Patent Application
20210394818
The disclosure relates to a vehicle steering mechanism. More particularly, the disclosure relates to a steering mechanism that does not include a rack and pinion.
A vehicle steering system includes a bar, an actuator, a roller, and a yoke. The bar has an anti-rotation section. The anti-rotation section has a flat surface. The bar is adapted for pivotable connection to a respective connecting rod at each end. The actuator is configured to translate the bar along a bar axis in response to rotation of an electric motor. The roller is in rolling contact with the flat surface to prevent rotation of the bar about the bar axis and limit deflection of the bar. The yoke contacts the bar opposite the roller to prevent translation of the bar perpendicular to the bar axis. The actuator may include a ball nut engaging a threaded portion of the bar via rollers such that rotation of the ball nut results in translation of the bar. The bar may not have a toothed section configured to mesh with a pinion gear. The bar may slide with respect to the yoke.
An actuator is suitable for a vehicle steering system which includes two knuckles, two wheels, and two connecting rods. Each of the two knuckles is supported to pivot about respective vertical axes and each defines respective wheel axes. Each if the two wheels is supported for rotation about a respective one of the wheel axes. Each of the two connecting rods is pivotably connected to a respective knuckle. The actuator includes a bar, a roller, and a yoke. The bar is pivotably connected to the two connecting rods. The bar has an anti-rotation section. The anti-rotation section has a flat surface. The roller contacts the flat surface to prevent rotation of the bar about a bar axis. The yoke contacts the bar opposite the roller to prevent translation of the bar perpendicular to the bar axis. The actuator may also include a motor driveably connected to a ball screw drive. The ball screw drive engages a threaded section of the bar to translate the bar along the bar axis in response to operation of the motor. The actuator may also include a belt driveably connecting the motor to the ball screw drive. The bar may not have a toothed section configured to mesh with a pinion gear.
A vehicle steering system includes a bar, a ball screw, a roller, and a yoke. The bar has a threaded section and an anti-rotation section. The anti-rotation section has a flat surface. The ball screw drive engages the threaded section to translate the bar along a bar axis. The roller contacts the flat surface to prevent rotation of the bar about the bar axis. The yoke contacts the bar opposite the roller to prevent translation of the bar perpendicular to the bar axis. The bar may slide with respect to the yoke. The bar may not have a toothed section configured to mesh with a pinion gear. The steering system may also include a motor driveably connected to the ball screw drive, for example by a belt. The steering system may also include a first knuckle and a first connecting rod. The first knuckle is configured to pivot about a first vertical axis. The first knuckle defines a first wheel axis. The first connecting rod pivotably connects at a first rod end to a first end of the bar and pivotably connected at a second rod end to the knuckle. A first wheel may be supported for rotation about the first wheel axis. The steering system may also include a second knuckle and a second connecting rod. The second knuckle is configured to pivot about a second vertical axis. The second knuckle defines a second wheel axis. The second connecting rod is pivotably connected at a third rod end to a second end of the bar and pivotably connected at a fourth rod end to the second knuckle. A second wheel may be supported for rotation about the second wheel axis.
Embodiments of the present disclosure are described herein. It should be appreciated that like drawing numbers appearing in different drawing views identify identical, or functionally similar, structural elements. Also, it is to be understood that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the embodiments. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.
The terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the following example methods, devices, and materials are now described.
Autonomous vehicles are steered by a control unit as opposed to a human driver. Therefore, the steering wheel 10 and shaft 12 of
Bar 14′ does not have a toothed section. Instead, it has a flat section 46. A roller 48 is supported in place of the pinion gear and is in rolling contact with flat section 46. As shown in
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the disclosure that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. As such, to the extent any embodiments are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments are not outside the scope of the disclosure and can be desirable for particular applications.
