“AFW-5” suspension for a means of transportation

Abstract

The invention relates to structural components of vehicles, and more particularly to the suspension of both conventional and special vehicles, such as ambulances, baby carriages and wheelchairs. The suspension comprises a quadrangular frame with a pair of arms attached thereto, where the ends of said arms are configured to be connected to the hubs of the respective wheels, and the suspension of the present invention comprises two pairs of armsa pair of identical transverse arms and a pair of identical longitudinal arms with the ends of the longitudinal arms configured to be connected to the hubs of the respective wheels, wherein each arm is rotatably attached by its central zone to the central portion of the corresponding side of a quadrangular frame through rubber-metal joint, wherein the arms contact surfaces are cylindrical, they are adapted for mechanical coupling of arms to each other and are oriented as follows: longitudinal left and right arms have their contact surfaces oriented upwards, while transverse front and back arms have their contact surfaces oriented downwards, contact surfaces of each arm are tangent to the plane extending through the axis of rotation of the arm and are located on one side of it, while each side of the quadrangular frame rests upon the hubs of two wheels through the corresponding arm. Each transverse and longitudinal arm is made as a pair of arms spaced apart and connected by at least one connecting rod, and each such spaced arm has the form of a parallelogram. The invention is based on the objective to provide the suspension, which is more reliable due to lower level of mechanical stresses in the suspension mechanisms, which results from creation of the conditions where the function of the mechanism for changing the direction of rotation is performed by a transverse arm having a length equal to the width of the suspension.

Claims

1. A vehicle suspension comprising a quadrangular rigid frame (1) with longitudinal arms (2) rotatably attached to a right and to a left side thereof, wherein ends of said longitudinal arms are designed to connect to a respective hub of a corresponding wheel (4), the suspension further comprising two transverse arms (3) rotatably fixed at a front and at a rear of the frame, characterized in that the transverse arms (3) are located above the longitudinal (2) arms and in sliding contact with the longitudinal arms, wherein vertical movement of the end of one arm results in the movement of all the other arms, the arms at the point of sliding contact (6) with each other have cylindrical surfaces to ensure contact in the entire range of movements, and configured to redistribute a weight of the frame (1) through the longitudinal arms (2) and the wheel hubs (4) directly and through the transverse arms (3) to the longitudinal arms (2) and the wheel hubs.

Description

(1) The essence of the invention is further explained by the drawings, where:

(2) FIGS. 1 and 2 is a general view of the suspension AFW-5,

(3) FIG. 3 illustrates the operation of the suspension arms,

(4) FIG. 4 is a general view of the suspension with split arms,

(5) FIG. 5 shows the structure of a split arm,

(6) FIGS. 6, 7 show body tilt,

(7) FIGS. 8, 9 show clearance change,

(8) FIGS. 10, 11 show the change of wheel track width, and

(9) FIGS. 12, 13 shows wheels rotation for different motion directions.

(10) The vehicle suspension AFW-5 according to the invention (FIGS. 1, 2, 3) consists of a rectangular frame 1, two longitudinal arms 2, two transverse arms 3, wheels 4 and rubber-metal joints 5 (shown schematically). The longitudinal arm 2 and the transverse arm 3 have cylindrical form in the contact zone 6. To expand the suspension applications, the frame 1 is complemented by the movable inserts 7 (FIG. 4), and each longitudinal arm 2 and each transverse arm 3 is made as a pair of arms spaced apart. Each spaced arm consists of a rocker 8, a plate 9, rods 10, an angular element 11 and a knuckle 12 (FIG. 5). The rockers 8 of each longitudinal and transverse spaced arms are connected by a connecting rod 13 and 14, respectively. A damper 15 and at least one linear actuator 16 are mounted on each connecting rod 13 and 14. The movable inserts 7 are movably attached to the frame 1 by supports 17 and are driven by linear actuators 18 (FIG. 4). The suspension is also provided with a conventional steering mechanism (not shown), a control system (not shown) for controlling the linear actuators 16 and 18. The control system contains an on-board computer and sensors to sense speed, steering position, as well as acceleration and tilt of the frame (not shown). The outputs of the speed, steering position, acceleration and frame tilt sensors are connected to the corresponding inputs of the on-board computer, and the outputs of the on-board computer are connected to the drives of the linear actuators 16 and 18 (not shown). The on-board computer may be a usual industrial controller with the appropriate software.

(11) The vehicle suspension AFW-5 according to the invention operates as follows.

(12) At the assembling stage, for proper operation of the suspension, the transverse arms 3 are mounted over the longitudinal arms 2 to ensure their contact 6. The length of the connecting rods 13 is adjusted according to the readings of the acceleration and tilt sensors obtained via the on-board computer (not shown) by way of changing the length of the linear actuators 16. Due to gravity the vehicle suspension self-aligns and evenly distributes its weight among four wheels, being four points of support (FIGS. 1, 2, 3). The longitudinal arms 2 and the transverse arms 3 can freely rotate during the movement of the vehicle due to the rubber-metal joints 5 (shown schematically), when a wheel 4 of one of the axles rolls over an obstacle. This leads to a change in the position of the longitudinal arms 2 and transverse arms 3 and also to a change in the spatial position of the frame 1, which results in the vehicle suspension self-aligning by gravity and even distribution of its weight among four wheels. In this case, the frame 1 takes the position of the averaged plane for the four points of contact of the wheels 4. The suspension maintains its operational capacity while the longitudinal arms 2 and transverse arms 3 are in contact (engagement) (the contact zone 6 is shown in FIG. 3).

(13) The suspension overcomes small obstacles due to the springing properties of the longitudinal 2 and transverse 3 suspension arms and metal-rubber joints 5 (FIGS. 1, 5).

(14) The use of the spaced longitudinal 2 and transverse 3 arms, rocker 8, plate 9, rods 10 of the suspension (FIG. 5) makes it possible to maintain the spatial parallelism of the axis of the rocker 8 and the axis of the plate 9 at any of their mutual positions (FIG. 5). Two spaced composite arms, such that one is fixed on the frame 1 and the other is attached to the insert 7, are connected by the angular element 11 and maintain the axis of the knuckle 12 at a constant angle to the plane of the frame 1, which enables to increase the vehicle steerability, to reduce the level of mechanical stress in the suspension components during vehicle turns, movement over the rough terrain, and to increase the reliability of the suspension.

(15) By changing the position of the insert 7 relative to the frame 1, i.e. by reducing the length of the supports 17 using the linear actuators 18, the distance between the wheels 4 of one axis, i.e. wheel track is defined (FIGS. 10, 11).

(16) While the nominal length of the connecting rods 13 is observed when the vehicle is in the horizontal position, deviation from said nominal length of the longitudinal connecting rods 13 (the decrease of the right rod length with equal increase of the left rod length and vice versa) connecting the split arms 2 and 3 allows tilting of the vehicle frame 1 to the right or to the left in order to compensate for the slope of the roadway, to allow passengers to exit from the vehicle or to pass a turn. In this context, in order to tilt to the right, it is necessary to reduce the right rod length and increase the left rod 13 length by equal amount and vice versa, to tilt to the left, it is necessary to reduce the left rod length and increase the right rod 13 length by the same amount.

(17) The vehicle suspension of the invention can change the road clearance. A synchronous and pairwise identical change in the length of the linear actuators 16 of the longitudinal and transverse linkage rods 13, 14 increases or decreases the suspension's clearance.

(18) The wheels 4 mounting makes it possible to realize additional possibilities in maneuvering, for example as shown in FIG. 12, 13.

(19) Based on the suspension AFW-5 it is possible to design: baby carriages and motorized wheelchairs, hospital wheelchairs and beds with a function of lateral tilt for comfortable moving a patient or movement along the slope, passenger cars with both conventional internal combustion engines (ICE) and electric motors. The use of the suspension AFW-5 in a passenger car gives a significant saving of materials (up to 20% by weight) due to the use of a flat bearing structure. Passing the turns with body tilt is easily implemented as well (like in case of a motorcycle). a quadramaran, a golf cart, a dolly, a lunar rover and the like.

(20) Support on all four wheels (uniform and constant weight distribution) is achieved without the use of spring elements, but only due to the connection of all the wheels 4 with each other and the gravity.

(21) Suspension is fully operational with four wheels 4 of different diameters.

LIST OF ITEMS IN THE DRAWINGS

(22) 1rectangular frame, 2longitudinal arm, 3transverse arm, 4wheel, 5rubber-metal joint, 6contact zone of arms, 7movable insert, 8rocker, 9plate, 10rod, 11angular element, 12knuckle, 13, 14connecting rods, 15damper, 16linear actuator of a connecting rod, 17support, 18linear actuator of the movable insert.