A connection system for connecting a component to a gear wheel, wherein the gear wheel comprises helical gearing having a tooth helix angle and a first connecting section, and the component comprises a second connecting section by way of which the component can be connected or is connected to the first connecting section, wherein the component, in the second connecting section, comprises at least one depression or elevation that is operatively connected to the first connecting section when the component is connected to the first connecting section, wherein the depression has a connection helix angle, and the connection helix angle is defined as follows: 0. The disclosure furthermore relates to a device for transmitting a rotational movement, comprising a rotatable component and a gear wheel, wherein the gear wheel and the component are connected by way of such a connection system.

A spindle for driving a bung of a cartridge. The spindle includes a generally circular shaft having an outer surface. The generally circular shaft extends from a distal end to a proximal end of said circular shaft. A first helical groove is provided along a first portion of the outer surface. The first helical groove having a first pitch. A second helical groove provided along a second portion of the outer surface of the generally circular shaft. The second helical groove overlapping the first helical groove. The second helical groove having a second pitch.

The present disclosure relates to a connection system for connecting a component to a gear wheel, wherein the gear wheel comprises helical gearing having a tooth helix angle and a first connecting section, and the component comprises a second connecting section by way of which the component can be connected or is connected to the first connecting section, wherein the component, in the second connecting section, comprises at least one depression or elevation that is operatively connected to the first connecting section when the component is connected to the first connecting section, wherein the depression has a connection helix angle, and the connection helix angle is defined as follows: 0. The disclosure furthermore relates to a device for transmitting a rotational movement, comprising a rotatable component and a gear wheel, wherein the gear wheel and the component are connected by way of such a connection system.

A core of a worm wheel has an axial end surface formed with a first annular recess, another axial end surface formed with a second annular recess, and a third annular recess formed in a radially outer region of the first annular recess. A rim portion has a first inner circumferential portion fixed to the first annular recess, a second inner circumferential portion fixed to the second annular recess, and a protrusion engaged with the third annular recess.

A worm wheel is provided in which a step is not formed near a tooth face meshing with a worm, and noise does not easily occur during power transmission. A worm wheel 1 includes a circular arc-shaped tooth section 5 that is a portion meshing with a worm 101 and configuring a circular tube worm gear, and a helical tooth section 4 that is connected to one end side of the circular arc-shaped tooth section 5. An angle of torsion at an arbitrary reference point 14 in a tooth depth direction of a tooth 3 on a boundary 7 between the circular arc-shaped tooth section 5 and the helical tooth section 4 is equal to an angle of torsion at a second reference point 15 corresponding to the first reference point 14 in the tooth depth direction of the tooth 3 in a diameter portion P0 of a throat of the circular arc-shaped section 5. As a result, a step is not formed on a tooth face on the boundary 7 between the circular arc-shaped tooth section 5 and the helical tooth section 4. A tooth face of the circular arc-shaped tooth section 5 and a tooth face of the helical tooth section 4 are smoothly connected.

A core of a worm wheel has an axial end surface formed with a first annular recess nad and another axial end surface formed with a second annular recess. An outer circumferential wall surface of a radially outer region of the second annular recess has a tapered surface extending from a bottom surface of the second annular recess to form an obtuse angle relative to the bottom surface, and a third annular recess formed radially outside the tapered surface. A cross-section of the third annular recess is a right-angled triangle having, as two sides, a surface parallel to the bottom surface of the second annular recess and a surface perpendicular to the bottom surface of the second annular recess. A rim portion has a first inner circumferential portion fixed to the first annular recess and a second inner circumferential portion fixed to the second annular recess.

A core of a worm wheel has an axial end surface formed with a first annular recess and another axial end surface formed with a second annular recess. A rim portion has a first inner circumferential portion fixed to the first annular recess and a second inner circumferential portion fixed to the second annular recess. An outer circumferential wall surface of the second annular recess extends from a bottom surface of the second annular recess so as to be perpendicular to the bottom surface. A depth of the second annular recess is at least 0.1 mm but not deeper than half of a gate thickness.