110 likes | 211 Views
BL 8.2 MIRROR UPGRADE. Front End Mirrors 8.2.1 (M101) and 8.2.2 (M201). Reasons for replacement:. To take advantage of improved beam quality after implementation of top-off-mode. Scope of Review.
E N D
BL 8.2 MIRROR UPGRADE Front End Mirrors 8.2.1 (M101) and 8.2.2 (M201)
Reasons for replacement: • To take advantage of improved beam quality after implementation of top-off-mode.
Scope of Review • New “plug and play” replacement design to minimize down time by performing installation on two day shutdown.
Differences between the new mirrors and the old: • New mirrors are longer to reduce the effects of the mirror benders on the ends of the mirror. • New mirrors are of a two piece, frit bonded design, with internal cooling. • Optical surface roughness will be improved. • New mirrors will have new, external to vacuum, mirror bending, enabling fine tuning of mirror radius in operation.
CALCULATION OF TORQUE REQUIREMENTS FOR BL 8.2.1 MIRROR BENDER • Given: • The horizontal mirror spring for the bender must provide a torque of 7750 ounce inches to each end of the mirror in order to bend it to the correct radius. • Find: • Suitable motor and gearhead to deliver required torque with a factor of safety near twice the required torque. • Solution: • A Parker step motor will generate 65 oz.-in. of torque, however a clutch will limit this torque to 50 oz.-in. A 50:1 gearhead with an efficiency of 85% will be used to raise the 50 oz.-in. to 2125 oz.-in. • The gearhead will drive a drive screw with a thread pitch of 5/8-18. While this thread will provide a further mechanical advantage of 33:1, its efficiency is only about 17%, which is reduced to 5.6:1. This will increase the torque delivered to 11,900 oz.-in. • This delivered torque provides a factor of safety is 1.54.