US2777027A - Electrical actuator - Google Patents

Electrical actuator Download PDF

Info

Publication number
US2777027A
US2777027A US252155A US25215551A US2777027A US 2777027 A US2777027 A US 2777027A US 252155 A US252155 A US 252155A US 25215551 A US25215551 A US 25215551A US 2777027 A US2777027 A US 2777027A
Authority
US
United States
Prior art keywords
arm
motor
section
cam
spring
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US252155A
Other languages
English (en)
Inventor
Tesh Kimble Frank
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bendix Aviation Corp
Original Assignee
Bendix Aviation Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bendix Aviation Corp filed Critical Bendix Aviation Corp
Priority to US252155A priority Critical patent/US2777027A/en
Priority to US321793A priority patent/US2745977A/en
Priority to JP1047154A priority patent/JPS335008B1/ja
Application granted granted Critical
Publication of US2777027A publication Critical patent/US2777027A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
    • H02K7/10—Structural association with clutches, brakes, gears, pulleys or mechanical starters
    • H02K7/102—Structural association with clutches, brakes, gears, pulleys or mechanical starters with friction brakes
    • H02K7/1021—Magnetically influenced friction brakes
    • H02K7/1023—Magnetically influenced friction brakes using electromagnets
    • H02K7/1025—Magnetically influenced friction brakes using electromagnets using axial electromagnets with generally annular air gap

Definitions

  • This invention relates to small electric actuators for operating various control devices such as valves, switches, etc. from a remote point, by simply closing an electric circuit.
  • An object of the invention is to provide an electrically driven actuator of very small size relative to its power.
  • Another object is to provide an actuator construction that combines extreme compactness with simple rugged assembly of the parts.
  • the invention relates to actuator units of the type consisting of a tiny electric motor coupled by a speed-reducing, torque multiplying, gear train to an output shaft adapted to be connected to the valve or other device to be actuated.
  • the output shaft actuates a shut-otf switch, which switch de-energizes the motor automatically and applies a brake to stop it quickly and lock the output shaft when the latter has been rotated through a predetermined angle.
  • the invention resides in details of design and assembly of such units which reduce their size and simplify their construction without impairing their performance. These details of design will be explained in the following description, with reference to the drawing, and are particularly defined in the claims.
  • Fig. 1 is a plan view of a complete actuator in accordance with the invention.
  • Fig. 2 is a vertical section in the plane IIII of Fig. 1.
  • Figs. 3, 4 and 5 are cross sections in the planes III-III, IVIV and V--V of Fig. 2.
  • Fig. 6 is a vertical detail section in the plane VT-VI of Fig. 3.
  • Fig. 7 is a vertical detail section in the plane VIIVII of Figs. 2 and 4.
  • Fig. 8 is an end elevation of the actuator, with the cover removed.
  • Fig. 9 is a schematic diagram showing the electrical circuit of the actuator.
  • the actuator depicted therein is made up of three sections, namely, a motor section it a switch section 11, and a gear train section 12.
  • the three sections are detachably secured together by screws 13 extending up from the gear train section 12 into the motor section 10, and by screws 14 extending down through the switch section 11 and into the gear train section 12.
  • the motor section is additionally secured to the switch section 11 by screws 15.
  • a removable cover can 10a is secured to the motor section by screws 1%.
  • the motor section It has a motor shaft 16 extending down through the switch section 11 and into the gear train section 12.
  • the lower end of this shaft has gear teeth 16a which mesh with a gear 17 in the gear train section 12.
  • the gear 17 is freely rotatable on a shaft 26 and has secured thereto a pinion 18 which meshes with a gear 19 which is freely rotatable on a shaft 27, and has secured thereto a pinion 24) which meshes with a gear 21 which is also free to rotate on the shaft 26, and has a pinion 22 secured thereto which meshes with a gear 23 which, with an associated pinion 24 secured thereto, is rotatable on the shaft 27.
  • the pinion 24 meshes with a gear 25 which is secured to the shaft 26 for rotation therewith.
  • the shaft 26 constitutes the output shaft for driving the switch, valve, or other element to be actuated. It extends below the lower end of the actuator and is provided with a splined end 26a for connection to the device to be actuated.
  • the gear train provides a very large speed reduction and a corresponding torque multiplication between the motor shaft 16 and the output shaft 26.
  • the motor shaft 16 extends through the switch section 11 but it does not have any driving connection with the latter.
  • the output shaft 26 also extends through the switch section 11 and is journaled in the upper and lower Walls thereof. It carries one or more earns 28, 23 in the switch section, which actuate the switch contacts. The operation of this portion of the apparatus will be described in detail later.
  • the motor section it) comprises a main frame 30 which consists of an upper end wall section 31, a motor field section 32, a lower end wall section 33, a pair of op.
  • the field section 32 of the frame is of rectangular exterior cross section, two sides 32a of which are of uniform thickness and the same thickness as the connecting sections 3434 and 3535 to which they are joined.
  • the other two opposite sides of the field section 32 are extended inwardly to form two field poles 32b-32b having cylindrical inner faces 32c32c respectively which are closely juxtaposed to the armature 37 of the motor.
  • a field winding 38 encircles one of the pole pieces 32b, and a field winding 39 encircles the other pole piece 32b.
  • the field winding 33 is retained in position by a pair of bus bars 41) and 41, and the field winding 39 is retained in position by a pair of bus bars 42 and 43 respectively.
  • Tubular insulation 4.5 surrounding the bus bars 40, 41, 4-2 and 43 insulates them from and provides cushioning between them and the field windings.
  • one terminal of the field winding 38 is connected to the bus bar 40, and one terminal of the field winding 39 is connected to the bus bar 42.
  • the other terminals of the two windings are both connected to the bus bar 41.
  • All four bus bars are mechanically supported in the frame end members 31 and 35, as shown in Fig. 2, apertures being provided therefor in the end walls 31 and 33, and the insulating bushings 45 electrically insulating the bus bars from the end walls.
  • the upper ends of the bus bars do not extend beyond the upper end wall 31, but the bus bars and 42 extend through the lower end wall 33 into the switching section 11, where they complete connection between the field windings and the rest of the circuit.
  • the bus bars 41 and 43 do not extend through the lower end wall.
  • Each brush 46 and 47 is formed of carbon and is relatively thin and is secured to a supporting clip 50 formed from sheet metal and having a saddle outer end section 50a which rides on the bus bar 41 or 43. Each brush may be secured to its clip 50 .in electrically conducting relation by copper-plating the rear face of the brush and soldering it to the clip 50. A small boss 46a on the rear side of the brush is extended through an aperture provided therefor in the clip 50 to reinforce the connection.
  • Each brush is spring-urged against the commutator by a torsion spring 52 which is wound around an insulating tube 53 supported on the end of a retaining screw 54 which extends from the brake section of the motor. the torsion spring 52 is engaged by the bus bar and the other end extends through an aperture provided therefor in the clip 50.
  • the brush construction described provides brushes of suflicient area to carry relatively large currents, without extending radially as far from the commutator as conventional brushes do.
  • the motor shaft 16 is rotatably supported by ball bearings 60 pressed into bushing members which in turn are pressed into apertures 61 provided therefor in the opposite end walls 31 and 33 respectively.
  • the radius of these apertures 61 is the same as the radius of curvature of the pole faces 32c, so that the pole faces and the bearing apertures can be machined in extremely accurate alignment with each other by the use of a single boring, reaming, or honing tool.
  • This is an important feature of the invention because it enables a very small air gap between the armature and the field pole faces. This small gap has the advantage of not only greatly increasing the power available from a motor of a given size, but enables successful operation of the motor on either one of the two field windings 38 or 39 alone.
  • the small air gap so greatly reduces the reluctance of the magnetic circuit that, with only one of the fields 38 or 39 energized, the flux is only slightly larger in the pole which is directly energized than in the opposite pole.
  • the field 38 is poled to magnetize the field in one direction
  • the field winding 39 is poled to magnetize the field in the opposite direction, to provide direction selectivity in the operation of the motor.
  • a brake is provided for locking the motor against rotation when it is not energized.
  • This brake is mounted at the upper end of the motor, above the upper end wall 31. It includes a lower brake frame member 70 (the lower end of which constitutes the bushing supporting the upper bearing 60), and a solenoid 71 positioned thereabove, which are maintained in desired spaced relation by spacer shims 72, and are anchored together and to the upper motor end wall 31 by the screws 54 which extend downwardly through apertures provided therefor in the solenoid 71 and the brake frame member 70, and are threaded into the upper motor end wall 31. As previously mentioned, two of these screws 54 extend past the upper motor end wall 31 and function as mechanical supports for the brush springs 52. The other two screws terminate at the lower surface of the motor upper end wall 31.
  • the upper face 70a of the brake frame member 70 constitutes a braking surface and is highly polished. Positioned immediately above this surface 70a is a brake plate 80 having a lining of cork or similar material 80.7
  • the brake plate 80 is provided with a central splined aperture which engages the splined upper end 1617 of the motor shaft for rotation therewith and longitudinal sliding movement with respect thereto.
  • the plate 80 is provided with an upwardly extending flange 80b against which there rests a disc 81 of magnetic material such as iron, constituting the armature of the sole One end of a noid 71.
  • This disc 81 is urged downwardly by a helical compression spring 83 which is compressed between an adjusting screw plug 84 positioned thereabove, and a ball 85 interposed between the lower end of the spring and the armature 81.
  • the spring 83 maintains brake plate 30 in frictional engagement with the stationary surface 70a except when the solenoid is energized. Energization of the solenoid lifts the disc 81, compressing the spring 83, to permit the brake plate 80 to rotate with respect to the brake surface 70a.
  • One terminal of the solenoid winding 88 (Fig. 2) is connected by a lead 87 (Fig. 4) to the bus bar 43 which supports and is electrically connected to the brush 47 (Fig. 3).
  • the other terminal of the solenoid winding 88 is grounded to the frame of the device.
  • the switch section 11 contains a pair of cams 28 and 29 which actuate contacts for opening and closing the motor circuit to cause the output shaft 26 to be rotated through a desired angle in either direction and automatically stopped.
  • the lower cam 29 actuates two contact arms 90 and 91 respectively
  • the upper cam 28 actuates two contact arms 92 and 93, which are behind arms 90 and 91 respectively, in Fig. 5.
  • Contact arm 93 is shown in Fig. 2. All four arms are identical and hence a description of arm 91 suffices for all.
  • Arm 91 is electrically connected to and pivots about the bus bar 40 which, as previously explained, extends from the'motor section of the device down to the switch section.
  • Arm 91 has riveted to its outer face a restoring spring 95 in the form of a leaf spring, the outer end of which contacts a strip of insulation 96 which lies against the wall of the switch housing.
  • This spring 95 exerts a force constantly on the contact arm 91, urging it toward the cam 29.
  • a second leaf spring 97 On the inner side of the contact arm 91 there is riveted a second leaf spring 97, the free end of which is normally displaced away from the arm 91 and is adapted to be contacted by the cam 29.
  • the other end of the spring 97 is bent away from the arm 91 to define therewith a slot which receives the bus bar 40.
  • Each of the arms 90, 91, 92 and 93 with the two springs 95 and 97 constitutes an integral arm assembly.
  • the extreme left end of the spring 97 is upset and extends into a groove provided therefor in a block of insulating material 99.
  • the two lower blocks 99-99 associated with the contact arms 90 and 91 respectively are separated from the two upper blocks 99-99, associated with the contact arms 92 and 93 respectively, by a horizontal insulating strip 100 which is retained in position by the two insulating strips 96-96 which lie against the opposite side walls of the switch housing.
  • Each block 99 has a threaded aperature 99a therein into which there is extended an adjusting screw 102.
  • the head of the screw lies exterior of the switch housing, but is partially covered by a plate 103 having holes therein aligned with the head, to permit adjustment. Since longitudinal movement of the screws 102 with respect to the housing is prevented, rotation of any screw shifts the associated insulating block 99 to move the associated contact arm assembly longitudinally in the housing.
  • stationary contacts 105, 106, 107 and 108 associated with the movable contact arms 90, 91, 92 and 93 respectively. These contacts are molded in a single block of insulating material 109 containing prongs which extend into a socket 110 (Fig. 2) which is mounted on the top of the switch housing 11 and is adapted to receive a standard plug for connecting the actuator to the control circuit.
  • the two contacts and 106 associated with the contact arms '90 and 91 respectively are electrically connected together, and hence they can be formed as a single bar extending through the insulating block 109.
  • the stationary contacts 107 and 108 are electrically disconnected from each other and are therefore formed separately.
  • the movable contact arms are made of magnetic material such as iron or steel, and there are embedded in the insulating block 109 permanent magnets 112 which are closely positioned to their associate contact arms when the latter are lying against their associated fixed contacts.
  • the actuator may be operated by a source of current such as the battery 115 and a switch 116 located at a remote point.
  • One terminal of the battery may be connected by a lead 117 to one terminal (the grounded terminal) of the brake solenoid 88.
  • the other terminal of the solenoid 88 is connected to one of the motor brushes 47, and that the other motor brush 46 is connected to one terminal of each of the field windings 38 and 39. As shown in Fig.
  • the other terminal of the field winding 38 is connected both to the movable contact arm 90 and the movable contact arm 92, whereas the other end of the other field winding 39 is connected to the movable contact arm 91 and the movable contact arm 93.
  • the remote switch 116 is adapted to connect the other terminal of the current source 115 selectively either to the contacts 105 and 106 simultaneously, or to the contact 108, or to the contact 107. As shown in the drawing (Fig. 5), the actuator output shaft 26 is in a neutral position into which it has been moved by connection of the source 115, through the switch 116, to the fixed contacts 105 and 106.
  • Energization of the solenoid winding 88 releases the brake so that the motor can run, and the direction in which it runs is determined by the polarity of the field winding 38.
  • the polarity is such that the cams 28 and 29 are rotated counterclockwise, as viewed in Fig. 9. It will be devisved that rotation of the output shaft and the cam 28 therewith through degrees opens the movable contact arm 92 off the fixed contact 107, thereby opening the motor circuit, and stopping the actuator in the new position.
  • the switch 116 is manipulated to apply current to the fixed contacts and 106. If at this time the output shaft and the cam 29 are in extreme clockwise position, the contact arm 90 will be closed on contact 105, thereby energizing the motor through the field winding 38 to rotate the shaft and the cam 29 in counterclockwise direction. When the cam reache neutral position, as shown in Fig. 9, it opens the arm 90 off the fixed contact 105 to stop the motor.
  • cam shapes shown in the drawing are merely representative of many shapes that can be employed, depending upon the particular angle through which it is desired to rotate the output shaft. Furthermore, different numbers of cams and associated contacts can be employed to obtain special operating characteristics. The invention does not lie in the particular circuit herein disclosed but rather in the structure of the elements which permits a varied number of contacts and cams to be employed.
  • a switch mechanism comprising: a shaft, a cam on said shaft, and a movable contact arm assembly pivotally supported adjacent one of its ends and comprising an arm positioned to bear against said cam intermediate its ends; a stationary contact positioned for make and break contact with the other end of said arm in response to rotation of said cam; means urging said arm toward said stationary contact with a force varying inversely with the distance therebetween; said arm assembly including spring means on the cam side of said arm normally spaced from said arm and adapted to be deflected toward the arm by lifting movement of said cam, to develop a spring force against the arm in direction urging it away from said fixed contact, said spring means having insufiicient stiffness to overcome said urging means, and said cam being so proportioned as to positively displace said arm following deflection of said spring means.
  • said spring means is a leaf spring secured at one end to said arm and projecting toward said cam, the free end of said leaf spring being normally displaced from said arm in juxtaposed relation to said cam.
  • a switching mechanism in which said one end of said arm assembly is bifurcate, defining a slot; a stationary pivot pin extending through said slot, and means supporting said arm longitudinally with respect to said pivot pin.
  • a switching mechanism according to claim 3 in which said supporting means comprises a block engaging the outer side of one branch of said bifurcate arm end opposite said pin; means supporting said block for longitudinal movement; and means for longitudinally adjusting said block.
  • a switching mechanism includingv a second movable contact arm assembly approximately parallel to said mentioned arm assembly and similarly positioned on the opposite side of said cam from said first mentioned arm assembly, and a pivot pin and supporting block for said second arm assembly, said two blocks lying against each other and each constituting a lateral support for the other.
  • a switching mechanism in which said' arm is of paramagnetic material and said means urging said cam toward said fixed contact comprises a permanent magnet adjacent said fixed contact, and means for supporting said fixed contact and said magnet in stationary relation, comprising a block of insulating material in which said contact and magnet are embedded and means for anchoring said block.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
  • Rotary Switch, Piano Key Switch, And Lever Switch (AREA)
US252155A 1951-10-19 1951-10-19 Electrical actuator Expired - Lifetime US2777027A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US252155A US2777027A (en) 1951-10-19 1951-10-19 Electrical actuator
US321793A US2745977A (en) 1951-10-19 1952-11-21 Motor frame structure and brush rigging
JP1047154A JPS335008B1 (enrdf_load_stackoverflow) 1951-10-19 1954-05-22

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US252155A US2777027A (en) 1951-10-19 1951-10-19 Electrical actuator

Publications (1)

Publication Number Publication Date
US2777027A true US2777027A (en) 1957-01-08

Family

ID=22954827

Family Applications (2)

Application Number Title Priority Date Filing Date
US252155A Expired - Lifetime US2777027A (en) 1951-10-19 1951-10-19 Electrical actuator
US321793A Expired - Lifetime US2745977A (en) 1951-10-19 1952-11-21 Motor frame structure and brush rigging

Family Applications After (1)

Application Number Title Priority Date Filing Date
US321793A Expired - Lifetime US2745977A (en) 1951-10-19 1952-11-21 Motor frame structure and brush rigging

Country Status (2)

Country Link
US (2) US2777027A (enrdf_load_stackoverflow)
JP (1) JPS335008B1 (enrdf_load_stackoverflow)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2975247A (en) * 1955-04-27 1961-03-14 Cons Electronics Ind Time delay relay

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3004179A (en) * 1961-10-10 Electric clock
US2865358A (en) * 1956-06-25 1958-12-23 Musgrave Orly Electric motor housings for gasoline engine starters
US3096453A (en) * 1961-06-14 1963-07-02 Bendix Corp Electric motor drive system
US4059339A (en) * 1976-01-08 1977-11-22 Knox Manufacturing Co. Brake mechanism for motor driven projection screen
JP6456059B2 (ja) * 2014-07-02 2019-01-23 日本電産サンキョー株式会社 ギアードモータおよび自動開閉ユニット

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1792244A (en) * 1930-03-03 1931-02-10 Robbins & Myers Brush holder
US1827102A (en) * 1927-05-21 1931-10-13 Penn Electric Switch Co Pressure actuated switch
US2039526A (en) * 1934-06-04 1936-05-05 Charles H Fennell Automatic control apparatus
US2262306A (en) * 1940-09-03 1941-11-11 Pacific Electric Mfg Corp Auxiliary circuit controlling switch
US2273671A (en) * 1939-09-26 1942-02-17 L R Teeple Company Magnet switch
US2345429A (en) * 1942-10-26 1944-03-28 Gen Electric Electric current collector
US2441593A (en) * 1944-05-27 1948-05-18 Charles L Paulus Electric servomotor unit
US2492023A (en) * 1945-01-19 1949-12-20 Westinghouse Electric Corp Control system for operating trolley frogs
US2544448A (en) * 1945-04-11 1951-03-06 Aero Supply Mfg Co Inc Motor operated valve shaft

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US406015A (en) * 1889-06-25 willson
US344801A (en) * 1886-06-29 Dynamo-electric machine
US278122A (en) * 1883-05-22 Dynamo-electric machine
US626496A (en) * 1899-06-06 lunoell
DE322989C (de) * 1913-12-21 1920-07-13 Jean Felix Paul De La Riboisie Zweipolige dynamoelektrische Maschine mit Selbsterregung
US2234926A (en) * 1938-05-21 1941-03-11 Chicago Flexible Shaft Co Electric motor
US2279982A (en) * 1939-03-15 1942-04-14 Henry L Glynn Rotary toothbrush
US2329151A (en) * 1942-02-26 1943-09-07 Singer Mfg Co Dynamoelectric machine construction
US2629061A (en) * 1949-04-15 1953-02-17 Gen Motors Corp Electric motor

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1827102A (en) * 1927-05-21 1931-10-13 Penn Electric Switch Co Pressure actuated switch
US1792244A (en) * 1930-03-03 1931-02-10 Robbins & Myers Brush holder
US2039526A (en) * 1934-06-04 1936-05-05 Charles H Fennell Automatic control apparatus
US2273671A (en) * 1939-09-26 1942-02-17 L R Teeple Company Magnet switch
US2262306A (en) * 1940-09-03 1941-11-11 Pacific Electric Mfg Corp Auxiliary circuit controlling switch
US2345429A (en) * 1942-10-26 1944-03-28 Gen Electric Electric current collector
US2441593A (en) * 1944-05-27 1948-05-18 Charles L Paulus Electric servomotor unit
US2492023A (en) * 1945-01-19 1949-12-20 Westinghouse Electric Corp Control system for operating trolley frogs
US2544448A (en) * 1945-04-11 1951-03-06 Aero Supply Mfg Co Inc Motor operated valve shaft

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2975247A (en) * 1955-04-27 1961-03-14 Cons Electronics Ind Time delay relay

Also Published As

Publication number Publication date
US2745977A (en) 1956-05-15
JPS335008B1 (enrdf_load_stackoverflow) 1958-07-04

Similar Documents

Publication Publication Date Title
US3419739A (en) Electromechanical actuator
US2539547A (en) Relay
US2323910A (en) Magnetic switch
US2364656A (en) Magnetic actuator
US2777027A (en) Electrical actuator
US2266536A (en) Electric relay
US2916585A (en) Switch assembly
US3525958A (en) Poled miniature relay with two-bladed pivoted armature
US2517052A (en) Electric switch
US3020425A (en) Electromagnetic motor
US3586940A (en) Apparatus with an electrical driving motor
US3553612A (en) Miniature relay with double air gap magnetic circuit
US2245230A (en) Relay
US2388951A (en) Snap-acting device
US2153401A (en) Electric switch
US3713055A (en) Auxiliary contact system for electromagnetic switching devices
US3585544A (en) Switch having magnetic latching means
US2272496A (en) Switching device
US2545587A (en) Electromagnetic relay
JPH0516126B2 (enrdf_load_stackoverflow)
US3340376A (en) Antibounce contact means
US2013990A (en) Direct current polar relay
US2407418A (en) Relay device
US3648204A (en) Switch having magnetic latching means
JPS6230187Y2 (enrdf_load_stackoverflow)