Cleaning system for a combine harvester with an eccentric sieve drive

Patent metadata

Field	Value
Publication number	US-9622415-B2
Application number	US-201514688649-A
Country	US
Kind code	B2
Filing date	Apr 16, 2015
Priority date	Apr 22, 2014
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A cleaning system for a harvester has a sieve that is moveable by a drive assembly that includes a rotary drive, —an eccentric device, a transmission connected to the eccentric device and to the sieve, which transmission cyclically varies the distance between the driving point of the eccentric device and the sieve coupling during each full rotation of the rotatable output shaft of the rotary drive, wherein, due to the cyclic variation of the distance between the driving point of the eccentric device and the sieve coupling, during each reciprocating sieve movement at least one of the accelerating portion of the throw stroke, the decelerating portion of the throw stroke, the accelerating portion of the return stroke and the decelerating portion of the return stroke has a duration that is different from the duration of at least one other of the portions of the reciprocating sieve movement.

First claim

The invention claimed is:

1. A combine harvester comprising:
a cleaning system comprising at least one sieve, an associated sieve drive assembly and a sieve coupling, said sieve drive assembly connected to the sieve by said sieve coupling, said sieve coupling defining a sieve pivot point between said sieve and said sieve drive assembly,
wherein said sieve is moveable by said sieve drive assembly to perform a reciprocating sieve movement having a throw stroke and a return stroke, said throw stroke and said return stroke each having an accelerating portion and a decelerating portion,
wherein the sieve drive assembly comprises:
a rotary drive comprising a rotatable output shaft having a center line;
an eccentric device fixedly connected to the rotatable output shaft of the rotary drive to rotate with the rotatable shaft, wherein the eccentric device has an eccentricity and a driving point, the driving point is rotatable around the center line of the rotatable shaft along a circular path having a radius that equals the eccentricity of the eccentric device; and
a transmission coupled between the eccentric device and the sieve coupling, the transmission is adapted to transfer the movement of the eccentric device to the sieve coupling and to cyclically vary the distance between the driving point of the eccentric device and the sieve coupling during each full rotation of the rotatable output shaft of the rotary drive, the transmission including a first length variation link element and a second length variation link element pivotally coupled to the first length variation link element at a common pivot point, the first length variation link element extending between a first end coupled to the eccentric device and a second end coupled to the second length variation link element at the common pivot point, the second length variation link element extending between a third end coupled to the first length variation link element at the common pivot point and a fourth end pivotably coupled to the sieve at the sieve pivot point defined by the sieve coupling such that the second length variation link element pivots relative to the sieve about the sieve pivot point,

wherein, due to the cyclic variation of the distance between the driving point of the eccentric device and the sieve coupling, during each reciprocating sieve movement at least one of the accelerating portion of the throw stroke, the decelerating portion of the throw stroke, the accelerating portion of the return stroke or the decelerating portion of the return stroke has a duration that is different from the duration of at least one other of said portions of the reciprocating sieve movement.

2. A combine harvester according to claim 1 , wherein the duration of the accelerating portion of the throw stroke is more than 25% of the duration of said reciprocation sieve movement.

3. A combine harvester according to claim 1 ,
wherein a relative angle between the first length variation link element and the second length variation link element is cyclically variable to cyclically vary the distance between the driving point of the eccentric device and the sieve coupling.

4. A combine harvester according to claim 3 , wherein the transmission further comprises a length variation drive mechanism that engages at least one of the first length variation link element, the second length variation link element or the common pivot point defined between the first length variation link element and the second length variation link element to cyclically vary the relative angle between the first length variation link element and the second length variation link element during each rotation of the rotatable output shaft.

5. A combine harvester according to claim 1 , wherein the eccentric device comprises a circular disc that is fixedly connected at a shaft connection point to the rotatable output shaft of the rotary drive to rotate with the rotatable output shaft, the shaft connection point is located at a distance from the center of the circular disc, wherein the center of the circular disc is the driving point of the eccentric device and the distance between the center of the circular disc and the connection point equals the eccentricity of the eccentric device.

6. A combine harvester according to claim 5 , wherein the transmission further comprises a link having an annular member, the annular member extends around the circular disc and is pivotable around said circular disc.

7. A combine harvester according to claim 1 , wherein the eccentric device comprises a crank connected to the rotatable output shaft of the rotary drive to rotate with the rotatable shaft, the crank further comprises a pivot connector adapted to pivotably connect the crank to the transmission.

8. A combine harvester according to claim 1 , wherein a relative angle between the first length variation link element and the second length variation link element is cyclically variable to cyclically vary the distance between the driving point of the eccentric device and the sieve coupling,
wherein the transmission further comprises a length variation drive mechanism that engages at least one of the first length variation link element or the second length variation link element to cyclically vary the relative angle between the first length variation link element and the second length variation link element during each rotation of the rotatable output shaft,
wherein the length variation drive mechanism comprises:
an eccentric length variation drive device coupled for rotation with said rotatable shaft, the eccentric length variation drive device having an eccentricity and a length variation driving point, the length variation driving point being rotatable around the center line of said rotatable shaft along a circular path having a radius that equals the eccentricity of the eccentric length variation drive device; and
a length variation drive linkage comprising a first end that is connected to the eccentric length variation drive device and a second end that is connected to at last one of the first length variation link element, the second length variation link element or the common pivot point defined between first length variation link element and the second length variation link element.

9. A combine harvester according to claim 8 , wherein the eccentric length variation drive device comprises a circular disc that is connected to the rotatable shaft to rotate with the rotatable shaft at a shaft connection point, the shaft connection point is located at a distance from the center of circular disc, in which the center of the circular disc is the length variation driving point of the eccentric length variation drive device and a distance between the center of the circular disc and the shaft connection point equals the eccentricity of the eccentric length variation drive device.

10. A method for cleaning harvested crop using a cleaning system comprising at least one sieve, an associated sieve drive assembly and a sieve coupling, said sieve drive assembly connected to the sieve by said sieve coupling, in a combine harvester, said sieve coupling defining a sieve pivot point between said sieve and said sieve drive assembly, wherein said sieve is moveable by said sieve drive assembly to perform a reciprocating sieve movement having a throw stroke and a return stroke, said throw stroke and said return stroke each having an accelerating portion and a decelerating portion, which method comprises the following steps:
rotating a rotatable output shaft of a rotary drive of the sieve drive assembly around a center line of the shaft, the rotary drive comprising a rotatable output shaft having a center line, an eccentric device fixedly connected to the

Assignees

• Cnh Ind America Llc

Inventors

• Duquesne Frank R G
• Van Hullebusch Bart G L

Classifications

• A01F12/448 Primary

  Sieve adjusting means · CPC title