A GEARBOX

Abstract: A gearbox comprising a combination of a planet gear having an outer ring (17), planet wheels (19) and a sunwheel (5) and a linear gear (1A, 1B; 2; 21; 22; 3; 13) with a drive shaft (4) mounted coaxially therein. A rotatable toothed sleeve (3) having inner teeth and outer teeth is mounted in a housing (24) in the linear gear for displacement in the axial direction of the linear gear and the drive shaft (4) with the aid of a gear shift (6). The gear shift (6) is journalled on a guide (8) and can be displaced by means of a gear shift displacing device (10) to different positions of engagement with teeth on the sunwheel (5) and with two toothed rings (21, 22) in the linear gear.

Description: A GEARBOX The present invention relates to a gearbox which com- prises a combination of a planet gear and a linear gear in accordance with the preamble of Claim 1. It is a well recognized fact that vehicles which are powered by internal combustion engines constitute a serious threat to the environment, particularly in city traffic. It would be particularly difficult to make any drastic reduction in such traffic, since this would unacceptably reduce the freedom of movement of the population. Various attempts to solve this problem have been made with the alternative use of electrically driven vehicles. The use of such vehicles, however, has not been successful because of problems relating to battery size and number. Accordingly, an object of the present invention is to provide a gearbox which will enable automotive vehicles to be powered by a combined internal combustion engine and electric motor with which a transition from engine drive to electric-motor drive, and vice versa, is ef- fected automatically with the aid of a control system which is controlled by a printed circuit card connected electrically to the gearbox. The novel and characteris¬ tic features of the invention are set forth in the characterizing clause of respective following Claims. The inventive gearbox enables the vehicle generator, start mccor, flywheel and clutch mechanism to be exclud¬ ed, wherein the actual planet gear itself replaces the flywheel mass and the clutch mechanism is replaced with a brake device mounted on the outer ring of the planet gear. All toothed gears in the gearbox are constantly in mesh, i.e. the gears are never moved out of contact with one another. The gear ratio is selected with the aid of a gear shift which is manoeuvered automatically by a control device goverened by a printed circuit control card. Other advantages a forded by means of the invention include cleaner exhaust gases, due to the possibility of driving the internal combustion engine at a constant, low speed, and also the recovery of energy by initial braking with the aid of the motor generator. A vehicle which is equipped with an inventive gearbox can be driven in cities and towns solely by electricity, with a limited number of batteries . The invention will now be described in more detail with reference to an embodiment of an inventive gearbox and with reference to the accompanying drawings, in which Figure 1 is a schematic, sectioned view of an inventive gearbox; and Figures 2 to 8 are schematic illustrations of the method in which the inventive gearbox operates. The gearbox illustrated in Figure 1 has two gear stages 1A, IB and 2 which are manoeuvered by a gear selector 3. The gear selector 3 has the form of a toothed or stepped sleeve which can be moved in a housing 24 in the axial direction of the toothed gear and the drive shaft 4, into different positions of engagement with the sunwheel 5 of the planet gear and with teeth on the linear gear. The gear selector 3 is manoeuvered by means of a gear shift 6 provided with cam rollers 7 which take-up rota¬ tion of the gear selector 3 and, at the same time, transfer displacement force to the gear selector. The gear shift 6 is joumalled on a guide 8 and is displaced with the aid of a rotary device 9 connected to a displacement device 10. The rotary device 9 is con¬ structed to receive pulses or signals from a control circuit card 11 and, in response thereto, to move the displacement device 10 to desired positions in a desired number of stages and at the rate at which the motor generator 12 is able to adapt the speed of the gear stages 1A, IB and 2 to engagement of the toothed sleeve 3 with the gears and with power transmission means 13 on the drive shaft 4, said power transmission means having the form of a splined element fixedly connected to the drive shaft 4. A return signal shall be delivered from the rotary device 9 to the control circuit card 11 in order for continued driving of the drive shaft 4 to take place. The motor generator 12 and the vehicle battery pack 25 can be cooled with the aid of the vehicle air-condition¬ ing system 14, wherein air can be automatically deflect¬ ed from the system with the aid of valves 15, when necessary. The manner in which the inventive gearbox operates will be seen from the schematic illustrations of Figures 2 to 8. When the vehicle is powered solely on batteries and the motor generator 12, for instance at speeds of up to 40 km/hour, the toothed sleeve 3 will have the position shown in Figure 2 , in which the disc brake 16 exerts a braking force on the outer ring 17 of the planet gear. The gear stage IB is driven by the motor generator 12 and in turn drives a toothed ring 21 which causes the planet wheel 19 of the planet gear to rotate within the outer ring 17, through the intermediary of the sunwheel 5. The drive shaft 4 is driven by a drive device 20 which is attached to the planet wheels 19 and also to the drive shaft 4. At speeds between 53 and 160 km/ hours for instance, the vehicle is powered by both the motor generator and the internal combustion engine in which case the toothed sleeve 3 has the position shown in Figure 3. Alternatively, in this operational state the motor generator may unction as a generator and charge the batteries. The drive from the motor genera¬ tor 12 is transmitted to the toothed ring 21, via the gear stage IB, and further to the drive shaft A, via the toothed sleeve 3 and the splined element 13. The inter¬ nal combustion engine is therewith started-up, by re- leasing the disc brake 16 and coordinating the rotary speed of the drive shaft 4 with the rotary speed of the gear stage 1A, IB, prior to moving the toothed sleeve 3 from the position shown in Figure 2 to the position shown in Figure 3 (Figure 1), this coordination being effected with the aid of the motor generator 12 and the control circuit card 11. At vehicle speeds of from 20 to 80 km/hour for instance, the vehicle is powered solely by the motor generator 12, wherein the disc brake 16 is in abutment with the outer ring 17 and the toothed sleeve 3 is in the position shown in Figure 4. In this case, the drive shaft 4 is driven through the inter¬ mediary of the gear stage IB, the shaft 18, the gear stage 2, the toothed ring 22, the toothed sleeve 3 and the splined element 13. The rotary speed of the gear stage 1A, IB is coordinated with the rotary speed of the drive shaft 4 when the toothed sleeve 3 is in the posi¬ tion shown in Figure 5, i.e. when both the shaft 23 of the internal combustion engine and the motor generator 12 are disconnected from the drive shaft 4. The rotary speed of the gear stage 2 is coordinated with the rotary speed of the drive shaft 4 when the toothed sleeve 3 is in the position shown in Figure 6, in which position the drive shaft 4 is not driven either by the motor genera¬ tor or by the internal combustion engine. The vehicle can also be driven by both the motor genera¬ tor and the internal combustion engine at speeds between 20 and 80 km/hour, in which case the toothed sleeve 3 is in the position shown in Figure 7 and the disc brake 16 is out of engagement with the outer wheel 17. The shaft 4 is driven, in this case, from the motor generator via the gear stage IB, the shaft 18, the gear stage 2, the toothed ring 22, the toothed sleeve 3 and the splined element 13. The rotary speed of the drive shaft 4 is therewith coordinated with the rotary speed of the gear stage 1A, IB with the aid of the motor generator 12 in the position shown in Figure 6. If the vehicle is to be driven between 80 and 160 km/hour by both the motor generator and the internal combustion engine, the toothed sleeve 3 is moved to the position shown in Figure 3, wherein the rotary speed of the gear stage 1A, IB is coordinated with the rotary speed of the drive shaft 4 when the toothed sleeve 3 is in the position shown in Figure 6. Creep gears, for instance for speeds of up to 20 km/hour, can be obtained with solely the motor generator, in which case the toothed sleeve 3 has the position shown in Figure 8. In this case, the disc brake 16 locks the outer ring 17 of the planet gear and the shaft 4 is driven via the planet gear, similar to that described above with reference to Figure 2. Both forward and reverse drives can be obtained. This gear position can be selected manually, or alternatively with solely electrical power to maximum vehicle speeds of 80 km/hour. In addition to the aforementioned gear positions, all other gear positions are selected automatically with the aid of the control circuit card 11, in accordance with vehicle speed and to the position of the accelerator peddle and the status of the battery capacity. The motor generator 12 can also be locked, i.e. firmly braked, wherewith vehicle drive is changed down from the internal combustion engine via the planet gear. This possibility enables the vehicle to be driven at speeds of between 80 and 120 km/hour with solely the internal combustion engine as the power source, which can give a so-called kick down effect when overtaking other vehi¬ cles, for instance.

Claims: C L A I M S 1. A gearbox comprising a combination of a planet gear and a linear gear each of which is connected to a respective drive motor, the linear gear comprising a drive shaft which is arranged coaxially with the gear, c h a r a c t e r¬ i z e d by a connecting element between the planet gear (5, 17, 19), the linear gear (1A, IB, 2, 3, 13, 21, 22) and the drive shaft (4) , said connecting element compris¬ ing a sleeve (3) which is provided with internal and external teeth, and which is rotatable around its axis and which can be displaced in the axial direction of the linear gear and the drive shaft by means of anoeuvering devices (6, 8, 10) into different positions of engagement with the planet gear, the linear gear and the drive shaft. 2. A gearbox according to Claim 1, c h a r a c t e r¬ i z e d in that the linear gear comprises toothed elements (21, 22) comprising two toothed rings of which one (21) is joumalled on the drive shaft (4) and the other (22) is joumalled on surrounding journal means. 3. A gearbox according to Claim 2 , c h a r a c t e r- i z e d in that said one toothed ring (21) has external teeth and said other toothed ring (22) has internal teeth. 4. A gearbox according to Claim 1 , 2 or 3, c h a r ¬ a c t e r i z e d in that a splined element (13) is fixedly mounted concentrically on the drive shaft (4) for engagement with the inner teeth of the toothed sleeve (3) . 5. A gearbox according to any one of Claims 1-3, c h a r a c t e r i z e d in that the means for dis¬ placing the toothed sleeve includes a gear shift (6) which is joumalled on a guide (8) and which can be dis¬ placed with the aid of a device (10) intended therefor. 6. A gearbox according to Claim 5, c h a r a c t e r¬ i z e d in that the gear shift displacing device (10) is connected to a rotary device, such as a stepping motor (9) , which is controlled by a control circuit card (11) for selection of a desired gear position. 7. A gearbox according to Claim 5 or 6, c h a r a c ¬ e r z e d in that the gear shift (6) is provided with cam rollers (7) for taking-up rotation of the toothed sleeve (3) while transferring displacement forces to said toothed sleeve at the same time. 8. A gearbox according to Claim 1, wherein the one drive motor is an internal combustion engine (23) and the other one a motor generator (12) .

Inventors: FJAELLSTROEM BENGT, FJAELLSTROEM, BENGT
Applicants: FJAELLSTROEM BENGT, FJAELLSTROEM, BENGT
Application year: 1992
Main classification: F16H37
IPC codes: B60K6, F16H63