192 clutches and power-stop control – Vortex-flow drive and clutch – With brake
Patent
1991-10-08
1993-02-16
Braun, Leslie A.
192 clutches and power-stop control
Vortex-flow drive and clutch
With brake
192 4A, 475 45, 74336R, F16H 4706, B60K 1706
Patent
active
051862913
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a transmission for a vehicle and a method for regulating a transmission.
PRIOR ART
Transmissions for use in vehicles generally comprise a gearbox of some type or another in order to permit driving under varying conditions. Various main types of gearboxes are known. One type consists of hydraulic gearboxes incorporating a hydraulic torque converter coupled in series to a gearbox comprising a number of planetary gears. The advantages of this type of gear box are that the regulation is effected automatically, the gear-changing can take place without drive power interruption, and the driver does not have to manoeuvre any clutch. In addition, on starting, the driver can easily regulate the desired drive torque by means of regulating only the accelerator pedal and, moreover, a high starting torque is obtained. The disadvantages are that these gearboxes are relatively complicated and therefore also expensive. Furthermore, they exhibit relatively high energy losses.
Another type of gearbox consists of a mechanical stepped gearbox. In this type of gear box, there are arranged, on parallel shafts, a number of pairs of gear wheels which, by means of selective engagement provide different gear ratios. When changing gear, the driver usually has to operate a clutch manually in order to produce a drive power interruption from the vehicle engine. This type of gearbox exhibits relatively small friction losses and it is considerably cheaper to manufacture than a hydraulic gearbox of the type described above.
In addition to these two main types of gearboxes, there are other variants of the same. For the purpose of improving the starting torque especially in heavy vehicles, it is known, in the case of stepped gearboxes, to arrange a hydraulic torque converter between a drive engine and a clutch. Such a construction means that the clutch is also exposed to high torques when the torque converter is engaged. The clutch is not usually dimensioned for these high torques, with the consequence that it should not be manoeuvred when the torque converter is engaged. The result of this is that such a transmission requires a special mode of driving and requires that the driver be trained for this, since otherwise the clutch plate risks being overloaded.
Another alternative transmission is described in British Patent Specification GB-A-2,193,766. In this transmission, a hydraulic torque converter is coupled together with a stepped gearbox. The torque converter is connected to a drive engine via two separate clutch plates. Upon activation of the one clutch plate, all the drive power is transmitted from the drive engine via the torque converter to the stepped gearbox. Upon activation of the other clutch plate, all the drive power is transmitted from the drive engine via a free wheel directly to the stepped gearbox. This transmission functions such that, upon starting-up and with the vehicle stationary, both the clutch plates are disengaged in order to produce a drive power interruption and to permit manoeuvring of the stepped gearbox so that a starting gear can be engaged. Thereafter, the one clutch plate is activated, by which means the torque converter is engaged and drive power is transmitted from the engine to the output shaft of the gearbox. When the vehicle has reached a certain speed, the first clutch plate is disengaged and the second clutch plate is activated instead, by which means the drive power is transmitted directly from the engine to the input shaft of the gearbox. Upon continued increase of speed, the stepped gearbox can be shifted after a certain time, this taking place with the aid of different clutches in the gearbox. When the vehicle has come to a halt, it is necessary to interrupt the drive power connection, which is effected by disengaging the clutch plate in question. In order to permit gear-changing during travel, it is necessary to control the engine speed in a suitable manner in order to produce or at least facilitate synchronisation before a new gear can be engaged.
American Pa
REFERENCES:
patent: 2084219 (1937-06-01), Salerni
patent: 2414359 (1947-01-01), Carnuagua et al.
patent: 3367211 (1968-02-01), Borman
patent: 3667309 (1972-06-01), Franz et al.
patent: 3670596 (1972-06-01), Hause
patent: 3715017 (1973-02-01), Jenney
patent: 3834499 (1974-09-01), Candellero et al.
patent: 4077502 (1978-03-01), Nitsche et al.
Hedstrom Lars-Gunnar
Westman Bjorn
Braun Leslie A.
Saab-Scania Aktiebolag
Ta Khoi A.
LandOfFree
Transmission for a vehicle does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Transmission for a vehicle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transmission for a vehicle will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2142508