Constant Mesh Gear Box
Constant mesh gearbox is certainly a type of Transmission where all or the majority of the gears are always in mesh with each other, as opposed to a sliding-gear transmission, where engagement is obtained by sliding some of the gears along a shaft into mesh. In a constant-mesh manual gearbox, Equipment ratios are selected by little Clutches that connect the various gear sets with their shafts so that power can be transmitted through them. The next diagram shows the set up of a continuous mesh gear box
Construction and functioning of a constant mesh gear box
Constant equipment mesh gearbox employed helical gears for power transmission. The gears are rigidly fixed in the lay shaft. The gears in output shaft rotates freely without engaging with shaft, therefore not really transmitting power. The gears in both shafts are at all times meshed together.
To engage the gears with output shaft dog clutch is used. the dog clutch can be shifted by the seletor fork shifted by gear lever.To provide reverse gearing a idler equipment is used.
When the gear lever is pushed, the apparatus selector fork pushes the dog clutch. The dog clutch engages the apparatus and the output shaft, thus power from lay shaft at this point transmitted to output shaft.
CONSTANT MESH GEARBOX
A continuous mesh transmission is 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 desired output to the many shaft by creating contact with the acceptable couple of the meshed gears.
A continuous mesh transmission typically comes with 4 forward speeds and 1 reverse manual transmitting configuration.
Why will we wish Constant Mesh Transmission?
The introduction of initial transmission system i.e. sliding mesh transmitting was a great success in cars trade as currently there is a system which might provide needed torsion and acceleration ratios want by the automobile to face the road challenges however still there were several vital issues with this equipment that raised the issue on its effectiveness and responsibility. the problems long-faced were as follows-
The shifting of gears wasn’t a simple task since the shifting needed a special technique that wasn’t in any respect everybody’s cup of tea, a talented driver was necessary for driving such vehicle, the special technique needed being Double-de-clutching.
Note – Double-de-clutching- it’s the technique since the name indicates that needed double engagement and disengagement of clutch for shifting 1 gear.
f i.electronic. once driver must shift the gear he preliminary presses the clutch pedal and produce the apparatus to the neutral, than once again he releases the clutch pedal and accelerate in order to extend the rate of the lay-shaft in order that the meshing of applicable gear will happen, save for he presses the clutch pedal and create the apparatus lever to the required gear and unleash the clutch pedal and at last the desired gear is obtained.
Since the gears are to be meshed square measure in continuous rotation with a completely different speed compared to the meshing of these gears will cause breakage to the apparatus teethes or continuous deterioration is there.
The shifting of gears is actually a terribly clamant method.High maintenance is needed 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 different types 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. As well dog clutches are given on the primary shaft: one between your clutch gear and the second gear; and the additional between the first gear and reverse gear. The primary shaft is made splined and all the gears are free to move onto it. Dog clutches can slide on the primary shaft and rotates with it. All the gears on the countershaft are completely fixed with it.
When the left dog clutch was created to slide to the left with the aid of the gear 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 main shaft, the second speed gear is achieved. Likewise, by sliding the right-hand dog clutch to the left and correct, the first speed gear and reverse equipment are attained respectively In this kind of gearbox, because all of the gears are in constant mesh, they are safe from being broken and unpleasant grinding audio does not take place while engaging and disengaging them.
Constant mesh gearbox is used for the smooth functioning of a car. They are used to increase the rotating push (Torque); that is accompanied by a reduction in quickness. It is a type of manual tranny. The invention of earliest manual gear system can be traced back to the nineteenth century. There are multiple gear ratios present which provides various torque and rate ratio. Additionally, the reverse mechanism is also present. This manual transmissions which are developed recently contain all of the gears mesh at any given point of time.
In technical terms, it can be thought as a gearbox in which all of the gears are at all times in a state of mesh. The gears remain fixed at their first positions. The gears will remain engaged at all times. Find out more about its structure, working, advantages, disadvantages and applications in this article.
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. Keeping in mind according to the equipment ratio, the speed of the counter shaft could be less that the rate of the engine. The apparatus ratio can be defined as the ratio of the teeth of driven gear to one’s teeth of the driver equipment.
2. Main shaft:
This shaft operates the speed of the vehicle. The power is manufactured available to the primary shaft through the gears from the counter shaft. This is done relative to the gear ratio.
3. Dog clutch:
Dog clutch is special feature of continuous mesh gearbox. It is utilized for the coupling of any two shafts. That is performed by interference. Using a dog clutch, numerous gears can be locked to the result and input shafts.
4. Gears:
The main work of the gears may be the transmission of power between your shafts. If the gear ratio is more than one, the main shaft will continue to work at a swiftness that is slower compared to the counter shaft, and vice versa. The set up of both reverse, in addition to forward gears, is present.
Working:
Forward gear selection:
From the input shaft, the power starts flowing and is divided into four parts. Each part goes to among the output gears, namely 1st, second, third and 4th. Gear ratios can be acquired for each of these. This can be done by the correct sliding of dog clutch over the teeth of the chosen gearwheel. After this the road of the energy movement completes. This happens because of the locking motion of the result shaft.
Reverse gear selection:
The energy will flow from the input shaft to the reverse gears. The power is after that transmitted from the invert gear to the invert idler. The idler wheel will change the path of the rotation. In the case of forwarding direction gear selection, the result gears will rotate in a direction opposite to the insight gears. But in the case of invert gear selection, the rotation can be in the same path as the insight shaft.
The steps are taken up to change any gear in the continuous mesh gearbox system:
1. The first step when one really wants to modify the gear would be the pressing of the clutch. After this comes the neutral state of the automobile to be performed. Proper optimization of the engine’s speed is required.
2. After the neutral gear, one moves ahead to the first equipment. The first equipment. This process is known as double clutching. Inefficiency in executing the above actions might result in a harsh and gnashing sound.
Advantages and Disadvantages of Continuous Mesh Gearbox:
Advantages:
The first and foremost benefit of the constant gear mesh may be the utilization of helical gears. The dual helical gears and the helical gears are really beneficial due to their quieter operating capabilities
There are numerous conditions which can cause harm. Regarding continuous mesh gearbox, any damage is suffered entirely by your dog clutch teeth. The teeth belonging to the apparatus tires remain intact. This is simply not the case for sliding mesh equipment box.
The other gear boxes are noisy and create an undesired din.
Disadvantages:
It really is less efficient than the others due to higher mesh teeth. Skill is necessary for it.
The double clutch mesh is necessary. This is necessary to have the spinning motions of the shaft.
Application:
Some of the vehicles which use this kind of gearboxes are farm trucks, motorcycles, and heavy 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 provided on the primary shaft i.e. one in between the clutch equipment and the second gear, and the additional between the first gear and the reverse gear.
Your dog clutch can slide on the shaft and rotate with it. While, all of the gears on the counter shaft are rigidly fixed with it.
As so when the left hand dog clutch was created to slide left by means of the apparatus shift lever, it meshes with the clutch gear and the top speed gear is obtained. When the remaining hands dog clutch meshes with second equipment, the second gear is obtained.
Similarly, by sliding right hand dog clutch to the left and right, the first speed gear and reverse gear are obtained respectively.
In this type of gearbox, all of the gears are in continuous mesh and hence for this reason, they are secure from being damaged and irritating grinding sound will not take place while engaging and disengaging.

Our construction and working of constant mesh gearbox is the best and most ingenious on the market.