Traction and suspension system

Abstract

The device has an electrical traction machine (20) suspended to a body of a hybrid or electric motorization vehicle and providing engine torque (CM) applied to rear wheels (3, 4). A mechanical link is provided between the machine and a deformable crossmember (2) to transmit torque effect (CR) with the engine torque to the crossmember for descending the rear wheels with respect to the body of the vehicle and for creating anti-squat effect during acceleration in electric propulsion of the vehicle. The link is provided with a connection shaft (30) connected to two levers (21, 33).

Claims

1. Suspension and traction system for a vehicle equipped with a frame and a propulsive element through rolling on the ground adapted to move the vehicle relative to the ground, comprising: two rotary electric motors, which are mounted to impart in the same direction an angular torque to the propulsive element in order to propel the vehicle on the ground, are controllable independently of each other and each comprise a stator and a rotor; wherein the two rotors are coupled to the propulsive element for transferring to it rotary motion through a transmission shaft, and have a common rotation axis which is fixed relative to the vehicle's frame; and the stators are controllable to rotate about the respective rotor independently of each other, and rigidly connected substantially to a same point, external to the motors, on which there can be exerted a thrust determined by a coordinated angular displacement of the stators about the respective rotors; a transmission for transmitting the thrust generated on said point to the propulsive element, wherein said shaft comprises at least two segments connected together by an articulation joint.

2. System according to claim 1, wherein the transmission is structured so that the thrust generates a displacement of said point.

3. System according to claim 2, wherein the transmission for transmitting the thrust is structured to reverse the direction of the thrust generated on said point to direct it towards the propulsive element.

4. System according to claim 3, wherein the transmission comprises a lever pivoted on the frame, the lever comprising an application point for said generated thrust and a force transmission point towards the propulsive element so that when the generated thrust moves the application point the lever moves the force transmission point.

5. System according to claim 4, wherein the lever comprises an oscillation axis which is fixed relative to the frame.

6. System as claimed in claim 5, wherein the lever's oscillation axis is intermediate to said application point for said generated thrust and to said force transmission point towards the propulsion element.

7. System according to claim 6, wherein the lever is connected to the stators of the two rotary electric motors via two respective rigid arms, wherein each rigid arm has a point or end respectively connected to one of a said stators and a point or end connected to the lever.

8. System according to claim 6, wherein the propulsive element is connected to the lever by means of a rigid arm.

9. System according to claim 5, wherein the lever is connected to the stators of the two rotary electric motors via two respective rigid arms, wherein each rigid arm has a point or end respectively connected to one of a said stators and a point or end connected to the lever.

10. System according to claim 5, wherein the propulsive element is connected to the lever by means of a rigid arm.

11. System according to claim 4, wherein the lever is connected to the stators of the two rotary electric motors via two respective rigid arms, wherein each rigid arm has a point or end respectively connected to one of a said stators and a point or end connected to the lever.

12. System according to claim 11, wherein the propulsive element is connected to the lever by means of a rigid arm.

13. System according to claim 4, wherein the propulsive element is connected to the lever by means of a rigid arm.

14. System according to claim 1, wherein the transmission is structured so that the thrust generates a displacement of said point.

Description

(1) The advantages of the invention will be clearer from the following description of a preferred embodiment of suspension and traction system, referring to the attached drawing in which

(2) FIG. 1 shows a principle diagram with components illustrated as in use.

(3) The illustrated system MC is used to set a propulsive element, in the form of a wheel, into rotation. The wheel, by rolling on a terrain T, moves an associated vehicle (not shown). The system MC is e.g. replicated on all the wheels of the vehicle.

(4) The system MC comprises two identical rotary electric motors 12, 14 which by means of a shaft 90 are able to rotate a wheel 92.

(5) The two electric motors 12, 14 are formed by a respective stator 12s, 14s and a respective rotor 12r, 14r.

(6) The rotors 12r, 14r are coaxial and have a common rotation axis indicated with X. The X axis is fixed relative to the vehicle's frame, e.g. by mounting the rotors 12r, 14r and/or the shaft 90 on a ball bearing (not shown) having a ring integral with the frame.

(7) Each stator 12s, 14s is connected to a respective rigid arm 22, 24, and the arms 22, 24 are connected to a common point P external to the electric motors 12, 14.

(8) The point P belongs or is connected to the end of a lever 40 which is oscillating, approximately at its center, around a axis Y fixed with respect to the frame of the vehicle. The other end of lever 40 (point Q) is connected to a hub 94 of the wheel 92 by a rigid arm 26.

(9) The rotation of the rotors 12r, 14r about the X axis sets into rotation the wheel 92 about its rotation axis W.

(10) By controlling the power supply of the electric motors 12, 14 (i.e. by giving more or less power than that required by the wheel 92) it is possible to move at the same time the stators 12s, 14s about the X axis, one clockwise and the other counter-clockwise.

(11) E.g. it is possible to achieve that the arms 22, 24 are raised and push upwards the point P (in this case the point P moves away from the X axis). The lever 40 then rotates about the Y axis and moves the point Q downwards. It follows that the arm 26 pushes the hub 94 downwards and towards the ground, thereby obtaining, among other things, a variation of the distance between the axes W and X, in the example being parallel. In the example, the Y axis is orthogonal to an imaginary vertical plane passing through X (and/or W).

(12) An upward movement of the hub 94 can be achieved by reversing all the motions described for the previous case (the point P approaches the axis X).

(13) Note that the rotary torque applied to the wheel 92 by the rotors 12r, 14r and the force imparted on the wheel 92 towards the ground by the stators 12s, 14s are independently controllable quantities. So it is e.g. possible, during an acceleration phase, to push more the wheel 92 towards the ground to increase its grip.

(14) The electrical power supply of the motors 12, 14 may be obtained, for example. by means of inverters or electronic power stages of known topology. An electronic control unit will take care to properly control the inverters or the electronic power stages so as to control the rotation regime of the wheel 92 and the height of the point P and Q.

(15) The system MC is open to many variations and variables.

(16) The electric motors 12, 14 need not be necessarily equal,

(17) On the shaft 90 it is preferable to mount at least an articulated joint 96, e.g. a Cardan joint, to allow or facilitate the offset of the axes W and X and/or a different orientation of the axis W.

(18) Each stator 12s, 14s may be connected to the point P also by different means from the arms 22, 24, and the point P does not necessarily represent a geometric point, being able to also be—for mechanical requirements—an extended element to which the stators 12s, 14s are connected at slightly spaced points.

(19) The lever 40 may be oscillating at a point other than its center, and the Y axis fixed with respect to the frame may be obtained e.g. by simple pivoting.

(20) Also the arrangement of the points Q and P on the lever 40 may vary, as well as the means for transferring the generated force from point Q to the wheel 92 by moving the stators 12s, 14s.

(21) It is preferable to fit a mechanical (e.g. helical) or gas spring in parallel to the arm 26, between the wheel 92 and the frame, to compensate the weight of the frame.