上游充互大学 Shanghai Jiao Tong University Types of Belts2.4 Grooved or Timing Belt >Requires toothed wheels,or sprockets. Sheaves have mating grooves into which the cogs on belts seat. >This is a more positive drive >Can transmit the high forces at low speeds,compete with chain drives Limited only by tensile strength of belt and shear strength of cogs
16 Types of Belts2,4 •Grooved or Timing Belt Requires toothed wheels, or sprockets. Sheaves have mating grooves into which the cogs on belts seat. This is a more positive drive Can transmit the high forces at low speeds, compete with chain drives Limited only by tensile strength of belt and shear strength of cogs
包布V带 切边V带 上泽充通大学 Shanghai Jiao Tong University Types of Belts2.4 V-Belt >Most belts have high-strength cords positioned at pitch diameter of belt cross section to increase tensile strength of belt. >Cords made from natural fibers,synthetic strands or steel >Embedded in firm rubber compound to provide flexibility needed to allow belt to pass around sheave. >Often outer fabric cover is added to give belt good durability. >V-shape causes belt to wedge tightly into groove Increases friction and allows high torques to be transmitted before slipping occurs. 17
17 Types of Belts2,4 •V-Belt Most belts have high-strength cords positioned at pitch diameter of belt cross section ⁼ to increase tensile strength of belt. Cords made from ⁼ natural fibers, synthetic strands or steel Embedded in firm rubber compound to provide flexibility needed to allow belt to pass around sheave. Often outer fabric cover is added to give belt good durability. V-shape causes belt to wedge tightly into groove ⁼ Increases friction and allows high torques to be transmitted before slipping occurs
上游充互大学 品 Shanghai Jiao Tong University Variety of Belts2 Example of V-Belt Construction (Dayco Corp., Dayton,Ohio) 普通V带 齿性V带 同步带 w和 (c)Timing belt (a)Wrapped construction (b)Die cut,cog type (f)Double angle V-belt (d)Poly-rib belt 89285w6828 多楔带 Vee-band 双面V带 Figure 13-3 Examples of v-be联组V带 Dayco Corp.,Dayton,Ohio)
18 Variety of Belts2 Example of V-Belt Construction (Dayco Corp., Dayton, Ohio) 双面V带 齿性V带 多楔带 同步带 Vee-band 联组V带 普通V带
上游充互大学 Shanghai Jiao Tong University Belt Standards Different organizations have established different standards for belts: RMA-MPTA-RAC Standard >Developed by the Rubber Manufacturers Association, the Mechanical Power Transmission Association,and the Rubber Association of Canada. ·ASAE Standards >Developed by the American Society of Agricultural Engineers. 19
19 Belt Standards • Different organizations have established different standards for belts: • RMA-MPTA-RAC Standard Developed by the Rubber Manufacturers Association, the Mechanical Power Transmission Association, and the Rubber Association of Canada. • ASAE Standards Developed by the American Society of Agricultural Engineers
上淄克通大学 Shanghai Jiao Tong University Belt Standards SAE Standards >Developed by the Society of Automotive Engineers. The standard codes are as follows: SAE Standard J636c:V-belts and pulleys SAE Standard J637b:Automotive V-belt drives SAE Standard J1278:SI synchronous belts and pulleys SAE Standard J1313:Automotive synchronous belt drives ◆ SAE Standard J1459:V-ribbed belts and pulleys 20
20 Belt Standards SAE Standards Developed by the Society of Automotive Engineers. The standard codes are as follows: SAE Standard J636c:V-belts and pulleys SAE Standard J637b:Automotive V-belt drives SAE Standard J1278:SI synchronous belts and pulleys SAE Standard J1313:Automotive synchronous belt drives SAE Standard J1459:V-ribbed belts and pulleys