tailieunhanh - Mechanical Engineers Data Handbook Episode 3

Tham khảo tài liệu 'mechanical engineers data handbook episode 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Feather Square Triangular Splines MECHANICAL engineer s data handbook 7 Q Woodruff key Splines are a means of keying a hub to a shaft where separate keys are not required. They consist of mating grooves in hub and shaft of rectangular triangular or involute form. The grooves are designed to allow axial sliding. Types of key The main types of key are the rectangular where the key ways are half the key depth the feather where the keyway is closed at each end the Gib-head used always at the end of a shaft and with a head so that it can be tapped into place the Woodruff key which is segmental and for use on tapered shafts and the inexpensive saddle and round keys. Strength of keys and splines A key is used to prevent a machine part from moving relative to another part. In the case of a shaft the key must be strong enough to transmit a high torque and is often made of alloy or high tensile steel. The fit may be either close or free if sliding is desired. The keyway in the shaft and hub is usually produced by milling. h-width depth L- length s - chamfer FT HỈ EES Gib head Feather Key applications Rectangular Round key Saddle key Internal External involute Gib head Rectangular STRENGTHS OF MATERIALS 41 Torque capacity d depth of spline or half depth of key r mean radius of spline or shaft radius for key n number of splines L length of spline or key b breadth of key T limiting torque ơc allowable crushing stress T allowable shear stress Keys T tbLr based on shear T aQdLr based on crushing Splines T acndLr based on crushing ơc about 7 MPa for steel A large variety of flexible couplings are used to accommodate angular parallel or axial misalignment. Several types are shown. Disk-type flexible coupling Moulded rubber Insert coupling Shaft couplings Shaft couplings may be solid or flexible . Solid couplings may consist simply of a sleeve joining the shafts the drive being taken by pins or keys. For large powers bolted flanges are used to give either a solid or .