MOTOR VEHICLE DRIVE

Description

[0001] The invention relates to a motor vehicle drive for the all-wheel drive of a motor vehicle, preferably a small truck, with a drive motor and a transmission unit which comprises a drive shaft which can be coupled to the drive motor, a plurality of transmission stages and a longitudinal differential gear with an output shaft.

[0002] Vehicles of this type are primarily used in municipal areas within urban areas, where they cover short distances at maximum speeds of 45 to 60 km / h. They are primarily designed as light-duty vehicles and are suitable for performing specialized work, such as cleaning, transporting, snow clearing, and the like. They can be equipped with removable specialized equipment. All of this requires the vehicle to be as compact as possible to ensure greater maneuverability when performing the work.

[0003] A drive system for small trucks of this type is disclosed in CH 684 789 A5. The drive system described therein consists of a diesel engine with an injection pump, a hydraulic variable-displacement pump, and a hydraulic motor that can drive the vehicle's drive wheels via a transmission unit. It goes without saying that such a drive system takes up a lot of space, thus contradicting the goal of compact vehicle dimensions.

[0004] The document DE-10 2016 205 150 discloses a drive train for a motor vehicle, which is provided with a transmission having a transmission housing and at least two interconnectable drive shafts. Furthermore, a clutch having a clutch shaft is assigned to the transmission, which clutch shaft can be coupled, on the one hand, to a drive shaft of a drive motor and, on the other hand, to the first shaft of the transmission, wherein the clutch shaft and the first shaft are arranged next to one another at least at the transmission point and extend at an angle to one another. While this enables a compact design of the drive train, it is not suitable, particularly for small trucks, which require a robust transmission unit to ensure the necessary power even under peak loads when equipped with removable special equipment such as snow plows, snow blowers, etc.

[0005] Publication WO 98 / 37614 relates to a drive system for electric vehicles in which a dual-rotor electric motor with an outer rotor and an inner rotor drives a first drive axle and a second drive axle. Torque and rotation are transmitted between the outer rotor and the first drive axle via a clutch and a first drive shaft, and between the inner rotor and the second drive axle via a second drive shaft, respectively. An accelerator pedal and a control switch are provided, through which signals are sent to the dual-rotor motor controller. Electronics monitor the speeds of the axles and control the corresponding valves.

[0006] In the document US-2010 / 0262347, a parking brake is mentioned in a disclosed vehicle, which is integrated in the rear drive shaft between the engine and the differential at the drive axles for the wheels.

[0007] The invention is based on the object of creating a motor vehicle drive of the type mentioned at the outset, which is of very simple construction, has a high degree of efficiency and thereby enables all-wheel drive.

[0008] This object is achieved by a motor vehicle drive for the all-wheel drive of a motor vehicle, preferably a small truck, with a drive motor as an electric motor and a transmission unit installed in a housing, which comprises a drive shaft which can be coupled to the drive motor, a plurality of transmission stages and a longitudinal differential gear with an output shaft, wherein the drive motor as an electric motor is arranged between the wheel axles and can be controlled by the driver via a control device using a manually adjustable actuating pedal to change its rotational speed, wherein the transmission unit is composed of the two transmission stages located one above the other, each with a pair of gears located on a shaft, wherein the shaft of the first transmission stage can be driven by a gear located on the drive shaft of the electric motor, which gear engages with one of the gears of the first transmission stage,wherein the drive shaft for coupling with the electric motor and the shafts of the two gear ratios are mounted parallel to each other in the housing, wherein the longitudinal differential gear is placed in the housing below the second gear ratio, the output shaft of which runs parallel to the shafts of the gear ratios.

[0009] This results in a compact drive design, as the electric motor takes up much less space than previously known drives with diesel and / or hydraulic engines. Furthermore, it requires no additional space perpendicular to the vehicle's direction of travel. This is advantageous for the optimal positioning of the vehicle's transmission output shaft. Furthermore, the electric motor is significantly easier to maintain and service than diesel and / or hydraulic engines. Added to this are the well-known environmentally friendly advantages of electric motors, which are also very quiet.

[0010] The compact design is also contributed to by the fact that the longitudinal differential is located in the transmission unit housing below the second gear stage. Its output shaft is aligned parallel to the shafts of the gear stages and is advantageously connected at each end to a cardan shaft for driving idler gears mounted on the wheel axles. Both cardan shafts extend approximately symmetrically relative to the longitudinal differential. For safe vehicle decommissioning, it is advisable to equip the output shaft of the longitudinal differential with a differential lock located outside the housing.

[0011] The invention is explained in more detail below using an exemplary embodiment with reference to the drawing. In the drawings: Fig. 1 is a schematic diagram of a motor vehicle drive with a drive motor according to the invention and a transmission unit coupled thereto; and Fig. 2 is a longitudinal section through the transmission unit according to Fig. 1 .

[0012] The Fig. 1 The diagram of a small-duty vehicle 1 shown is primarily designed for use in municipal applications, where the vehicle typically covers short distances at maximum speeds of 45 to 60 km / h. The vehicle can be used both as a small truck and as a special-purpose vehicle for cleaning, snow removal, and similar specialized work. For this purpose, it can be equipped with appropriate special equipment, such as a removable snow removal machine on the front or a salt spreader or water pump on the rear, which are not shown in detail.

[0013] The small load vehicle 1 has two wheel axles 3, 4 with wheels 5a, 5b and 6a, 6b respectively, which can be driven by an all-wheel drive 7 consisting of a drive motor 8 and a transmission unit 9.

[0014] According to the invention, the drive motor is an electric motor 8, which is arranged and positioned directly next to the transmission unit 9 between the wheel axles 3, 4, as seen in the direction of travel. This electric motor 8 can be controlled by the driver via a control device 27 using a manually adjustable actuating pedal 26 to change its rotational speed.

[0015] This arrangement means it doesn't take up any additional space transverse to the vehicle's direction of travel. This is advantageous in terms of the positioning of the drive's output shaft relative to the center longitudinal plane. It is also easy to install and remove, and easily accessible for any maintenance and repair work on the vehicle.

[0016] As is particularly evident from Fig. 2 As can be seen, the gear unit 9 is itself designed as a transmission gear that can easily be provided with different transmission ratios. It consists of two superimposed transmission stages 10, 11, each with a gear pair 14a, 14b and 15a, 15b mounted on a shaft 12 or 13, respectively, whereby the shaft 12 of the first transmission stage 10 is drivable by a gear 17 mounted on the drive shaft 16 of the electric motor 8, which gear engages with one of the gears 14a of the first transmission stage 10. The gear unit 9 is installed in a housing 18, in which the drive shaft 16 with an outwardly projecting power take-off shaft 16' for the electric motor 8 and the shafts 12, 13 of the two transmission stages 10, 11 are mounted parallel to one another.

[0017] The transmission unit 7 also contains a longitudinal differential gear 19 arranged in the housing 18 below the second transmission stage 11, the output shaft 20 of which is mounted in the housing 18 parallel to the shafts 12, 13 of the two transmission stages and is connected at both ends to a cardan joint shaft 21, 22 for driving deflection wheels 23 and 24 respectively located on the wheel axles 3, 4.

[0018] By arranging the electric motor 8 directly next to the transmission unit 9 between the wheel axles 3, 4, it is possible to align both cardan shafts 21, 22 approximately symmetrically relative to the longitudinal differential gear 19. This allows for a structural simplification of the transmission compared to the prior art. A differential lock 25 for safely immobilizing the vehicle is installed outside the housing 18 in the output shaft 20. Furthermore, the transmission housing 18, and thus also the electric motor 8 attached to it, are mounted, for example, on rubber mounts to minimize noise and vibration.

[0019] The use of an electric motor 8 directly adjacent to the transmission unit 9 enables a very compact drive design and also offers the specific advantages of electric motors, both in terms of control, maintenance, and repair of the motor, as well as meeting increasingly important environmental requirements. The simply constructed transmission is therefore particularly well suited for the work to be performed with the vehicle.

Claims

1. Motor vehicle drive for the all-wheel drive of a motor vehicle, preferably a small truck, with a drive motor as an electric motor (8) and a transmission unit (9) installed in a housing (18), which comprises a drive shaft (16), that can be coupled to the drive motor, a plurality of gear ratios (10, 11), and a longitudinal differential gear (19) with an output shaft (20), characterized in that the drive motor as an electric motor (8) is arranged between the wheel axles (3, 4) and can be controlled by the driver via a control device (27) using a manually adjustable actuating pedal (26) to change its rotational speed, wherein the transmission unit (9) is composed of the two superimposed gear ratios (10, 11), each with a gear pair (14a, 14b; 15a, 15b) mounted on a shaft (12 or 13), wherein the shaft (12) of the first gear ratio is driven by a gear (17) mounted on the drive shaft (16) of the electric motor, which gear engages with the one gear (14a) of the first gear ratio (10), wherein the drive shaft (16) for coupling to the electric motor (8) and the shafts (12, 13) of the both gear ratios (10, 11) are mounted parallel to one another in the housing (18), wherein the longitudinal differential gear (19) is placed in the housing (18) below the second gear ratio (11), the output shaft (20) of which extends parallel to the shafts (12, 13) of the gear ratios (10, 11).

2. Motor vehicle drive according to claim 1, characterized in that the output shaft (20) of the longitudinal differential gear (19) is provided with a differential lock (25) located outside the housing (18).

3. Motor vehicle drive according to claim 1 or 2, characterized in that the output shaft (20) is connected at both ends to a cardan joint shaft (21, 22) for driving deflection wheels (23, 24) mounted on the wheel axles (3, 4), wherein both cardan joint shafts (21, 22) are aligned approximately symmetrically relative to the longitudinal differential gear.