Slewing rings with two rows of balls, toothed and idle produced by Distitec have the following technical characteristics:
Outer and inner ring are mainly composed of carbon steel C45 (UNI 7845) or alloy steel 42CrMo4 (UNI
7846) both to the initial reclaimed condition. The use of one or the other material is linked to specific mechanical requirements, including tenacity and hardness but also to technological factors. 42CrMo4 offers the possibility of obtaining a greater depth of the hardened layer of the raceways
and therefore the higher load capacity. C45 (or equivalent) is the material with which most of the standard bearings with small to medium diameters are built, 42CrMo4 is used for medium to large diameters and for many special constructions. The induction hardening to which the raceways are subjected is necessary to increase the load capacity of the bearing and to preserve the raceways from plasticization phenomena due to pressure contact with the rolling elements. The hardness of the sliding tracks of the rolling elements after this treatment can reach 62 HRc. The depth of hardening varies according to the dimensions and therefore to the loads to be supported.
TECHNICAL FEATURES
Rolling elements: The balls, built according to DIN 5401, are used for bearings with four contact points, while cylindrical rollers, built according to DIN 5402, for crossed roller bearings and both are produced in 100Cr6 (UNI 3097) hardened steel. ). The hardness of these elements reaches 64 HRc.
Spacers made of materials such as NYLON or P.T.F.E (TEFLON) with high mechanical characteristics. They are used to keep elements separate and avoid contact. The spacers may not be provided in those applications where the admissible loads of the fifth wheel must be of high bearing capacity.
Seals or gaskets made of NBR nitrile elastomer. This gasket closes the vacuum that is created between one ring and the other, preventing the entry of dirt and impurities, dust and moisture. Proper lubrication increases the effectiveness of the seals.
Grease: The slewing rings that Distitec produces are supplied with an initial lubrication of the ball or roller sliding track with specific greases listed in the use and maintenance manual that we supply together with the product and on which there are indications for a correct periodic relubrication.
Grease nipples: Distitec slewing rings are supplied with special grease nipples positioned in the special seats recessed in the diameter where there is no toothing or where it is requested by the customer in special executions.
Cylindrical toothing with straight teeth (see photo) performed respecting all the technical features of this type of toothing. The drawing issued by Distitec indicates all parameters relating to the toothing for a correct execution of the pinion that will mesh with it. The standard surface hardness of the tempered material used reaches a maximum of 30 HRc (42CrMo4) and this hardness value may not always be acceptable to preserve the life of the toothing in some applications. A high rotation torque that produces a high frictional stress on the tooth, high rotation speeds, unfavorable environmental conditions with the presence of dust or abrasive elements, or the need to bring the life cycle of the slewing ring to its maximum, means that the induction hardening treatment is also carried out on the teeth. The treatment can be carried out only on the side or on the side and bottom of the tooth, depending on the loads and the type of application. The maximum surface hardness that can be obtained is 60 HRc.
Having a large availability of machinery at your disposal DISTITEC can produce slewing rings with so many different and particular executions. Holes and millings details have never stopped us from providing the customer with the special requested product.