When a rotation speed difference between rotary members of a mode switching clutch is equal to or less than a predetermined value during travel in a belt travel mode, there is a likelihood that the mode switching clutch would be secured to a lock mode in which power operating in two directions is transmitted. At this time, since switching to a gear travel mode is prohibited, it is possible to curb occurrence of a shock when power is simultaneously transmitted via a first power transmission path and a second power transmission path in a transition period of switching to the gear travel mode.

A drive system for a vehicle includes a first electromagnetic device directly coupled to a first planetary gear set and a second electromagnetic device directly coupled to a second planetary gear set. In a first mode of operation, a clutch is engaged to couple the second planetary gear set to the first planetary gear set and a brake is disengaged to allow rotation of the second planetary gear set and in a second mode of operation, the brake is engaged to limit rotation of the second planetary gear set and the clutch is disengaged.

Various embodiments provide a timing belt tensioner for a 3D printer and the 3D printer. In those embodiments, the timing belt tensioner includes: a mounting frame, an idler and an elastic member, where the idler is connected to the mounting frame, and a timing belt of the 3D printer is wound around the idler, and is configured to drive a movement mechanism of the 3D printer to move on an XY plane; and the elastic member is configured to connect the mounting frame and a base of the 3D printer such that the mounting frame drives the idler to slide to a balance position relative to the base under an elastic force of the elastic member. When at the balance position, a balance is reached between the elastic force of the elastic member and a tensile force of the timing belt acting on the idler.

Various embodiments provide a timing belt tensioner for a 3D printer and the 3D printer. In those embodiments, the timing belt tensioner includes: a mounting frame, an idler and an elastic member, where the idler is connected to the mounting frame, and a timing belt of the 3D printer is wound around the idler, and is configured to drive a movement mechanism of the 3D printer to move on an XY plane; and the elastic member is configured to connect the mounting frame and a base of the 3D printer such that the mounting frame drives the idler to slide to a balance position relative to the base under an elastic force of the elastic member. When at the balance position, a balance is reached between the elastic force of the elastic member and a tensile force of the timing belt acting on the idler.

A transmission system is disclosed, having a clutch module with an input and a first and a second output. Between the first output and the input, a first clutch device is present, and between the second output and the input a second clutch device is present. The transmission system further includes a transmission module having a first partial transmission and a second partial transmission, in which the two outputs of the clutch module are connected to the two inputs of the transmission module.

The invention relates to a gear train unit, comprising a plurality of planetary gear train stages, which are connected one after the other and which each comprise a ring gear, a sun gear, and a plurality of planet gears supported on a planet carrier, wherein the sun gear of each following planetary gear train stage is formed by the planet carrier of the preceding planetary gear train stage. The gear train unit comprises a driving element, which forms the sun gear of the first planetary gear train stage, and an output element, which forms the planet carrier of the last of the gear planetary gear train stages connected one after the other. The driving element is supported by means of first bearings arranged in the region of ends of the driving element, in such a way that the driving element can rotate about a longitudinal axis of the driving element, and at least some of the planet carriers of the planetary gear train stages are supported on the driving element in the region between the first bearings by means of bearings. The invention makes it possible to provide a gear train unit having a plurality of planetary gear train stages connected one after the other that is economical, extremely robust, and very compact and that additionally can transmit very high power.

The invention relates to a gear train unit, comprising a plurality of planetary gear train stages, which are connected one after the other and which each comprise a ring gear, a sun gear, and a plurality of planet gears supported on a planet carrier, wherein the sun gear of each following planetary gear train stage is formed by the planet carrier of the preceding planetary gear train stage. The gear train unit comprises a driving element, which forms the sun gear of the first planetary gear train stage, and an output element, which forms the planet carrier of the last of the gear planetary gear train stages connected one after the other. The driving element is supported by means of first bearings arranged in the region of ends of the driving element, in such a way that the driving element can rotate about a longitudinal axis of the driving element, and at least some of the planet carriers of the planetary gear train stages are supported on the driving element in the region between the first bearings by means of bearings. The invention makes it possible to provide a gear train unit having a plurality of planetary gear train stages connected one after the other that is economical, extremely robust, and very compact and that additionally can transmit very high power.

A transmission gearing includes a sun gear, a planetary unit and a high speed unit. The sun gear is mounted on a slowly rotating gear shaft. The planetary unit includes a planetary toothed gear wheel and a planetary shaft gear wheel, which are both mounted on a planetary shaft. The planetary shaft gear wheel has a diameter that is larger than that of the planetary toothed gear wheel and smaller than that of the sun gear. The planetary toothed gear wheel engages the sun gear. The high speed unit includes a quickly rotating gear shaft on which a high speed shaft gear is mounted. The high speed shaft gear has a diameter that is smaller than that of the planetary shaft gear wheel. A drive belt engages both the planetary shaft gear wheel and the high speed shaft gear. The slowly rotating gear shaft is parallel to the planetary shaft.

A power-assisted steering assembly for a vehicle comprises: a motor shaft for transmitting torque from a motor; a steering rack; a primary transmission mechanism; a secondary transmission mechanism; a motor coupling; and a rack coupling. The primary transmission mechanism is configured to transmit power from the motor shaft to the steering rack and includes a drive belt. The secondary transmission mechanism is configured to transmit power from the motor shaft to the steering rack upon a failure of the primary transmission mechanism. The motor coupling is configured to transmit power from the motor shaft to the primary transmission mechanism and the secondary transmission mechanism. The rack coupling is configured to transmit power from the primary transmission mechanism and the secondary transmission mechanism to the steering rack. Prior to the failure of the primary transmission mechanism, the motor coupling and rack coupling are configured to transmit a greater amount of power to the primary transmission mechanism than to the secondary transmission mechanism.

A power unit of a utility vehicle includes a power source for travel of the utility vehicle, a continuously variable transmission, a gear transmission, and an output mechanism. The gear transmission includes a GT input shaft, a GT output shaft, and first and second GT intermediate shafts that transmit rotational power from the GT input shaft to the GT output shaft. The first GT intermediate shaft is disposed on one side with respect to the GT input shaft, and the second GT intermediate shaft is disposed on the other side with respect to the GT input shaft.