Constant Mesh Gear Box
Constant mesh gearbox is usually a type of Transmission where all or the majority of the gears are always in mesh with one another, instead of a sliding-gear transmission, where engagement is obtained by sliding a few of the gears along a shaft into mesh. In a constant-mesh manual gearbox, Gear ratios are chosen by little Clutches that connect the many gear sets with their shafts so that power is usually transmitted through them. The following diagram shows the set up of a constant mesh gear box
Construction and working of a continuous mesh gear box
Constant equipment mesh gearbox employed helical gears for power tranny. The gears are rigidly fixed in the lay shaft. The gears in result shaft rotates freely without engaging with shaft, thus not transmitting power. The gears in both shafts are generally meshed together.
To engage the gears with result shaft dog clutch can be used. the dog clutch is definitely shifted by the seletor fork shifted by gear lever.To supply invert gearing a idler gear is used.
When the apparatus lever is pushed, the gear selector fork pushes the dog clutch. Your dog clutch engages the apparatus and the output shaft, therefore power from lay shaft now transmitted to result shaft.
CONSTANT MESH GEARBOX
A constant mesh transmission is that a kind of manual transmission in which sliding gears from the sliding mesh gearbox is 
replaced with the constantly meshed combines of gears as well as the new shifting products named dog clutches sq . measure introduced which assists in transmittal the required output to the many shaft by creating connection with the acceptable pair of the meshed gears.
A continuous mesh transmission typically comes with 4 forward speeds and 1 reverse manual tranny configuration.
Why will we wish Constant Mesh Transmission?
The introduction of initial transmission system i.electronic. sliding mesh transmitting was an excellent success in vehicles trade as currently there was a system which might provide needed torsion and swiftness ratios want by the vehicle to face the road challenges nevertheless still there were several vital problems with this equipment that raised the issue on its performance and responsibility. the problems long-faced were as follows-
The shifting of gears wasn’t an easy task because the shifting needed a particular technique that wasn’t whatsoever everybody’s cup of tea, a talented driver was necessary for traveling such vehicle, the special technique needed being Double-de-clutching.
Note – Double-de-clutching- it’s the technique since the name indicates that needed dual engagement and disengagement of clutch for shifting one gear.
f i.electronic. once driver needs to shift the gear he preliminary presses the clutch pedal and create the apparatus to the neutral, than once again he releases the clutch pedal and accelerate in order to extend the quickness of the lay-shaft in order that the meshing of relevant gear will take place, save for he presses the clutch pedal and create the gear lever to the desired gear and unleash the clutch pedal and at last the required gear is obtained.
Since the gears are to be meshed square measure in continuous rotation with a totally different speed than the meshing of these gears may cause breakage to the apparatus teethes or continuous deterioration is there.
The shifting of gears is actually a terribly clamant method.High maintenance is necessary as slippy and meshing of gears causes resistance to wear of shafts and gears.
MAIN PARTS
Clutch Shaft.
Lay Shaft or counter Shaft.
Main Shaft.
Dog clutch.
Gears.
There are various kinds of gears with both spur and helical gears like:
Clutch gear.
First gear.
Second gear.
Reverse gear.
WORKING PRINCIPLE:
In Constant Mesh Gearbox gearbox, all gears of the main shaft are in constantly meshed with the corresponding gears of the layshaft or countershaft. Too dog clutches are provided on the main shaft: one between the clutch equipment and the next gear; and the other between the first gear and reverse gear. The primary shaft is manufactured splined and all the gears are free to move on it. Dog clutches can slide on the main shaft and rotates with it. All of the gears on the countershaft are completely fixed with it.
When the left dog clutch is made to slide to the left by making use of the apparatus shift lever, it meshes with the clutch gear and the very best speed gear is obtained. When the left dog clutch meshes with the next gear on the primary shaft, the next speed gear is achieved. Likewise, by sliding the right-hand dog clutch left and correct, the first speed equipment and reverse gear are attained respectively In this type of gearbox, because all of the gears are in constant mesh, they are safe from being damaged and unpleasant grinding audio does not occur while engaging and disengaging them.
Constant mesh gearbox can be used for the smooth working of an automobile. They are used to increase the rotating force (Torque); that is accompanied by a decrease in speed. It is a type of manual transmitting. The invention of earliest manual gear system could be traced back again to the nineteenth century. There are multiple equipment ratios present which gives various torque and velocity ratio. Along with this, the reverse construction and working of constant mesh gearbox mechanism is also present. This manual transmissions which are developed lately contain all the gears mesh at any given point of time.
In specialized terms, it can be thought as a gearbox where all of the gears are generally in circumstances of mesh. The gears remain fixed at their unique positions. The gears will stay engaged all the time. Find out more about its structure, working, advantages, disadvantages and applications in this post.
Construction:
It is made up of following components:
1. Counter shaft or Lay Shaft:
This shaft is in direct connection with the clutch and the primary shaft. Remember according to the gear ratio, the velocity of the counter shaft may be less that the rate of the engine. The gear ratio can be explained as the ratio of the teeth of driven equipment to one’s teeth of the driver equipment.
2. Main shaft:
This shaft operates the speed of the vehicle. The power is made available to the main shaft through the gears from the counter shaft. This is done relative to the gear ratio.
3. Dog clutch:
Dog clutch is particular feature of continuous mesh gearbox. It is utilized for the coupling of any two shafts. This is done by interference. Utilizing a dog clutch, various gears can be locked to the result and input shafts.
4. Gears:
The primary work of the gears is the transmission of power between the shafts. If the gear ratio is several, the main shaft will continue to work at a swiftness that is slower than the counter shaft, and vice versa. The set up of both reverse, and also forward gears, is present.
Working:
Forward gear selection:
From the input shaft, the power starts flowing and is split into four parts. Each part goes to one of the output gears, namely 1st, second, third and 4th. Gear ratios can be acquired for each of them. This could be done by the correct sliding of dog clutch over one’s teeth of the chosen gearwheel. After this the path of the energy circulation completes. This happens because of the locking motion of the result shaft.
Reverse gear selection:
The power will flow from the input shaft to the reverse gears. The power is after that transmitted from the invert gear to the reverse idler. The idler wheel changes the path of the rotation. In the case of forwarding direction equipment selection, the output gears will rotate in a path opposite to the insight gears. However in the case of invert gear selection, the rotation is usually in the same direction as the insight shaft.
The steps are taken to change any gear in the constant mesh gearbox system:
1. The first rung on the ladder when one really wants to change the gear would be the pressing of the clutch. Following this comes the neutral state of the vehicle to be performed. Proper optimization of the engine’s speed is required.
2. After the neutral equipment, one moves forwards to the first gear. The first equipment. This process is called dual clutching. Inefficiency in carrying out the above guidelines might lead to a harsh and gnashing sound.
Benefits and drawbacks of Continuous Mesh Gearbox:
Advantages:
The first and foremost benefit of the continuous gear mesh is the usage of helical gears. The double helical gears and the helical gears are extremely beneficial due to their quieter operating capabilities
There are numerous conditions which can cause harm. Regarding continuous mesh gearbox, any damage is suffered completely by your dog clutch teeth. One’s teeth belonging to the gear tires remain intact. This is not the case for sliding mesh equipment box.
The other equipment boxes are noisy and create an undesired din.
Disadvantages:
It is less efficient compared to the others due to higher mesh teeth. Skill is required for it.
The double clutch mesh is necessary. This is necessary to have the spinning motions of the shaft.
Application:
Some of the vehicles designed to use this kind of gearboxes are farm trucks, motorcycles, and large machinery.
In this kind of gearbox, all of the gears of the main shaft are in continuous mesh with the corresponding gears of the counter shaft or lay shaft.
Two dog clutches are given on the main shaft i.electronic. one among the clutch equipment and the next gear, and the various other between the first equipment and the reverse gear.
Your dog clutch can slide on the shaft and rotate with it. While, all the gears on the counter shaft are rigidly fixed with it.
As so when the left hands dog clutch was created to slide left by means of the apparatus change lever, it meshes with the clutch gear and the very best speed equipment is obtained. When the remaining hand dog clutch meshes with second gear, the second gear is obtained.
Similarly, by sliding right hand dog clutch left and right, the 1st speed gear and reverse gear are obtained respectively.
In this kind of gearbox, all the gears are in continuous mesh and hence because of this, they are secure from being damaged and irritating grinding sound will not happen while engaging and disengaging.
