Device for adjusting the rotation angle of the camshaft of an internal combustion engine in relation to a drive wheel

System, for adjusting an engine camshaft with respect to a driving wheel, comprising:

• a first part movable together with an engine camshaft,
• a second part movable together with a driving wheel,
• a fluid pressure circuit operable to selectively change relative positions of the first and second parts, and
• a locking element operable to selectively mechanically lock the first and second parts in fixed relative positions,
• wherein said locking element is configured selectively to control fluid flow in the fluid pressure circuit,
• wherein locking element exhibits a stepped configuration which is operable to change fluid pressure applied to change the relative positions of the first and second parts as a function of positions of the locking pin, and
• wherein the locking element is movable between a first unlocking position blocking a part of the fluid pressure circuit leading to the pressure spaces and a second unlocking position opening said part of the fluid circuit leading to the pressure spaces.

System, for adjusting an engine camshaft with respect to a driving wheel, comprising:

• a first part movable together with an engine camshaft,
• a second part movable together with a driving wheel,
• a fluid pressure circuit operable to selectively change relative positions of the first and second parts, and
• a locking element operable to selectively mechanically lock the first and second parts in fixed relative positions,
• wherein said locking element is configured selectively to control fluid flow in the fluid pressure circuit,
• wherein said first part is an interior part,
• wherein said second part is a wheel enclosing the interior parts,
• wherein one of said interior part and wheel have a plurality of cells and the other of said interior part and wheel have respective webs extending into respective ones of said cells and forming respective pressure spaces at opposite sides of the respective webs, or herein said fluid pressure circuit is operable to selectively change the fluid pressure in said pressure spaces,
• wherein said locking element is operable to selectively rotatably lock the interior part and wheel together, and
• wherein the locking element is movable between a first unlocking position blocking a part of the fluid pressure circuit leading to the pressure spaces and a second unlocking position opening said part of the fluid circuit leading to the pressure spaces.