetic field is formed. The external magnetic field formed outside of the electric motor during operation is in the form of a constant magnetic field.

A method is provided for fabricating an insulated metal coil for an electrical machine. The method includes 3D printing a metal coil having a plurality of turns. The method further includes subsequently infiltrating insulating material between the turns of the metal coil to electrically insulate the turns from each other.

A method is provided for fabricating an insulated metal coil for an electrical machine. The method includes 3D printing a metal coil having a plurality of turns. The method further includes subsequently infiltrating insulating material between the turns of the metal coil to electrically insulate the turns from each other.