Reducer of the "Neva MB-2" walk-behind tractor: diagram and device, purpose and operating rules

The gearbox is an indispensable component of any technique where an engine is used, since without it, the transmission of rotary motion is impossible. Structurally, this element in the Neva-MB-2 walk-behind tractors is similar to the parts used in other equipment, but in order to learn more about it, it is necessary to study the issue in more detail.

A gear-chain unit is installed in the design of the walk-behind tractor, the main task of which is the transmission of rotational motion, and therefore, the change in the rotational speed of the cutters. It is thanks to the gearbox from the driven pulley that the mechanical action is transmitted to the wheels of the equipment, whereby the speed and direction change.

There is oil inside the housing, which is necessary to ensure the operation of the gearbox. The element is enclosed in a robust sealed housing. Its kinematic diagram consists of a chain and two stars located in opposite directions. The lower one is called the driven one, since it stands on the shaft and drives the entire system of the walk-behind tractor.

The gearbox of the walk-behind tractor includes the following important parts:

• screws;
• bearings;
• axles;
• asterisks;
• frame;
• bushings;
• shift levers;
• gear wheels;
• shaft;
• clutch;
• half shafts;
• pay;
• spring.

These are not all the elements that are involved in the design of the gearbox, but they are the main ones. Failure of one of them leads to loss of performance and subsequent repairs.

Compared to a worm gear, the gear-chain is more reliable. It is convenient and easy to operate, and can support the reverse function. As a rule, this is a collapsible design, where all the elements are connected to each other by bolts, thanks to which you can inspect the condition of the chains and gears if necessary. Such gearboxes are installed on large walk-behind tractors, which need a strong and reliable unit to transmit power to the wheels and cutters.

In order for the user to have to deal with a breakdown of the walk-behind tractor as rarely as possible, it is required to monitor the operation of not only the engine, but also the gearbox. Experts give their advice on what basic requirements must be observed during operation.

• It is important to use only high-quality oil, and at the same time regularly check its presence inside the element. According to GOST, TAD-17I or an analogue, which can also be easily found in stores - TAP-15V, is ideal for this gearbox.
• A complete oil change should be carried out after the motorcycle clock set by the manufacturer. The instructions for users indicate that the replacement should be made 30 hours after the first start of the walk-behind tractor, and subsequently after 150 hours.
• If the walk-behind tractor is put on storage, then all working fluids are removed from it, and the necessary moving elements are lubricated.
• Periodically, the user is required to check the degree of tension of the gear chain. If it sags, then it is replaced with a new one, since this element cannot be repaired.
• Replacing the stuffing box can be done independently, thanks to the fully collapsible design of the described unit.

It is worth saying that the gearbox from the Neva-MB-2 walk-behind tractor is repaired quickly and easily. This is possible due to the fact that you can always find spare parts for it on the market. Such a need arises when the following symptoms appear:

• oil starts to appear on the output shaft;
• the chain is jammed;
• no kinematic connection;
• no gear shifting.

In all these cases, it is required to disassemble and inspect the gearbox. If oil leaks, the problem can be eliminated by simply replacing the cuff, which can lose its original qualities over time. Jamming is always associated with a broken chain, so this problem can only be eliminated by a complete replacement. If this element is intact, but there is no kinematic connection, you should pay attention to the sprockets present in the design. One of them could break off.

In the absence of a gear change, a cracker is inspected, which can be destroyed. Sometimes the threaded part of the handle is cut off. If the user begins to notice that oil leakage is observed on the shift shaft, then this is not always an indicator of a breakdown. Sometimes the permissible oil level in the gearbox is simply exceeded. The excess just needs to be drained.

It is worth remembering that improper start-up and adjustment can also lead to malfunctions during the operation of the gearbox, therefore the manufacturer advises to carefully study the instructions before using the equipment.

The following video is about the disassembly and repair of the gearbox.