MXPA01002761A - One piece trailing arm for torsional springs - Google Patents

Abstract

An axle assembly for a vehicle or a trailer includes an outer housing, an axle shaft and a plurality of bushings. The axle shaft is a single piece unitary construction which includes an activator shaft portion, a trailing arm portion and a spindle portion. The outer housing is adapted to be secured to the frame of the vehicle or trailer while the spindle portion is adapted to support a wheel assembly of the vehicle or trailer. Another embodiment has a single piece unitary axle which includes an activator shaft portion and a trailing arm portion. A spindle is secured to the trailing arm portion to complete the axle assembly.

Description

REAR ARM OF A PIECE FOR TORSION SPRINGS Field of the Invention The present invention relates to an axle structure for use in trailers, automobiles and other vehicles. More particularly, the present invention relates to an axle structure that includes a pair of one-piece rear arms, each having a plurality of elastomeric bushings. This structure is inserted in a housing that is then connected to the vehicle frame. BACKGROUND OF THE INVENTION Trailers are designed to be connected to a conventional automobile or light truck through the use of a trailer hitch. These trailers are designed to carry some type of cargo and generally have single or multiple axle units to support their weight and the weight of their cargo. Most trailers are rated up to a capacity of approximately 3,178 kg (7,000 pounds) and this capacity can be increased with the use of additional axles. The prior art trailers have been constructed with steel leaf springs as part of the axle structure, with the purpose of absorbing the shock. These leaf springs are attached to the trailer frame with the trailer axle positioned below the spring. This method of supporting the load and absorbing the shock is both functional and relatively economical. One of the problems associated with this method of supporting the load is that a single axle will transmit the shock between the two wheels. This shock transmission increases the rolling, affects the alignment of the trailer and promotes instability. Also, if the leaf springs are not sufficiently damped, the trailer may reach a resonance point. This resonance can cause an awkward travel, results in loss of control of the vehicle and / or causes serious damage to the vehicle. Due to the above noted problems and others, the towing industry has converted to using rubber torsion springs in the axle structures as substitutes for leaf springs. The torsional rubber springs are part of an axle structure that includes an outer housing that typically holds the frame of a trailer, an inner member positioned within the outer housing, a plurality of bushings placed between the inner member and the outer housing, a separate articulation or activation arm connected to the inner member and a separate spindle, connected to the activation arm or arm. The spindle has a hub connected to it, which supports a wheel structure. Spring torsional spring axle structures are particularly advantageous for users of trailers that have more delicate items such as boats, horses, snow vehicles, etc. When torsional rubber bushings are used, trailers generally tow better, are not subject to resonant vibration and provide a better overall ride. When designing the shaft structure using rubber torsional springs, it is preferable to have the rubber work in compression instead of shear, since the rubber is stronger in compression and weaker in shear. It is also not preferable to permanently seal the axle structure and it is preferable to limit the number of individual components required to assemble the axle structure, to assist in reducing the overall costs and complexities of the axle structure.

SUMMARY OF THE INVENTION The present invention provides a technique with a trailer axle structure that includes an outer housing, an inner member and a plurality of bushings positioned between the inner member and the outer member. The inner member includes a unitary longitudinal arrow, an activation arm and spindle. The unitary design of the inner member reduces the number of parts required for the inner member, together with the costs associated with the machining of the various individual parts of the prior art systems.

In one embodiment of the present invention, the spindle is a separate component which is then welded to the activation arm and unitary longitudinal arrow. Other advantages and objects of the present invention will be apparent to those skilled in the art from subsequent detailed description, appended claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings that illustrate the best mode currently contemplated for carrying out the invention: Figure 1 is a partial perspective view of a trailer incorporating the single-spring torsional spring axle structure, in accordance with the present invention; Figure 2 is a cross-sectional side view of the rubber torsional spring axle structure shown in Figure 1; Figure 3 is a perspective view of the trailer axle shown in Figure 2; Figure 4 is a cross-sectional side view of the trailer axle shown in Figure 3; Figure 5 is a side view of one of the bushings shown in Figure 2; Figure 6 is a side view of one of the end collars shown in Figure 2; Figure 7 is an exploded perspective view of a trailer axle according to the present invention; Figure 8 is a cross-sectional side view of a rubber torsional spring shaft, according to another embodiment of the present invention; Figure 9 is a cross-sectional end view of the rubber torsional spring shaft shown in Figure 8; Figure 10 is a cross-sectional end view of a rubber torsional spring shaft, according to another embodiment of the present invention; and Figure 11 is a cross-sectional end view of a rubber torsional spring shaft, according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Now with reference to the drawings in which like reference numerals designate similar or corresponding parts throughout the various views, illustrated in Figure 1, a trailer structure incorporating the spring torsional spring system unique according to the present invention and which is generally indicated by the reference number 10. The trailer structure 10 comprises a frame 12, an axle structure 14 and a pair of wheel structures 16 (only one of which is illustrated) ). The shaft structure 14 is fastened to the bottom of the frame 12 by welding, fastening or other means known in the art. The wheel structure 16 includes a tire 18 which is rotatably supported with respect to the shaft structure 14, as is well known in the art. While the present invention is illustrated for exemplary purposes in conjunction with the trailer structure 10, it is within the scope of the present invention to use the axle structure 14 in other applications including but not limited to the rear axle of a light truck or automobile. with displacement by the front wheels. Now with reference to Figure 2, the structure of axis 14 is illustrated in cross section. The shaft structure 14 comprises an outer housing 20, a left shaft 22, a right shaft 24, a plurality of elastomeric bushings 26, a pair of end collars 28 and a pair of backing plates 30. The outer housing 20 is a tube of generally rectangular cross section, which is designed to extend across the width of the trailer. The outer housing 20 is fastened to the frame 12 by welding, fastening or other means known in the art. Now with reference to Figures 2 to 4, the left axis 22 is a one-piece formed component that includes a driver shaft portion 40. A rear arm portion 42 and a spindle portion 44 in a continuous arrow. The resistance of the left axle 22 is improved by using a hollow construction that increases the moment of inertia without increasing the weight of the left axle 22. The left axle 22 is preferably manufactured using a hydro-forming process, but other manufacturing processes known in the art can be used for the manufacture of the left axis 22. The right axis 24 is symmetrically opposed to the left axis 22. In this way, the detailed description for the left axis 22 applies equally to the right axis 24 The actuating arrow portion 40 begins with a generally rectangular tubular end 48 which transitions to a circular section 50. The plurality of elastomeric bushings 26 are located on the tubular end 48 and the end collar 28 is located in the circular section 50. The back arm portion 42 includes a first transition section 52, an oval section 54, a second transition section 56 and a generally circular section 58. The first transition section 52 transforms the circular section 50 into the oval section 54 The second transition section 56 transforms the oval section 54 into the circular section 58 The circular section 58 transits towards the Spindle 44. The spindle portion 44 is machined to provide the structure necessary to support the various seals and bearings associated with the wheel structure 16. As illustrated in Figures 1 and 2, the back plate 30 is a plate generally rectangular which is secured to the circular section 58 by welding or other means known in the art. The backing plate 30 is used to support the various stationary members of the wheel structure 16. Now with reference to Figures 2 and 5, illustrates one of the elastomeric bushings 26. The bushings 26 have a generally rectangular outer periphery, with generally planar outer surfaces 60, each with a scalloped region 62, for adjustment purposes. A rectangular opening 64 having flat inner surfaces 66 extends through the hub 26. The flat inner surfaces 66 are placed at a preferred angle of 45 ° with respect to the corresponding flat outer surfaces 60. It will be appreciated that the displacement angle of 45 ° can be any convenient angle, for example 40 ° or 50 °. The bushing 26 is dimensioned to fit within the outer housing 20 and on the rectangular tubular end 48 of the trigger arrow portion 40 with a specified percentage compression of the bushing 26. While the present invention is described using generally rectangular bushes 26, it is within of the scope of the present invention to use other shapes including but not limited to triangular, pentagonal or hexagonal, if desired. Now with reference to Figures 2 and 6, one of the end collars is illustrated. The end collar 28 is fabricated from a rigid elastomer or other polymer support surface and is generally rectangular in cross section. The collar 28 defines a circular opening 70, which is dimensioned to receive the circular section 50 of the activating arrow portion 40. It will be appreciated that the device shown in Figures 2 and 6 are in fact two halves, one of which is illustrated in dotted lines in Figure 6. The two halves corresponding to each other by quick coupling members 62, to form the full-end collar. The manufacturing and assembly process is as follows. A straight rectangular pipe member is preferably formed by a hydroforming process to produce a formed shaft 22 and shaft 24. The spindle portion 22 for each shaft 22 and 24 is machined as well as any other surfaces on the shafts 22 and 24. The back plate 30 is fastened to each axis 22 and 24. The bushings 26 are molded in free rubber to have the rectangular outer shape with the surface 60, festoons 62 and opening 64. Preferably, an elastomeric compound comprising natural rubber with various additives, it is used. The elastomeric bushings are then attached to the tubular end 48 of the activating arrow portion 40 of both shafts 22 and 24 with an adhesive at room temperature. The number of bushings used per axle 22 and 24, its spacing and the precise formulation of the compound used to form the bushing can be varied depending on the performance characteristics desired. In addition, any suitable adhesive or alternating form may be employed, the bushings 26 may simply be frictionally adjusted on the tubular end 48, the bushings 26 may be molded directly to the arrow portion 40 by means known in the art, or the bushings 26 may be molded directly within the housing 20 by means known in the art. The end collar 28 is then placed in each circular section 50 of the driving shaft portion 40 of each shaft 22 and 24. Each shaft 22 and 24 with the hubs 26 and the end collar 28 positioned thereon are inserted in the anterior housing As an option, the edges of the housing 20 adjacent to the collar 28 can be folded after the assembly of the shafts 22 and 24 to retain the collar 28 in position. This folding arrangement further ensures the scale chamber which now encloses the bushings 26. In operation, as the wheel structure 26 is subjected to the force and shock of the road, the spindle portion 44 and the rear arm portion 42 rotate the driving arrow portion 40 such that the driving arrow portion 40 transfers the shock to the inner surfaces 66 of the bushings 26. The bushings 26 are then compressed between the driving shaft portion 40 and the outer housing 20. According to FIG. level of shock or forces is increased, so is the compression of the bushings 26. In this way the bushings 26 absorb the force and shock of the road. Now with reference to Figure 7, an axle structure 122 according to another embodiment of the present invention is discussed. The shaft structure 122 is a direct replacement for the shaft 22. Also, it will be understood that a symmetric opposite shaft structure similar to the shaft structure 122 can be a direct replacement for the shaft 24. The shaft structure 122 is the same as the axis 22 except that the spindle portion 44 has been replaced by a separate machined spindle 144. The shaft structure 122 includes the trigger arrow portion 40 and the rear arm portion 42. The trigger arrow portion 40 starts with the generally rectangular pipe end 48 which transits the circular section 50. The rear arm portion 42 includes a first transition section 52 that transforms the circular section 50 into the oval section 54. The second transition section 56 transforms the oval section 54 in the circular section 56. The spindle 144 is fastened to a circular section 58 by welding or by other means known in the art. With the spindle 144 attached to the circular section 58, the function, operation and assembly described above for the axis 22 apply to the shaft structure 122, likewise. Now with reference to Figures 8 and 9, a cross section of an axle structure 114 is described. The axle structure 114 comprises the outer housing 20, the left axle 22, the right axle 24 and a single elastomeric bushing 126. The 126 bushing is a bushing attached in mold. In one embodiment, the bushing 126 is attached in the mold to the arrow portion 40 of the axes 22 and 24 and press fit into the outer housing 20. In another embodiment, the bushing 126 is attached in a mold within the outer housing 20 and the arrow portion 40 of the axes 22 and 24, should they snap into the central opening of the bushings 126. The function, operation and characteristics of the axle structure 114 are the same as those described above for the shaft structure 14. Now with reference to Fig. 14, a cross-section of an axle structure 214 is described. The axle structure 214 comprises the outer housing 20, the left axle 22, the right axle 24 and a plurality of axes. elastomeric bushings 226. Bushings 226 are generally cylindrical in shape that are positioned with the inner corners of the outer housing 20, adjacent to a flat wall of the rectangular tubular end 48. Each bushing 226 extends continuously over the arrow portion 40 similar to the hub 126 shown above in Figure 8. The function, operation and characteristics of the axle structure 214 are the same as described above for the shaft structure 14. Now with reference to Figure 11, a cross section of an axle structure 314 is described. The axle structure 314 comprises the outer housing 20, the left axle structure 22, the right shaft structure 24 and a plurality of elastomeric bushing structures 326. Each bushing structure 326 comprises an elastomeric member 328 that is in-mold attached to an inner rectangular member 330. The rectangular member 330 is dimensioned to fit under pressure on the portion of arrow 40 of each axis 22 and 24. The shaft structure 314 is assembled by snapping the plurality of bushing structures 326 onto the shaft. arrow portion 40 and then this structure is inserted into the outer housing 20 similar to that described above for the shaft structure 14. The function, operation and characteristic of the shaft structure 314 are the same as those described above for the structure of shaft 14. The advantages of the present invention include the following: 1) The elastomeric bushings work in compression, the most convenient use of an elastomer. 2) The elastomeric bushings can be molded in free form, a low cost manufacturing process. 3) The elastomeric bushings can be attached to the inner member at room temperature with an adhesive. 4) The structure is easily assembled in a housing or vehicle axle structure. 5) The system is permanently sealed against moisture penetration and road salts. 6) No welding or fasteners are required to retain the bushing structure in the system. 7) The elastomeric bushings, once installed, require a high load in order to extract the bushings from the axle structure. 8) The elastomeric bushings allow easy adjustment of the load capacities of the system when adding or eliminating bushings. 9) The cost of the mold and the cost of the assembly equipment is relatively low.

) The number of operating parts is reduced and the cost is reduced. 11) The replacement of a steel spring with the elastomer spring system generally reduces the weight of the vehicle. 12) The hollow shaft further reduces the weight of the system. While the foregoing detailed description illustrates the preferred embodiment of the present invention, it will be understood that the present invention is susceptible to modification, variation and alteration without departing from the scope and fair meaning of the appended claims.

Claims (20)

1. CLAIMS 1. An axle structure for use in a vehicle, the axle structure is characterized in that it comprises: an outer housing having a generally rectangular cross section, the front housing is adapted to be fastened to the vehicle; a first unitary axis comprising a first trigger arrow portion and a first rear arm portion positioned adjacent the first trigger arrow portion, the first rear arm portion is angled with respect to the first trigger arrow portion, the first activating arrow portion is placed inside the outer housing; and at least one first bushing positioned between the outer housing and the first actuating portion of the first unitary axis. The shaft structure according to claim 1, characterized in that the first unitary shaft further comprises a first spindle portion positioned adjacent to the first rear arm portion, the first spindle portion adapted to support a wheel structure of the vehicle. 3. The axle structure according to claim 2, characterized in that the first rear arm portion is generally perpendicular to the first trigger arrow portion. The shaft structure according to claim 3, characterized in that the first spindle portion is generally perpendicular to the first back arm portion. The shaft structure according to claim 1, characterized in that the first rear arm portion is generally perpendicular to the first activating arrow portion. 6. The axis structure according to claim 1, characterized in that it also comprises a second unitary axis, the second unitary axis comprises a second trigger arrow portion and a second rear arm portion positioned adjacent to the second trigger arrow portion, the second The rear arm portion is angled with respect to the second trigger arrow portion, the second trigger arrow portion is positioned within the outer housing. 7. The axle structure according to claim 6, characterized in that it further comprises at least a second bushing placed between the outer housing and the second activating arrow portion. The shaft structure according to claim 7, characterized in that at least one second bushing is constituted by an elastomeric member and a metal member. The shaft structure according to claim 7, characterized in that at least one second bushing comprises a plurality of bushings 10. The shaft structure according to claim 6, characterized in that the first unitary shaft further comprises a first spindle portion positioned adjacent the first portion of the rear arm and the second unitary shaft further comprises a second spindle portion positioned adjacent to the second. rear arm portion, each of the first and second spindle portions are adapted to support a wheel structure of the vehicle. The shaft structure according to claim 10, characterized in that the first rear arm portion is generally perpendicular to the first trigger arrow portion and the second rear arm portion is generally perpendicular to the second trigger arrow portion. The shaft structure according to claim 11, characterized in that the first spindle portion is generally perpendicular to the first rear arm portion and the second spindle portion is generally perpendicular to the second rear arm portion. The shaft structure according to claim 6, characterized in that the first rear arm portion is generally perpendicular to the first trigger arrow portion and the second rear arm portion is generally perpendicular to the second trigger arrow portion. 14. The shaft structure according to claim 1, characterized in that at least one first bushing is constituted by an elastomeric member and a metal member. The shaft structure according to claim 1, characterized in that at least one first bushing comprises a plurality of bushings. 16. A unitary axis for use in a vehicle, the unitary axis is characterized in that it comprises: an activating arrow portion, the activating arrow portion is adapted to be inserted in a vehicle housing; and a rear arm portion adjacent to the trigger arrow portion, the rear arm portion is angled with respect to the trigger arrow portion. The shaft structure according to claim 16, characterized in that the unitary shaft further comprises a spindle portion positioned adjacent to the rear arm portion, the spindle portion adapted to support a wheel structure of the vehicle. 18. The shaft structure according to claim 17, characterized in that the rear arm portion is generally perpendicular to the activating arrow portion. 19. The axle structure according to claim 18, characterized in that the spindle portion is generally perpendicular to the rear arm portion. The shaft structure according to claim 16, characterized in that the rear arm portion is generally perpendicular to the activating arrow portion.