A doffer column with increased critical speed

Abstract

The present invention discloses a doffer column with improved critical speed, comprising: a vertical shaft, a plurality of doffers spaced apart on the vertical shaft, and a plurality of spacers; a closed end is provided at the bottom of the hollow vertical shaft, and an external thread is extended downward from the center of the closed end; the doffer column also comprises a tensioning component, the upper and middle parts of the tensioning component are hollow structures, provided with internal threads, and the lower part is provided with a head end, and the outer part of the head end is provided with a hexagonal head; the upper part of the tensioning component is located between the lowest spacer and the extended section of the vertical shaft, and a gap is provided between the upper end of the tensioning component and the closed end of the vertical shaft. The lower end of the vertical shaft of the present application is closed, which greatly increases the rigidity of the vertical shaft and greatly improves the critical speed of the doffer column; at the same time, the external thread section of the present application is integrated with the vertical shaft, the structure is simpler and more compact, and assembly is easier. Only one tensioning component is required to connect with the vertical shaft provided with the extended section, and no independent internal thread component is required.

Description

Technical Field

[0001] The invention belongs to the technical field of cotton pickers, and in particular relates to a cotton doffing column with an improved critical speed. Background Art

[0002] Initially, available doffers for spindle-type cotton pickers consisted of a set of doffers supported on a solid shaft. Some of the doffers were in the form of flat discs with spacers inserted between them. The discs were sandwiched between the spacers, and a nut threaded onto the external threads at the end of the solid shaft tightly clamped the discs and spacers, allowing them to rotate along with the solid shaft.

[0003] A threaded stub shaft at the bottom of the doffer column receives a tensioning nut that provides preload, sandwiching the doffers and spacer or hub, causing them to rotate with the doffer shaft. The small amount of mounting space at the lower end of the doffer column typically requires a relatively thin nut with minimal thread engagement.

[0004] Deere & Company's patent application number CN201110295870.2 proposes a high-speed doffer column with improved shaft preload and reduced weight. The column comprises a tensioning component and an internally threaded component supported at one mounting end of a vertical shaft, into which the tensioning component is screwed. The shaft can be hollow and have a larger diameter than conventional shafts to reduce weight, increase rigidity, and thereby improve critical speed. The preload structure does not require a nut and has an increased thread engagement length or amount compared to previously available structures. However, the hollow vertical shaft has low rigidity, particularly since its lower end is not sealed. Tests have shown that this significantly affects the critical speed of the doffer column. Furthermore, the structure is complex and not very convenient to assemble. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a doffer column with an improved critical speed, the doffer column comprising: a vertical shaft, a plurality of doffers spaced apart on the vertical shaft, and a plurality of spacers, the vertical shaft is hollow, and the hollow vertical shaft has an upper mounting end and a lower mounting end; a closed end is provided at the bottom of the hollow vertical shaft, and an external thread is extended downward from the center of the closed end, and the extension section is thinner than the hollow vertical shaft; the doffer column also comprises a tensioning component, the upper and middle parts of the tensioning component are hollow structures, provided with an internal thread, the lower part is provided with a head end, and the outside of the head end is provided with a hexagonal head; the upper part of the tensioning component is located between the lowest spacer and the extension section of the vertical shaft, the diameter of the upper part of the tensioning component is approximately equal to the outer diameter of the vertical shaft, and the diameter of the middle part of the tensioning component is smaller than the diameter of the upper part; a gap is provided between the upper end of the tensioning component and the closed end of the vertical shaft.

[0006] Preferably, a washer, a bearing assembly, an oil retaining ring and a protective cover are provided between the lower end of the lowest spacer and the head end of the tensioning component, an inner ring is provided on the inner side of the bearing assembly, and the middle part of the tensioning component is located on the inner side of the washer, the inner ring, the oil retaining ring and the protective cover.

[0007] Preferably, there is a distance between the upper portion of the tensioning member and the upper surface of the shield, and they are spaced apart from each other.

[0008] The present application designs the lower end of the hollow vertical shaft into a closed structure, and the center of the end extends downward to form a screw shape with an external thread; the corresponding tensioning component is provided with an internal thread; the lower end of the vertical shaft of the present application is closed, which greatly increases the rigidity of the vertical shaft, and the critical speed of the cotton removal column is greatly improved; at the same time, the external thread section of the present application is integrated with the vertical shaft, the structure is simpler and more compact, and assembly is easier. Only one tensioning component is required to connect with the vertical shaft with an extension section, and no independent internal thread component is required. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The following is further described in detail with reference to the accompanying drawings and specific embodiments:

[0010] Figure 1 The diagram is a structural diagram of a doffer column with an improved critical speed according to the present invention.

[0011] Figure 2 is an enlarged view of the mounting and column preload assembly. DETAILED DESCRIPTION

[0012] like Figure 1 、 2 The present invention discloses a doffer column with increased critical speed, wherein a doffer column assembly 10 for a harvester row unit of a conventional cotton picker is shown. The doffer column structure 10 includes a plurality of doffers 12 supported on a vertical shaft 14 for rotation about an axis 15. The doffers 12 are vertically spaced apart on the shaft 14 by spacers 16. The doffers 12 rotate with the shaft 14 over multiple rows of spindles and untie and remove cotton from the spindles in the rows.

[0013] Each doffer 12 includes a generally horizontal, circular metal disk or base plate 22 supporting radially outwardly and downwardly directed projections 24 in a conventional manner. A circular hole 26, slightly larger in diameter than the shaft 14, is located in the center of the base plate 22. The doffers 12 are slid into position on the shaft 14, with the spacers 16 interposed between adjacent doffers on the shaft. An upper mounting flange 32, secured to the upper end 14U of the shaft 14 adjacent the highest doffer base plate 22, mounts the upper end 14U to the row unit adjacent to the row unit drive assembly, which is located in the upper portion of the row unit housing and drivingly connected to the flange 32. A retaining assembly 28 tensions the shaft 14 to securely hold the doffers 12 and spacers 16 between the flange 32 and the bearing assembly 30, allowing the doffers and spacers to rotate with the vertical shaft. The retaining assembly 28 sufficiently pre-tensions the shaft 14 to prevent the doffers from rotating relative to the vertical shaft 14.

[0014] The retaining assembly 28 includes a tensioning component 36 and an externally threaded component 40. The outer diameter of the upper portion 36U of the tensioning component is approximately equal to the outer diameter of the vertical shaft 14, and the diameter of the middle portion 36L of the tensioning component is smaller than the diameter of the upper portion 36U; the tensioning component 36 includes a head end located at the other end of the thread 42, so that the upper portion 36U and the middle portion 36L of the tensioning component are hollow structures with internal threads, and the lower portion is a head end with a hexagonal head on the outside of the head end; the upper portion 36U of the tensioning component is located between the lowest spacer 16 and the extension section of the vertical shaft 14.

[0015] The upper end of the tensioning member 36 is spaced apart from the closed end of the vertical shaft 14 to provide space for forward rotation.

[0016] Washer 58 is secured between inner race 60 and the headed end of bearing assembly 30. Slinger 64 is positioned on lower portion 36L and abuts the upper end of inner race 60. Cup-shaped shield 66 opens downwardly above slinger 64 and bearing assembly 30 and is secured between the lowermost spacer 16 and slinger 64 for rotation with inner race 60, slinger 64, and shaft 14.

[0017] When the tensioning assembly is tightened, the washer 58, inner race 60, oil deflector 64, and shroud 66 are sandwiched between the headed end and the lowermost spacer 16, which extends downward from the lowermost doffer 12 around the assembly 36. The radially inward-most portion of the spacer 16 (or doffer hub) and the base plate 22 of the doffer 12 are securely secured between the bearing assembly 30 and the flange 32 for rotation therewith. This preload is sufficient to prevent relative rotation between the doffer column components. The offset of the step 36A relative to the shroud 66 facilitates vertical movement of the assembly 36 relative to the bearing assembly 30 when the headed end is rotated to adjust the preload. This arrangement allows for easier adjustment and provides for more thread engagement.

[0018] The shaft is a hollow structure with a larger outer diameter than that of a solid shaft to reduce weight, increase rigidity, and increase the critical speed of the doffer column; the lower end of the vertical shaft is closed, which further increases the rigidity of the vertical shaft and greatly improves the critical speed of the doffer column.

[0019] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A doffer column with an increased critical speed, comprising: A vertical shaft, a plurality of doffers spaced apart on the vertical shaft, and a plurality of spacers, wherein the vertical shaft is hollow and has an upper mounting end and a lower mounting end; the characteristic is that a closed end is provided at the bottom of the vertical shaft, an extension section extending downward from the center of the closed end is provided with an external thread, and the extension section is thinner than the vertical shaft; the doffer column also includes a tensioning component, the upper and middle parts of the tensioning component are hollow structures, provided with an internal thread, the lower part is provided with a head end, and the outer part of the head end is provided with a hexagonal head; the upper part of the tensioning component is located at the lowest spacer The diameter of the upper portion of the tensioning member is approximately equal to the outer diameter of the vertical shaft, and the diameter of the middle portion of the tensioning member is smaller than the diameter of the upper portion; a gap is provided between the upper end of the tensioning member and the closed end of the vertical shaft; a washer, a bearing assembly, an oil retaining ring and a shield are provided between the lower end of the lowest spacer and the head end of the tensioning member, an inner ring is provided inside the bearing assembly, and the middle portion of the tensioning member is located inside the washer, inner ring, oil retaining ring and shield; a distance is provided between the upper portion of the tensioning member and the upper portion of the shield, and the tensioning member is separated from each other; The washer is fixed between the inner ring and the headed end of the bearing assembly, the oil slinger is positioned on the middle of the tensioning component and adjacent to the upper end of the inner ring, the cup-shaped shield is above the oil slinger and the bearing assembly, and is open downward and fixed between the lowest spacer and the oil slinger, and rotates with the inner ring, the oil slinger and the shaft.

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