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Page 3 - Rotary Mowers; Table of Contents
Rotary Mowers 1 Toro University Technical Training Table of Contents Historical Background...................................................................................................... 2 Theory of Operation.........................................................................................
Page 4 - Historical Background
2 Rotary Mowers Toro University Technical Training Historical Background The first practical concept of a rotary type mower goes back to the 1930's. The concept evolved from the need for a grass maintenance tool that could cut long grass acceptably without the cost and sophistication of a reel mower...
Page 6 - Theory of Operation
4 Rotary Mowers Toro University Technical Training Theory of Operation Dec k housing Blade Blade mounting and drive s ys tem There are three basic structural members to a rotary cutting unit. Cutter Deck Housing The deck housing supports the blade hubs with their drive mechanism and is shaped to car...
Page 7 - Blade spindle assembly
Rotary Mowers 5 Toro University Technical Training Power transfer from the engine to the blades is typically done by way of belts and transfer shafts. Belt drives typically transfer a high percentage of the available horsepower to the blade and generally produce much less noise than hydraulic drive ...
Page 8 - Cutting Action; Cutting Blade Design
6 Rotary Mowers Toro University Technical Training Cutting Action Cutting action A rotary mower cuts grass by impacting the blade cutting edge against the grass blades at a very high velocity. This cutting action requires that the blade cutting edge is sharp and rotating at an adequate speed. Three ...
Page 9 - Rotary mower clip; Requirements for
Rotary Mowers 7 Toro University Technical Training Rotary mower clip To understand rotary cutting theory you must understand the concept of clip. Clip can be defined as the forward distance traveled by the cutting unit during one revolution of the blade. This distance is divided by the number of bla...
Page 10 - Equipment Application
8 Rotary Mowers Toro University Technical Training Equipment Application Rotary mowing equipment is designed for a specific application. The misapplication of rotary mowing equipment can only result in abuse, poor qualities of cut and costly downtime. The following application factors will affect th...
Page 13 - Productive Equipment Operation
Rotary Mowers 11 Toro University Technical Training Productive Equipment Operation Experience has shown that a high percentage of the problems that develop on turf equipment do not require an overhaul or disassembly type correction. In many cases a problem has developed over a period of time and it ...
Page 14 - Ground speed
12 Rotary Mowers Toro University Technical Training Wheel traction and hill climbing Wheel traction Tire pressure in the traction wheels is critical for maximum traction capability. Over-inflated tire pressure can cause spinning and tearing out of the turf in adverse conditions. if lowering the tire...
Page 15 - Noise level and condition of equipment
Rotary Mowers 13 Toro University Technical Training Mowing patterns Mowing patterns It is normally beneficial to cut a given area in a pattern that will allow the grass to re discharged onto the previously cut grass area. If this is not done, the horsepower requirement increases due to the blade hav...
Page 17 - Cutting Unit Adjustments; Height of cut and attitude; Consistent blade height
Rotary Mowers 15 Toro University Technical Training Cutting Unit Adjustments Height of cut and attitude Height of cut adjustment and attitude The height of cut is usually set by the placement of spacers on the castor wheel shafts or with the height of the rollers on contour type cutting units. The e...
Page 18 - Inspection Maintenance and Repairs; Blade Removal and Installation
16 Rotary Mowers Toro University Technical Training Inspection Maintenance and Repairs Cutting efficiency and air flow The efficiency of a rotary cutting unit is directly related to the air flow within the deck. Inspect and clean out periodically to maintain air flow The underside of the cutting dec...
Page 19 - Spindle assembly
Rotary Mowers 17 Toro University Technical Training Spindle assembly Housing Shaft Spacer and Seal Surface Pulley Seals Matched Bearing Set The deck spindles usually run at approximately 2000 to 2500 RPM. They feature tapered roller bearing for impact resistance and durability. The spindles can be d...
Page 20 - Inspecting drive belts and pulleys; Drive belt failures
18 Rotary Mowers Toro University Technical Training Inspecting drive belts and pulleys • Oil or grease contamination • Debris in pulleys • Damaged or rusted pulleys • Proper installation and tensioning Periodically inspect drive belts and pulleys. A good time to do this is after cleaning the machine...
Page 21 - Belt noise; Belt vibration or whipping
Rotary Mowers 19 Toro University Technical Training Belt noise Belt Chirp • Chirp occurs on all types of belts. • Caused by momentary slippage. • Dust can be a contributing factor. • Never apply belt dressing. • Chirps or squeaks will not harm belts. Belt Squeal • Occurs during shaft acceleration. •...
Page 22 - Rotary Blade Inspection and Sharpening
20 Rotary Mowers Toro University Technical Training Rotary Blade Inspection and Sharpening Inspectthe blades To assure a quality of cut. The cutting edge of the blade must be kept in a sharp condition. A dull blade will produce a ragged cut and will require an excessive amount of engine horsepower t...
Page 24 - OEM Blades
22 Rotary Mowers Toro University Technical Training OEM Blades • Specifically designed for the intended deck. • Meets all of the required tests. – Hardness – Object expulsion • Meets the mowing and quality demands. • Life expectancy. When discussing rotary blades, keep in mind that OEM blades are de...
