Wheelchair Bearings

According to the Ministry of Labor and Social Protection, in Russia there are now more than 320 thousand people who can only move on wheelchairs. Considering that many people with disabilities have two such chairs (a folding version for travel in transport and a basic model for everyday use), as well as the fact that many such wheelchairs are operated in medical institutions and boarding schools, the total Russian park of wheelchairs exceeds 500 thousand copies. .

Wheelchairs for hundreds of thousands of Russians are the only way to gain mobility, the ability to independently make purchases, work, engage in sports, etc.

The market value of hand-operated strollers, depending on the manufacturer and the quality of the components, starts from 30-40 thousand rubles. The most affordable strollers with electric drive are sold from 100 thousand rubles, and models of Western manufacturers with improved ergonomics can be purchased for 400-600 thousand rubles, which is comparable to the price of a new car.

Cheap models of domestic production, which are allocated free of charge for Russians with disabilities as part of social programs, often have low reliability and short service life. According to the testimony of many "wheelchairs", such a product "crumbles" in an average of two years! This is facilitated by the small adaptability of Russian cities to the movement of wheelchairs - lack of ramps, high curbs. The road reagents sprinkled on the streets of Russian cities also cause accelerated corrosion of the moving parts of wheelchairs.

All this leads to the fact that the need for regular repair of strollers becomes another problem for people with limited mobility, whose life is already full of difficulties and trials.

Wheel for the disabled

In the simplest case, a wheelchair consists of a folding or stationary metal frame with armrests and footrests, seats of one or another design, as well as two front and two rear wheels. Wheelchair dimensions are standardized. In particular, GOST R 50602-93 is in force in the Russian Federation, which describes the maximum dimensions for width, height and length. However, for the diameters of the front and rear wheels there are no such standards, and they, depending on the models and manufacturers, they can vary in a fairly wide range.

The widest range of sizes for the front wheels is from 120 to 380 mm. In general, the larger the front wheel, the higher the obstacles the chair can overcome. For rear wheel drive strollers with manual transmission, the dimensions are more conservative. The most common two sizes are 540 and 610 mm (22 and 24 inches).

The front and rear wheels of wheelchairs can be pneumatic type with hollow tires and inflatable chambers, which provide a higher level of cushioning and comfort, or with more wear-resistant cast tires.

The front wheels, which have impact loads and the hubs of which are exposed to moisture and dirt, are essentially consumables. Depending on the intensity of use, they often have to be changed or repaired.

Bearings as a guarantee of mobility

Wheelchair mobility is ensured by at least 12 ball bearings, operating both in the front and rear wheels, and in the swivel mechanisms of the front wheels.

The possibility of turning the front wheels is provided by a special turning mechanism, consisting of a fork in which the wheel is fixed, and an axis, which is inserted into the corresponding glass on the wheelchair frame. The mobility of the axis is determined by two pillow block bearings. Due to the fact that the rotary mechanism is located very low above the ground and is exposed to moisture, dirt, sand and anti-ice agents, closed bearings with metal seals are mainly used here.

The hubs of the front and rear wheels also use ball bearings with metal or polymer seals that protect against leaching of grease and the ingress of dirt on the rolling surface. Cast front wheels are often made non-separable and non-repairable, while the hub bearings are imprinted on the wheel disc.