The tooth profile of a sprocket should ensure smooth and free engagement and disengagement of the chain links, prevent chain slippage, and have a simple shape for easy machining. GB/T1243-97 specifies the end face tooth profile (Table 9-3) and shaft face tooth profile (Table 9-4) for roller chain sprockets. Since the roller surface tooth profile and the sprocket tooth profile are non-conjugate, the sprocket tooth profile design has considerable flexibility, meaning it can be used within both maximum and minimum ranges. If the sprocket uses a standard tooth profile, the end face tooth profile does not need to be drawn on the sprocket working drawing; it is only necessary to indicate that it is manufactured according to GB/T1243-97. However, the shaft face tooth profile must be drawn for machining the blank.

At present, the most widely used car trolley in my country's coal mines is the electric circular chain trolley. This type of trolley uses a high-strength circular chain as the traction mechanism, has a simple structure, reliable operation, wear resistance, and long service life. The maximum stroke of the trolley currently in use can only reach the edge of the cage, which cannot meet the requirements of all working conditions [3]. In the transportation operation of mine cars, in order to load, lift and unload the mine cars, it is often necessary to use a trolley to move the position of the mine cars within a short distance, such as pushing the mine cars into and out of the cage or tipper, which plays an important role in improving the automation level of mine hoisting and reducing the labor intensity of workers [1]. According to their location of use, trolleys can be divided into the following categories: (1) Trolleys set in front of the cage. The characteristic of this type of trolley is that it pushes one or two mine cars into the cage and pushes out the empty cars in the cage at the same time. Therefore, only a small thrust is needed, but the action is required to be relatively fast, so as not to prolong the hoisting work...

First, the chain pitch is too large or the sprocket teeth are too small. Too large a pitch leads to poor matching between the roller and the gear, easily causing the roller to break; too small a tooth count prevents the roller from being fully engaged, also easily causing cracks. Repair: Select a chain with a smaller pitch or increase the number of teeth on the sprocket, depending on the actual situation. Second, debris in the sprocket teeth grooves causes the roller to be squeezed and break. Repair: Remove the debris from the tooth grooves or replace the chain. Third, the chain creeps too high on the sprocket teeth. This is due to a mismatched chain or being too loose, resulting in excessive creep. Repair: Replace the chain or, depending on the situation, appropriately tension the chain. Fourth, the chain is subjected to excessive impact force, exceeding its maximum load. Repair: Reduce the load to decrease the impact on the chain.

         Timing chains, chain specifications, chain conveyors, conveyor chains, lifting chains, stainless steel chains, chain drives. Chains, also known as roller chains, may be unfamiliar to many when it comes to product applications, but they are used in various mechanical equipment. These include transmission chains, conveyor chains, automotive transmission chains, motorcycle chains, agricultural machinery chains (harvesting equipment, etc.), forklift chain chains (lifting equipment, etc.), escalator chains, bulk material conveying chains, construction machinery chains (pavers, etc.), sugar refining machinery chains, palm oil machinery chains, and stainless steel chains for food machinery (such as conveyor chains for pancake machines in Linyi).

The sprocket tooth profile must ensure smooth and easy engagement and disengagement of the chain links, minimizing impact and contact stress during engagement, and should be easy to machine. A commonly used sprocket end face tooth profile is shown in Figure 1. It consists of three circular arcs aa, ab, and cd, and a straight line bc, referred to as the three-circular-arc-straight-line tooth profile. The tooth profile is machined using standard cutting tools. It is not necessary to draw the end face tooth profile on the sprocket working drawing; simply indicate "tooth profile manufactured according to 3RGB1244-85 specifications" on the drawing. However, the axial tooth profile of the sprocket should be drawn, as shown in Figure 2. Refer to relevant design manuals for its dimensions. Parameter calculations have already been mentioned and will not be repeated. Figure 3 shows four commonly used sprocket structures. Small-diameter sprockets are generally made as a single piece (Figure 3a), medium-diameter sprockets are often made as spokes, with holes in the spokes for ease of handling, mounting, and weight reduction (Figure 3b), large-diameter sprockets…