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Types of mowers



S.Seifullin Kazakh Agro-Technical University

Technical faculty

Department of Agricultural and grain processing machinery

LABORATORY WORK

) on subject) on subjecton subject «Adjustment and linkage of Agricultural machines»

Theme: Haymaking machinery

 

Astana 2011

 

Considered and approved at the meeting of Methodological Council of S.Seifullin Kazakh Agro-Technical University Protocol №___ «___»_______________2012 «APPROVED» Chairman of Methodological Council of S.Seifullin Kazakh Agro-Technical University Protocol №___ _____________A.M.Abdyrov «___»_______________2012  

 

Authors: Yeskhozhin К. – Candidat of Techical Sciense, Associate Professor of the Department of Agricultural and post-harvesting Machines.

 

 

Educational-methodical __________ is designed for training on discipline "Fundamentals of tractors" for students on specialty 5B080600 - "Agricultural techniques and technology"

 

Educational-methodical instructions are made according to the working curriculum of specialty.

Methodical instructions are intended for students of specialties 5В080600 – « Agricultural techniques and technology» and includes laboratory occupation tasks and independent work, educational literature lists and control questions for self-examination.

 

 

Reviewers: Doctor of Technical Science, Professor S.O. Nukeshev;

 

 

Reviewed and recommended at a meeting of the Department of Agricultural and post-harvesting Machines.

Protocol № ___, of "__" ___________ 2012.

 

 

Reviewed and recommended at a meeting of the methodical commission of Technical Faculty.

Protocol № ___, of "__" ___________ 2012.

 

Purpose of the work:

1. To study the construction of mowers, Rotary Mowers, Drum mowers, Disc mowers and its important functions.

2. To study the construction of Safety devices,components and its functions.

3. To study the body types of mower conditioners.

4. Controls and adjustments

5. Swath treatment machinery

6. Subsoilers

 

Mowers

Mowers are used to cut grass and other forage crops. The cut material is left in a swath for further treatment in the process of making hay or silage. Many farmers speed up their hay and silage making with a combined mower conditioner.

Cutter-bar mowers were used for many years but they have now been replaced by disc or drum rotary mowers. A few farmers use a flail mower.

Types of mowers

Rotary Mowers.Rotary mowers have a high work rate and relative freedom from blockages, even in heavy or tangled crops. Working speeds of up to 15 km/h (9 mph) can be achieved in good conditions.

Self-propelled rotary mowers have their own engine. Mounted and trailed models are power take-off driven and some are front-mounted, leaving the rear linkage free for swath treatment machinery.

Disc and drum rotary mowers have cutting widths from 1.4 to 10.0 m; self-propelled ma­chines may have a working width of up to 14 m. Drum mowers have two or four large-diameter drums each with two or three blades similar to those of a domestic rotary mower. Disc mowers have a number of smaller diameter discs with a cutting width of about 0.4 m. Each disc has two or three free-swinging replaceable blades. A typical 3.0 m cut disc mower has seven cutting discs.

 

Figure 14.1 A trailed mower and conditioner cutting and treating a 3.2 m swath in a single operation. The mower is swung behind the tractor by a hydraulic ram for transport. (Taarup)

 

Drum mowers.The large diameter rotors of a drum mower are driven from the top, either by a system of gears or a toothed belt. Positive drive is necessary to prevent the replaceable blades on adjacent drums coming into contact with each other. The rotors turn at speeds in the region of 1,000 rpm.

The drive is arranged so that the drums contra-rotate on a two-drum mower to form a single swath behind the machine. Three-drum mowers are less common. They leave one full swath and one half swath, which is completed on the next pass. The wider, four-drum mowers leave two complete swaths and trailed models usually have a central drawbar which can be angled for cutting on either side of the tractor.

A typical two-drum mower with a cutting width of 1.9 m needs a tractor of about 40 kW (55 hp) and a four-drum mower cutting a 3 m swath requires at least 55 kW (75 hp).

Figure 14.1 A drum mower

 

Disc mowers. Wider models of trailed disc mower with a central and two wing-cutting units have a pivot­ing hitch arrangement which allows the wing units to follow uneven ground contours. The cutting discs, carried on a bar which runs along the ground are gear-driven and timed to prevent the blades on adjacent discs coming into contact with each other.

Skids at each end of the bar prevent excessive wear on the underside of the housing contain­ing the gears, which drive the discs at about 3,000 rpm. Each pair of discs contra-rotates so that, for example, a four-disc model leaves two swaths. The discs at each end of the bar have a steel cone which acts as a deflector to keep the cut material well away from the standing crop. A tractor of at least 45 kW (60 hp) is required for a 2.6 m mounted disc mower with six discs and a minimum of 60 kW (80 hp) is required for a 3.0 m combined mounted mower conditioner.

Rotary mowers have protective shields above, at the side and behind the cutting mechanism to protect bystanders from injury from flying debris. Never walk behind a rotary mower when it is cutting, or allow others to do so.

Most cutter bars have a heavy balance spring which, when correctly adjusted, allows the bar to follow un-level surfaces and maintain the correct cutting height. Others have a hydro-pneumatic suspension system which automatically lifts and lowers the cutter bar to follow ground contours.

 

Figure 1. This 2.8 m cut disc mower has contra-rotating, gear driven discs. The cutting discs are timed so that the blades on each one are at 90 degrees to the next. (Kuhn)

Figure 14.2 A disc mower with individual shaft driven cutting discs carried on a bar with a spacing block between each. (Lely)

Plate 14.3 The mower cutter bar is raised and lowered by a hydraulic ram. A strong spring alongside the ram allows the cutter bar to float over uneven ground. The discs are driven via multiple vee-belts and a gearbox. The conditioner is driven by a shaft from a small gearbox behind the vee-belt pulley. (Lely)

 

 




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