Push-through universal joint assembly

Abstract

A universal joint assembly for a steering shaft assembly includes first and second yokes. The universal joint assembly further includes a hollow spider defining a central opening extending from a first end to a second end, the first yoke being operatively coupled to the hollow spider and positioned at the first end of the hollow spider, and the second yoke being operatively coupled to the hollow spider and positioned at the second end of the hollow spider. The universal joint assembly further includes a sliding shaft extending through the first yoke and aligned with the central opening of the hollow spider, the sliding shaft being selectively translated through the central opening.

Description

FIELD OF THE INVENTION

[0001] The embodiments disclosed herein relate to vehicle steering systems and, more particularly, to a push-through universal joint assembly for use in vehicle steering systems. BACKGROUND

[0002] Steering systems include a steering shaft assembly that connects a steering input device (e.g., a steering wheel) to an output component or assembly for performing steering maneuvers for a vehicle. The steering shaft assembly typically includes multiple segments operatively coupled together with various linkages. One type of linkage is a universal joint, which accommodates relative movement of the connected components along the steering shaft assembly.

[0003] Technological advances related to vehicle steering systems, particularly in autonomous or semi-autonomous vehicles, may require greater column retraction capability compared to conventional column retraction distances to increase the space available to the driver. "Retraction" refers to a movement of the steering column toward and / or fully into the instrument panel. Connective components, particularly universal joints, complicate efforts to increase retraction distance due to their size, shape, and geometry. Therefore, improvements to these limitations would be strongly supported by the vehicle steering system industry and vehicle OEMs. SUMMARY

[0004] According to one aspect of the disclosure, a universal joint assembly for a steering shaft assembly comprises a first yoke and a second yoke. The universal joint assembly further includes a hollow spider defining a central opening extending from a first end to a second end, the first yoke being operatively coupled to the hollow spider and positioned at the first end of the hollow spider, and the second yoke being operatively coupled to the hollow spider and positioned at the second end of the hollow spider. The universal joint assembly further includes a sliding shaft extending through the first yoke and aligned with the central opening of the hollow spider, the sliding shaft being selectively translated through the central opening.

[0005] According to another aspect of the disclosure, a hollow spider for a universal joint assembly in a steering shaft assembly includes a first side, a second side, a third side, and a fourth side. The hollow spider also includes a first axial end and a second axial end. The hollow spider further includes an outer surface. The hollow spider still further includes an inner surface defining a central opening sized to receive a shaft therethrough.

[0006] According to another aspect of the disclosure, a steering shaft assembly for a vehicle steering system includes a first yoke. The steering shaft assembly further includes a first shaft assembly component operatively coupled to the first yoke. The steering shaft assembly further includes a second yoke. The steering shaft assembly further includes a second shaft assembly component operatively coupled to the second yoke. The steering shaft assembly further includes a hollow spider defining a central opening extending from a first end to a second end, the first yoke being operatively coupled to the hollow spider and positioned at the first end of the hollow spider, and the second yoke being operatively coupled to the hollow spider and positioned at the second end of the hollow spider.The first shaft assembly component extends through the first yoke and is aligned with the central opening of the hollow star, wherein the first shaft assembly component is selectively translated through the central opening.

[0007] These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: Fig. Figure 1 is a schematic illustration of a vehicle steering system; Fig. Figure 2 is a perspective, disassembled view of a portion of the vehicle steering system including a slider through the universal joint components of the vehicle steering system; Fig. 3 is a perspective view of the part of the vehicle steering system of Fig. 2 is in an assembled state; Fig. 4 a side view of the part of the vehicle steering system of Fig. 2 and Fig. 3 is in the assembled state; Fig. 5 is a perspective, disassembled view of the portion of the vehicle steering system according to another aspect of the disclosure; and Fig. 6 is a perspective view of the part of the vehicle steering system of Fig. 5 is in an assembled state. DETAILED DESCRIPTION

[0009] The following discussion relates to various embodiments of the disclosure. Although one or more of these embodiments may be described in greater detail than others, the disclosed embodiments should not be interpreted or otherwise used as limiting the scope of the disclosure, which includes the claims. Furthermore, those skilled in the art will understand that the following description has broad application, and the discussion of one embodiment is intended only as an example of that embodiment and does not imply that the scope of the disclosure, which includes the claims, is limited to that embodiment.

[0010] First, with reference to Fig. 1, a vehicle 20 is generally illustrated in accordance with the principles of the present disclosure. The vehicle 20 may include any vehicle, such as a car, a truck, an SUV, a minivan, a crossover, any other passenger vehicle, any suitable commercial vehicle, or any other suitable vehicle. While the vehicle 20 may be a wheeled passenger vehicle for use on roads, the principles of the present disclosure may be applicable to other vehicles, such as aircraft, tractors, boats, or other vehicles. The vehicle 20 may include a propulsion system 30, such as an ignition system, an electronic system, or combinations thereof.

[0011] The vehicle 20 further includes a steering system 40. The steering system 40 may be configured as a driver interface steering system, an autonomous driving system, or a system enabling both a driver interface and autonomous steering. The steering system 40 may include an input device 42, such as a steering wheel, wherein a driver can mechanically provide steering input by turning the steering wheel. A steering column assembly 44 includes a steering column 45 extending along an axis from the input device 42 to an output assembly 46. The output assembly 46 may include a pinion shaft assembly, an I-shaft, a universal joint, steer-by-wire components, or any other feature conventionally located opposite the input device 42.

[0012] The steering column 45 includes one or more axially adjustable parts, for example, an upper shell 48 and a lower shell 50 that are axially adjustable relative to each other. It is contemplated that additional shells may be used in some embodiments. It should be noted that other structural features of the steering column 45 may be part of the upper shell 48 and the lower shell 50, such as brackets, rails, other devices, or combinations thereof.

[0013] The steering column 45 is movable through a range of positions from a fully extended position to a fully retracted position. In the fully extended position, the upper shell 48 and the lower shell 50 are moved axially such that the input device 42 is located near an operator of the vehicle. In the retracted position, the upper shell 48 and the lower shell 50 are moved axially such that the input device 42 is farther from an operator of the vehicle compared to the extended position. In some embodiments, the retracted position may correspond to stowing the input device 42. For example, it may be advantageous to place the input device 42 in a stowed location during autonomous driving.During operation, the axial movement of the upper shell 48 and the lower shell 50 can be effected manually by an operator or electromechanically by a telescopic or translational actuator. This axial movement serves to adjust between the extended position, the retracted position, and all intermediate positions.

[0014] A steering gear assembly 54, the output assembly 46, and the steering input device 42 may be connected via a steering shaft assembly 56. The steering gear assembly 54 may be configured as a rack and pinion steering gear, a recirculating ball steering gear, or any other type of steering gear associated with autonomous steering systems and driver interface steering systems. The steering gear assembly 54 may then be connected to a drive axle 58 via an output shaft 60. The output shaft 60 may include a pitman arm and a sector gear and / or various traditional components. The output shaft 60 is operatively connected to the steering gear assembly 54 such that rotation of the steering shaft assembly 56 causes a reactive movement of the output shaft 60 and causes the drive axle to turn wheels 62.It should be noted that the steering components described herein may be part of a steer-by-wire system or a system that includes a direct mechanical connection across the entire length of the components.

[0015] With reference to Fig. 2, a push-through universal joint assembly 100 according to a first embodiment is illustrated in a disassembled state. The universal joint assembly 100 includes a hollow spider 102, a first yoke 104, a second yoke 106, a shaft tube 108, and a sliding shaft 110. In the illustrated embodiment, the hollow spider 102 is shown to be substantially rectangular with rounded corners. More specifically, the hollow spider 102 includes a first side 112, a second side 114, a third side 116, and a fourth side 118. The first side 112 and the third side 116 are located on opposite sides of the hollow spider 102 and have no adjacent corners. The second side 114 and the fourth side 118 are located on opposite sides of the hollow spider 102 and have no adjacent corners.Each side 112, 114, 116, 118 defines a corresponding hole 120 extending through the side from an outer surface 122 of the hollow star 102 to an inner surface 124 of the hollow star 102.

[0016] Each of the holes 120 of the hollow star 102 is sized and positioned so that a portion of a bearing assembly 125 is disposed therein and secured to the hollow star 102. Specifically, the bearing assembly 125 includes a bearing 127, a pin 129, and a mechanical seal 131. In some embodiments, the mechanical seal 131 may not be required depending on the intended use. Regardless of whether the mechanical seal is included, during assembly, the pin 129 is press-fitted—or otherwise secured—into the hole 120 of the hollow star 102, and the bearing 127 is pressed into a hole defined by one of the yokes 104, 106 and onto the pin 129. Each of the four bearing assemblies 125 is installed into the overall assembly in the manner described above.

[0017] While the hollow star 102 is illustrated as being substantially rectangular, it is understood that other general shapes are conceivable and fall within the scope of this disclosure. As a non-limiting example, a circular star may be employed.

[0018] Regardless of the particular general shape of the hollow star 102, the hollow star 102 defines a central opening 126 defined by the inner surface 124 of the hollow star 102 and extending completely through the hollow star 102 from a first end 128 to a second end 130 of the hollow star 102.

[0019] Now with reference to Fig. 3, the push-through universal joint assembly 100 is shown in an assembled state. The universal joint assembly 100 is used to connect two components and allows each component to rotate about different axes. In particular, the first yoke 104 is connected to the hollow spider 102 via the bearing assemblies 125, which are disposed in the holes 120 defined by the first side 112 and the third side 116 of the hollow spider 102. This allows the first yoke 104 to be positioned at the first end 128 of the hollow spider 102 and to pivot about a first axis A. The second yoke 106 is connected to the hollow spider 102 via the bearing assemblies 125, which are disposed in the holes 120 defined by the second side 114 and the fourth side 118 of the hollow spider 102. This allows the second yoke 106 to be positioned at the second end 130 of the hollow star 102 and to pivot about a second axis B.In the illustrated embodiment, the first axis A and the second axis B are aligned approximately perpendicular to each other.

[0020] Both the first yoke 104 and the second yoke 106 are operatively coupled to or integrally formed with a corresponding component that is part of the overall steering shaft assembly 56. Such components may include, for example, a shaft extending from the steering wheel 42, an intermediate shaft, and a rack and pinion gear. However, these components do not represent a limitation on the components that can be coupled to the hollow spider 102 using the yokes 104, 106. Regardless of which exact components are coupled to the hollow spider 102, the universal joint assembly 100 enables the components to be operatively coupled to one another while allowing varying degrees of rotational freedom (i.e., about axes A and B).

[0021] With reference to Fig. 4, the universal joint assembly 100 is shown in an assembled state with the sliding shaft 110 enclosed to illustrate one advantage of the hollow spider 102. The sliding shaft 110 is at least partially disposed within the shaft tube 108 and includes a splined portion 140 that is in splined engagement with a splined inner portion 142 ( Fig. 2 and Fig. 3) of the shaft tube 108. Through the serration between the sliding shaft 110 and the shaft tube 108, torque can be transmitted from one to the other and vice versa, so that the sliding shaft 110 and the shaft tube 108 rotate with each other accordingly. The rotational movement of these components is transmitted to (or from) the first yoke 104, which is operatively coupled to the shaft tube 108. In the illustrated embodiment of Fig. 2 to 4, the shaft tube 108 and the first yoke 104 are separate components that are functionally coupled to each other. The coupling can be accomplished in any suitable manner, including, for example, press-fitting and caulking or welding. This connection enables the transmission of torque to (or from) the second yoke 106, as well as to all components connected to the second yoke 106.

[0022] As in Fig. As shown in Figure 4, the sliding shaft 110 is capable of translation through the central opening 126 of the hollow spider 102. This allows the sliding shaft 110 to move significantly further compared to a universal joint that does not include a central opening or does not have an opening large enough to allow the sliding shaft 110 to pass completely through the spider 102. This is particularly advantageous in a steering shaft assembly that requires a large collapse or buckling distance.

[0023] Now with reference to Fig. 5 and Fig. 6, another embodiment of the universal joint assembly is shown and generally designated by the number 200. The universal joint assembly 200 is identical - or nearly identical - to the universal joint assembly 100 used in conjunction with Fig. 2 to 4, but including an integrally formed first yoke and shaft tube designated by the numeral 202. The integrally formed first yoke and shaft tube 202 is a single, monolithically formed component. A hollow star is identical to the hollow star 102 of Fig. 2 to 4, is in Fig. 5, however, is designated by the number 204. The description of the hollow star 204 will not be repeated here.

[0024] The hollow star 204 is structured to define holes identical to the holes 120 of the hollow star 102, in Fig. 5 are marked with the number 220. As with the holes of Fig. 2 to 4, the holes 220 are sized and positioned so that a portion of a bearing assembly 225 can be disposed therein. The components of the bearing assembly 225 (i.e., a bearing 227, a pin 229, and a seal 231) and the assembly process are described above in connection with Fig. 2 to 4 and are not repeated here.

[0025] The dimensions and geometry of the central opening 126 are customized to accommodate the diameter of the sliding shaft 110 and to meet the joint angle requirements of the pivoting components attached to the hollow spider 102.

[0026] The embodiments disclosed herein maximize the collapse or buckling distance of a sliding shaft attached to a universal joint while avoiding drastic reconfiguration of the entire spider. The universal joint assembly 100, 200 can be used in multiple sliding shaft configurations to meet performance requirements.

[0027] Although the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention may be modified to include any number of variations, changes, substitutions, or equivalent arrangements not described herein, but which are within the spirit and scope of the invention. Although various embodiments of the invention have been described, it should be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be considered limited by the foregoing description.

Claims

[1] Universal joint assembly for a steering shaft assembly, comprising: a first yoke; a second yoke; a hollow star defining a central opening extending from a first end to a second end, wherein the first yoke is operatively coupled to the hollow star and positioned at the first end of the hollow star, wherein the second yoke is operatively coupled to the hollow star and positioned at the second end of the hollow star; and a sliding shaft extending through the first yoke and aligned with the central opening of the hollow star, the sliding shaft being selectively translated through the central opening. [2] The universal joint assembly of claim 1, wherein the universal joint assembly further comprises a shaft tube coupled to the sliding shaft and the first yoke, the sliding shaft, the shaft tube, and the first yoke being rotationally coupled to each other. [3] The universal joint assembly of claim 2, wherein the shaft tube and the first yoke are integrally formed as a single, monolithically formed component. [4] The universal joint assembly of claim 2, wherein the shaft tube and the first yoke are separate components that are operatively coupled together. [5] A universal joint assembly according to claim 4, wherein the shaft tube and the first yoke are welded together. [6] A universal joint assembly according to claim 4, wherein the shaft tube and the first yoke are press-fitted and caulked together. [7] The universal joint assembly according to claim 2, wherein the sliding shaft has a serration portion that engages with a serration inner portion of the shaft tube to rotationally couple the sliding shaft and the shaft tube to each other. [8] The universal joint assembly of claim 1, wherein the first yoke is operatively coupled to a first pair of opposite sides of the hollow spider and the second yoke is operatively coupled to a second pair of opposite sides of the hollow spider. [9] A universal joint assembly according to claim 8, wherein the hollow star has a rectangular cross-section. [10] The universal joint assembly of claim 8, wherein the first yoke and the second yoke are operatively coupled to the hollow star, wherein a plurality of bearing assemblies are operatively coupled to the hollow star. [11] A hollow star for a universal joint assembly in a steering shaft assembly, comprising: a first page, a second page, a third page and a fourth page; a first axial end and a second axial end; an outer surface; an interior surface defining a central opening sized to that it absorbs a wave through it. [12] A hollow star according to claim 11, wherein the first side, the second side, the third side and the fourth side form a rectangular star. [13] A hollow star according to claim 12, wherein the first side, the second side, the third side and the fourth side are connected by respective rounded corners. [14] Steering shaft assembly for a vehicle steering system, comprising: a first yoke; a first shaft assembly component operatively coupled to the first yoke; a second yoke; a second shaft assembly component operatively coupled to the second yoke; and a hollow star defining a central opening extending from a first end to a second end, wherein the first yoke is operatively coupled to the hollow star and positioned at the first end of the hollow star, wherein the second yoke is operatively coupled to the hollow star and positioned at the second end of the hollow star, wherein the first shaft assembly component extends through the first yoke and is aligned with the central opening of the hollow star, wherein the first shaft assembly component is selectively translated through the central opening. [15] A steering shaft assembly according to claim 14, wherein the first shaft assembly component is a handwheel shaft, an intermediate shaft or a rack and pinion. [16] The steering shaft assembly of claim 14, wherein the steering shaft assembly further comprises a shaft tube coupled to the first shaft assembly component and to the first yoke, wherein the first shaft assembly component, the shaft tube, and the first yoke are rotationally coupled to each other. [17] The steering shaft assembly of claim 16, wherein the shaft tube and the first yoke are integrally formed as a single, monolithically formed component. [18] The steering shaft assembly of claim 16, wherein the shaft tube and the first yoke are separate components that are operatively coupled together.

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