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Rotary Index Driver Using a Linear Motor

IP.com Disclosure Number: IPCOM000043348D
Original Publication Date: 1984-Aug-01
Included in the Prior Art Database: 2005-Feb-04
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Panissidi, HA: AUTHOR

Abstract

The linear hydraulic motor drive for an axis arm of a manipulator is shown in Fig. 1 and described in U.S. Patent 3,848,515. This same hydraulic motor in modified form is used to drive a rotary indexing table or a manipulator sweep axis, as shown in Fig. 2. The linear hydraulic motor 10 is modified by reorienting the cam follower plungers 12 90Πin the motor, as shown in Fig. 3, and mounting four rotary multilobe cams 14, as shown in Fig. 4, one under each plunger. The rotary cams 14 are fastened to a shaft 16 supported by the motor driving a feedback potentiometer or encoder 18 at one end and a pinion 20 at the opposite end. The pinion 20 meshes with a large sweep gear 22, as shown in Fig. 2, rotating a manipulator arm assembly or transfer table (not shown).

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Rotary Index Driver Using a Linear Motor

The linear hydraulic motor drive for an axis arm of a manipulator is shown in Fig. 1 and described in U.S. Patent 3,848,515. This same hydraulic motor in modified form is used to drive a rotary indexing table or a manipulator sweep axis, as shown in Fig. 2. The linear hydraulic motor 10 is modified by reorienting the cam follower plungers 12 90OE in the motor, as shown in Fig. 3, and mounting four rotary multilobe cams 14, as shown in Fig. 4, one under each plunger. The rotary cams 14 are fastened to a shaft 16 supported by the motor driving a feedback potentiometer or encoder 18 at one end and a pinion 20 at the opposite end. The pinion 20 meshes with a large sweep gear 22, as shown in Fig. 2, rotating a manipulator arm assembly or transfer table (not shown). With torque loads usually exceeding several thousand inch pounds, the gear backlash becomes a serious problem, requiring an additional implementation of aligner wheel 23 and plunger 24. The linear motor 10 rotates the sweep gear 22 to within plus or minus one degree of the angular position and the final positional accuracy is obtained by the engagement of the aligner wheel 23 and plunger 24. The number of teeth on the aligner wheel 23 limits the number of indexing positions.

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