56 THE DISTRIBUTOR’S LINK Spirol International Corporation 30 Rock Avenue, Danielson, CT 06239 Tel: 1-860-774-8571 Fax:. 1-860-774-2048 Email: info@spirol.com www.spirol.com HOW TO PROPERLY PIN A SHAFT & HUB ASSEMBLY by Caroline Mallory, SPIROL Application Engineer One of the primary benefits of using a Coiled Spring Pin to affix a hub or gear to a shaft is the Coiled Pin’s ability to prevent hole damage. Another benefit is that the Coiled Pin absorbs wider hole tolerances than any other press-fit pin. This translates to lower total manufacturing costs of the assembly. There are a few design guidelines that must be adhered to in order to achieve the maximum strength of the pinned system and prevent damage to the assembly: The design guidelines can be divided into two groups: 1) the shaft and hub, and 2) the pin. Shaft and Hub Considerations The hole in a shaft should not exceed 1/3 of the shaft diameter. For mild steel and nonferrous shafts, standard duty pins are recommended. The extra strength of a heavy duty pin is only beneficial if the hole is less than 1/4 the diameter of the shaft or if the shaft is hardened (Figure 1). It is recommended that the hub be designed with a minimum wall thickness of 1.5 times the diameter of the pin. Otherwise, the strength of the hub will not match the shear strength of the pin (Figure 1). As the wall thickness of the hub increases, so does the area of material around the pin. The diameter of the holes through both the shaft and hub should be precision matched to eliminate any movement of the pin within the holes. It is recommended that the difference between the hole diameters in the hub and shaft not exceed 0.05mm (.002”) to prevent movement of the parts relative to each other. Otherwise, the pin will be subject FIGURE 1 to dynamic loading such that a very small change in velocity could equate to a significant change in force impacting the assembly. The hole should be centered in both the shaft and hub to prevent stress concentration and ensure there is enough material around the pin to withstand the applied forces. If the holes cannot be precision matched, dividing the tolerance between the shaft and hub is recommended. The larger half of the tolerance should be applied to the component with the longest engagement length, and the smaller half should be applied to the other component. Countersinks on the holes are not recommended. In addition, the outer diameter of the shaft (OD) and the inner diameter of the collar (ID) should be designed such that the distance between the shear planes (OD-ID) does not exceed 0.13mm (.005”). In both cases, an unsupported length of pin in an area where torque may be applied is created. This could cause a bending moment, which shortens the lifespan of the pin (Figure 2). FIGURE 2 A countersink increases the distance between the shear planes. This can put the pin in bending and thus reduce the strength of the pin. please turn to page 216
106 THE DISTRIBUTOR’S LINK FTI -
108 THE DISTRIBUTOR’S LINK Eckart
110 THE DISTRIBUTOR’S LINK NEFDA
116 THE DISTRIBUTOR’S LINK MAFDA
MWFA 33rd ANNUAL FASTENER SHOW ELK
122 THE DISTRIBUTOR’S LINK Rotor
124 THE DISTRIBUTOR’S LINK THE BI
126 THE DISTRIBUTOR’S LINK NFDA -
THE DISTRIBUTOR’S LINK 129 We are
THE DISTRIBUTOR’S LINK 131
138 THE DISTRIBUTOR’S LINK NCFA -
140 THE DISTRIBUTOR’S LINK Sems a
142 THE DISTRIBUTOR’S LINK SFA -
THE DISTRIBUTOR’S LINK 145
148 THE DISTRIBUTOR’S LINK Commun
THE DISTRIBUTOR’S LINK 151
154 THE DISTRIBUTOR’S LINK MWFA -
THE DISTRIBUTOR’S LINK 157
160 THE DISTRIBUTOR’S LINK Cable
THE DISTRIBUTOR’S LINK 163
166 THE DISTRIBUTOR’S LINK SEFA -
THE DISTRIBUTOR’S LINK 169 Sherex
THE DISTRIBUTOR’S LINK 171
MF Supply, a woman owned and operat
178 THE DISTRIBUTOR’S LINK IS SEO
180 THE DISTRIBUTOR’S LINK INxSQL
THE DISTRIBUTOR’S LINK 183
THE DISTRIBUTOR’S LINK 187 Full L
THE DISTRIBUTOR’S LINK 195 Lindst
THE DISTRIBUTOR’S LINK 197
200 THE DISTRIBUTOR’S LINK NEW SY
THE DISTRIBUTOR’S LINK 203 SPIROL
THE DISTRIBUTOR’S LINK 205 SAVING
208 THE DISTRIBUTOR’S LINK THE AR
210 THE DISTRIBUTOR’S LINK THE BU
THE DISTRIBUTOR’S LINK 213 Tector
216 THE DISTRIBUTOR’S LINK HOW TO
THE DISTRIBUTOR’S LINK 219 Roger
222 THE DISTRIBUTOR’S LINK FASTEN
226 THE DISTRIBUTOR’S LINK ECKART
228 THE DISTRIBUTOR’S LINK WHY A
230 THE DISTRIBUTOR’S LINK FASTEN
232 THE DISTRIBUTOR’S LINK SOCIAL
MWFA 62nd ANNUAL GOLF OUTING EAGLEW
THE DISTRIBUTOR’S LINK 237 Labora
MWFA 62nd ANNUAL GOLF OUTING EAGLEW
THE DISTRIBUTOR’S LINK 241
WHAT THE UAW ELECTION AT VOLKSWAGEN
THE DISTRIBUTOR’S LINK 245 Bay Ma
THE DISTRIBUTOR’S LINK 247 ISO 90
250 THE DISTRIBUTOR’S LINK WHAT T
THE DISTRIBUTOR’S LINK 253 FASTEN
Loading...
Loading...
Loading...
SHARE A PAGE FROM THIS MAGAZINE OPTION 1: Click on the share tab above, or OPTION 2: Click on the icon (far right of toolbar) and then click on the icon (top right of the page). |
Copyright © Distributor's Link, Inc. All Rights Reserved | Privacy Policy