When should I change the drive belts of the auxiliary units and what affects their wear?


Polycline belts are widely used to transmit torque in a number of different components: air conditioner compressor, generator or hydraulic pressure pump. Due to the reduction of the working volume of engines and increasing their environmental indicators of the belts of additional equipment, they work today in much more difficult conditions than a few years ago. What is the frequency of replacement of these belts and from which their wear depends?

Polyclinic belts are mainly used in the drive of the auxiliary units of internal combustion engines. There are no such belts in hybrid cars, there is an air conditioner compressor or a generator in motion by independent electric motors. Considering that at present, the number of operated cars with DVS exceeds the amount of hybrid, manufacturers seek to simplify the maintenance of these systems (which, unfortunately, is not evaluated by an increase in service life). Therefore, many new cars are equipped with the so-called «serpentine system», when one polyclinic belt simultaneously leads to several components. Belts work along the guide rollers, overtaking clutches of generators, as well as damagers of tweeted oscillations of the crankshaft. An important element is the tensioner that supports constantly specified tension. It is very important to install the belt exactly the right length. One of the most common mistakes allowed by a hundred is a weak tension resulting from the installation of too long belt.

«Each belt is subject to periodic replacement, and its fault in the first place can be judged by a characteristic whistle. Replacement frequency always determines the vehicle manufacturer. As a rule, it is approximately 100,000 km, but directly depends on the operating conditions: in heavy conditions (for example, a tow truck, taxi or nuts with trailers) is significantly lower. In the old cars it was possible to pull the drive belt by manually auxiliary aggregates. Today, when automatic tensioners are responsible for this, the precedence of any sign of wear of the polyclinic belt should be replaced with a new one, «Tomashchman advises from SKF.

During operation, the belts are subjected to wear: rubber elements are erased, and the rubber itself can harden and crumble. Additional danger represent any chemicals, for example, cleaners or spent engine oil, which can reduce rubber strength when hit. Weather conditions have adverse effects. The drive belts of the auxiliary aggregates usually do not have a protective coating, so frost or, for example, dirt can accelerate the destruction of the material from which they are made. An incorrectly installed or worn pulleys also affect belt wear.

«However, a whistle drive belt auxiliary aggregate always means wear out of this component. This may indicate a malfunction of any dish, which leads it in motion. The belt begins to slip on the roller due to overload. Increased resistance that belt has to overcome, usually arises due to a faulty generator (for example, its bearing), low charge of the battery or due to the electrical system. Given this, it is necessary to conduct a visual inspection of all elements and devices, as well as thoroughly check the health of their work. In SKF service bulletins, special attention is paid to this, «Tomas Okhman emphasizes.

The late replacement of the drive belt of the auxiliary aggregates can lead to its discontinuity while driving. In this case, the amount of damage will depend on the engine design. If the broken polyclinic belt has responded to the movement of the coolant pump, the continuation of the trip can lead to irreversible consequences. In the absence of proper cooling, the engine will quickly overload and will lead to expensive repair. In case of breaking (separate), the battery charge belt is enough for a few kilometers of the trip.

«In many compact engines, one polycliner belt can bring multiple devices. Because of this, pulleys are used, which are installed close to each other. As a result, the bending angles of the belt increase, which significantly complicates the conditions for its work. This means that in addition to regular checks and timely replacement, a significant contribution to the proper work of the belt makes the use of high-quality parts. For example, SKF polyclinic belts, the creation of which is carried out in close cooperation with vehicle manufacturers. The new polyclinic belt is relatively inexpensive. So we recommend changing the belt when replacing the timing drive, in which this component needs to be dismantled, «- concludes Tomas Okhman.