Steering system for a vehicle

Abstract

The present invention relates to a mechanical steering system for longer vehicles and trucks. The steering system is designed for a wheel and axle assembly with non- steerable wheels where the wheels are in a fixed position on the axle, such that the wheel and axle assembly pivots around its centre point when turning the vehicle. The steering system of the present invention allows a heavier load bearing, as carrying load or axle load on the wheel and axle assembly, and a stronger or more robust steering system as the weak point of a wheel and axle assembly is the connection of the wheels to the axle in traditional steering axle systems.

Description

[0001] P16032PC00 1

[0002] STEERING SYSTEM FOR A VEHICLE

[0003] Field of the invention

[0004] The present invention relates to a steering system for longer vehicles and to provide a system where the vehicles can have increased loadbearing and a longer distance between the front and rear axles without influencing rotation properties of the vehicle.

[0005] Background

[0006] Steering systems for larger vehicles and trucks require taking into an account turning or rotation radius for the vehicle. The longitudinally spacing between the load bearing axles of the vehicle is important in allowing carrying maximum loads with minimum road damage. Such spacing is also important for vehicles which have a belt crawler undercarriage between the front and the rear axle.

[0007] In dead axle systems, the axle itself rotates in response to steering input without transmitting power to the wheels, but rather serves primarily as a mounting point for the wheels. Dead axle systems are used for vehicles such as trailers with solid rear axles and no independent suspension.

[0008] Articulated steering is another known technology commonly used in large vehicles and machinery, such as articulated trucks, loaders, as well as in certain types of construction equipment. In these system, the vehicle is divided into two or more sections connected by a pivot joint. The steering occurs by pivoting these sections relative to each other, rather than by turning the wheels.

[0009] W006005124 discloses a unitary axle system which is pivotably arranged around a longitudinal centre of the trailer and further alternative arrangements where two unitary axles are mounted on a bogey, where the bogey being pivotably relative to the trailer to provide an angle of steer.

[0010] GB821330 discloses a trailer having two sets of wheels spaced from each other with the front set of wheels mounted on an axle so as to be capable of both a pivotal movement and a limited longitudinal movement relative to the trailer. The axle is connected oppoited site sides of its pivotal mounting point in the trailer to the rear end of a pair of steering rods, where the forward ends of the steering rods are connectable to the tractor symmetrically on opposite sides of the vertical axis.

[0011] US5,255,754 discloses an axle construction for larger vehicles having a steerable axle for increased maneuverability. The axle construction comprises a steering axle arranged to the chassis frame parallel with the axle and below the central axis of the steerable axle. The steering axle is connected to the ends of longitudinal supports or shafts on each side of the steerinhg axle by steering arms. The steering arms are centrally connected to the P16032PC00 2 steering axle and the longitudinal supports are then connected to the upper end of a stearing arm one one side and to the lower end of a steering arm on the other side. The steering axle and the steering arms are turned by means of an intermediate steering rod resulting in moving a longitutinal support forward on one side and moving a longitutinal support backwards on the other side.

[0012] Summary of the Invention

[0013] The present invention provides a mechanical steering system for longer vehicles and trucks. The steering system is designed for a wheel and axle assembly with nonsteerable wheels where the wheels are in a fixed position on the axle, such that the wheel and axle assembly pivots around its centre point when turning the vehicle. The pivotal connection of the wheel and axle assembly may be to the chassis of the vehicle or to an axle arm being pivotally arranged to the vehicle. This is referred to as a steerable axle. The steering system of the present invention allows a heavier load bearing, as carrying load or axle load on the wheel and axle assembly, and a stronger or more robust steering system as the weak point of a wheel and axle assembly is the connection of the wheels to the axle in traditional steering axle systems. Furthermore, the solution provided herein also allows a longer distance between the front and rear wheel and axle assembly without compromising the turning radius of a vehicle of a certain length, as well as for vehicles using four-wheel steering systems or steering both front and rear axles when tuning the vehicle. Although the steering system disclosed herein may be more in line with a rear axle steering system as used for longer trucks, the system may also be implemented for front axle steering for increasing the load bearing of the front wheel and axle assembly.

[0014] The steering system comprises a wheel and axle assembly with non-steerable wheels and a left and right longitudinal control rod connected to the left and right side of the axle. The left and right longitudinal control rod are further connected to a left and right pivotal arms respectively, where the pivotal arms are pivotally connected to on the chassis of the vehicle on the left and the right side of the centre of the vehicle. The left and right pivotal arms are downward extending, and the pivotal connection enables a forwards and backwards movement of the left and right pivotal arms and thereby the left and right longitudinal control rods. So, when the axle is turned for steering the vehicle, a synchronised pushing force is applied on either of the left and right pivotal arm and a simultaneous and pulling force is applied on the other of the left and right pivotal arms. This results in a pushing force on one of the first left and right side of the axle and a pulling force on the other of the left and right side of the axle respectively through the longitudinal control rods, which rotates or turns the wheel and axle assembly around it's centre point for steering of the vehicle. P16032PC00 3

[0015] Furthermore, the present invention provides a steering system for a vehicle with a beltcrawler undercarriage mounted under the vehicle, where the front and the wheel axle assembly may be required to be near the front and the rear end of the chassis and where an increased load bearing may be required.

[0016] The belt crawler units have a static central wheel attached to the chassis or the undercarriage of the vehicle and at least a front and rear wheel attached to front and rear pivotal frame arms. When the belt-crawler undercarriage is not in use or in a resting position, the belt crawler units have a linear shape under the vehicle. However, during operation the front and rear wheels of the crawler units are lowered by a radial movement of the front and rear pivotal frame arms forming a triangular shaped belt. The belt crawler units may also comprise further frame components, such as a longitudinal telescopic connection arm connecting the front and the rear wheel. These variations are shown and further outlined in figure 7.

[0017] In order to facilitate the shape-change of the belt crawler units at least one of the frame portions comprises a telescopic suspension element for altering the length of one or more frame portions. The radial movement of the front and rear pivotal frame arms is facilitated by vertical telescopic suspension elements, which are connected to the front and rear pivotal frame arms. This is shown and further outlined in figure 7. The suspension elements in one or more frame portions enable the belt crawler units to maintain circumferential tension on the crawler belt of the belt crawler units through the shape changing of each belt crawler unit between a linear shape and a triangular shape.

[0018] In some embodiments the centre wheel is arranged with a drive axle for rotating or driving the belt of the belt crawler units. The front and rear wheels, as well as the any additional belt wheels arranged on frame arms of the belt crawler units may be driven by additional drive shafts connected to the frame through mechanical transfer components such as internal drive shafts, angled drive components, chains and cogwheels. All the wheels of the belt crawler units may also be powered by electrical motors.

[0019] The present invention further provides a drive and steering system for vehicles such as four-wheel vehicles in combination with the belt-crawler undercarriage of the invention. Such a drive and steering system may comprise axle connector with a movable connection to the chassis of the vehicle and a movable connection to the axle assembly for pivotal movement of the distal end of the axle connector for co-ordinated operation of the vehicle drivetrain, drive and axle system or a belt crawler undercarriage. In such embodiments, the vehicle drive shaft may comprise a main vehicle drive shaft and connecting drive shaft within the axle connector. P16032PC00 4

[0020] In some embodiments the suspension systems for belt crawler units and the drive and steering system may be independently controlled, but the suspension systems for belt crawler and the drivetrain may also be co-ordinated through a computer system.

[0021] It is an object of the present invention to overcome and / or ameliorate the aforementioned drawbacks of the prior art and to provide an improved and / or alternative and / or additional steering system for a vehicle for a wheel and axle assembly having a steerable axle.

[0022] The objects underlying the present invention are particularly solved by the features defined in the independent claims. The dependent claims relate to preferred embodiments of the present invention. Further additional and / or alternative aspects are discussed below. Moreover, it is a preferred object of the present invention to provide steering system for vehicles with a belt-crawler configured for changing the shape of each belt crawler unit between a linear shape and a triangular shape. It is also a preferred object of the present invention to provide a steering and drive system for a vehicle adapted to operate with the shape changable belt-crawler undercarriage.

[0023] Thus, at least one of the preferred object of the present invention is solved by a steering system for a vehicle, where the system comprises: I) a wheel and axle assembly comprising left and right wheels and an axle, where the axle is a steerable axle, II) a left and right pivotal arm, the left and right pivotal arms are downward extending from a pivotal connection to the chassis of the vehicle at the proximal end of the left and right pivotal arms, ill) a first left and right longitudinal control rod further comprising a connection to the left and right side of the axle and a connection to the distal end of the left and right pivotal arms respectively, where the left and right pivotal arms are adapted to receive a pushing force (A) on one of the left and right pivotal arms and pulling force (B) on the other of the left and right pivotal arms to apply a synchronized pushing force (A) and pulling force (B) on the left and the right side of the steerable axle through the first left and right longitudinal control rods respectively.

[0024] Another preferred object of the present invention is solved by steering system for a vehicle, where the system comprises: I) a first wheel and axle assembly, comprising left and right wheels and a steerable axle and steering components for the first wheel and axle assembly further comprising: ii) a first left and right pivotal arm, said first left and right pivotal arms are downward extending from a pivotal connection to the chassis of the vehicle, ill) a first left and right longitudinal control rod further comprising a connection to the left and right side of the axle and a connection to the left and right pivotal arms respectively, iv) a second left and right longitudinal control rod further comprising a connection to the left and right pivotal arms, where the left and right pivotal arms are adapted to receive a synchronized pushing force (A) and pulling force P16032PC00 5

[0025] (B) on each of the left and right pivotal arms through the second left and right longitudinal control rods. The system further comprises v) a second wheel and axle assembly arranged in front of the first wheel and axle assembly, the second wheel and axle comprising left and right wheels and a steerable axle and steering components for the second wheel and axle assembly further comprising: vi) a second left and right pivotal arms, said second left and right pivotal arms are downward extending from a pivotal connection to the chassis of the vehicle, vii) a third left and right longitudinal control rod further comprising a connection to the left and right side of the second axle and a connection to the second left and right pivotal arms respectively, and viii) a fourth left and right longitudinal control rod further comprising a connection at the forward end to the second left and right pivotal arm, where the fourth left and right longitudinal control rods are connected at the backwards end to the first left and right pivotal arm, and where the synchronized pushing force (A) and pulling force (B) on each of the first left and right pivotal arms applies a synchronised pushing force (A) and pulling force (B) on each of the on the left and the right side of the first and second steerable axle through the first left and right longitudinal control rods and the third left and right longitudinal control rods respectively.

[0026] Another preferred object of the present invention is solved by a drive and steering system for a vehicle, where the system comprises: i) a wheel and axle assembly, comprising left and right wheels and an axle, wherein the axle is a steerable axle, ii) an axle connector comprising a movable connection to the chassis of the vehicle and a movable connection to the wheel and axle assembly for pivotal movement of the distal end of the axle connector, and iii) a vehicle drive shaft, said vehicle drive shaft comprising a main vehicle drive shaft and connecting drive shaft within the axle connector. The system further comprises a steering assembly, said steering assembly further comprising: iv) a left and right pivotal arm, said left and right pivotal arms are downward extending and pivotally connected to the chassis of the vehicle for a forwards and backwards movement of the left and right pivotal arms, and v) a first left and right longitudinal control rod further comprising a connection to the left and right side of the axle and a connection to the left and right pivotal arms respectively, where the left and right pivotal arms are adapted to receive a synchronized pushing force and pulling force on each of the left and right pivotal arms to apply a synchronized pushing force and pulling force on the left and the right side of the steerable axle through the first left and right longitudinal control rod respectively for steering the vehicle.

[0027] One of the preferred objects of the present invention is solved by a drive system for a vehicle with a belt-crawler undercarriage mounted under said vehicle, where the system comprises: i) a wheel and axle assembly, comprising left and right wheels and an axle, wherein the axle is a steerable axle, ii) an axle connector comprising a movable P16032PC00 6 connection to the chassis of the vehicle and a movable connection to the wheel and axle assembly for pivotal movement of the distal end of the axle connector, ill) at least one belt crawler unit adapted for a shape change between a linear shape and a triangular shape by a pivotal vertical movement of front and / or rear frame arms and a front and rear wheels rotatably connected to the distal end of the front frame arm and rear frame arms respectively. The system further comprises iv) a steering assembly further comprising: v) a left and right pivotal arm, said left and right pivotal arms are downward extending and pivotally connected to the chassis of the vehicle for a forwards and backwards movement of the left and right pivotal arms, vi) a first left and right longitudinal control rod further comprising a connection to the left and right side of the axle and a connection to the left and right pivotal arms respectively. The left and right pivotal arms are adapted to receive a synchronized pushing force and pulling force on each of the left and right pivotal arms to apply a synchronized pushing force and pulling force on the left and the right side of the steerable axle through the first left and right longitudinal control rod respectively for steering the vehicle.

[0028] In the present context the term "pivotal arm" refers to a linkage arm or a Pitman arm with at least three connection points. The pivotal arm is pivotally arranged or connected to the chassis of the vehicle to facilitate pulling and pushing the left and right sides of an axle for steering a vehicle. The pivotal arm is downward extending, where the upper end or proximal end of the pivotal arm is connected to the chassis of the vehicle and the lower end or the distal end of the pivotal arm is connected to the first longitudinal control rod.

[0029] In the present context the term "first longitudinal control rod" refers to a link rod or link arm connected to the left or right side of the axle and to a pivoting portion of the pivotal arm. Such a longitudinal control rod may comprise a longitudinal control rod or a torque rod.

[0030] In the present context the term "second longitudinal control rod" refers to a link rod or link arm connected to the left and pivotal arm at the forward end and to a steering mechanism at the rear end for applying a synchronized pushing force and pulling force on the left and the right pivotal arms. Such a longitudinal control rod may comprise a longitudinal control rod or a torque rod.

[0031] In the present context the terms "axle connector" and "axle arm" are used for a mechanical connection arm comprising a movable connection to the chassis of the vehicle and a movable connection to the axle assembly for pivotal movement of the distal end of the axle connector / axle arm. The axle connector / axle arm is provided for co-ordinated operation of the vehicle drive and axle system as well as for use when a vehicle is P16032PC00 7 arranged with a belt crawler undercarriage. Such an axle connector may comprise a three-point connection.

[0032] In an embodiment of the present invention the wheels of the wheel and axle assembly are in a fixed position on the axle and the wheel and axle assembly pivots around its centre point when turning the vehicle.

[0033] In an embodiment of the present invention the wheel and axle assembly is pivotally connected to the chassis of the vehicle.

[0034] In an embodiment of the present invention the wheel and axle assembly is pivotally connected to an axle arm or axle connector, said axle arm being connected to the chassis of the vehicle.

[0035] In an embodiment of the present invention the axle arm or axle connector is pivotally connected to the chassis of the vehicle.

[0036] In an embodiment of the present invention the axle pivots or turns around it's centre point for steering the vehicle.

[0037] In an embodiment of the present invention the left and right pivotal arms are statically and pivotally connected to the vehicle through a respective connection at the proximal end for a forwards and backwards movement of the distal end of the left and right pivotal arms.

[0038] In an embodiment of the present invention the left and right pivotal arms are pivotally connected to the chassis of the vehicle at the upper end of the downward extending left and right pivotal arms.

[0039] In an embodiment of the present invention the left and right pivotal arms are parallel arranged to the chassis through a corresponding left and right pivotal connection for identical opposite pivotal movement of the left and right pivotal arms.

[0040] In an embodiment of the present invention the statical and pivotal connection of the left and right pivotal arms to the vehicle is a connection to the chassis of the vehicle.

[0041] In an embodiment of the present invention the pivotal connection of the left and right pivotal arms to the chassis of the vehicle is at the proximal end of each of the left and right pivotal arms.

[0042] In an embodiment of the present invention the left and right pivotal arms are statically and pivotally connected to the chassis of the vehicle for a forwards and backwards movement of the distal end of the left and right pivotal arms. P16032PC00 8

[0043] In an embodiment of the present invention the left and right pivotal arms are downward extending from their the pivotal connection to the chassis of the vehicle adapted for a forwards and backwards movement of the left and right pivotal arms.

[0044] In an embodiment of the present invention the left and right pivotal arms movably connected to the first left and right longitudinal control rod at the lower end of the left and right pivotal arms.

[0045] In an embodiment of the present invention the connection of the first left and right longitudinal control rods to the left and right pivotal arms is a movable connection.

[0046] In an embodiment of the present invention the connection of the first left and right longitudinal control rods to the left and right pivotal arms is a pivotal connection.

[0047] In an embodiment of the present invention the left and right pivotal arms movably connected respectively to the second left and right longitudinal control rod between the pivotal connection of the left and right pivotal arms to the chassis and the movable connection to the first left and right longitudinal control rod.

[0048] In an embodiment of the present invention the left and right pivotal arms and the connection to the first longitudinal control rod is above the centre line of the wheel and axle assembly.

[0049] In an embodiment of the present invention the left and right pivotal arms and the connection to the first longitudinal control rods is below the centre line of the wheel and axle assembly.

[0050] In an embodiment of the present invention the left and right pivotal arms and the connection to the first longitudinal control rods is at or above the centre line of the wheel and axle assembly.

[0051] In an embodiment of the present invention the connection of the first left and right longitudinal control rod to the left and right pivotal arms is a movable connection, such as a pivotal connection.

[0052] In an embodiment of the present invention the connection of the first left and right longitudinal control rod to the left and right pivotal arms allows at least a two-axis movement.

[0053] In an embodiment of the present invention the connection of the first left and right longitudinal control rod to the left and right side of the axle allows at least a three-axis movement. P16032PC00 9

[0054] In an embodiment of the present invention the connection of the first left and right longitudinal control rod to the left and right side of the axle is a three-axis mechanical joint.

[0055] In an embodiment of the present invention the first left and right longitudinal control rod is connected to the left and right pivotal arm at or near the distal end of the left and right pivotal arms.

[0056] In an embodiment of the present invention the steering system further comprises a "central" steering device arranged to be connected to the left and right pivotal arm for applying a pushing force on one of the first left and right longitudinal control rod and for applying a pulling force on the other of the left and right longitudinal control rod respectively.

[0057] In an embodiment of the present invention the steering system further comprises a second left and right longitudinal control rod connected to the left and right pivotal arm.

[0058] In an embodiment of the present invention the second left and right longitudinal control rod is arranged in the opposite direction of the first left and right longitudinal control rod respectively.

[0059] In an embodiment of the present invention the connection from the "central" steering device to the left and right pivotal arms comprises a second left and right longitudinal control rod.

[0060] In an embodiment of the present invention the connection from the "central" steering device to the left and right pivotal arms comprises one or more left and right longitudinal control rods.

[0061] In an embodiment of the present invention the connection of the second left and right longitudinal control rod to the left and right pivotal arms is positioned between the pivotal connection of the left and right pivotal arms to the chassis and the connection of the left and right pivotal arms to the first left and right longitudinal control rods.

[0062] In an embodiment of the present invention the second left and right longitudinal control rod connected to the left and right pivotal arm at or near the distal end of the left and right pivotal arm.

[0063] In an embodiment of the present invention the connection of the pivotal arm to the second left and right longitudinal control rod comprises a plurality of connection points.

[0064] In an embodiment of the present invention the plurality of connection points for the second left and right longitudinal control rod to the left and right pivotal arm respectively is adapted for adjusting the steering angle of the axle assembly. P16032PC00 10

[0065] In an embodiment of the present invention the second left and right longitudinal control rods are arranged for a forwards and backwards movement of the left and right pivotal arms to provide a synchronized pushing force (A) and pulling force (B) on each of the left and right pivotal arms to apply a synchronized pushing force (A) and pulling force (B) on the left and the right side of the steerable axle through the first left and right longitudinal control rods respectively for steering the vehicle.

[0066] In an embodiment of the present invention the synchronized pushing force (A) and pulling force (B) on each of the left and right pivotal arms comprise applying a pushing force (A) on one side of the steerable axle and a synchronized pulling force (B) on the other side of the steerable axle through the first left and right longitudinal control rods respectively.

[0067] In an embodiment of the present invention the steering system is adapted for front axle steering.

[0068] In an embodiment of the present invention the steering system is adapted for rear axle steering.

[0069] In an embodiment of the present invention the steering system is adapted for both front and rear axle steering.

[0070] In an embodiment of the present invention the steering system is adapted for two or more wheel and axle assemblies. The two or more wheel and axle assemblies may be closely arranged on the vehicle.

[0071] In an embodiment of the present invention the steering system further comprises: I) a second wheel and axle assembly arranged in front of the first wheel and axle assembly, the second wheel and axle comprising left and right wheels and a steerable axle, II) a second left and right pivotal arms, said second left and right pivotal arms are downward extending from a pivotal connection to the chassis of the vehicle, ill) a third left and right longitudinal control rod further comprising a connection to the left and right side of the second axle and a connection to the second left and right pivotal arms respectively, and iv) a fourth left and right longitudinal control rod further comprising a connection at the forward end to the second left and right pivotal arm, where the fourth left and right longitudinal control rods are connected at the backwards end to the first left and right pivotal arm between the pivotal connection to the chassis and the connection to the first left and right longitudinal control rods to receive a synchronized pushing force (A) and pulling force (B) on each of the second left and right pivotal arms to apply a synchronized pushing force (A) and pulling force (B) on the left and the right side of the second steerable axle through the second left and right longitudinal control rod respectively. P16032PC00 11

[0072] In an embodiment of the present invention the synchronized pushing force (A) and pulling force (B) on each of the first fist left and right pivotal arms generates a synchronized pushing force (A) and pulling force (B) on each of the second left and right pivotal arms to apply a synchronized pushing force (A) and pulling force (B) on the left and the right side of the first and second steerable axle through the first left and right longitudinal control rods and the third left and right longitudinal control rods respectively.

[0073] In an embodiment of the present invention the third left and right longitudinal control rods further comprise a connection to the left and right side of the second axle and a connection to the second left and right pivotal arms respectively.

[0074] In an embodiment of the present invention the fourth left and right longitudinal control rods are connected at the forward end to the second left and right pivotal arm between the pivotal connection to the chassis and the connection to the first left and right longitudinal control rods.

[0075] In an embodiment of the present invention the fourth left and right longitudinal control rods are connected at the backwards end to the first left and right pivotal arm between the pivotal connection to the chassis and the connection to the first left and right longitudinal control rods.

[0076] In an embodiment of the present invention the connection of the second pivotal arm to the fourth left and right longitudinal control rod comprises a plurality of connection points.

[0077] In an embodiment of the present invention the plurality of connection points for the fourth left and right longitudinal control rod to the left and right pivotal arm respectively is adapted for adjusting the steering angle of the axle assembly.

[0078] In an embodiment of the present invention the steering angle of the first axle assembly and the steering angle of the second axle assembly may be different by connecting the second left and right longitudinal control rods and the fourth left and right longitudinal control rods at different positions of the plurality of connection points on the first and second pivotal arms respectively.

[0079] In an embodiment of the present invention the steering system further comprises an axle connector movably connected to the chassis of the vehicle and movably connected to the axle for pivotal movement of the distal end of the axle.

[0080] In an embodiment of the present invention the movable connection of the axle connector to the axle allows at least a three-axis movement of the axle around it's centre point.

[0081] In an embodiment of the present invention the movable connection of the axle connector to the axle is a three-axis mechanical joint connected to the centre of the axle. P16032PC00 12

[0082] In an embodiment of the present invention the wheel and axle assembly further comprise transmission mechanism for the wheels.

[0083] In an embodiment of the present invention the steering system further comprises suspension devices for the left and right side of the vehicle.

[0084] In an embodiment of the present invention the suspension devices for the left and right side of the vehicle comprise springs and / or shock absorbers.

[0085] In an embodiment of the present invention the shock absorbers of the left and right suspension elements for the left and right side of the vehicle further comprise a telescopic shock absorber.

[0086] In an embodiment of the present invention the axle connector comprises a movable connection to a central frame structure arranged in or attached to the chassis of the vehicle.

[0087] In an embodiment of the present invention the axle connector is arranged to have a three-point connection between the chassis and the wheel and axle assembly.

[0088] In an embodiment of the present invention the three-point connection of the axle connector between the chassis and the axle comprises two connections to the chassis and one connection to the axle.

[0089] In an embodiment of the present invention the three-point connection of the axle connector between the central frame structure and the wheel and axle assembly comprises two connection points to the central frame structure and one connection to the axle.

[0090] In an embodiment of the present invention the movable connection of the axle connector to the wheel and axle assembly allows at least a three-axis movement.

[0091] In an embodiment of the present invention the movable connection of the axle connector to the chassis comprises a hinge-connection.

[0092] In an embodiment of the present invention the movable connection of the axle connector to the central frame structure comprises a hinge-connection.

[0093] In an embodiment of the present invention the axle connector and / or the central frame structure comprises a housing.

[0094] In an embodiment of the present invention the connection between the main vehicle drive shaft and the connecting drive shaft allows a pivotal movement of the axle connector. P16032PC00 13

[0095] In an embodiment of the present invention the connection between the main vehicle drive shaft and the connecting drive shaft is a U-joint.

[0096] In an embodiment of the present invention the main vehicle drive shaft is positioned in the central frame structure.

[0097] In an embodiment of the present invention the transfer of drive from the vehicle engine to the front and rear wheels is a mechanical transfer.

[0098] In an embodiment of the present invention the drive and steering system may further comprise suspension devices for the left and right side of the vehicle.

[0099] In an embodiment of the present invention the suspension devices for the left and right side of the vehicle are arranged between the chassis and the axle.

[0100] In an embodiment of the present invention the suspension devices for the left and right side of the vehicle comprise telescopic shock absorbers.

[0101] In an embodiment of the present invention an extension or retraction of the telescopic shock absorbers of the left and right suspension elements may be controlled / regulated.

[0102] In an embodiment of the present invention the drive and steering system is adapted to operate with a vehicle having a belt-crawler undercarriage mounted under said vehicle, said belt-crawler undercarriage comprising at least one belt crawler unit adapted for a shape change between a linear shape and a triangular shape.

[0103] In an embodiment of the present invention the at least one belt crawler unit further comprising front and rear frame arms and a front and rear wheel rotatably connected to the distal end of the front frame arm and rear frame arms respectively.

[0104] In an embodiment of the present invention the at front and / or rear frame arms further comprise a telescopic suspension element.

[0105] In an embodiment of the present invention the at least one belt crawler unit is adapted for a shape change between a linear shape and a triangular shape by a pivotal vertical movement of front and / or rear frame arms and a front and rear wheels rotatably connected to the distal end of the front frame arm and rear frame arms respectively,

[0106] In an embodiment of the present invention the at least one belt crawler unit further comprises a longitudinal telescopic connection arm.

[0107] In an embodiment of the present invention the longitudinal telescopic connection arm comprises a telescopic suspension element. P16032PC00 14

[0108] In an embodiment of the present invention the at least one belt crawler unit further comprises a front and a rear vertical telescopic suspension elements for raising or lowering the at least one belt crawler unit to or from the ground.

[0109] In an embodiment of the present invention the the telescopic suspension element of the front and / or rear frame arms, the front and rear vertical telescopic suspension elements and the one or more lateral telescopic suspension elements of the longitudinal telescopic connection arm facilitate the change of the shape of each belt crawler unit between a linear shape and a triangular shape by an adjustable length of the front and / or rear frame arms and the change of angle between at least one static central wheel and the front wheel and the rear wheel, and an adjustable length of the longitudinal telescopic connection arm to maintain tension on the crawler belt during the shape change of the crawler belt.

[0110] In an embodiment of the present invention each of the telescopic suspension elements of the belt-crawler undercarriage may be independently controlled and / or synchronized, such as by a computing device.

[0111] In an embodiment of the present invention the control of the telescopic suspension element of the front and rear frame arms and the front and rear (adjustable) vertical telescopic suspension element is synchronised.

[0112] In an embodiment of the present invention the control of the telescopic suspension element of the front and rear frame arms, the front and rear (adjustable) vertical telescopic suspension element, and the one or more lateral telescopic suspension elements of the longitudinal telescopic connection arm is synchronised.

[0113] In an embodiment of the present invention each of the front and rear telescopic suspension elements for the left and right side of the vehicle and each of the telescopic suspension elements) of the at least one belt crawler unit may be independently controlled, such as by a computing device.

[0114] In an embodiment of the present invention the drive and steering system is adapted to operate with a vehicle comprising at least one belt crawler unit connected to the vehicle chassis, said at least one belt crawler unit further comprising a front and a rear vertical telescopic suspension elements for raising or lowering the at least one belt crawler unit to or from the ground.

[0115] In an embodiment of the present invention each of the front and rear telescopic suspension elements for the left and right side of the vehicle and the front and a rear vertical telescopic suspension elements of the at least one belt crawler unit may be independently controlled. P16032PC00 15

[0116] In an embodiment of the present invention each of the front and rear telescopic suspension elements for the left and right side of the vehicle and the front and a rear vertical telescopic suspension elements of the at least one belt crawler unit are controlled by a computing device.

[0117] In an embodiment of the present invention the control of each of the front and rear telescopic suspension elements for the left and right side of the vehicle and the front and a rear vertical telescopic suspension elements of the at least one belt crawler unit is synchronized.

[0118] In an embodiment of the present invention the drive and steering system is adapted for a front wheel and axle assembly.

[0119] In an embodiment of the present invention the drive and steering system is adapted for a rear wheel and axle assembly.

[0120] In an embodiment of the present invention the drive and steering system is adapted for both a front and rear wheel and axle assembly.

[0121] In an embodiment of the present invention the drive and steering system for a front and rear wheel and axle assembly are a mirror like image.

[0122] Description of various embodiments

[0123] The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus, are not limitative of the present invention, and wherein:

[0124] FIG. 1 shows a side view of the steering system of the present invention.

[0125] FIG. 2 is a side view of a steering system for the left and the right side of the vehicle.

[0126] FIG. 3 is top view outlining the operation of a steering system.

[0127] FIG. 4 is a side view of a steering system for the left and the right side of the vehicle with multiple connection points for rear steering components.

[0128] FIG. 5 shows the combination of a wheel and axle assembly with an axle connector in combination with the steering system of the invention.

[0129] Fig. 6 is a side view of a steering system for two wheel and axle assemblies.

[0130] FIG. 7 is a top view of steering and drive system for a vehicle according to one embodiment of the invention.

[0131] FIG. 8 outlines possible movements of the wheel and axle assembly in relation to the steering and drive system of the invention. P16032PC00 16

[0132] FIG. 9 is a side view of a shape changeable belt crawler unit mounted on a vehicle.

[0133] Figure 1 is a schematic drawing of a steering system for a vehicle according to the present invention, where the drawing shows the components for either the left or the right side of the vehicle. The steering system is designed for a wheel and axle assembly having left and right wheels 2 and an axle 3, where the axle is a steerable axle. A pivotal arm 4 is arranged downward extending from the chassis 14 of the vehicle by a pivotal connection for a forward (A) and backward movement (B) of the pivotal arms. The pivotal connection 5 of the pivotal arm 4 to the chassis of the vehicle is made at or near the proximal end of each of the pivotal arm 4. A longitudinal control rod 6 is arranged between the axle 3 and the pivotal arm 4 by a movable connection 7 and a pivotal connection 8 at or near the distal end of the pivotal arm 4. The steering components of the system of the present invention, i.e. the left and right pivotal arms (4) and the connection to the first longitudinal control rod are positioned above the centre line (C) of the wheel and axle assembly.

[0134] Figure 2 is a schematic drawing of a steering shown in Fig. 1 for the left and the right side of the vehicle, where the far components are shown with a dotted line and in lighter colour. The drawing further shows a second left and right longitudinal control rod lOa / lOb connected 11 to the left and right pivotal arm 4 at or near the distal end of the left and right pivotal arm 4. The left and right pivotal arms 4, said left and right pivotal arms are downward extending in a forwards (far) and backwards (near) position from the pivotal connection 5. A synchronized pushing force (far) and pulling force (near) is applied on the axle (3) as (a) the second longitudinal control rod 10a pushes on the pivotal arm 4a and thereby on the axle 3a through the first longitudinal control rod 6a (far) and (b) the second longitudinal control rod 10b pulls on the pivotal arm 4b and thereby on the axle 3b through the first longitudinal control rod 6b (near).

[0135] Figure 3 is a schematic drawing of an operation of a steering system for a vehicle according to the present invention where a steerable axle pivots or turns around it's centre point for steering the vehicle for steering the vehicle. In Fig 3a the vehicle is making a left turn as the right side (upper) of the axle is being pushed by a pushing force from the right second longitudinal control rod 10 through pivotal arm 4 onto the right first longitudinal control rod 6. A synchronised pulling force on the left (lower) side of the axle by a pulling force from the left second longitudinal control rod 10 through pivotal arm 4 onto the left first longitudinal control rod 6. The axle pivots or turns around it's centre point for steering the vehicle through an axle connector 12. In Fig. 3b the vehicle is going straight and in Fig. 3c the vehicle is making a right turn, opposite to Fig. 3a, where a pushing force is applied on the left side of the axle and a pulling force is being applied on the right side of the axle. P16032PC00 17

[0136] Figure 4 is a schematic drawing similar to Fig. 2 for the left and the right side of the vehicle, showing multiple connections 11 to the second left and right longitudinal control rod 10. The far components are shown with a dotted line and in lighter colour (as in Fig. 2). The left and right pivotal arms 4, said left and right pivotal arms are downward extending in a forwards (far) and backwards (near) position from the pivotal connection 5. A synchronized pushing force and pulling force is applied on the axle (3) as the second longitudinal control rod 10 pushes on one pivotal arm 4 and thereby on the axle 3 through the first longitudinal control rod 6 the second longitudinal control rod 10b pulls on the other pivotal arm 4 and thereby on the axle 3 through the respective first longitudinal control rod. The connection 11 to the second left and right longitudinal control rod 10 is adjustable in this embodiment along the length of the left and right pivotal arm 4 between the pivotal connection 5 and the connection 8 to the left and right longitudinal control rod (shown as connection points 11a, lib, 11c). In Fig. 4A, the second left and right longitudinal control rod 10 are connected to connection 11a on the pivotal arm 4, whereas in Fig. 4B the second left and right longitudinal control rod 10 are connected to connection 11c on the pivotal arm 4 providing an adjustable or changeable steering angle of the axle assembly.

[0137] Figure 5 is a schematic drawing showing how the wheel and axle assembly is connected to the vehicle chassis by an axle connector 12. The steering system for a steerable axle assembly, having left and right wheels 2 and an axle 3, comprises a pivotal arm 4 downward extending from the chassis 14 of the vehicle by a pivotal connection for a forward (A) and backward movement (B) of the pivotal arms. The pivotal connection 5 of the pivotal arm 4 to the chassis of the vehicle is made at or near the proximal end of the pivotal arm 4. A longitudinal control rod 6 is arranged between the axle 3 and the pivotal arm 4 by a movable connection 7 and a pivotal connection 8 at or near the distal end of the pivotal arm 4. The axle connector 12 is movably connected 13 to the chassis 14 of the vehicle and pivotally connected 15 to the axle for pivotal movement of the distal end of the axle. The movable connection 15 of the axle connector 12 to the axle may be arranged to allow at least a three-axis movement of the axle 3 around it's centre point. The drawing also shows the vehicle drive shaft, where the vehicle drive shaft is divided into a main vehicle drive shaft 17 and connecting drive shaft 18 and where the connecting drive shaft 18 is housed within the axle connector 12.

[0138] Figure 6 is a schematic drawing of a steering system for two wheel and axle assemblies, showing both the left and the right side of the vehicle. The figure shows a first wheel and axle assembly (on the right side) having left and right wheels 2 and a steerable axle 3 and the steering components for the first wheel and axle. The steering components comprise a first left and right pivotal arm 4 being downward extending from a pivotal connection 5 to the chassis 14 of the vehicle at the proximal end of the left and right P16032PC00 18 pivotal arms 4. The first left and right pivotal arms 4 have multiple connections lla-c to the second left and right longitudinal control rod 10. The first left and right longitudinal control rods 6 further comprising a connection 7 to the left and right side of the axle 3 and a connection 8 to the left and right pivotal arms 4 respectively. A second left and right longitudinal control rod 10 are shown having a connection 11 to the left and right pivotal arms 4 between the pivotal connection 5 to the chassis 14 and the movable connection to the first left and right longitudinal control rod 6 of the left and right pivotal arms 4. The drawing further shows a second wheel and axle assembly arranged in front of the first wheel and axle assembly, where the second wheel and axle comprises left and right wheels 20 and a steerable axle 30 and steering components for the second wheel and axle assembly. The steering components further comprise a second left and right pivotal arm 40 being downward extending and pivotally connected 50 to the chassis 14 of the vehicle as well as a third left and right longitudinal control rod 60 further comprising a connection 70 to the left and right side of the second axle 30 and a movable connection 80 to the second left and right pivotal arms 40 respectively. Fourth left and right longitudinal control rods 100 are further shown being connected 110 at the forward end to the second left and right pivotal arm 40 between the pivotal connection 50 to the chassis and the connection 70 to the first left and right longitudinal control rods. The fourth left and right longitudinal control rods 100 are connected 110 at the backwards end to the first left and right pivotal arm 4 between the pivotal connection 5 to the chassis and the connection 8 to the first left and right longitudinal control rods 6. This setup allows a synchronized pushing force and pulling force on each of the first left and right pivotal arms (4) to generate a synchronised pushing force and pulling force on each of the on the left and the right side of the first (3) and second (30) steerable axle through the first left and right longitudinal control rods (6) and the third left and right longitudinal control rods 60 respectively.

[0139] Figure 7 is a schematic drawing of steering and drive system for a vehicle according to one embodiment of the invention. A top view shows the wheel and axle assembly connected to an axle connector 12. The axle connector 12 having three connections points to provide strength for the connection from the chassis to the axle, with two hinge-like connections 13 to the chassis 14 and one movable connection 15 to the axle allowing at least a three-axis movement of the connecting component. The drawing shows the steering system for the left and the right side of the vehicle. The components are arranged such that the pivotal arm 4 has a pivotal connection 5 to the chassis of the vehicle and a pivotal connection 8 of the first longitudinal control rod 6. The first longitudinal control rod 6 has a movable connection 7 to the axle 3 and a second longitudinal control rod 10 also has a pivotal connection 11 to the pivotal arm 4. A "central" steering device 9 is arranged to be connected to the left and right pivotal arm 4 through the left and second longitudinal control rod 10 for applying a synchronized P16032PC00 19 pushing force on one of the first left and right longitudinal control rod 6 and a pulling force on the other of the left and right longitudinal control rod 6 respectively. The vehicle drive shaft is divided into a main vehicle drive shaft 17 and connecting drive shaft 18 and where the connecting drive shaft 18 is housed within the axle connector 12. The drawing further shows suspension devices 16 on arranged on the left and the right side of the axle.

[0140] Figure 8 outlines possible movements of the wheel and axle assembly in relation to the steering and drive system of the invention. Fig. 8A and 8B show a front view of the wheel and axle assembly and how an uneven suspension is possible as the right wheel goes down and the left wheel goes up. In Fig. 8C and 8D a top view shows the steerable axle making a turn, where the wheel and axle assembly rotates around it's centre point of connection to the axle connector. Fig. 8E and 8F show up and downwards movement of the wheel and axle assembly based on the pivotal movement of the axle connector in combination with the pivotally connected first longitudinal control rod.

[0141] Figure 9 shows a side view of a shape changeable belt crawler unit in mounted on a vehicle. In Fig 9A the belt crawler unit 21 is in a linear shape with the lateral telescopic suspension element 24 of the rear telescopic suspension arm 25 fully extended and the front and rear adjustable vertical suspension elements 23,23 are retracted. The front wheel suspension unit 16 and the rear wheel suspension unit 16 are also shown in relation to the front and rear wheel 2 of the vehicle. The drawing shows the axle connector 12 for the front and rear wheel and axle assembly extending from the front and rear axles 3 and being connected to the chassis 14. The drawing further shows a longitudinal control rod 6 connected to the axle 3 and to the pivotal arm 4. In Fig. 9B the belt crawler has a triangular shape, where the lateral telescopic suspension element 24 of the longitudinal telescopic connection arm 25 is retracting, but the front and rear adjustable vertical suspension elements 22,23 as well as the telescopic suspension element 26 of the rear pivotal frame arm 27 are extending. Furthermore, the sloping of the axle connector 12 is increased as compared to when the belt crawler unit 21 is in a linear shape. The telescopic suspension element 27 of the rear pivotal frame arm, the front and rear vertical telescopic suspension elements 22,23, and the lateral telescopic suspension element 24 of the longitudinal telescopic connection arm 25 facilitate the change of the shape of each belt crawler unit between a linear shape and a triangular shape. This is possible due to the adjustable length of the rear frame arm 2 and the change of angle between the central wheel 28 and the front wheel 29 and the rear wheel 30 mounted on the distal end of the front 31 and the rear 27 frame arms of the beltcrawler unit 21, as well as an adjustable length of the longitudinal telescopic connection arm 25. Thereby a tension on the crawler belt 32 during the shape change of the crawler belt. P16032PC00 20

[0142] As used herein, including in the claims, singular forms of terms are to be construed as also including the plural form and vice versa, unless the context indicates otherwise. Thus, it should be noted that as used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0143] Throughout the description and claims, the terms "comprise", "including", "having", and "contain" and their variations should be understood as meaning "including but not limited to", and are not intended to exclude other components.

[0144] The present invention also covers the exact terms, features, values and ranges etc. in case these terms, features, values and ranges etc. are used in conjunction with terms such as about, around, generally, substantially, essentially, at least etc. i.e., "about 3" shall also cover exactly 3 or "substantially constant" shall also cover exactly constant.

[0145] The term "at least one" should be understood as meaning "one or more", and therefore includes both embodiments that include one or multiple components. Furthermore, dependent claims that refer to independent claims that describe features with "at least one" have the same meaning, both when the feature is referred to as "the" and "the at least one".

[0146] It will be appreciated that variations to the foregoing embodiments of the invention can be made while still falling within the scope of the invention. Features disclosed in the specification, unless stated otherwise, can be replaced by alternative features serving the same, equivalent or similar purpose. Thus, unless stated otherwise, each feature disclosed represents one example of a generic series of equivalent or similar features.

[0147] Use of exemplary language, such as "for instance", "such as", "for example" and the like, is merely intended to better illustrate the invention and does not indicate a limitation on the scope of the invention unless so claimed. Any steps described in the specification may be performed in any order or simultaneously, unless the context clearly indicates otherwise.

[0148] All of the features and / or steps disclosed in the specification can be combined in any combination, except for combinations where at least some of the features and / or steps are mutually exclusive. In particular, preferred features of the invention are applicable to all aspects of the invention and may be used in any combination.

Claims

P16032PC00 21Claims1. A steering system for a vehicle (1), the system comprising:- a wheel and axle assembly, comprising left and right wheels (2) and an axle (3), wherein the axle is a steerable axle,- a left and right pivotal arm (4), said left and right pivotal arms are downward extending and pivotally connected (5) to the chassis (14) of the vehicle for a forwards and backwards movement of the left and right pivotal arms (4),- a first left and right longitudinal control rod (6) further comprising a connection (7) to the left and right side of the axle (3) and a connection (8) to the left and right pivotal arms (4) respectively, characterised in that the left and right pivotal arms (4) are adapted to receive a synchronized pushing force (A) and pulling force (B) on each of the left and right pivotal arms (4) to apply a synchronized pushing force (A) and pulling force (B) on the left and the right side of the steerable axle through the first left and right longitudinal control rod (6) respectively for steering the vehicle.

2. The steering system according to claim 1, wherein the connection (8) of the first left and right longitudinal control rod (6) to the left and right pivotal arms (4) allows at least a two-axis movement.

3. The steering system according to claim 1, wherein the connection of the first left and right longitudinal control rod (6) to the left and right side of the axle (3) allows at least a three-axis movement.

4. The steering system according to claim 1, wherein the first left and right longitudinal control rod (6) is connected to the left and right pivotal arm (4) at or near the distal end of the left and right pivotal arms (4).

5. The steering system according to claim 1, wherein the steering system further comprises a "central" steering device (9) arranged to be connected to the left and right pivotal arm (4) for applying a pushing force on one of the first left and right longitudinal control rod (6) and for applying a pulling force on the other of the left and right longitudinal control rod (6) respectively.

6. The steering system according to claim 1, wherein the steering system further comprises a second left and right longitudinal control rod (10) connected (11) to the left and right pivotal arm (4) at or near the distal end of the left and right pivotal arm (4).P16032PC00 227. The steering system according to claim 6, wherein the second left and right longitudinal control rod (10) is arranged in the opposite direction of the first left and right longitudinal control rod (6) respectively.

8. The steering system according to claim 6, wherein the connection (11) of the pivotal arms (4) to the second left and right longitudinal control rods (10) comprises a plurality of connection points to adjust the steering angle of the axle assembly.

9. The steering system according to claim 1, wherein the axle pivots or turns around it's centre point for steering the vehicle.

10. The steering system according to claim 1, wherein the left and right pivotal arms (4) and the connection to the first longitudinal control rods is at or above the centre line (C) of the wheel and axle assembly.

11. The steering system according to claim 1, wherein the steering system further comprises an axle connector (12) movably connected (13) to the chassis (14) of the vehicle and movably connected (15) to the axle for pivotal movement of the distal end of the axle.

12. The steering system according to claim 12, wherein the movable connection (15) of the axle connector to the axle allows at least a three-axis movement of the axle (3) around it's centre point.

13. The steering system according to any of the preceding claims, wherein the steering system is adapted for both front and rear axle steering.

14. The steering system according to claim 1, wherein the steering system further comprises:- a second wheel and axle assembly arranged in front of the first wheel and axle assembly, the second wheel and axle comprising left and right wheels (20) and a steerable axle (30),- a second left and right pivotal arms (40), said second left and right pivotal arms are downward extending from a pivotal connection (50) to the chassis (14) of the vehicle,- a third left and right longitudinal control rod (60) further comprising a connection (70) to the left and right side of the second axle (30) and a connection (80) to the second left and right pivotal arms (4) respectively, and- a fourth left and right longitudinal control rod (100) further comprising a connection (110) at the forward end to the second left and right pivotal arm (40), characterised in thatP16032PC00 23 the fourth left and right longitudinal control rods (100) are connected (110) at the backwards end to the first left and right pivotal arm (4) between the pivotal connection (5) to the chassis and the connection (7) to the first left and right longitudinal control rods to receive a synchronized pushing force (A) and pulling force (B) on each of the second left and right pivotal arms (40) to apply a synchronized pushing force (A) and pulling force (B) on the left and the right side of the second steerable axle through the second left and right longitudinal control rod (60) respectively.

15. The steering system according to claim 14, wherein the connection (110) of the second pivotal arm (40) to the fourth left and right longitudinal control rod (100) comprises a plurality of connection points.

16. The steering system according to claim 14-15, wherein the steering angle of the first axle assembly and the steering angle of the second axle assembly may be different by connecting the second left and right longitudinal control rods (10) and the fourth left and right longitudinal control rods (100) at different positions of the plurality of connection points on the first and second pivotal arms respectively.

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