An electric power tool includes an electric motor with a motor gear, an output shaft with an input gear, a coupling that connects the motor gear to the input gear, and a housing that houses the motor, the motor gear, the coupling and the input gear. The coupling includes a shaft portion and two connective portions arranged at opposite ends of the shaft portion for connection to the motor gear and input gear, respectively. The motor gear and the input gear, each, have a cambered profile allowing a tilting movement of the coupling with respect to an axial position of one of the motor gear and the input gear that has a cambered profile.

An assist mechanism includes: an electric motor in which a rotor has a magnet and a stator has a winding; a shaft-shaped member in which a worm engaged with a worm wheel is formed; and a coupling that couples an output shaft of the electric motor and the shaft-shaped member to each other. The smallest rotation order among rotation orders of the electric motor and a rotation order of the worm are prime to each other.

An assist mechanism includes: an electric motor in which a rotor has a magnet and a stator has a winding; a shaft-shaped member in which a worm engaged with a worm wheel is formed; and a coupling that couples an output shaft of the electric motor and the shaft-shaped member to each other. The smallest rotation order among rotation orders of the electric motor and a rotation order of the worm are prime to each other.

A flexible coupling includes a first flange having an outer edge, a first surface, a second surface opposite the first surface, and a first plurality of passages. A second flange including an outer edge section, a first surface section, a second surface section opposite the first surface section, and a second plurality of passages. A connecting element extends between and connecting the first flange and the second flange through one of the first plurality of passages and one of the second plurality passages. The connecting element includes a connecting member having a first stop element and a second stop element. A compliant component is arranged on the connecting element. The compliant component is positioned on the connecting member between one of: the first stop element and the first surface; the second stop element and the second surface section; and between the second surface and the first surface section.

An isolator decoupler comprising a shaft, a pulley journalled to the shaft, a one-way clutch engaged with the shaft, a spring carrier engaged with the one-way clutch, the spring carrier having a spring carrier surface, a torsion spring having a first end laser welded to the pulley and a second end laser welded to the spring carrier, the torsion spring having a volute with a width w, an annular spring support member having a spring support member outside surface, the annular spring support member independently moveable from the spring carrier and independently moveable from the shaft, a gap g between the annular spring support member and the spring carrier, the gap g being less than the width w, the first end comprising a first end coil, the first end coil bearing upon the spring support member outside surface, the first end coil laser welded to the spring support member outside surface, a torsion spring radial contraction limited by engagement with the spring carrier surface, and the gap g and the width w have a relationship (w−2r)>(g+c1+c2) were g>0.

An isolator decoupler comprising a shaft, a pulley journalled to the shaft, a one-way clutch engaged with the shaft, a spring carrier engaged with the one-way clutch, the spring carrier having a spring carrier surface, a torsion spring having a first end laser welded to the pulley and a second end laser welded to the spring carrier, the torsion spring having a volute with a width w, an annular spring support member having a spring support member outside surface, the annular spring support member independently moveable from the spring carrier and independently moveable from the shaft, a gap g between the annular spring support member and the spring carrier, the gap g being less than the width w, the first end comprising a first end coil, the first end coil bearing upon the spring support member outside surface, the first end coil laser welded to the spring support member outside surface, a torsion spring radial contraction limited by engagement with the spring carrier surface, and the gap g and the width w have a relationship (w−2r)>(g+c1+c2) were g>0.

A brake device for braking rotation of an input shaft includes a selectively operable trigger brake that includes: a static element; a trigger brake shaft mounted for rotational and axial movement relative to the static element and the input shaft; a preloaded torsion spring rotationally coupled to the input shaft but permitting a limited rotational movement between the trigger brake shaft and the input shaft; a roller jamming mechanism operable upon the relative rotation between the trigger brake shaft and the input shaft exceeding a predetermined amount to stop rotation of the input shaft upon operation of the trigger brake; and a brake actuator for selectively moving the trigger brake shaft into and out of engagement with a contact surface of the static element. Engagement of the contact surface of the static element and the trigger brake shaft overcomes the preload of the torsion spring.

A brake device for braking rotation of an input shaft includes a selectively operable trigger brake that includes: a static element; a trigger brake shaft mounted for rotational and axial movement relative to the static element and the input shaft; a preloaded torsion spring rotationally coupled to the input shaft but permitting a limited rotational movement between the trigger brake shaft and the input shaft; a roller jamming mechanism operable upon the relative rotation between the trigger brake shaft and the input shaft exceeding a predetermined amount to stop rotation of the input shaft upon operation of the trigger brake; and a brake actuator for selectively moving the trigger brake shaft into and out of engagement with a contact surface of the static element. Engagement of the contact surface of the static element and the trigger brake shaft overcomes the preload of the torsion spring.

A coupling for allowing torque transmission between a first and second shaft, the coupling comprising: a cup-shaped portion provided at a first end of said first shaft and a first end of said second shaft being positioned within said cup-shaped portion; and said coupling further comprising a biasing means positioned between said first and second shafts, such that said biasing means is in contact with both of said first and second shafts. A shaft system can include the first coupling in combination with a third shaft and a second coupling that is provided between the third shaft and either a second end of said first shaft or a second end of said second shaft. The second coupling is identical to the first coupling.

The present invention relates to a shaft for a propulsion system configured to rotate a reducing mechanism about a rotational axis, the shaft comprising: —a first end configured to engage with an input gear of the reducing mechanism, —a first bellows and a second bellows, the first bellows and the second bellows being rotationally symmetrical about the rotational axis, the first bellows extending between the first end and the second bellows, and —a frustoconical body mechanically connecting the first bellows and the second bellows.