Drive unit comprising a motor, a clutch and a gear box with a snap connection in the clutch release system

A drive unit comprising:

• (a) a motor with a motor casing (28) and a motor output member (5) rotating about an axis of rotation;
• (b) a gear box with a gear box casing (27) fixed to said motor casing (28);
• (c) a pulled-type clutch unit for torque transmission between said motor and said gear box, said clutch unit having an axis coaxial with said axis of rotation and including
• (aa) a clutch housing (25) mounted to said output member (5) for rotation about said axis;
• (bb) an annular clutch release member (16) mounted for common rotation with said clutch housing (25) and for axial movement with respect to said clutch housing (25);
• (cc) a clutch release system (3) including
• (aaa) a non-rotating clutch release unit (3a) preassembled with said gear box casing (27) for axial movement along said axis with respect to said clutch housing (25);
• (bbb) a release system ring member (11) mounted on said non-rotating clutch release unit (3a) by clutch release bearing means (3b) for rotation about said axis and for common axial movement with said non-rotating clutch release unit (3a);
• (dd) a releasable locking mechanism (2) interconnecting said annular clutch release member (16) and said release system ring member (11) for common axial movement, said annular clutch release member (16) comprising a radially outward sleeve member (16f) and said release system ring member (11) comprising a radially inward sleeve member (11), said sleeve members (16f), (11) being axially coextensive over at least part of their respective axial lengths,
• (1) said outward sleeve member (16f) being provided with a plurality of circumferentially distributed slots (12), each of said slots (12) penetrating through said outward sleeve member (16f) with an angle .alpha. of inclination of less than 90.degree. with respect to said axis, said angle diverging towards said motor output member (5);
• (2) said inward sleeve member (11) being provided with an annular groove (17) in its radially outer surface (19), said annular groove (17) being substantially in radial alignment with radial inner ends of said slots (12);
• (3) roller members (13) being provided in said slots (12) and engaging said annular groove (17);
• (4) said roller members (13) having terminal portions (13a) extending beyond the radially outer surface (16g) of said outer sleeve member (16f);
• (5) a roller engagement ring (15) surrounding said outward sleeve member (16f) at a location axially between said roller members (13) and said motor output member (5), said roller engagement ring (15) engaging said terminal portions (13a) of said roller members (13) in the axial direction;
• (6) spring means (70) acting against said roller engagement ring (15) such as to urge said roller members (13) towards said radially inner ends of said slots (12) and--in the locked condition--into engagement with said annular groove (17);
• (7) the radially outer surface of said inward sleeve member (11) comprising a conically shaped terminal section (18) urging said roller members (13) towards the radially outward ends of said slots (12) when said inward sleeve member (11) is inserted into said outward sleeve member (16f) before said roller members (13) can enter into said annular groove (17) such as to axially lock said sleeve members (16f,11) with respect to each other;
• (8) a locking mechanism release ring (20) axially engaging said terminal portions (13a) of said roller members (13) on the side remote from said roller engagement ring (15);
• and
• (9) an aperture (30) being provided in said gear box casing (27) in such a position as to grant access to said locking mechanism release ring (20) in view of axially shifting said locking mechanism release ring (20) against the action of said spring means (70).