Patent ID: 8052562

Claim:
A transmission arrangement for coupling a starter-generator electrical machine with an internal combustion engine at a transmission ratio that is a function of the rotational speed of the internal combustion engine, said transmission arrangement comprising: a transmission having a variable transmission ratio, wherein the ratio of a rotational speed of the electrical machine to that of the internal combustion engine is greater at a low rotational speed of the internal combustion engine than at a high rotational speed of the internal combustion engine, wherein the electrical machine includes an output shaft that is directly non-rotatably connected with a sun gear of a planetary gear train, an output shaft of the internal combustion engine is operatively connected with a planet carrier that is connected with the electrical machine output shaft through a freewheeling mechanism for enabling the sun gear to turn at a higher rotational speed than that of the planet carrier; and a control device for controlling the transmission by switching the transmission ratio, wherein the control device includes a spring and is held by means of spring force in a first condition in which the rotational speed ratio of the electrical machine to that of the internal combustion engine is a first rotational speed ratio, and as the rotational speed of the internal combustion engine increases the control device is switched to a second condition in which the rotational speed ratio is a second rotational speed ratio that is lower than the first rotational speed ratio, and wherein planet gears carried by the planet carrier mesh with a ring gear against which the control device acts to regulate ring gear rotational speed.