Patent Application
20200148286
The present disclosure is generally related to vehicle cab suspension systems.
Current two (2)-point cab suspension system performance is less than desired. In vehicles such as a self-propelled windrower, for instance, the stiff, rubber isolation mounts are at the front of the cab and positioned over a front axle of the windrower traction unit. Vertical movements of either, or both sides, of the axle are directly transmitted to the isolation mounts with little suspension benefit. Suspension units (e.g., low frequency suspension units, including coil or air spring over shock absorber) are positioned at the rear corners of the cab, reward of the front axle, owing to the fact that windrowers have been borne from tractor designs and the observation that the operator, for whom which ride comfort is desired, sits closest to the suspension units.
Many aspects of certain embodiments of 2-point cab suspension systems and methods can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present systems and methods. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
In one embodiment, a suspension system for a vehicle cab, the suspension system comprising: a structural assembly; a cab mounted to the structural assembly; a front axle coupled to the structural assembly; plural suspension units arranged forward of the axle and disposed between the cab and the structural assembly; and plural isolation mounts arranged rearward of the axle and disposed between the cab and the structural assembly.
Certain embodiments of a two-point (herein, also 2-point) cab suspension system and method are disclosed that arrange suspension units between the cab and the chassis forward of the axle and isolation mounts between the cab and the chassis rearward of the axle. Through this arrangement, excitation forces from the axle are dampened in view of the proximity of the primarily low frequency dampening attributes of the suspension units, leading to improved comfort for an operator in the cab when compared to conventional 2-point cab suspension arrangements. The embodiments described below are in the context of a vehicle embodied as an agricultural vehicle, and in particular, a self-propelled windrower, with the understanding that cab suspension systems for other vehicles may be used in some embodiments.
Digressing briefly, windrower cab suspension systems are generally an outgrowth of tractors (e.g., row crop tractors). Row crop tractors with 2-point cab suspension systems generally have rubber mounts arranged toward the front of the cab and suspension units arranged toward the rear of the cab. Windrowers, due to their unique drive arrangement, are somewhat like a row tractor but flipped around. Legacy designs for the windrower essentially have applied the row tractor cab suspension systems to the windrower cab suspension systems, with the fore and aft arrangement of rubber mounts and suspension units between the cab and the chassis, despite the fact that row crop tractors also have an axle proximal to where the operator sits. One school of thought preserving that arrangement over the years is the observation that the operator sits closer to the rearward suspension units than the rubber mounts in the windrower, and hence vibrations (low frequency vibrations) resulting from the windrower navigating over the soil surface of a field and transmitted through the axle to the cab are best handled by arranging the suspension units in proximity to where the operator sits in the cab. In contrast, certain embodiments of 2-point cab suspension systems improve ride comfort by flipping the arrangement of conventional row tractors (and windrowers), arranging the suspension units toward the front, closer to the axle, which more effectively counters the forces emanating from the axle by virtue of windrower travel across the field.
Having summarized certain features of a 2-point cab suspension system of the present disclosure, reference will now be made in detail to the description of a 2-point cab suspension system as illustrated in the drawings. While an example 2-point cab suspension system will be described in connection with these drawings, there is no intent to limit it to the embodiment or embodiments disclosed herein. For instance, as indicated above, certain embodiments of a 2-point cab suspension system are described in the context of its use in an agricultural vehicle, and in particular, a self-propelled windrower. However, in some embodiments, the 2-point cab suspension system may be used in other agricultural vehicles, or in vehicles used in other industries, including mining, construction, military, government, etc. Further, although the description identifies or describes specifics of one or more embodiments, such specifics are not necessarily part of every embodiment, nor are all of any various stated advantages necessarily associated with a single embodiment. On the contrary, the intent is to cover all alternatives, modifications and equivalents included within the scope of the disclosure as defined by the appended claims. Further, it should be appreciated in the context of the present disclosure that the claims are not necessarily limited to the particular embodiments set out in the description.
Note that references hereinafter made to certain directions, such as, for example, “front”, “rear”, “left” and “right”, are made as viewed from the rear of the vehicle (e.g., windrower) looking forwardly. The terms fore and aft and transverse, as used herein, are referenced to the longitudinal centerline of the windrower chassis as the windrower travels in a forward direction.
Referring now to
A coupled working implement, depicted in
The windrower 10 also includes the 2-point cab suspension system 12, which includes plural suspension units arranged forward of the front axle of the windrower 10 and plural isolation mounts (e.g., rubber mounts) that are arranged rearward of the front axle of the windrower 10, all disposed between the cab 18 and the chassis 14, to improve ride comfort for the operator, as explained further below. Note that for air spring-based suspension units, additional components may include a source of air (e.g., compressor) as is known to those having ordinary skill in the art.
During a harvesting operation, the windrower 10 moves forward through the field with the header 22 lowered to a working height. Ground conditions (e.g., moist ground, soft ground, etc.), including ground surface topology (e.g., bumpy terrain, smooth terrain, obstacles, etc.), encountered by the tires, may impose low frequency vibrations on the cab 18 (and also experienced by an operator) during the ride. The 2-point cab suspension system 12 ensures a comfortable ride for the operator despite the condition of the terrain the windrower 10 encounters.
Attention is now directed to
The isolation mounts 30 may be configured as known rubber mounts, which have a deformation under cab load that is measured in millimeters. As is known, the isolation mounts 30 are applicable for dampening high-frequency (e.g., greater than approximately 10-12 Hz) vibrations, such as those small displacement disturbances that are generated by the machine (windrower) or machine components (e.g., hydraulic pumps, the engine, etc.).
The suspension units 28 are applicable for dampening primarily low-frequency vibrations, such as those generated by virtue of the windrower 10 traversing a field. Note that the low natural frequency of the suspension units 28 means the suspension units 28 are capable of dampening high frequencies, though the physical needs of their design (e.g., holding up a heavy cab) also means they do transmit high frequency vibration through their structure. That is, the terrain causes the low frequency vibrations that emanate through the tires 16, chassis 14 (
In one′ embodiment, the suspension units 28 operate under passive control (e.g., not electronically or manually adjustable in the field). In some embodiments, the suspension units 28 may operate under active or semi-active control.
Attention is now directed to
In one embodiment, the mount bracket 38 is of a generally rectangular, U-shaped configuration, with the top surface of the mount bracket 38 affixed to a bottom surface (or intervening structure) of the cab 18, and at one end (forward end) of the front mount bracket 38, affixed (e.g., bolted) between the U-shaped walls of the front mount bracket 38 to a top mounting end (e.g., ring or trunnion mount) of the front suspension unit 28. Variations to the design of the front mount bracket 38 may be used to achieve a similar function, as would be appreciated by one having ordinary skill in the art in the context of the present disclosure.
Coupled to one of the sub-frames (sub-frame 34B), at a forward end proximal to the bracket 36, is a transverse member 40, which in one embodiment is configured as a Panhard rod. The transverse member 40 is pivotably attached to a mounting bracket 42. In one embodiment, the mounting bracket 42 may be configured as a trunnion affixed (e.g., welded, tacked, etc.) to the top and internal side surfaces of the sub-frame 34B. The transverse member 40 extends inwardly and transverse to the sub-frame 34B (and beneath a portion of the cab 18, extending to approximately the longitudinal midline of the cab 18). In some embodiments, the transverse member 40 may be coupled to the opposing sub-frame 34A instead. The pivotable movement of the transverse member 40 enables movement in an arc as the cab 18 moves up and down. The transverse member 40 is attached at the end opposite the mounting bracket 42 directly or indirectly via a structural member or frame (e.g., a U-shaped bracket attached to the underside of the cab 18) to the underside surface of the cab 18, approximately at the longitudinal midline of the cab 18. Though the isolation mounts 30 secure the back of the cab 18 to the sub-assembly, side-to-side movement at the front of the cab 18 is restrained by the transverse member 40.
It should be appreciated by one having ordinary skill in the art, in the context of the disclosure, that particular details of the assembly and/or construction of the 2-point cab suspension system 12 is illustrative of one embodiment, and that variations to the above description may be implemented to achieve a similar function as long as the relative arrangement of the suspension units 28 and the isolation mounts 30 is preserved.
In view of the above description, it should be appreciated that one embodiment of a 2-point cab suspension method 44, depicted in
Any process descriptions or blocks in flow diagrams should be understood as representing steps in a process, and alternate implementations are included within the scope of the embodiments with additional steps, as would be understood by those reasonably skilled in the art of the present disclosure.
In this description, references to “one embodiment”, “an embodiment”, or “embodiments” mean that the feature or features being referred to are included in at least one embodiment of the technology. Separate references to “one embodiment”, “an embodiment”, or “embodiments” in this description do not necessarily refer to the same embodiment and are also not mutually exclusive unless so stated and/or except as will be readily apparent to those skilled in the art from the description. For example, a feature, structure, act, etc. described in one embodiment may also be included in other embodiments, but is not necessarily included. Thus, the present technology can include a variety of combinations and/or integrations of the embodiments described herein. Although the systems and methods have been described with reference to the example embodiments illustrated in the attached drawing figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the disclosure as protected by the following claims.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2018/000367 | 4/12/2018 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62492381 | May 2017 | US |
