tailieunhanh - Bearing Design in Machinery Episode 3 Part 5

Tham khảo tài liệu 'bearing design in machinery episode 3 part 5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Fig. 13-12 Grease lubrication of crane wheel bearings from FAG 1986 with permission of FAG and Handel AG . Crane Wheel Bearing Lubrication An example of grease lubrication in a crane wheel is shown in Fig. 13-12. The crane wheel runs on a rail. The grease is fed through holes in the stationary shaft between two self-aligning spherical roller bearings. The design limits the grease volume between the two bearings. The grease passes through the two bearings and the surplus grease is discharged through a double labyrinth seal clearance. Lithium soap base grease is used. The time period between grease replacements is approximately one year. Grease-Quantity Regulators An example of large bearing housing that is designed for avoiding overfilling during relubrication by grease guns is shown in Fig. 13-13. This design is widely used for large electric motors SKF 1992 . The grease is fed at the bottom of the housing near the left side of the outer ring. The design of the housing includes Copyright 2003 by Marcel Dekker Inc. All Rights Reserved. Fig. 13-14 Grease chamber for double-sealed bearings from SKF 1992 with permission . grease packing and penetrates into the bearing. This design of a double-sealed bearing combined with noncontact labyrinth seals protects the bearing from dust. Dust Environment Small bearings in a dusty environment are fully packed with grease. However for large bearings it is important to prevent overfilling with grease which results in overheating and early failure of the bearing. An example of a double-shaft hammer mill for crushing large material FAG 1986 exposed to a severe dust environment is shown in Fig. 13-15. This example combines a design for a grease-quantity regulating disk that prevents overfilling and a separate arrangement for packing the grease between the labyrinth and felt seals. Regulating Disk The bearing housing design consists of a regulating disk that rotates together with the shaft. It .