Front suspension assembly and suspension system for a vehicle

Abstract

Front suspension assembly (18, 20) for a vehicle (12), the suspension assembly (18, 20) comprising: a tire (22) rotatable about a first axis (24), wherein a tire central axis (26) passes through the tire (22) perpendicular to the first axis (24), and wherein the tire (22) has an outer surface (28) with a contact surface center (30) that is a point on the tire central axis (26), wherein a ground plane (16) intersects the contact surface center (30) transversely to the tire central axis (26); a wheel carrier (32) supporting the tire (22), wherein a first plane (34) intersects the wheel carrier (32) horizontally at the first axis (24); a first handling connecting element (36) having a first distal end (40) extending above the first plane (34) is coupled to the wheel carrier (32);a second handling connecting element (38) having a second distal end (42) coupled to the wheel carrier (32) below the first level (34), wherein a handling axis (44) intersects both the first and the second distal end (42) of the first and second handling connecting elements (36, 38), respectively; a first driving connecting element (46) having a third distal end (50) coupled to the wheel carrier (32) above the first level (34); a second driving connecting element (48) having a fourth distal end (52) coupled to the wheel carrier (32) below the first level (34), wherein a driving axis (54) intersects both the third and the fourth distal end (50, 52) of the first and second driving connecting elements (46, 48), respectively;wherein the first and / or the second drive connecting element (46, 48) are arranged offset relative to the respective first and second handling connecting elements (36, 38) in order to minimize a transverse distance (56) between the handling axis (44) and the drive axis (54) along the floor plane (16) where the handling axis (44) and the drive axis (54) intersect the floor plane (16); wherein: the first handling connecting element (36) extends substantially along a first connecting axis (60); the second handling connecting element (38) extends substantially along a second connecting axis (62); the first drive connecting element (46) extends substantially along a third connecting axis (64); the second drive connecting element (48) extends substantially along a fourth connecting axis (66); the third connecting axis (64) is arranged above the second connecting axis (62);and the second driving connecting element (48) is displaced relative to the second handling connecting element (38), characterized in that the suspension assembly (18, 20) further comprises an imaginary steering axis (80) extending transversely to the first axis (24) and arranged outwards in the direction of the tire (22) from the first, second, third and fourth distal ends (40, 42, 50, 52); wherein the first connecting axis (60) intersects the imaginary steering axis (80) at a first point (84); wherein the second connecting axis (62) intersects the imaginary steering axis (80) at a second point (86); wherein the third connecting axis (64) intersects the imaginary steering axis (80) at a third point (88); wherein the fourth connecting axis (66) intersects the imaginary steering axis (80) at a fourth point (90) cuts;and wherein the fourth point (90) intersects the imaginary steering axis (80) above the second point (86), so that the second driving linkage element (48) is displaced with respect to the second handling linkage element (38).

Description

TECHNICAL AREA The present disclosure relates to a suspension system for a vehicle according to the preamble features of claim 1. BACKGROUND Vehicles have been designed to have a suspension system. Roads can have bumps or potholes, and when a vehicle drives over a bump or pothole, the suspension system can dampen the movement of the vehicle's sprung mass, thus creating a smoother ride. There are various types of suspension systems, such as short-arm, long-arm, and multi-link suspension systems. The short-arm suspension system uses an upper control arm that is positioned above a lower control arm and is shorter than it. The upper and lower control arms are connected to a steering knuckle by upper and lower ball joints. The multi-link suspension system uses a single upper control arm mount and a pair of lower link arms connected to a steering knuckle by ball joints. From the generic patent US 2009 / 0218783A1, a front suspension assembly for a vehicle with the features according to the preamble of claim 1 is known. US 4,863,188A describes a similar front suspension assembly for a vehicle. US 7 891 684 B1 also describes a similar front suspension assembly for a vehicle. US 7 048 286 B2 also describes a similar front suspension assembly for a vehicle. The object of the invention is to create a front suspension assembly for a vehicle that minimizes feedback due to unwanted torque perceived by the driver of the vehicle at a steering wheel. SUMMARY This problem is solved by a front suspension assembly having the features of claim 1. The front suspension assembly is intended for a vehicle and comprises a tire that is rotatable about a first axis. A tire centerline runs through the tire perpendicular to the first axis. The tire has an outer surface with a contact patch centerline that is a point on the tire centerline. A ground plane intersects the contact patch centerline transversely to the tire centerline. The assembly also includes a wheel carrier that supports the tire. A first plane intersects the wheel carrier horizontally at the first axis. The assembly further comprises a first handling connector and a second handling connector. The first handling connector has a first distal end that is coupled to the wheel carrier above the first plane. The second handling connector has a second distal end that is coupled to the wheel carrier below the first plane.A handling axis intersects both the first and second distal ends of the first and second handling connectors, respectively. The assembly also includes a first and a second driving connector. The first driving connector has a third distal end that is coupled to the wheel carrier above the first level. The second driving connector has a fourth distal end that is coupled to the wheel carrier below the first level. A driving axis intersects both the third and fourth distal ends of the first and second driving connectors, respectively. The first and / or second driving connectors are offset relative to the corresponding first and second handling connectors to minimize the transverse distance between the handling axis and the driving axis along the ground plane where the handling axis and the driving axis intersect the ground plane. The present disclosure also provides for a front suspension system for a vehicle. The system comprises a first suspension assembly and a second suspension assembly spaced apart from the first suspension assembly. Each of the first and second suspension assemblies comprises the tire, handling connecting elements, and driving connecting elements, respectively, as described immediately above. The first and / or the second driving connecting element is displaced relative to the respective first and second handling connecting elements to minimize a lateral distance between the handling axis and the driving axis along the ground plane where the handling axis and the driving axis intersect the ground plane. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic front view of a vehicle. Fig. 2 is a schematic front view of a front suspension system comprising a first suspension assembly and a second suspension assembly, with a pair of tires separated from their respective assemblies. Fig. 3 is a schematic cross-sectional view of a rim and tire. Fig. 4 is a schematic enlarged cross-sectional view of the tire for the circled area labeled 4 in Fig. 3. Fig. 5 is a schematic perspective view of the first suspension assembly, with the tire separated from the assembly. Fig. 6 is a schematic enlarged view of a handling axis and a driving axis passing through a ground plane to identify a transverse distance between the handling axis and the driving axis for the circled area labeled 6 in Fig. 5.Figure 7 is a schematic top view of the first suspension assembly, with the tire separated from the assembly. Figure 8 is a schematic, enlarged view of an imaginary steering axis and tire centerline passing through the ground plane, for identifying a steering scrub radius for the circled area labeled 8 in Figure 2. Figure 9 is a schematic graph of the steering scrub radius for the pair of tires about an angle by which the tires are pivoted relative to a second plane. DETAILED DESCRIPTION Those skilled in the art will recognize that terms such as "above", "below", "upwards", "upwards", "downwards", "downwards", "on top", "on the bottom", "left", "right", etc. are used to describe the figures and do not constitute limitations on the scope of disclosure as defined by the accompanying claims. Furthermore, the term "substantially" may denote a slight inaccuracy or minor deviation in a condition, quantity, value, dimension, etc. With reference to the figures, in which the same reference numerals indicate identical or corresponding parts throughout the different views, a front suspension system 10 for a vehicle 12 is shown generally in Fig. 1 and Fig. 2. Vehicle 12 can be a motor vehicle, such as a passenger car, a sports car, a truck, etc. Furthermore, Vehicle 12 can be a hybrid vehicle that uses an internal combustion engine and one or more motor-generators. Additionally, Vehicle 12 can be an electric vehicle that uses one or more motor-generators and does not use an internal combustion engine. As another example, Vehicle 12 can be a vehicle that uses an internal combustion engine but does not use motor-generators. It is clear that, alternatively, Vehicle 12 cannot be a motor vehicle. With reference to Figures 1 and 2, the vehicle 12 has a structure 14. The front suspension system 10 supports the structure 14, and the structure 14 is spaced from a ground plane 16, which may be aligned with a road or the ground. The structure 14 can be one or more of the following: a chassis, a support structure, a frame, a subframe, a body, a strut, a sheet, an outer skin, etc. The structure 14 can be any suitable configuration. Additionally, the structure 14 can be any component of a sprung mass of the vehicle 12, including the body, frame, subframe, chassis, outer skin, or any load-bearing component supported by the front suspension system 10. The front suspension system 10 can dampen the movement of the structure 14 as the vehicle 12 moves over the road, represented by the ground plane 16, to provide smoother driving characteristics. As best shown in Fig. 2, the front suspension system 10 comprises a first suspension assembly 18 and a second suspension assembly 20 spaced apart from the first suspension assembly 18. The first and second suspension assemblies 18, 20 work together to dampen the movement of the structure 14. The components of the first and second suspension assemblies 18, 20 are essentially the same, except that the suspension assemblies 18, 20 are located on opposite sides of the vehicle 12. Therefore, the first suspension assembly 18 can be provided for the front driver's side of the vehicle 12, and the second suspension assembly 20 can be provided for the front passenger's side of the vehicle 12.Due to the similarities of the suspension assemblies 18, 20, only the components of one side of the front suspension system 10 are explained in detail below. The first suspension assembly 18 referred to above can also be called a front suspension assembly. With reference to Fig. 3, the first suspension assembly 18 comprises a tire 22 rotatable about a first axis 24. A tire central axis 26 passes through the tire 22 perpendicular to the first axis 24, and therefore the tire central axis 26 lies in a vertical plane. The tire central axis 26 can pass through a center of the tire 22, as shown in Fig. 3. The tire 22 has an outer surface 28 with a contact patch center 30, which is a point on the tire's central axis 26. The ground plane 16 intersects the contact patch center 30 transversely to the tire's central axis 26. As best shown in Fig. 4, the contact patch center 30 is specifically the point where the tire's central axis 26 and the outer surface 28 of the tire 22 intersect the ground plane 16, which is the road or ground when the vehicle 12 is in operation. The first suspension assembly 18 may also include a rim that supports the tire 22, the rim and the tire 22 acting together to define a wheel. Referring to Fig. 2, the suspension assembly 18 comprises a wheel carrier 32, which supports the tire 22. The wheel carrier 32 is shown in dashed lines in Fig. 2 for illustrative purposes only. The wheel carrier 32 supports the wheel, which comprises the rim and the tire 22, so that the wheel can rotate about the first axis 24 independently of the wheel carrier 32. Consequently, the wheel carrier 32 does not rotate about the first axis 24. When the vehicle 12 brakes, a braking force is exerted on the tire 22 at the contact patch center point 30, generating one or more reaction forces through the first suspension assembly 18. To brake the vehicle 12, a braking mechanism can be arranged between the tire 22 and the wheel carrier 32 to slow down, stop, or prevent the rotation of the tire 22 about the first axis 24, thereby slowing down or stopping the movement of the vehicle 12. Referring to Fig. 2 and Fig. 5, a first plane 34 intersects the wheel carrier 32 horizontally at the first axis 24. The first plane 34 divides the wheel carrier 32 into an upper section and a lower section. Generally, the lower section of the wheel carrier 32 is closer to the ground plane 16 than the upper section of the wheel carrier 32. The first plane 34 can divide the wheel carrier 32 into equal or unequal sections. With further reference to Fig. 2 and Fig. 5, the first suspension assembly 18 also includes a first handling connecting element 36 and a second handling connecting element 38. The first handling connecting element 36 has a first distal end 40 that is coupled to the wheel carrier 32 above the first level 34. Furthermore, the second handling connecting element 38 has a second distal end 42 that is coupled to the wheel carrier 32 below the first level 34. A handling axis 44 intersects both the first and the second distal ends 40, 42 of the first and second handling connecting elements 36, 38, respectively. In general, the first and the second handling connecting elements 36, 38 contribute to maintaining a rigid front suspension system 10. Additionally, the first and second handling connecting elements 36, 38 can counteract loads when the vehicle 12 is performing a turn, i.e.moves along a curve of the road. With further reference to Fig. 2 and Fig. 5, the first suspension assembly 18 further comprises a first drive connection element 46 and a second drive connection element 48. The first drive connection element 46 has a third distal end 50 which is coupled to the wheel carrier 32 above the first level 34. Furthermore, the second drive connection element 48 has a fourth distal end 52 which is coupled to the wheel carrier 32 below the first level 34. A driving axis 54 intersects both the third and the fourth distal ends 50, 52 of the first and second driving connecting elements 46, 48, respectively. In general, the first and second driving connecting elements 46, 48 support the provision of smooth driving behavior of the vehicle 12. In addition, the first and second driving connecting elements 46, 48 can counteract loads acting in the forward and reverse directions (i.e.,forward and reverse loads), for example when the vehicle accelerates or brakes. The first, second, third, and fourth distal ends 40, 42, 50, 52 can be coupled to the wheel carrier 32 in a ball-and-socket configuration or any other suitable configuration. Regarding the ball-and-socket configuration, the wheel carrier 32 can, for example, have multiple ball studs attached to it, and the first, second, third, and fourth distal ends 40, 42, 50, 52 can each have a socket in which a respective ball stud is located. The ball studs can be angled as desired to allow for a projection spacing. Adjacent to the wheel, space is limited, and therefore the position of the first and second handling connecting elements 36, 38 and the first and second driving connecting elements 46, 48 can improve the performance of the vehicle 12. The first distal end 40 of the first handling connecting element 36 and the third distal end 50 of the first driving connecting element 46 are tightly packed together and high on the wheel carrier 32 above the first plane 34 for camber and tilt stiffness. The second distal end 42 of the second handling connecting element 38 and the fourth distal end 52 of the second driving connecting element 48 are tightly packed together to maintain camber stiffness and support during braking.Specifically, moving the first handling connecting element 36 and the first driving connecting element 46 relative to each other and / or moving the second handling connecting element 38 and the second driving connecting element 48 relative to each other can improve the performance of the vehicle 12, as further explained below. As best shown in Figs. 5 and 6, the first and / or the second driving connection element 46, 48 are arranged offset relative to the first and second handling connection elements 36, 38, respectively, to minimize a lateral distance 56 between the handling axis 44 and the driving axis 54 along the ground plane 16 at the points where the handling axis 44 and the driving axis 54 intersect the ground plane 16. As explained above, the contact surface center point 30 is located where the tire central axis 26 and the outer surface 28 of the tire 22 intersect the ground plane 16. The handling axis 44 and the driving axis 54 intersect the ground plane 16, and the lateral distance 56 is located between the points where the handling axis 44 and the driving axis 54 intersect the ground plane 16. Therefore, the transverse distance 56 between the handling axis 44 and the driving axis 54 runs adjacent to the center of the contact surface 30 along the ground plane 16. The phrase "and / or" should be interpreted as encompassing a non-exclusive logical "or," meaning at least one of the first drive-connecting element 46 or the second drive-connecting element 48. Therefore, in certain embodiments, the first drive-connecting element 46 is displaced relative to the first handling-connecting element 36, or the second drive-connecting element 48 is displaced relative to the second handling-connecting element 38. In other embodiments, the first drive-connecting element 46 is displaced relative to the first handling-connecting element 36, and the second drive-connecting element 48 is displaced relative to the second handling-connecting element 38. Minimizing the lateral distance 56 can minimize feedback in a steering mechanism when the vehicle 12 is cornering. Feedback in the steering mechanism can be caused by traction forces (i.e., during acceleration) and / or braking forces (i.e., during deceleration). Therefore, the feedback that a driver can perceive in a steering wheel is minimized by this configuration of the front suspension system 10. For example, any vibration and / or pulling felt in the steering wheel can be minimized by this configuration of the front suspension system 10. Simply put, unwanted torques in the steering wheel can be minimized with this configuration of the front suspension system 10, as further explained below. Referring to Fig. 5, the fourth distal end 52 of the second drive-connecting element 48 is spaced transversely from the handling axis 44 by a distance 58 on the drive axis 54, where the distance 58 is approximately 42.0 millimeters (mm) to approximately 54.0 mm, in order to minimize the transverse distance 56 between the handling axis 44 and the drive axis 54. Minimizing the distance 58 between the fourth distal end 52 of the second drive-connecting element 48 on the drive axis 54 and the handling axis 44 minimizes the transverse distance 56 between the handling axis 44 and the drive axis 54 along the floor plane 16 where the handling axis 44 and the drive axis 54 intersect the floor plane 16. As an example, the distance 58 is approximately 42.0 mm. The transverse distance 56 can be minimized by displacing the second drive connecting element 48 relative to the handling connecting element 38. As best shown in Fig. 2 and Fig. 5, the second drive connecting element 48 is, for example, arranged at least partially above the second handling connecting element 38 in a transversely spaced relationship such that the second drive connecting element 48 is displaced with respect to the second handling connecting element 38. In other words, the second drive connecting element 48 is vertically displaced with respect to the second handling connecting element 38.In certain embodiments, the fourth distal end 52 of the second drive-connecting element 48 is arranged along the drive axis 54 at least partially above the second distal end 42 of the second handling-connecting element 38 in a transversely spaced relationship such that the second drive-connecting element 48 is displaced relative to the second handling-connecting element 38. By raising the second drive-connecting element 48 relative to the second handling-connecting element 38, the second distal end 42 can be moved closer to the handling axis 44, thereby minimizing the transverse distance 56. Referring to Fig. 7, the first handling connecting element 36 can extend substantially along a first connecting axis 60, and the second handling connecting element 38 can extend substantially along a connecting axis 62. Additionally, the first driving connecting element 46 can extend substantially along a third connecting axis 64, and the second driving connecting element 48 can extend substantially along a fourth connecting axis 66. As best shown in Fig. 5, the fourth connecting axis 66 is therefore arranged above the second connecting axis 62 such that the second driving connecting element 48 is displaced relative to the second handling connecting element 38.In certain embodiments, the fourth connecting axis 66 is arranged above the second connecting axis 62 such that the fourth distal end 52 of the second driving connecting element 48 is displaced relative to the second distal end 42 of the second handling connecting element 38. The handling connecting elements 36, 38 and the driving connecting elements 46, 48 can have any suitable configuration. The reference to the fact that the handling connecting elements 36, 38 and the driving connecting elements 46, 48 extend substantially along their respective connecting axes 60, 62, 64, 66 serves to account for contours, etc., in the handling connecting elements 36, 38 and in the driving connecting elements 46, 48. For illustrative purposes only, the handling connecting elements 36, 38 and the driving connecting elements 46, 48 are shown schematically in Fig. 2 as being substantially straight, and the handling connecting elements 36, 38 and the driving connecting elements 46, 48 are shown in Figs. 5 and 7 as having contours.In certain embodiments, the handling connecting elements 36, 38 and the driving connecting elements 46, 48 can be substantially straight such that they run coaxially with their respective connecting axes 60, 62, 64, 66. Alternatively, in other embodiments, as shown in Figs. 5 and 7, the handling connecting elements 36, 38 and the driving connecting elements 46, 48 extend substantially along their respective connecting axes 60, 62, 64, 66, i.e., they do not run coaxially with their respective connecting axes 60, 62, 64, 66. Referring to Fig. 2, the handling connecting elements 36, 38 and the driving connecting elements 46, 48 each also have a proximal end 68, 70, 72, 74 for attaching the respective handling connecting elements 36, 38 and the driving connecting elements 46, 48 to the structure 14 of the vehicle 12. Specifically, the first handling connecting element 36 can have a first proximal end 68 spaced apart from the first distal end along the first connecting axis 60. Similarly, the second handling connecting element 38 can have a second proximal end 70 spaced apart from the second distal end 42 along the second connecting axis 62. Furthermore, the first driving connecting element 46 can have a third proximal end 72, which is spaced apart from the third distal end 50 along the third connecting axis 64.Similarly, the second driving connecting element 48 can have a fourth proximal end 74, which is spaced apart from the fourth distal end 52 along the fourth connecting axis 66. As shown in Fig. 2, the first, second, third, and fourth proximal ends 68, 70, 72, 74 therefore attach the respective handling connecting elements 36, 38 and the driving connecting elements 46, 48 to the structure 14. The handling connecting elements 36, 38 and the driving connecting elements 46, 48 are attached to the structure 14 in such a way that the handling connecting elements 36, 38 and the driving connecting elements 46, 48 can rotate at their respective proximal ends 68, 70, 72, 74 in response to road surface irregularities, steering maneuvers, etc. As shown in Fig. 2 and Fig.As shown in Figure 7, in certain embodiments the second handling connecting element 36 and the first driving connecting element 46 are both shorter in length than the second handling connecting element 38 and the second driving connecting element 48. As mentioned above, the lateral distance 56 can be minimized by displacing the first driving connecting element 46 relative to the first handling connecting element 36. As best shown in Fig. 7, for example, the third distal end 50 of the first driving connecting element 46 is spaced at least partially within the first distal end 40 of the first handling connecting element 36 away from the tire 22 in a laterally spaced relationship such that the first driving connecting element 46 is spaced from the first handling connecting element 36. With reference to the displacement of the second drive-connecting element 48 relative to the second handling-connecting element 38, and with reference to Fig. 5, the first and second connecting axes 60, 62 of the first and second handling-connecting elements 36, 38, respectively, can be spaced apart from each other by a first distance 76 along the handling axis 44. Furthermore, the third and fourth connecting axes 64, 66 of the first and second drive-connecting elements 46, 48, respectively, can be spaced apart from each other by a second distance 78 along the drive axis 54. The second distance 78 is shorter than the first distance 76, so that the second drive-connecting element 48 is displaced relative to the second handling-connecting element 38. As best shown in Fig. 2, the second drive-connecting element 48 is specifically arranged above the second handling-connecting element 38 relative to the ground plane 16.In other words, the second handling connecting element 38 is arranged closer to the ground plane 16 than the second driving connecting element 48. Furthermore, the fourth distal end 52 of the second driving connecting element 48 is arranged at least partially above the second distal end 42 of the second handling connecting element 38 in a transversely spaced relationship along the driving axis 54. The first and second handling connecting elements 36, 38, and the first and second driving connecting elements 46, 48 generate an imaginary steering axis 80, which can also be referred to as a virtual steering axis. When the wheel carrier 32 is pivoted to steer the vehicle 12, the imaginary steering axis 80 changes accordingly, and the tire 22 pivots accordingly about the imaginary steering axis 80. As explained above, the wheel carrier 32, in particular, carries the tire 22, and when the steering wheel is turned, the wheel carrier 32 and the tire 22 therefore pivot accordingly, thus changing the imaginary steering axis 80. Referring to Fig. 2 and Fig. 5, the imaginary steering axis 80 can extend transversely to the first axis 24 and can be arranged outwards towards the tire 22 from the first, second, third, and fourth distal ends 40, 42, 50, 52. In other words, the imaginary steering axis 80 is spaced away from the handling axis 44 and the driving axis 54 from the structure 14. Therefore, the imaginary steering axis 80 can be arranged near the tire's central axis 26 to minimize forces in the steering mechanism due to traction and braking forces. The imaginary steering axis 80 and the contact patch center 30 are spaced apart to define a steering roll radius 82 (see Fig. 8, taken from Fig. 2) where the imaginary steering axis 80 intersects the ground plane 16.Minimizing the lateral distance 56 between the handling axis 44 and the driving axis 54 along the ground plane 16 minimizes changes in the steering scrub radius 82 when the tire 22 is pivoted about the imaginary steering axis 80. In other words, the lateral distance 56 between the handling axis 44 and the driving axis 54 minimizes the steering scrub radius 82 when the tire 22 is pivoted about the imaginary steering axis 80. The imaginary steering axis 80 intersects the ground plane 16, and the steering scrub radius 82 is identified in Fig. 8 as being located between the contact patch center 30 and the imaginary steering axis 80 along the ground plane 16. The tire central axis 26 is shown in Fig. 2 at two different positions for a given tire 22 for illustrative purposes. Specifically, the tire central axis 26 is shown passing through the tire 22, which is separated from the wheel carrier 32. In the same figure, the tire central axis 26 is shown as if the tire 22 were coupled to the wheel carrier 32, to illustrate the relationship between the imaginary steering axis 80 and the tire central axis 26 when the tire 22 is coupled to the wheel carrier 32. Similarly, the tire central axis 26 is shown in Fig. 5 as if the tire 22 were coupled to the wheel carrier 32, to illustrate the relationship between the imaginary steering axis 80 and the tire central axis 26 when the tire 22 is coupled to the wheel carrier 32. The imaginary steering axis 80 changes when the wheel carrier 32 is moved to pivot the tire 22 about the imaginary steering axis 80. Therefore, controlling the movement of the imaginary steering axis 80 can control the scrub radius 82. In general, the scrub radius 82 changes when the tire 22 is pivoted about the imaginary steering axis 80. In other words, the wheel carrier 32 pivots when the steering wheel is turned to change the direction in which the vehicle 12 is moving, thus pivoting the tire 22 accordingly about the imaginary steering axis 80. Thus, the imaginary steering axis 80 changes when the steering wheel is turned. The scrub radius 82 creates a lever arm about the imaginary steering axis 80, which acts on or is transmitted to the wheel carrier 32 and subsequently acts on or is transmitted via the wheel carrier 32 to the steering mechanism.Specifically, the steering scrub radius 82 generates a side-to-side lever arm, not a forward-backward lever arm. By controlling the steering scrub radius 82 when the tire 22 pivots about the imaginary steering axis 80—that is, when the vehicle 12 is steered or turned around a curve—the feedback perceived by the driver can be minimized. A limited amount of space exists adjacent to the wheel, and therefore the positions of the first and second handling linkages 36, 38, and the first and second driving linkages 46, 48, can minimize the steering scrub radius 82. The steering scrub radius 82 is further explained below. Referring to Fig. 5, the first connecting axis 60 can intersect the imaginary steering axis 80 at a first point 84, and the second connecting axis 62 can intersect the imaginary steering axis 80 at a second point 86. Furthermore, the third connecting axis 64 can intersect the imaginary steering axis 80 at a third point 88, and the fourth connecting axis 66 can intersect the imaginary steering axis 80 at a fourth point 90. The fourth point 90 can intersect the imaginary steering axis 80 above the second point 86 such that the second driving connecting element 48 is displaced relative to the second handling connecting element 38. In other words, the second point 86 is located closer to the ground plane 16 than the fourth point 90. Therefore, the second driving connecting element 48 is located at least partially above the second handling connecting element 38 in a transversely spaced relationship.In certain embodiments, the first and third points 84, 88 intersect the imaginary steering axis 80 at the same position. Alternatively, the first and third points 84, 88 intersect the imaginary steering axis 80 at different positions (see Fig. 2). Referring to Fig. 7, the first distal end 40 of the first handling connecting element 36 is spaced a first length 92 from the imaginary steering axis 80 along the first connecting axis 60 at the handling axis 44. The third distal end 50 of the first driving connecting element 46 is spaced a second length 94 from the imaginary steering axis 80 along the third connecting axis 64 at the driving axis 54. The first length 92 is shorter than the second length 94, so that the third distal end 50 of the first driving connecting element 46 is displaced relative to the first distal end 40 of the first handling connecting element 36. Therefore, the third distal end 50 of the first driving connecting element 46 is at least partially spaced within the first distal end 40 of the first handling connecting element 36 in a transversely spaced relationship away from the tire 22. Referring to Figs. 2 and 5, the first suspension assembly 18 can also include a tie rod connecting element 96 coupled to the wheel carrier 32 to rotate the wheel carrier 32. The tie rod connecting element 96 is coupled to a rack that is coupled to the steering wheel. When the steering wheel is turned, the rack that moves the tie rod connecting element 96 moves, and the movement of the tie rod connecting element 96 rotates the wheel carrier 32 to pivot the tire 22 about the imaginary steering axis 80. In certain embodiments, the tie rod connecting element 96 crosses a top surface 98 of the second drive connecting element 48 (see Figs. 5 and 7). The tie rod connecting element 96 can be arranged in any suitable position and orientation to rotate the wheel carrier 32.The first and second handling linkages 36, 38, the first and second driving linkages 46, 48, and the tie rod linkage 96 can be described as a five-link front suspension assembly. Furthermore, the handling linkages 36, 38 and the driving linkages 46, 48 can be described as control arms. Additionally, the first suspension assembly 18 can further comprise a shock absorber 100 (see Fig. 2 and Fig. 5) which is attached to the second handling linkage 38. The shock absorber 100 is also attached to the structure 14 of the vehicle 12. The shock absorber 100 dampens the movement of the sprung mass of the vehicle 12. In certain embodiments, the shock absorber 100 is arranged between the first driving linkage 46 and the first handling linkage 36. The shock absorber 100 can have a coupling end 102 which is attached to the second handling linkage 38. Generally, the coupling end 102 is spaced apart from the distal end 42 of the second handling linkage 38 and from the wheel carrier 32. The shock absorber 100 has been removed from Fig. 7 for illustrative purposes only. With further reference to Fig. 2 and Fig. 5, the strut 100 can each have a coil spring 104 and a piston / rod / cylinder assembly 106. The coil spring 104 of the strut 100 at least partially surrounds the piston / rod / cylinder assembly 106 of the strut 100. It can be seen that the strut 100 can have components and configurations other than those described above. Referring again to both the first and second suspension assemblies 18, 20 mentioned above, these suspension assemblies 18, 20 work together. When the vehicle 12 applies the brakes in a curve, it is desirable to control the scrub radius 82 of the front wheels to minimize feedback in the steering wheel. Specifically, the pulling and / or shaking perceived by the driver in the steering wheel is minimized by controlling the scrub radius 82. When substantially equal braking forces are applied to the tires 22, a similar scrub radius 82 is applied to the respective tires 22, producing similar loads on the tie rod connecting elements 96, which substantially cancel each other out.Therefore, it is desirable that the lever arms generated by the steering roll radius 82 of the tires 22 when the vehicle 12 is driving around a curve and braking (thereby slowing down the vehicle 12) essentially cancel each other out in order to minimize the feedback perceived by the driver. Referring to the graph in Fig. 9, the scrub radius 82 can assume different values, depending on whether the vehicle 12 is traveling straight ahead, i.e., the tires 22 of both the first and second suspension assemblies 18, 20 are essentially straight, or whether the vehicle 12 is turning, i.e., the tires 22 of both the first and second suspension assemblies 18, 20 are pivoted. The scrub radius 82 of each tire 22 changes when the respective wheel carrier 32 pivots, due to the change in the imaginary steering axis 80 of each suspension assembly 18, 20. In other words, each of the tires 22 will pivot together when the steering wheel is moved, i.e., turned, to change the direction in which the vehicle 12 is moving. When the vehicle turns, for example, one wheel can pivot to the inside, and the other wheel can pivot to the outside.In general, the wheel that pivots inwards, i.e., performs a rotation inwards, can have a negative angle 116, and the wheel that pivots outwards, i.e., is rotated outwards, can have a positive angle 114. The graph in Fig. 9 represents a curve 108 to identify the relationship between the tires 22. The y-axis represents the steering scrub radius 82 of each tire 22 of the front suspension system 10 in millimeters (mm), and the x-axis represents an angle 110 (see Fig. 7) by which each tire 22 pivots, in degrees (°). A second plane 112, as shown in Fig. 7, is perpendicular to the first axis 24. In certain embodiments, the second plane 112 intersects the tire center axis 26. The second plane 112 represents that the vehicle 12 travels substantially straight along the road and that the tires 22 are therefore substantially straight, i.e., that the tires 22 are substantially parallel to each other. The tires 22 are described as substantially parallel to each other to account for camber angles, other variations, etc., between the wheels.Figure 7 represents the angle 110 by which the tires 22 can pivot relative to the second plane 112, encompassing both an inward and an outward rotation. For illustrative purposes, angle 110 denotes both the positive angle 114, i.e., an outward rotation, and the negative angle 116, i.e., an inward rotation. For Ackermann correction, the front wheels rotate with different radii in a curve. For example, one front wheel moves around a curve with a first radius, while a second front wheel moves around the curve with a second radius that differs from the first. Thus, when the vehicle 12 travels around a curve, the tire 22 that pivots towards the inside of the curve has an angle 110° that is larger than that of the other tire 22, since tire 22 is rotating around a circle with a smaller diameter. Therefore, the tires 22 generally do not pivot by exactly the same angle 110° when the vehicle 12 travels around a curve. When the vehicle 12 turns either left or right, the wheel carrier 32 pivots to change the imaginary steering axis 80, thereby pivoting the tire 22 relative to the second plane 112 by the desired angle 110 (the same occurs at the other wheel carrier 32 and the other tire 22). For example, if the tire 22 pivots to the inside of a curve, so that a front face of this tire 22 pivots away from the center of the vehicle 12, the angle 110 can be the negative angle 116. If the tire 22 pivots to the outside of a curve, so that a front face of this tire 22 pivots toward the center of the vehicle 12, the angle 110 can be the positive angle 114. Therefore, the positive numbers along the x-axis of the graph (Fig.9), that one tire 22 pivots by the positive angle 114, and the negative numbers along the x-axis of the graph represent that the other tire 22 pivots by the negative angle 116. Simply put, the angle 110 for a rotation of one tire 22 inwards is the negative angle 116 on the x-axis, and the angle 110 for a rotation of the other tire 22 outwards is the positive angle 114 on the x-axis. With further reference to the graph of Fig. 9, the negative numbers along the y-axis represent the negative scrub radius 82 of the respective tire 22, which occurs when the imaginary steering axis 80 is located outside the tire's central axis 26 (i.e.,, when the imaginary steering axis 80 is located on the ground plane 16 outside the tire central axis 26), and the positive numbers along the y-axis represent the positive steering roll radius 82 of the respective tire 22, which occurs when the imaginary steering axis 80 is located inside the tire central axis 26 (i.e., when the imaginary steering axis 80 is located on the ground plane 16 inside the tire central axis 26). It is desirable to compensate for the scrub radius 82, which is related to the steering forces between the tires 22, as explained above, in order to minimize the feedback perceived by the driver. Specifically, minimizing the difference between the scrub radii 82 when the tires 22 are pivoted together about the imaginary steering axis 80 of the respective tires 22 can minimize the feedback perceived by the driver. Therefore, the configuration of the front suspension system 10 described herein minimizes the difference between the scrub radius 82 of the first and second front suspension assemblies 18, 20. Additionally, the configuration of the front suspension system 10 described herein produces a substantially similar scrub radius 82 between the first and second front suspension assemblies 18, 20, as shown by curve 108 in Fig. 9.In other words, when the tire 22 of both the first and second suspension assemblies 18, 20 is pivoted to steer, i.e., to turn, the vehicle 12, the scrub radius 82 can change similarly between the tires 22. Simply put, curve 108 in Fig. 9 shows that the scrub radius 82 is essentially symmetrical between the tires 22 when the vehicle 12 is turning. For example, if the tires 22 are substantially parallel to each other, allowing the vehicle 12 to travel straight ahead, the angle 110 on the x-axis is 0 degrees (°), and the scrub radius 82 on the y-axis is approximately -5.5 mm for each of the tires 22. In another example, if the tires 22 are pivoted relative to the second plane 112 for a first turning radius of the vehicle 12, i.e., for a fully turned steering wheel or a maximum turn of the steering wheel, allowing the vehicle 12 to turn left or right, the difference in the scrub radius 82 between the tires 22 is less than 1.0 mm. For illustrative purposes only, the steering scrub radius 82 of each of the front wheels at the first turning radius is approximately 17.0 mm, and therefore the difference between the steering scrub radii 82 of each of the tires 22 is less than 1.0 mm, and it may be zero specifically for this example. Due to the Ackermann correction, the angle 110 around which each wheel rotates is different. For an intermediate turning radius of the vehicle 12, i.e., with the steering wheel turned halfway or with the steering wheel turned by half its maximum rotation, the tire 22 turning outwards, for example, has an angle 110 of approximately 15.0° with a scrub radius 82 of approximately 2.0 mm, and the tire 22 turning inwards has an angle 110 of approximately -18.0° with a scrub radius 82 of approximately 2.0 mm. For illustrative purposes only, the difference between the scrub radii 82 of each tire 22 at the intermediate turning radius is therefore less than 1.0 mm, and it can be zero in this particular example. The lateral distance 56 between the handling axis 44 and the driving axis 54 of the respective first and second suspension assemblies 18, 20 along the ground plane 16, where the handling axis 44 and the driving axis 54 of the respective first and second suspension assemblies 18, 20 intersect the ground plane 16, produces a difference in the steering roll radius 82 between the respective tires 22 of the first and second suspension assemblies 18, 20 of less than 3.0 mm when each tire 22 is pivoted together about the imaginary steering axis 80 of the respective first and second suspension assemblies 18, 20, regardless of whether the steering wheel is turned completely or whether any partial rotation of the steering wheel takes place.Therefore, the difference between the scrub radii 82 of the left and right tires 22 is minimized, thereby minimizing the feedback perceived by the driver when braking during a steering wheel turn for cornering the vehicle 12. The curve 108 shown in Fig. 9 demonstrates that the scrub radius 82 between the respective tires 22 for inside / outside turns when the vehicle 12 is cornering is substantially proportional to each other. Furthermore, the front suspension system 10 described herein improves the Ackermann steering correction of the vehicle 12, thereby minimizing the vibration perceived in the steering wheel when the vehicle 12 is cornering. For example, the front suspension system 10 can achieve an Ackermann correction of sixty percent or greater to minimize vibration.

Claims

Front suspension assembly (18, 20) for a vehicle (12), the suspension assembly (18, 20) comprising: a tire (22) rotatable about a first axis (24), wherein a tire central axis (26) passes through the tire (22) perpendicular to the first axis (24), and wherein the tire (22) has an outer surface (28) with a contact surface center (30) that is a point on the tire central axis (26), wherein a ground plane (16) intersects the contact surface center (30) transversely to the tire central axis (26); a wheel carrier (32) supporting the tire (22), wherein a first plane (34) intersects the wheel carrier (32) horizontally at the first axis (24); a first handling connecting element (36) having a first distal end (40) extending above the first plane (34) is coupled to the wheel carrier (32);a second handling connecting element (38) having a second distal end (42) coupled to the wheel carrier (32) below the first level (34), wherein a handling axis (44) intersects both the first and the second distal end (42) of the first and second handling connecting elements (36, 38), respectively; a first driving connecting element (46) having a third distal end (50) coupled to the wheel carrier (32) above the first level (34); a second driving connecting element (48) having a fourth distal end (52) coupled to the wheel carrier (32) below the first level (34), wherein a driving axis (54) intersects both the third and the fourth distal end (50, 52) of the first and second driving connecting elements (46, 48), respectively;wherein the first and / or the second drive connecting element (46, 48) are arranged offset relative to the respective first and second handling connecting elements (36, 38) in order to minimize a transverse distance (56) between the handling axis (44) and the drive axis (54) along the floor plane (16) where the handling axis (44) and the drive axis (54) intersect the floor plane (16); wherein: the first handling connecting element (36) extends substantially along a first connecting axis (60); the second handling connecting element (38) extends substantially along a second connecting axis (62); the first drive connecting element (46) extends substantially along a third connecting axis (64); the second drive connecting element (48) extends substantially along a fourth connecting axis (66); the third connecting axis (64) is arranged above the second connecting axis (62);and the second driving connecting element (48) is displaced relative to the second handling connecting element (38), characterized in that the suspension assembly (18, 20) further comprises an imaginary steering axis (80) extending transversely to the first axis (24) and arranged outwards in the direction of the tire (22) from the first, second, third and fourth distal ends (40, 42, 50, 52); wherein the first connecting axis (60) intersects the imaginary steering axis (80) at a first point (84); wherein the second connecting axis (62) intersects the imaginary steering axis (80) at a second point (86); wherein the third connecting axis (64) intersects the imaginary steering axis (80) at a third point (88); wherein the fourth connecting axis (66) intersects the imaginary steering axis (80) at a fourth point (90) cuts;and wherein the fourth point (90) intersects the imaginary steering axis (80) above the second point (86), so that the second driving linkage element (48) is displaced with respect to the second handling linkage element (38). Suspension assembly (18, 20) according to claim 1, wherein the second drive connecting element (48) is arranged at least partially in a transversely spaced relationship above the second handling connecting element (38) such that the second drive connecting element (48) is displaced relative to the second handling connecting element (38). Suspension assembly (18, 20) according to claim 1, wherein the third distal end (50) of the first driving connecting element (46) is at least partially spaced within the first distal end (40) of the first handling connecting element (36) in a transversely spaced relationship away from the tire (22) such that the first driving connecting element (46) is spaced away from the first handling connecting element (36). Suspension assembly (18, 20) according to claim 1, wherein: the first and second connecting axes (60, 62) of the first and second handling connecting element (36, 38) are spaced apart from each other by a first distance (76) along the handling axis (44); and the third and fourth connecting axes (64, 66) of the first and second driving connecting element (46, 48) are spaced apart from each other by a second distance (78) along the driving axis (54), wherein the second distance (78) is shorter than the first distance (76), so that the second driving connecting element (48) is displaced with respect to the second handling connecting element (38). Suspension assembly (18, 20) according to claim 1, wherein: the imaginary steering axis (80) and the contact surface center point (30) are spaced apart to define a steering roll radius (82) where the imaginary steering axis (80) intersects the ground plane (16); and the lateral distance (56) between the handling axis (44) and the driving axis (54) minimizes the steering roll radius (82) when the tire (22) is pivoted about the imaginary steering axis (80). Suspension assembly (18, 20) according to claim 1: wherein the first distal end (40) of the first handling connecting element (36) is spaced apart from the handling axis (44) by a first length (92) with respect to the imaginary steering axis (80) along the first connecting axis (60); wherein the third distal end (50) of the first driving connecting element (46) is spaced apart from the driving axis (54) by a second length (94) with respect to the imaginary steering axis (80) along the third connecting axis (64); and wherein the first length (92) is shorter than the second length (94) such that the third distal end (50) of the first driving connecting element (46) is displaced with respect to the first distal end (40) of the first handling connecting element (36). Suspension assembly (18, 20) according to claim 6, wherein: the imaginary steering axis (80) and the contact surface center point (30) are spaced apart to define a steering roll radius (82) where the imaginary steering axis (80) intersects the ground plane (16); and the lateral distance (56) between the handling axis (44) and the driving axis (54) minimizes the steering roll radius (82) when the tire (22) is pivoted about the imaginary steering axis (80). Suspension assembly (18, 20) according to claim 1, wherein the fourth distal end (52) of the second drive connecting element (48) is spaced at the drive axis (54) in the transverse direction from the handling axis (44) by a distance (58), wherein the distance (58) is approximately 42.0 mm to approximately 45.0 mm in order to minimize the transverse distance (56) between the handling axis (44) and the drive axis (54).

Images