Rotary mower
A sickle mower is a lawnmower in which a horizontally mounted knife rotating at high speed cuts off the blades of grass, similar to the way a sickle works . Sickle mowers can be hand-held devices; many self-propelled lawn tractors and ride-on mowers also work on this principle; Sickle mowers are also available as attachments for. B. for municipal vehicles.
functionality
One or more cutter bars, driven by a petrol or electric motor, rotate with a vertical axis of rotation and high speed in a bell-shaped housing that is open at the bottom. The outer ends of the cutter bars (with the exception of the air cushion mowers) have a certain aerodynamic angle of attack , similar to that of a propeller , which creates an air flow from the clippings up into the housing. This straightens the grass before it is cut. The stalks are cut off by the blades rotating at high circumferential speed and thrown away by the air flow generated by the cutter bar or blown out of the bell housing, so they can be collected in a grass catcher. The possibility of mowing and collecting the crop in one operation makes rotary mowers particularly popular for use in private gardens, where leaving them behind as mulch is usually undesirable. The majority of walk-behind lawnmowers are sickle mowers, but they are also used in lawn tractors and ride-on mowers. With the latter, several cutter bars per housing or even entire mowers are sometimes arranged next to one another in order to achieve a larger working width.
The rotary mowers used in agriculture have a similar functional principle to rotary mowers .
The advantages of sickle mowers are good area coverage and less susceptibility to faults (compared to cylinder mowers , for example , where foreign objects such as branches and stones can become wedged in the spindle). In addition, it is possible to vary the distance between the mower and the ground and thus adjust the cutting height. With hand-held lawnmowers, this is usually done by adjusting the height of the wheels; with ride-on mowers or lawn tractors, the mower is raised or lowered.
The disadvantage compared to reel and bar mowers is an inaccurate and unclean cut of the blades of grass, as this is done freely with sickle mowers and not against a counter knife.
Executions
- Petrol rotary mowers with two or four-stroke engines are powerful and suitable for large areas. However, they are relatively loud and burden z. Partly also through their exhaust gases the environment, which is why their use in settlement areas is often subject to restrictions.
- Electric rotary mowers with mains operation work quietly and are well suited for areas of 50 to 400 square meters, but have a limited radius of action due to the required power cable. There is also a risk of electrical accidents if the cable is damaged when driven over.
- Cordless sickle mowers are a subspecies of electric mowers , thanks to an electric motor fed by an accumulator , they have a free radius of action, but only a limited running time and lower electrical power.
- Air cushion mowers differ from other sickle mowers in that a fan wheel sucks in ambient air and then presses it out below the mower's housing bell, whereby it slides on the air cushion and, in contrast to a conventional hand-operated sickle mower, does not need any running wheels. As a result, air cushion mowers have advantages in terms of mobility compared to the conventional variants, which is why they are preferably used on steep or winding terrain.
equipment
Knife and Collector are interchangeable, as an accessory, in some versions mulch unit to be installed.
The use of a suction pump is optional for petrol sickle mowers.
The power rake is controversial as an accessory .
Technical specifications
Typical technical data for hand-operated electric rotary mowers with cable connection are:
| el. power | 1000 to 2000 watts |
| Cutting width | 30 to 53 cm |
| Cutting height | 20 to 70 mm |
| Range with battery operation | approx. 300-2500 m² |
Typical technical data for hand-operated (possibly with selectable wheel drive) petrol rotary mowers are
| power | 1.6 to 4.4 kW (2.2 to 6 hp) |
| Cutting width | 40 to 56 cm |
| Cutting height | 20 to 90 mm |
| Sound power level | 93 to 98 dB |
swell
- ↑ Information from several advertising websites compiled.
- ↑ Information collected from manufacturer sites (Viking, Gardena, Güde, Herkules).