The discussion below is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.
Aspects of the invention relate to a mixer for feed, provided with an auger.
A mixer is usually provided with an auger with a vertical shaft, often provided with one or more spiral mixing blades. The mixer can for instance be made up of a wheeled diet feeder cart commonly pulled by a tractor, in which case the shaft of the auger can be driven by the tractor by way of a power take-off shaft. Alternatively, the mixer can be supported by standards and be driven by an external motor, usually an electric motor. Alternatively, the mixer can be a self-propelled and/or self-loading vehicle.
In the case of larger tractors and electric drives the input shaft is often driven at a speed of 1,000 rpm or higher. In diet feeder carts often gearboxes are used which are composed of a right-angle gearbox, usually connected to one, two or more planetary reduction gearboxes placed one behind the other, in order to reduce the speed to the speed desired for the auger, usually c. 40 rpm maximum. In order to control the temperature of the oil in these comparatively rapidly rotating gearboxes, the gearboxes are provided with an oil tank and a cooling radiator. Such a cooling system uses a lot of oil, as a result of which the maintenance costs are comparatively high.
This Summary and the Abstract herein are provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary and the Abstract are not intended to identify key features or essential features of the claimed subject matter, nor are they intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the Background. It is one of the objects of the invention to improve the prior art roof assembly.
An aspect of the invention is to provide a mixer for feed provided with a drive with more favorable oil consumption and lower maintenance costs.
An aspect of the invention is attained with a mixer for feed, which mixer is provided with at least one auger and a gearbox with an input driving shaft and an output shaft for driving the auger. The mixer comprises an air mover for generating an air flow along the gearbox.
In this process heat is dissipated by way of the oil by the air flow. It was found that by using such a combined air and oil cooling, oil consumption and maintenance costs are lowered substantially. The use of an oil tank, radiator, hoses and the like can be avoided. At an input speed of 1,000 rpm a lot of heat is generated, especially in the case of the right-angle gearing, where the speed is highest, and to a lesser degree in the planetary reduction gearboxes. It was found that so much heat is generated that the temperature of the lubricating oil used can rise to far above 90 degrees in the case of continuous use. In such a case the oil will age rapidly as a result of combustion and will no longer provide sufficient lubrication. The seals will also age quickly and the gearbox will suffer damage. With a system as described herein excess heating of the oil is prevented in an economically advantageous manner, as a result of which it no longer has to be replaced or has to be replaced less frequently. A cooling radiator is no longer required and the maintenance costs are low.
These advantages are not attained using already familiar cooling systems where oil is circulated through the gearboxes by way of an oil pump, after which the oil is passed through a heat exchanger. In that process heat is dissipated with the aid of a fan. The cooled oil is then returned to the gearboxes. Such a system is relatively expensive as a result of the use of a pump with a suction filter, an oil tank and a fan. Such a system has a large oil capacity. Replacing the oil thus increases the maintenance costs. Surprisingly, it was found that an air flow along the right-angle gearbox itself has sufficient effect on the temperature and on the oil's keeping properties, with it being possible to use a simpler design which has lower maintenance costs.
The gearbox can for instance comprise one or more reduction gearboxes, with the input and output shafts being essentially parallel. Alternatively, the gearbox can comprise a right-angle gearbox, with the output shaft being a vertical shaft for driving the auger by way of one or more reduction gearboxes. The reduction gearboxes serve to further reduce the speed of the rotation of the output shaft and can for instance comprise one or more, say two, planetary reduction gearboxes. The air flow can be passed along these reduction gearboxes as well.
The air mover for generating an air flow can for instance comprise a fan on the underside of the right-angle gearbox. In that case the fan can be arranged such that the air flow along the right-angle gearbox is directed downwards. This prevents dirt from the environment or from the floor being sucked upwards in the direction of the gearbox or the reduction gearboxes. Alternatively, the air flow can be generated parallel to the horizontal shafts.
Oil for lubricating the right-angle reduction gearing can be circulated by way of an oil circuit which extends partly outside the right-angle gearbox and in the process crosses the range of the generated air flow. In the range of the air flow the circulated oil cools, which can then be returned to the gearing to be cooled. Such an oil circuit can for instance comprise a spiral line in the range between the right-angle gearbox and the fan.
The right-angle reduction gearing usually comprises a first conical gear mounted on the drive shaft and, mating with the first conical gear, a second conical gear which is mounted on the output shaft and meshes with the first conical gear which is at right angles to it. The section of the oil circuit extending outside the right-angle gearbox preferably connects to an opening in the gearbox near the mesh point of the two right-angle conical gears, more particularly at a point which—looking in the direction of rotation of the gears—is behind the mesh point of the conical gears. The right-angle reductive gearing has a driving, pumping action by which the oil can be driven by way of the said opening into the external part of the oil circuit. Because of this there is no need to use a pump and the oil can be circulated in an efficient manner.
For a still more efficient temperature control the device can be provided with one or more temperature sensors on one or more of the parts of the device which are under thermal load, and a control unit for controlling the air mover for generating an air flow on the basis of a signal generated by the sensor, or for triggering an alarm.
The air mover for generating an air flow can for instance be driven with the aid of an electric motor or with the aid of a mechanical drive.
Aspects of the invention will be elucidated further with reference to the drawings.
a and b: are representations in perspective of a drive of the mixer according to
The front auger 4 is driven with the aid of a right-angle reduction gearing 8a shown in
The right-angle reduction gearing 8a further comprises a vertical output shaft 16 (see
The right-angle reduction gearing 8a is lubricated with oil in the gearbox 22. Near the mesh point 23 of the two conical gears 19, 21 the oil is discharged into an oil circuit by way of an opening 22a (illustrated schematically with a dashed circle behind the mesh point 23) in the gearbox 22 proximate moving components of the gearing 8a to receive oil therefrom, for example, with the aid of the driving action of the two meshing conical gears 19, 21. By way of the oil circuit having the opening 22a in the gearbox 22 and successively comprising, a vertical oil line 24, a spiral circuit section 25 and a vertical line 26, the oil is returned to an oil line opening 20 in the area of the planetary gearboxes 17, 18, where the oil is returned once more to the gearbox 22. As a result of this structure and action, a recirculation circuit for the oil is created. The spiral circuit section 25 is in line with an opening 27 in a base plate 28 of the diet feeder cart 1. In this opening 27 a fan 29 has been mounted, which is driven by an electric motor 30. When the fan 29 is in operation, it sucks in air. The air flow, indicated in the figure by the arrows, is directed downwards, so that air is guided along outer walls of the gearbox 22 of the gearing 8a. The gearbox 22 is cooled by this. The air flow also passes by portion(s) of the oil circuit such as through the spiral section 25 of the oil circuit. This ensures that the oil in the circuit is properly cooled before it is passed back to the oil inlet 20 in the gearbox 22. This way a very effective combined air and oil cooling is obtained.
Referring back to
An alternative mixer 40 is shown in
In this embodiment also the reduction gearbox 9 between the intermediate power take-off shaft 12 and the drive shaft 10 is provided with a fan 44, which in this embodiment is mounted on the input shaft of the reduction gearbox 9. The fan 44 is arranged to generate an air flow along the outside of the reduction gearbox 9.
For a still more efficient temperature control the apparatus can be provided with one or more temperature sensors 50a, 50b, schematically illustrated, that can be inside or outside the gearbox 22, on a part of the oil circuit 24, 25, 26, and/or on one or more of the parts of the apparatus which are under thermal load. A control unit or controller 52 embodied with analog and/or digital circuitry, which can include a microprocessor with memory and software receives the signal(s) from the sensor(s) 50a, 50b and is configured to control operation of the air mover, for example by controlling operation of motor 31. In addition or in the alternative, the controller 52 can trigger an alarm 54 on the mixer 1 and/or the tractor 2. If desired, a single controller 52 can be used to receive temperature signals from more than one the gearing 8a, 8b and/or 9 on the mixer 1.
Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above as has been held by the courts. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.
Number | Date | Country | Kind |
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2012242 | Feb 2014 | NL | national |