107:
20:
196:
215:), and those where a rotating asymmetrical vane swings through a cylinder of two different radii. The differential pressure between the two sides of the vane gives rise to an unbalanced force and thus a torque on the output shaft. Vane actuators require a number of sliding seals and the joints between these seals have tended to cause more problems with leakage than for the piston and cylinder type.
137:
235:
of a petrol engine to work a quarter-turn oscillating vane actuator. Such windscreen wipers worked adequately when the engine was running under light load, but they were notorious that when working hard at top speed or climbing a hill, the manifold vacuum was reduced and the wipers slowed to a crawl.
163:
that identifies the position of the output shaft and an inbuilt control system. The input control signal to the servo indicates the desired output position. Any difference between the position commanded and the position of the encoder gives rise to an error signal that causes the motor and geartrain
123:
Stepper motors are a form of electric motor that has the ability to move in discrete steps of a fixed size. This can be used either to produce continuous rotation at a controlled speed or to move by a controlled angular amount. If the stepper is combined with either a
206:
Both hydraulic and pneumatic power may be used to drive an actuator, usually the larger and more powerful types. As their internal construction is generally similar (in principle, if not in size) they are often considered together as
244:
Rotary actuators are used in a vast range of applications. These require actuators of all sizes, power and operating speed. These can range from zero power actuators that are only used as display devices, such as
187:. As a current is applied, the wire is heated above its transition temperature and so changes shape, applying a torque to the output shaft. When power is removed, the wire cools and returns to its earlier shape.
159:
is a packaged of several components: a motor (usually electric, although fluid power motors may also be used), a gear train to reduce the many rotations of the motor to a higher torque rotation, a
53:
The simplest actuator is purely mechanical, where linear motion in one direction gives rise to rotation. The most common actuators are electrically powered; others may be powered
312:
227:
is available, but not pneumatic power, rotary actuators have even been made to work from vacuum power. The only common instance of these was for early automatic
88:, does not necessarily produce any rotation but merely generates a precise torque which then either causes rotation or is balanced by some opposing torque.
128:
or at least a single datum sensor at the zero position, it is possible to move the motor to any angular position and so to act as a rotary actuator.
211:
actuators. Fluid power actuators are of two common forms: those where a linear piston and cylinder mechanism is geared to produce rotation (
330:
316:
257:, through to actuators for large civil engineering projects such as sluice gates and dams. Examples are... Car wiper, etc
254:
172:
106:
168:
143:
295:
273:
Zero power actuators are those, such as display gauges, that do not deliver a tangible output torque
349:
62:
228:
288:
19:
232:
200:
28:
250:
246:
195:
160:
125:
73:
24:
343:
140:
118:
111:
81:
85:
184:
72:
The motion produced by an actuator may be either continuous rotation, as for an
58:
156:
150:
77:
54:
164:
to rotate until the encoder reflects a position matching that commanded.
66:
43:
39:
136:
224:
47:
194:
135:
105:
18:
183:
A recent, and novel, form of ultra-lightweight actuator uses
307:
305:
331:"What is a Rotary Actuator and how are they Used"
76:, or movement to a fixed angular position as for
253:that operate pipeline and process valves in the
199:Hydraulic or pneumatic rotary actuator, using a
315:. Hydraulics & Pneumatics. Archived from
231:on cars up until around 1960. These used the
8:
280:
266:
7:
14:
171:of this type is widely used for
1:
289:"Nanomuscle rotary actuator"
366:
148:
116:
313:"Rotary actuator designs"
173:radio-controlled models
255:petrochemical industry
203:
146:
114:
92:Actuator power sources
84:. A further form, the
31:
198:
191:Fluid power actuators
139:
109:
22:
296:SparkFun Electronics
223:Where a supply of
204:
167:A simple low-cost
147:
115:
97:Electric actuators
32:
249:. Others include
229:windscreen wipers
357:
335:
334:
327:
321:
320:
309:
300:
299:
293:
285:
274:
271:
219:Vacuum actuators
161:position encoder
126:position encoder
42:that produces a
23:Electric rotary
365:
364:
360:
359:
358:
356:
355:
354:
340:
339:
338:
329:
328:
324:
311:
310:
303:
291:
287:
286:
282:
278:
277:
272:
268:
263:
251:valve actuators
247:air core gauges
242:
233:manifold vacuum
221:
201:rack and pinion
193:
181:
153:
134:
121:
104:
99:
94:
36:rotary actuator
29:butterfly valve
17:
12:
11:
5:
363:
361:
353:
352:
342:
341:
337:
336:
322:
319:on 2010-12-26.
301:
279:
276:
275:
265:
264:
262:
259:
241:
238:
220:
217:
192:
189:
180:
177:
149:Main article:
133:
130:
117:Main article:
112:stepper motors
103:
102:Stepper motors
100:
98:
95:
93:
90:
82:stepper motors
74:electric motor
27:controlling a
25:valve actuator
15:
13:
10:
9:
6:
4:
3:
2:
362:
351:
348:
347:
345:
332:
326:
323:
318:
314:
308:
306:
302:
297:
290:
284:
281:
270:
267:
260:
258:
256:
252:
248:
239:
237:
234:
230:
226:
218:
216:
214:
210:
202:
197:
190:
188:
186:
178:
176:
174:
170:
165:
162:
158:
152:
145:
142:
141:Radio control
138:
131:
129:
127:
120:
119:Stepper motor
113:
110:A variety of
108:
101:
96:
91:
89:
87:
83:
79:
75:
70:
68:
64:
60:
59:hydraulically
56:
55:pneumatically
51:
49:
45:
41:
37:
30:
26:
21:
325:
317:the original
283:
269:
243:
240:Applications
222:
212:
208:
205:
182:
166:
154:
122:
86:torque motor
71:
52:
35:
33:
333:. Firgelli.
213:illustrated
209:fluid power
185:memory wire
179:Other types
132:Servomotors
78:servomotors
261:References
157:servomotor
151:servomotor
65:stored in
46:motion or
350:Actuators
61:, or use
344:Category
40:actuator
16:AE motor
67:springs
225:vacuum
63:energy
48:torque
44:rotary
38:is an
292:(PDF)
169:servo
144:servo
80:and
57:or
346::
304:^
294:.
175:.
155:A
69:.
50:.
34:A
298:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
