Power unit (1) for industrial machines (O) of the type comprising: one motor (2) and one pulley (3) splined to the shaft (4) of the motor (2), operatively connected to the components (5) of the industrial machine (0) via a driving belt (6); a supporting base (7) of the motor (2) arranged so that it rests on a bearing surface (8). The pulley (3) is of the expandable type and the supporting base (7) is associated with displacement means (10) suited to move it away from the bearing surface (8) during the stopping stage of the motor (2) in order to arrange the driving belt (6) on a reduced radius of the expandable pulley (3) when the motor (2) is at rest. Industrial machine (20) of the type comprising the power unit (1).

A variable speed transmission (20) includes a sprocket (46) mounted on a first shaft (22) for rotation therewith. A variable effective diameter pulley (30) is mounted for rotation on a driven shaft (32). The pulley includes a pair of pulley halves (80, 82) having opposed inclined belt engaging surfaces (84, 86) and splines (90, 94) extending from the pulley halves. The splines are intermeshed so that the pulley halves may be drawn together or separated while rotating as a unit. A split shaft (130), including two half shafts (132,134), extend within the pulley halves. Each half shaft engages one of the pulley halves such that as the half shafts are moved relative to one another, the pulley halves are moved one relative to the other. A pulley control mechanism (66) is provided for moving the halves of the split shaft simultaneously such that the center line of the pulley remains fixed as the pulley halves move together or apart. An endless chain assembly (60) is mounted around the gear and variable effective diameter pulley arrangement to transmit rotation therebetween. The belt includes edge portions (234) for engaging the pulley and an intermediate portion (230) for engaging the sprocket (46). An idler pulley (50) is controlled by an idler tensioner actuation mechanism (52) to maintain tension on the belt as the effective diameter of the pulley is varied.

The present invention relates to A V-belt continuously variable transmission for a straddle-type vehicle, such as an all terrain vehicle, for transmitting driving force of an engine to a driving wheel, the V-belt continuously variable transmission comprising a primary sheave, and a secondary sheave, wherein a movable sheave half of the primary sheave is located on an outer side in a vehicle width direction with respect to a fixed sheave half of the primary sheave, and further comprising a sheave drive mechanism located on an outer side in the vehicle width direction with respect to the movable sheave half of the primary sheave, to control respective groove widths of the primary sheave and the secondary sheave through driving force of an electric motor, wherein at least a part of the electric motor is located above and in front of a primary sheave shaft as viewed in a sheave shaft direction.

Die Erfindung betrifft einen Hilfsaggregate-Antrieb, insbesondere für eine Brennkraftmaschine (1), mit variabler Übersetzung, wobei ein Antriebsriemen (4) über eine in ihrem wirksamen Durchmesser (D) variable Antriebs-Riemenscheibe, (5) weiterhin über ein unterschiedlich positionierbares Spannrollensystem (6), mit Hilfe dessen die gewünschte Übersetzung einstellbar ist, sowie über zumindest eine einem Hilfsaggregat zugeordnete Abtriebs-Riemenscheibe (3a-3d) geführt ist. Erfindungsgemäß besteht das Spannrollensystem aus zwei Spannrollen (6a,6b), zwischen denen der Antriebsriemen (4) hindurch geführt ist, wobei die beiden Spannrollen (6a,6b) auf einer Tragplatte (8) angeordnet sind, die in einer zur Antriebsriemen-Ebene parallelen Ebene verdrehbar ist. Die Tragplatte kann ein Zahnradsegment (12) tragen, welches mit einem Ritzel (11a) eines elektrischen Stellmotors (11) kämmt. Ferner greift an der Tragplatte ein im wesentlichen die Riemenspannung abstützendes Federelement (14) an.