Steering column assembly for vehicle

Abstract

A steering column assembly (10) for a vehicle, comprising: an elongate steering column (20) rotatably mounted about a longitudinal axis (L) configured for attachment of a steering wheel (A) at one end; a first gear (40) configured to rotate with the elongated steering column (20); a motor (80) having an output portion that meshes with the first gear (40); and first and second bearings (50, 60) configured for rotatable mounting of the elongate steering column (20) and located on one side of the first gear (40) along the longitudinal axis (L), where the first and second bearings (50, 60) are spaced from each other along the longitudinal axis (L).

Description

Technical Field

[0001] The present invention relates generally to steering column assemblies for vehicles, and more particularly to steering column assemblies for steer-by-wire vehicles. More particularly, although not exclusively, the present invention relates to steering column assemblies, steer-by-wire systems including such steering column assemblies, and vehicles including such steering column assemblies. Steering column assemblies of the type used in steer-by-wire vehicles are typically part of a torque feedback element, generally referred to as a handwheel actuator or handwheel actuator system, or form part of a handwheel actuator or handwheel actuator system. Background Art

[0002] In a steer-by-wire arrangement, a steering wheel is connected to one end of a rotatably mounted steering column, the angular displacement of which is measured to generate a signal which is used to control the orientation of the vehicle's steering wheels. The arrangement is also typically provided with an electric torque motor connected to the steering column to provide a controlled amount of torque in the opposite direction to the torque applied by the driver, thereby providing the driver with a sense of road feel. The electric torque motor typically forms part of a torque feedback element.

[0003] Torque is applied to the steering column via a gear mounted on the steering column and rotatable therewith. It has been found that misalignment between the gear rotatable therewith and the output of the electric torque motor can lead to excessive wear of the components and eventual failure. Various support devices have been provided to the steering shaft and gear in an attempt to maintain proper alignment, but these devices are often difficult to assemble and require a large packaging volume.

[0004] It would be desirable to provide a steering column assembly in which proper alignment is maintained between a gear that rotates with the steering column and the output of an electric torque motor while minimizing packaging volume. Summary of the invention

[0005] It has been found that the above mentioned problems can be solved by providing a steering column assembly in which a pair of bearings are provided on one side of a gear which is rotatable with the steering column.

[0006] According to the present invention, a steering column assembly for a vehicle comprises:

[0007] an elongated steering column or steering shaft (hereinafter referred to as steering column) which is rotatably mounted about a longitudinal axis and configured at one end for attachment of a steering wheel;

[0008] a first gear configured to rotate with the elongated steering column;

[0009] a motor having an output engaged with the first gear; and

[0010] a first bearing and a second bearing configured for rotational mounting of the elongated steering column and located on one side of the first gear along the longitudinal axis,

[0011] Wherein, the first bearing and the second bearing are spaced apart from each other along the longitudinal axis.

[0012] Advantageously, providing a pair of bearings on the same side of the first gear that is rotatable with the steering column allows for easier control of the position of the first gear relative to the worm gear(s) and / or worm(s). This ensures that correct alignment is maintained between the meshing gears so that friction and wear are minimized.

[0013] Furthermore, the arrangement of the bearing relative to the first gear allows for a reduction in the overall packaging volume and total number of parts of the steering column assembly as compared to arrangements where the bearings are located on both sides of the first gear.

[0014] Furthermore, by arranging the bearings in this manner, manufacture of the steering column assembly is simplified.

[0015] The steering column assembly may be or may include a hand wheel actuator system.

[0016] The first gear and the motor may form part of a torque feedback element.

[0017] The steering wheel may also be referred to as a hand wheel or a hand wheel transmission in other cases.

[0018] The steering column assembly may include a sensor or sensor module mounted or secured to the elongated steering column. The sensor or sensor module may extend around the elongated steering column.

[0019] It will be appreciated that by providing a sensor or sensor module mounted to an elongated steering column, the need for a separate sensor housing is eliminated, thereby reducing the size of the overall steering column assembly.The sensor or sensor module may be located within a housing of the steering column assembly.

[0020] The first bearing and / or the second bearing may extend around the elongated steering column.

[0021] In one embodiment, the first gear is located between the ends of the elongated steering column. The first gear may be located between a first end and a second end of the elongated steering column. The first end may be an upper end. The second end may be a lower end. The first end may be configured for attachment of a steering wheel.

[0022] The second end may define or include an output shaft. The output shaft may form part of the torque feedback element.

[0023] The first gear may be located midway along the elongated steering column.The first gear may be or may include a worm gear.

[0024] The first bearing and the second bearing may be located between the first gear and an end of the elongated steering column opposite an end configured for attachment of the steering wheel.

[0025] The first bearing and the second bearing may be located between the first gear and the second or lower end of the elongated steering column.

[0026] The first bearing and / or the second bearing may be configured to hold or maintain a position of the first gear along the longitudinal axis.The first bearing and the second bearing may operate together to hold or maintain a position of the first gear along the longitudinal axis.

[0027] In one embodiment, the first bearing and / or the second bearing may be or include an annular bearing. The annular bearing may be or include a roller bearing.

[0028] Each of the first bearing and the second bearing may be or include an annular bearing.

[0029] In one embodiment, a diameter (eg, inner diameter and / or outer diameter) of the first bearing is different than a diameter (eg, inner diameter and / or outer diameter) of the second bearing.

[0030] The diameter (eg, inner diameter and / or outer diameter) of the first bearing may be greater than the diameter (eg, inner diameter and / or outer diameter) of the second bearing.

[0031] In one embodiment, the diameter (eg, inner diameter and / or outer diameter) of the first bearing is equal to the diameter (eg, inner diameter and / or outer diameter) of the second bearing.

[0032] The diameter (eg, inner diameter and / or outer diameter) of the first bearing may be equal to the diameter (eg, inner diameter and / or outer diameter) of the second bearing.

[0033] The first bearing may be located between the first gear and the second bearing.

[0034] Each of the first bearing and the second bearing can be received on an end of the elongated steering column. Each of the first bearing and the second bearing can be received on a lower end of the elongated steering column or on an end of the elongated steering column opposite to an end for attaching a steering wheel.

[0035] The elongated steering column may include an annular step or shoulder. The first gear may be located between the annular step and the first bearing.

[0036] In one embodiment, a portion of the first bearing abuts a portion of the first gear such that the first gear is retained or captured between the annular step and the first bearing.

[0037] The first bearing and / or the second bearing may retain the first gear on the elongated steering column.

[0038] The elongated steering column may include a further annular step or shoulder.The second bearing may abut the further annular step.

[0039] The steering column assembly may include an annular retaining ring, an annular fixing nut or a nut (hereinafter referred to as an annular retaining ring).

[0040] The annular retaining ring may be located between the second bearing and a lower end of the elongated steering column, or may be located between the second bearing and an end of the elongated steering column opposite an end configured for attachment of a steering wheel.

[0041] An annular retaining ring may be received on the end of the elongated steering column.

[0042] The annular retaining ring may be received on a lower end of the elongated steering column or on an end of the elongated steering column opposite an end configured for attachment of a steering wheel.

[0043] The annular retaining ring may abut the second bearing.

[0044] The steering column assembly may include a housing.

[0045] The first gear, the first bearing and / or the second bearing may be enclosed within the housing.

[0046] The first gear, the first bearing and / or the second bearing may be located within the housing.

[0047] In one embodiment, the first bearing and the second bearing are configured to provide support for the first gear within the housing along or in the direction of the longitudinal axis.

[0048] The first bearing and the second bearing may each be positioned or located between the elongated steering column and the housing.

[0049] An inner surface of each bearing may contact an outer surface of the elongated steering column, and an outer surface of each bearing may contact an inner surface of the housing.

[0050] The first bearing may be press-fitted on the elongated steering column. The second bearing may be press-fitted in the housing. The first bearing and / or the second bearing may be received in a bearing seat, such as inside the housing.

[0051] The steering column assembly may include an end plate, and the sensor or sensor module may be located between the housing and the end plate. The elongated steering column may extend through the end plate, such as through a hole in the end plate.

[0052] The output of the motor may comprise a worm gear or worm meshing with the first gear.

[0053] The steering column assembly may include a pair of motors. Each motor may have a corresponding motor output. Each output may include a corresponding worm gear meshing with the first gear. The pair of motors and / or the corresponding worm gear may form part of a torque feedback element.

[0054] The steering column assembly may include a controller, such as an electronic control unit (ECU), configured to control the motor output of each motor.

[0055] The steering column assembly may include a first worm and a second worm. Each of the first worm and the second worm may be driven by a corresponding motor, wherein the worms are both meshed with the first gear.

[0056] In one embodiment, the worm meshes with the first gear on diametrically opposite sides of the first gear.

[0057] The worm(s) and the first gear may form or comprise a worm gear set.

[0058] In one embodiment, the first gear is press fit onto the elongated steering column or output.

[0059] In one embodiment, the first gear is over-molded onto the elongated steering column or output portion.

[0060] The elongated steering column may comprise a plurality of parts or sections. The elongated steering column may comprise two parts or sections.

[0061] The first gear, the first bearing and / or the second bearing may be located on the first component or section. The first component or section may be or may include an output shaft. The output shaft may form a torque feedback element or a part thereof.

[0062] The elongated steering column assembly may include a second component or section that can be connected to the first component or section. The first component or section may be connected to the first component or section via a torsion bar. The first component or section may be connected to the second component or section via a threaded connection. The second component or section may be or may include an input shaft.

[0063] The second component or section may be configured at the free end for attachment of a steering wheel or hand wheel actuator.

[0064] The first component or section may include an annular retaining ring.

[0065] The first component or section of the elongated steering column may be enclosed or located within the housing.The housing may form a torque feedback element or a part thereof.

[0066] Another aspect of the present invention provides a steering column assembly for a steer-by-wire vehicle as described above.

[0067] Another aspect of the present invention provides a steer-by-wire system including the above-mentioned steering column assembly.

[0068] Another aspect of the present invention provides a vehicle including the above steering column assembly or the above steer-by-wire system.

[0069] It should also be noted that the housing receives multiple components of the assembly, including the motor, first and second gears, worm, bearings, torque sensor and housing for the MTL, which are then secured by covers that are either separate or part of the assembly. This simplifies the design by eliminating the complexity of assembling multiple component housings. In addition, it facilitates the correct positioning of all components in the assembly.

[0070] For the avoidance of doubt, any feature described herein is equally applicable to any aspect of the present invention.

[0071] Another aspect of the present invention provides a computer program element that includes and / or describes and / or defines a three-dimensional design for use with simulation means or three-dimensional additive or subtractive manufacturing means or equipment (such as a 3D printer or CNC machine tool), the three-dimensional design including an embodiment of the above-mentioned steering column assembly.

[0072] Within the scope of the present application, it is expressly intended that the various aspects, embodiments, examples and alternatives listed in the preceding paragraphs, claims and / or the following description and drawings, in particular their individual features, may be used independently or in any combination. That is, all embodiments and / or the features of any embodiment may be combined in any manner and / or combination unless these features are incompatible. For the avoidance of doubt, the terms "may", "and / or", "for example", "such as" and any similar terms used herein should be interpreted as non-restrictive, so that any feature described does not necessarily exist. In fact, without departing from the scope of the present invention, any combination of optional features may be explicitly envisioned, whether or not these features are explicitly claimed for protection. The applicant reserves the right to modify any initially filed claims accordingly or to submit any new claims, including the right to modify any initially filed claims to make them dependent on and / or include any features of any other claims, even if the claims were not initially made in this manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0074] Figure 1 is a schematic diagram of a steer-by-wire system according to the present invention;

[0075] Figure 2 is a side cross-sectional view of a steering column assembly according to an embodiment of the present invention taken through a longitudinal axis of an elongated steering column;

[0076] Figure 3 is taken through the longitudinal axis of the slender steering column Figure 2 a side cross-sectional view of the device; and

[0077] Figure 4 is a side cross-sectional view of a longitudinal axis steering column assembly according to another embodiment of the present invention, taken through the longitudinal axis of the elongated steering column. DETAILED DESCRIPTION

[0078] Figure 1 A steer-by-wire system S for a vehicle according to the present invention is shown, the steer-by-wire system comprising a steering column assembly or handwheel actuator system 10 (hereinafter referred to as the steering column assembly). The steer-by-wire system S includes a handwheel actuator in the form of a steering wheel or handwheel actuator A (hereinafter referred to as the steering wheel) to allow the vehicle driver to provide input steering commands. The steering wheel A is connected to the end of an elongated steering column or shaft 20 (hereinafter referred to as the steering column).

[0079] Steering input applied via the steering wheel A is measured by a steering sensor which forms part of the steering column assembly. Figure 1 Schematically shown as C. A signal representing the steering input (i.e., the rotation of the steering wheel A and the steering column 20) is transmitted from the sensor C to the electronic control unit (ECU) D, which in turn controls the steering shaft actuator E, such as the front axle actuator (FAA). The steering shaft actuator E applies the steering input to the steering shaft F, thereby steering the steered wheel G according to the rotational position of the steering wheel A.

[0080] The electronic control unit D is also configured to supply current to a torque feedback motor 80 connected to the elongated steering column 20 and applying a torque opposite to the torque applied at the steering wheel A, so as to provide the driver with a sense of "road feel". In this embodiment, the torque feedback motor 80 forms part of a torque feedback unit (TFU).

[0081] Figure 2 and Figure 3 A first variation of the steering column assembly 10 is shown, which is formed Figure 1 The steering column assembly 10 includes an elongated steering column 20 mounted for rotation about its longitudinal axis L and having a first end 22 with a connection feature 22a for a steering wheel A ( Figure 1 ). The first gear 40 is located between the first end 22 and the second end 24 and is configured to rotate with the elongated steering column 20. The first gear 40 may also be referred to as a wheel gear in other cases.

[0082] As will be described in greater detail below, the first gear 40 meshes with the output of each of two identical torque feedback motors 80 that are operable to apply torque in a direction opposite to the torque applied by the steering wheel A. The first bearing 50 and the second bearing 60 each extend around the elongated steering column 20 and are located between the first gear 40 and the second end 24 .

[0083] As will be described in more detail below, the bearings 50, 60 support the rotation of the elongated steering column 20 and maintain the position of the first gear 40 in the direction of the longitudinal axis L within the housing 70. By maintaining the position of the first gear 40, proper meshing between the first gear 40 and the output of the torque feedback motor 80 can be maintained, which helps to minimize component friction and wear.

[0084] The elongated steering column 20 is composed of two parts, namely a first section 20a and a second section 20b connected together by a torsion bar 26 having a pair of opposing external spline heads 26a, 26b. Each of the spline heads 26a and 26b is press-fitted into a corresponding flat recess of the first section 20a and the second section 20b. As will be described in more detail below, the first gear 40, the first bearing 50 and the second bearing 60 are located on the first section 20a, which is a hollow tubular portion extending to the second end 24 located in the housing 70. In this embodiment, the first section 20a can be an output shaft (OPS) or can include an output shaft (OPS).

[0085] In the present embodiment, the second section 20 b is a solid rod having a flat concave portion 22 b extending in the direction of the longitudinal axis L at its lower end (the lower end being opposite to the first end 22 ).

[0086] The first section 20 a includes a first radially extending annular step or shoulder 28 , a second radially extending annular step or shoulder 30 , and a third radially extending annular step or shoulder 32 (hereinafter referred to as annular steps) sequentially spaced from one another along the longitudinal axis L. The annular steps 28 , 30 , 32 all face the second end 24 and provide a stepped profile along the first section 20 a of the elongated steering column 20 such that the outer diameter of the first section decreases toward the second end 24 .

[0087] Specifically, the first portion 34 having a first outer diameter is located between the annular steps 28 and 30; the second portion 36 having a second outer diameter smaller than the first outer diameter is located between the annular steps 30 and 32; and the third portion 38 having a third outer diameter smaller than the second outer diameter is located between the third annular step 32 and the second end 24. The second portion 36 is shorter than the first portion 34 or the third portion 38 in the direction of the longitudinal axis L.

[0088] The first gear 40 is received on the second end 24 and is press-fitted onto the first portion 34 of the elongated steering column 20 until the first gear abuts the first annular step 28. The first gear 40 has a plurality of teeth 42 arranged around its circumference that mesh with the output of the torque feedback motor 80. The first gear 40 also includes a radially extending planar abutment surface 44 on the upper side that abuts the first annular step 28 and a longitudinally extending inner collar 46 that contacts the first portion 34. The abutment surface 44 extends radially beyond the first annular step 28 and both act together to prevent movement of the first gear 40 along the longitudinal axis L beyond the first annular step 28 toward the first end 22.

[0089] An annular recess 48 is provided on the underside of the first gear wheel 40 and on the radial outer side of the inner collar 46 .

[0090] The first bearing 50 is an annular bearing and is located between the first gear 40 and the second bearing 60. The first bearing 50 is received on the second end 24 and has an inner race 52 that is press-fitted on the first portion 34 of the elongated steering column 20. The upper side of the inner race 52 abuts against the free end of the inner collar 46 to retain the first gear 40 between the first annular step 28 and the first bearing 50. The radially outer surface of the outer race 54 contacts the first inner surface 72 of the housing 70, and the lower side of the outer race 54 contacts the shoulder 76 adjacent to the first inner surface 72 of the housing 70. The inner race 52 and the outer race 54 together contain a plurality of spherical bearings 56 to facilitate supported rotation of the first section 20a relative to the housing 70.

[0091] The second bearing 60 is also an annular bearing and is located between the first bearing 50 and the second end 24 of the elongated steering column 20. The second bearing 60 is received on the second end 24, and the inner diameter of the second bearing is smaller than the inner diameter of the first bearing 50. The second bearing 60 is spaced from the first bearing 50 along the longitudinal axis L, and the second bearing has an inner race 62, which is mounted on the second portion 36 of the elongated steering column 20 and abuts the second annular step 30. The radial outer surface of the outer race 64 is press-fitted into the second inner surface 74 of the housing 70, and the outer race 64 includes a pair of O-rings 66. It will be appreciated that the O-rings 66 are optional.

[0092] Similar to the first bearing 50, the inner race 62 and the outer race 64 together include a plurality of spherical bearings 68 to further facilitate supported rotation of the first section 20a relative to the housing 70. The inner race 62 is longer than the second portion 36 of the elongated steering column 20 in the direction of the longitudinal axis L so that a portion of the second bearing 60 cantilevers over the third annular step 32.

[0093] An annular retaining ring 90 is received on the second end 24 and is press-fitted on the third portion 38 of the first section 20a between the second bearing 60 and the second end 24. The annular retaining ring 90 has an annular abutment surface 92 at an upper end that abuts against a lower surface of the inner raceway 62 of the second bearing 60 so that the second bearing 60 is retained between the second annular step 30 and the annular retaining ring 90.

[0094] A pair of identical electric motors 82, 84 each have a respective identical motor output shaft, which is directly driven by the respective motor 82, 84. Each output shaft has a respective output worm 86, 88, which extends with their longitudinal axes parallel to each other and is rotatably mounted relative to the housing 70. The worms 86, 88 mesh with the first gear 40 on diametrically opposite sides of the first gear. Each motor 82, 84 is located in a motor housing 83, which has an interface board 85 for connecting to a controller (not shown). The worms 86, 88 and the first gear 40 constitute a worm gear set in this embodiment, and a controller (not shown), such as an electronic control unit (ECU), can be configured to control the motor output of each motor 82, 84.

[0095] The housing 70 encloses the first section 20a of the elongated steering column 20, the first gear 40, and the first bearing 50 and the second bearing 60. The housing 70 has an upper side 78a and a lower side 78b, and in this embodiment is composed of two parts, including a main body 70a with an intermediate bearing bracket 71a and a generally cup-shaped end portion 70b. The first bearing 50 is positioned between the elongated steering column 20 and the main body 70a and contacts the first inner surface 72. The second bearing 60 is also positioned between the elongated steering column 20 and the main body 70a and is press-fitted into the second inner surface 74. The cup-shaped end portion 70b also includes a mechanical travel limiter (MTL-not shown) configured to limit the range of rotation of the elongated steering column 20 starting from the straight ahead position.

[0096] The sensor module 94 is mounted on the second section 20b of the elongated steering column 20 between the first gear 40 and the first end 22 and nests within a recess of the intermediate bearing bracket 71a. The sensor module 94 is configured to detect rotation of the elongated steering column 20 in use.

[0097] It should be noted that housing 70 receives the various components of the assembly, including motors 82 and 84, gears 40, worms 86 and 88, bearings 50 and 60, a torque sensor (not shown), and a housing for the MTL (not shown), which are then secured by covers that may be separate or part of the assembly. This simplifies the design by eliminating the complexity of assembling multiple component housings. This also facilitates proper positioning of all components within the assembly.

[0098] To assemble the steering column assembly 10, the second bearing 60 is press-fitted into the second inner surface 74 of the housing 70 from the lower side 78b with the cup-shaped end portion 70b removed. The first gear 40 and the first bearing 50 are press-fitted onto the first section 20a so that the first gear 40 is retained between the first annular step 28 and the first bearing 50. The elongated steering column 20, with the attached first gear 40 and the first bearing 50, is then received into the upper side 78a of the housing 70 so that the first gear 40 meshes with each of the worms 86, 88 and the lower side of the outer race 54 contacts the shoulder 76 of the housing 70. The second end 24 of the elongated steering column 20 extends from the upper side 78a of the housing 70 through the second bearing 60. Finally, the annular retaining ring 90 is received on the second end 24 from the lower side 78a of the housing 70 and is press-fitted onto the third portion 38 of the first section 20a between the second bearing 60 and the second end 24. The cup-shaped end portion 70 b is then attached to the body 70 a so as to enclose the first section 20 a of the elongated steering column 20 , the first gear 40 , and the first and second bearings 50 , 60 within the housing 70 .

[0099] During use, steering input applied through the steering wheel A provides torque to the elongated steering column 20. In order to provide a sense of "road feel", the torque feedback motor 80 provides feedback torque to the elongated steering column 20 in the opposite direction of the steering input. The feedback torque is applied by rotation of the worm 86, 88, which in turn applies torque to the first gear 40. The rotation of the first gear 40 causes the elongated steering column 20 to rotate.

[0100] The rotation of the first section 20a of the elongated steering column 20 within the housing 70 is supported by each of the bearings 50, 60. In addition, the position of the first gear 40 along the longitudinal axis L is maintained by the interaction between the first and second bearings 50, 60, the housing 70 and the annular steps 28, 30, 32.

[0101] Reference now Figure 4 , Figure 4 A second variation of a steering column assembly 110 is shown, which is formed Figure 1 A part of a steer-by-wire system S according to the invention. Figure 4 The layout and Figure 2 and Figure 3 The arrangement is similar to that of the present invention, wherein like features are represented by like reference numerals increased by "100", and only the differences are described in detail, and Figure 4 Some details may be omitted.

[0102] The steering column assembly 110 differs from the steering column assembly 10 in that the first gear 140 is overmolded on the elongated steering column 120. The first section 120a includes a first radially extending annular step or shoulder 128, a second radially extending annular step or shoulder 130, and a third radially extending annular step or shoulder 132. Figure 2 and Figure 3 The steering column assembly 110 is similar to the steering column assembly 10 of the present invention. However, the steering column assembly 110 includes a fourth radially extending annular step or shoulder 129 located between the first annular step 128 and the second annular step 130. The fourth annular step 129 is defined by a radially extending annular rib 131. In addition, an annular recess 133 is defined between the first annular step 128 and the upper side 135 of the annular rib 131.

[0103] The annular steps 128 , 129 , 130 , and 132 all face the second end 124 and provide a stepped profile along the first section 20 a of the elongated steering column 20 such that the outer diameter of the first section decreases toward the second end 24 .

[0104] The first portion 134 having a first outer diameter is located between the annular steps 129 and 130, the second portion 136 having a second outer diameter smaller than the first outer diameter is located between the annular steps 130 and 132, and the third portion 138 having a third outer diameter smaller than the second outer diameter is located between the third annular step 132 and the second end 124. The second portion 136 is shorter than the first portion 134 or the third portion 138 in the direction of the longitudinal axis L. In addition, the outer diameter of the first section 120a in the recess 133 is the same as the first outer diameter of the first portion 134.

[0105] The first gear 140 is overmolded in the recess 133, and its position in the direction of the longitudinal axis L is maintained by the first annular step 128 and the upper side 135 of the annular rib 131. The first gear 140 has a plurality of teeth 142 arranged around its circumference, which mesh with the output of the torque feedback motor 180. The first gear 140 also includes an annular base portion 144, which has a substantially square cross-sectional shape. The annular base portion 144 abuts against the first annular step 128 and the upper side 135 of the annular rib 131. The annular base portion 144 extends radially beyond the first annular step 128 and the upper side 135 of the annular rib 131 to prevent the first gear 140 from moving in either direction along the longitudinal axis L.

[0106] The first bearing 150 is an annular bearing. Figure 2 and Figure 3 1, and is located between the first gear 140 and the second bearing 160. The first bearing 150 is received on the second end 124 and has an inner raceway 152 that is press-fitted on the first portion 134 of the elongated steering column 120. In this case, the upper side of the inner raceway 152 abuts against the fourth radially extending annular step 129 rather than against a portion of the first gear 140. The first bearing 150 is spaced from the first gear 140 by the radially extending annular rib 131.

[0107] The steering column assembly 120 is assembled in a manner similar to the steering column assembly 20 described above, except that the first gear 140 is overmolded onto the first section 120a rather than being press-fitted thereon.

[0108] It will be appreciated by those skilled in the art that numerous modifications of the embodiments described above are conceivable without departing from the scope of the present invention.

[0109] Those skilled in the art will also appreciate that any combination of the above features and / or features shown in the accompanying drawings has obvious advantages over the prior art and therefore falls within the scope of the invention described herein.

Claims

1. A steering column assembly for a vehicle, comprising: an elongated steering column rotatably mounted about a longitudinal axis and configured at one end for attachment of a steering wheel; a first gear configured to rotate with the elongated steering column; a motor having an output portion, wherein the output portion is meshed with the first gear; as well as a first bearing and a second bearing, the first bearing and the second bearing being configured for rotatable mounting of an elongated steering column and the first bearing and the second bearing being located on one side of the first gear along the longitudinal axis, Wherein, the first bearing and the second bearing are spaced apart from each other along the longitudinal axis.

2. The steering column assembly of claim 1 , wherein the first gear is located between ends of the elongated steering column, and the first bearing and the second bearing are located between the first gear and an end of the elongated steering column opposite an end configured for attachment of a steering wheel.

3. The steering column assembly of any one of the preceding claims, wherein each of the first and second bearings comprises an annular bearing, and wherein the diameter of the first bearing is greater than the diameter of the second bearing.

4. The steering column assembly of claim 3, wherein the first bearing is located between the first gear and the second bearing.

5. The steering column assembly of claim 4, wherein the elongated steering column includes an annular shoulder and the first gear is located between the annular shoulder and a first bearing.

6. The steering column assembly of claim 5, wherein a portion of the first bearing abuts a portion of the first gear such that the first gear is retained between the annular shoulder and the first bearing.

7. The steering column assembly of claim 6, wherein the elongated steering column includes a further annular shoulder, the second bearing abutting the further annular shoulder.

8. The steering column assembly of claim 4, including an annular retaining ring located between the second bearing and an end of the elongated steering column opposite an end configured for attachment of a steering wheel.

9. The steering column assembly of claim 8, wherein the annular retaining ring abuts the second bearing.

10. A steering column assembly according to any preceding claim, comprising a housing, and wherein the first gear, the first bearing and the second bearing are enclosed within the housing.

11. The steering column assembly of claim 10, wherein the first bearing and the second bearing are configured to provide support for a first gear within the housing along the longitudinal axis.

12. A steering column assembly according to claim 10 or 11, wherein each of the first and second bearings are positioned between the elongate steering column and a housing.

13. A steering column assembly according to any one of claims 10 to 12, wherein the first bearing is press fit on the elongate steering column and the second bearing is press fit within the housing.

14. A steering column assembly according to any preceding claim, wherein the output from the motor comprises a worm which meshes with the first gear.

15. A steering column assembly according to any preceding claim, comprising a pair of motors each having a respective motor output, wherein each output comprises a respective worm meshing with the first gear.

16. The steering column assembly of claim 15, wherein the worm meshes with the first gear at diametrically opposed sides of the first gear.

17. A steering column assembly according to any preceding claim, wherein the first gear is press fit onto the elongate steering column.

18. The steering column assembly of any one of claims 1 to 16, wherein the first gear is over-molded onto the elongated steering column.

19. The steering column assembly of any one of the preceding claims, wherein the elongate steering column comprises a plurality of sections, wherein the first gear, first bearing and second bearing are located on a first section.

20. The steering column assembly of claim 19, wherein the elongated steering column assembly includes a second section connectable to the first section, wherein the second section is configured for attachment of a steering wheel at a free end.

21. A steering column assembly according to claim 19 or claim 20 when dependent on claim 8, wherein the first section comprises an annular retaining ring.

22. A steering column assembly according to claim 19 or claim 20 when dependent on claim 10, wherein the first section of the elongate steering column is located within the housing.

23. A steering column assembly according to any preceding claim for use in a steer-by-wire vehicle.

24. A steer-by-wire system comprising a steering column assembly according to any one of the preceding claims.

25. A vehicle comprising a steering column assembly according to any one of claims 1 to 23 or a steer-by-wire system according to claim 24.

Images