Newsgroups: comp.robotics
Path: brunix!uunet!pipex!uknet!brunel!eepgggv
From: Gregory.Vines@brunel.ac.uk (Gregory Vines)
Subject: Re: direct drive motors?
Message-ID: <C9Dnuz.2FF@brunel.ac.uk>
Organization: Brunel University, West London, UK
References: <25998@mindlink.bc.ca>
Date: Tue, 29 Jun 1993 10:01:46 GMT
Lines: 44

In article <25998@mindlink.bc.ca> Cliff_Lum@mindlink.bc.ca (Cliff Lum) writes:
>> Willard MacDonald writes:
>>
>> Msg-ID: <20ned9INN48e@ymir.cs.umass.edu>
>> Posted: 28 Jun 1993 18:48:09 GMT
>>
>> Org.  : Department of Computer Science, University of Massachusetts
>>
>> Keywords:motors
>>
>> Hi,
>> Does anybody know of a supplier of motors capable of direct drive.
>> i.e.  I want to drive a robot leg without a transmission between the motor
>> and the leg to allow it to be backdrivable.
>> Thanks
>> Bill
>>
>>
>
>The motors if electric all need some sort of speed reduction. Best to use a
>gearhead that has no backlash such as those from HARMONIC Drive Technologies.
>I think this company also sells the motor and the gearhead as a unit.
>If you don't want to use a transmission you would have to use a hydraulic
>motor. Lots of torque.
>
Sorry, but I have to disagree.  There are several makes of direct-drive electric
motors out there.  Try NSK, or Dynaserv.  In general you can get 10-400Nm at
around 60 rev/min, with NO gear reduction!  However, expect them to be MASSIVE!

>
>Hope that helps
>cliff
>
Ditto,
		Greg
		
		
Gregory Vines (Grad Student),		|  e-mail: Gregory.Vines@brunel.ac.uk
Electrical Engineering Department,	|  'phone: (0895) 274000 ext. 2896
Brunel University,                      +--------------------------------------
Uxbridge, Middlesex,			|  A wise person disregards the sayings
England. UB8 3PH			|	of others (subtle).


