Being an integral part of the transmission, the clutch tiller performs the function of transmitting torque from the crankshaft of the engine to the gearbox (gearbox shaft). With it, during the gear shift occurs the separation of the power plant and gearbox. Due to this mechanism, the tiller starts moving and stops without stopping the motor.
If in the conceived construction design of the factory-made motorcycles, no coupling is provided for, it can be assembled on its own.
Coupling is based on the action of the friction clutch (sliding friction force).
This transmission component is intended for:
- torque transmission;
- torsional vibration damping;
- smooth gear shift;
- non-impact gear connection;
- connection and short-term disconnection of the ICE from the gearbox;
- disconnecting the transmission from the flywheel.
The mechanism makes it possible to temporarily uncouple the tiller power train and the engine crankshaft. In addition, tiller using the clutch without jerks proceeds to action. Having a great importance for agricultural vehicles when moving, the clutch allows you to start off (although without it it is possible to do it, but it is very difficult).
As a reliable component of the transmission has proven itself centrifugal clutch. It has found its use in automatic transmissions. Its main working elements include a flywheel, a pulley, a hub with a key and a lock groove, a flange, a casing, a sleeve, a bearing, a lock ring.
An important role is also played by the differential, directly related to the clutch. Tasks are assigned to it to improve the maneuverability of heavy-class tillers and to ensure a smooth turn. Coupling and differential in “symbiosis” regulate the rotation of the wheel part of the tiller at different speeds. Besides, the power transmission mechanisms are equipped with wheel locking functions. However, in some models, the differential is replaced by a special device that turns off one wheel while driving.
On modern models, tiller usually uses a friction clutch. It is installed between the gearbox and the engine. In friction clutches, the driven elements are closely connected with the gearbox primary shaft (or another, following the grip, transmission unit), and the drive elements. with the engine crankshaft. As a rule, the leading and driven parts are made in the form of round flat discs, sometimes made in a cone variation (for example, tiller and BCH-735 and Kutaisi Super-600) and shoe (Gutbrod, Mepol Terra).
In the case of the production of these working bodies in the form of V-belt pulleys, additional tensioning rollers are introduced, allowing them to set their position, the degree of tension from the control belt of the belts, disconnect and connect the engine to the transmission.
Device and principle of operation.
Friction clutch type consists of:
- control mechanism;
- leading part;
- driven elements.
The leading part is formed from the end surface of the flywheel of the motor and the pressure plate, which rotates with the wheel. However, the disk can move in the axial direction relative to the flywheel. Between them there is a driven disc, it’s hub is located on the slotted driven shaft. Cylindrical springs mounted with preliminary compression are placed around the circumference of the pressure disc.
The role of the springs is to press the pressure disk, in which they rest against one end, and the other into the casing, together with the driven end surface of the flywheel. As a result of these actions, the clutch comes continuously on.
The control mechanism includes squeezing levers, which are connected to the pressure plate using rods and layering with the pedal. Turning off the clutch, the operator sends the force from the pedal or lever with a fork or cable to the squeezing levers through a suspension with a release bearing. The outer end connected to the pressure plate with bolts, the levers, while compressing the springs, retract the disks driven from the pressure plate, due to which the clutch is disengaged.
The bearing reduces friction, eliminating the contact of the stationary cutting and rotating arms. Usually in the configuration three levers placed at an angle of 120 degrees to each other. With the help of the spring, the details of the control mechanism are returned to the initial position. The layoff is separated by the gap size necessary for the complete disengagement of the clutch from the levers. If this distance is not observed, there is a slip of the clutch, wear of the friction linings. When the gap exceeds the required distance, the clutch is not fully disengaged.
Types of clutch, their features.
Depending on the design characteristics of motorcycles.
The clutch for tiller can be of the following types:
- friction (discussed above);
- single, two-disk;
According to the type of friction, the mechanism under consideration is classified into wet ones operating in an oil bath and dry ones operating in air. In accordance with the mode of inclusion emit a permanent closed and non-permanently closed clutch.
The centrifugal works due to the following working bodies: a clutch cable, a transmission’s primary shaft, a flywheel, a clutch lever, a release bearing, a handle, a driven disc, an actuation lever, a stem mushroom, a lock washer, an off fork. Centrifugal devices have not found wide application due to their tendency to slip, which is typical for loads, and wear on friction surfaces.
When the hydraulic system through the connecting rod when you press the pedal moves the piston, pushing hydraulic fluid through a particular channel. The piston under the action of the pressure of the working medium acts on the lever through the connecting rod. Spring, he returns to the original position.
Multidisc and single-disk principle of operation practically does not differ from each other. The advantages of the first are based on the compact dimensions of the friction discs, the smoothness of the clutch engagement. The disadvantages are the worst cooling conditions, problems in obtaining a clean inclusion. Two-disk mechanisms are installed due to the super power of the power unit, the need to transfer increased torque, to increase the service life.
The belt-drive clutch, which provides the torque from the engine to the gearbox, is considered one of the first and is inferior to the mechanisms listed above because it has several minuses: high level of wear, unreliability, low efficiency, impracticality when working with powerful engines.
So, as the principle of the device provides for serious friction of composite parts, natural wear and tear can not be avoided. It is possible to make a clutch on the tiller with your own hands. However, owners of motorized machines who have no experience in the plumbing business are not recommended to perform this operation.
Consider an example of creating a mechanism for a heavy tiller. The basis is the flywheel and the primary shaft of the Moskvich car box, a steering knuckle with a hub from Tavria, a profile B, a driven pulley on two streams and a steel billet as a crankshaft (suitable from GAZ-69). The self-made product begins with turning the steel billet on a lathe so that the resulting hub can be mounted on the hub. After landing of the pulley on the honed shaft, the seat should be machined according to the diameter on the inner ring of the pulley under the support bearing, which should “sit down” ideally.
If the hub is without gaps, and the pulley is scrolling, this is a sign of a correctly completed task. Turn the part and do the same on the reverse side. In the next step, in the pulley using a drill and a drill (5 mm), make six holes equidistant from each other. Since the bolts will be 10 mm, on the reverse side, it is necessary to drill out the holes in the wheel, which gives movement to the driving belt, with a 12 mm drill.
A pulley is mounted on the flywheel, the same drill should be drilled, and the two parts pulled together with a bolt for fixing. While the pulley is on the wheel, put the marks on the flywheel through the holes made on it before the tunnels. Remove your pulley and drill all six holes.
Using bolts (10 mm), tighten the structure, the thread without the cap should be equal to 60 mm. Grind the crankshaft inside the disc. To prevent the flywheel from striking, it is also necessary to grind its surface and then center it on the bore.
It may be necessary to trim the inner plane of the flywheel together with the pulley a little on the lathe. The metal layer is removed no more than 1 m. Beforehand, the wheel is set to send, check the beating of the planes, it should not exceed 0.1 mm. Ultimately, the basket remains mounted on the wheel.