Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D59/00—Self-acting brakes, e.g. coming into operation at a predetermined speed
  • F16D59/02—Self-acting brakes, e.g. coming into operation at a predetermined speed spring-loaded and adapted to be released by mechanical, fluid, or electromagnetic means
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D27/00—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor
  • F16D27/10—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings
  • F16D27/108—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings with axially movable clutching members
  • F16D27/112—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor with an electromagnet not rotating with a clutching member, i.e. without collecting rings with axially movable clutching members with flat friction surfaces, e.g. discs
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D27/00—Magnetically- or electrically- actuated clutches; Control or electric circuits therefor
  • F16D2027/007—Bias of an armature of an electromagnetic clutch by flexing of substantially flat springs, e.g. leaf springs

Definitions

• Rotary brakes transfer torque from a rotatable shaft to a stationary housing and are applicable to, but not limited to commonly used actuation methods including electromagnetic, pneumatic, and hydraulic.
• axial movement of internal components is used to capture or engage the rotatable rotor, which results in a mechanical connection between a stationary component and the components that translate axially.
• Common methods of mechanically connecting axially moveable components include splines, pins, studs and bushings, all of which require mechanical clearance to operate freely. Clearance leads to stiffness losses and torsional backlash which can result in undesirable motion of a locked axis in an application. Thus, a need exists for apparatus for controlling rotary motion resulting in zero-backlash.
• GB 878,273 discloses a rotary motion control apparatus including a housing of an annular shape having a cylindrical outer surface extending between first and second ends and an operational cavity, a rotor rotationally received in the operational cavity, with the rotor including a hub, an annular shaped friction facing and a disk extending between the friction facing and the hub and allowing flexible movement of the friction facing relative to the hub, an actuation plate of an annular shape, with the actuation plate moveably connected to the housing by a shell slideable on studs, with the friction facing being intermediate the actuation plate and the housing, and springs biasing the actuation plate towards the friction facing to sandwich to the friction facing intermediate the housing and the actuation plate, with the actuation plate being moved against the bias of the springs.
• a rotary motion control apparatus with zero-backlash.
• a rotary motion control apparatus is provided with a flexible plate secured to the housing and to the actuation plate and moveably connecting the actuation plate to the housing.
• the flexible plate has sufficient flexibility to allow the actuation plate and the flexible plate secured thereto to move axially away from the housing to sandwich the friction facing intermediate the housing and the actuation plate and relative to the housing and the flexible plate secured thereto.
• the housing of the rotary motion control apparatus includes an output flange having the second of first and second spaced, parallel, planar surfaces abutting with the first end of the housing and abutting with the friction facing.
• the rotary motion control apparatus further includes an electromagnet located in the housing on a same side of the actuation plate as the springs and drawing the actuation plate towards and against the bias of the springs, with an annular cavity in the housing receiving the electromagnet.
• Cylindrical cavities in the housing receive the springs, with the cylindrical cavities located in the housing concentrically within and spaced from the annular cavity.
• First fasteners extend through the flexible plate and into the actuation plate, with the first fasteners extending into the annular cavity.
• Second fasteners extend through the flexible plate and into the housing, with the second fasteners located concentrically within the cylindrical cavities. Bores extend through the actuation plate, with the second fasteners extending through the bores.
• Figure 1 shows an exploded perspective view of a rotary motion control apparatus with the actuation mechanism removed for ease of illustration.
• Figure 2 shows a cross sectional view of the rotary motion control apparatus of Figure 1 including an actuation mechanism and in a disengaged position.
• Figure 3 shows a cross sectional view of the rotary motion control apparatus of Figure 1 including an actuation mechanism and in an engaged position.
• Apparatus 10 includes a housing 12 of an annular shape. In one manner of operation, housing 12 is held stationary relative to ground, such that apparatus 10 operates as a brake. Housing 12 has a cylindrical outer surface 14 extending between first and second ends 16 and 18. A cylindrical bore 20 axially extends between ends 16 and 18 and generally concentrically to surface 14. A cylindrical cavity defined by a cylindrical wall 22 axially extends from end 16 towards but spaced from second end 18 generally concentrically to and spaced inward from outer surface 14 and terminates in a radially extending wall 24. An annular cavity 26 extends axially from radially extending wall 24 towards but spaced from end 18 and concentrically to, intermediate and spaced from cylindrical bore 20 and outer surface 14.
• a plurality of cylindrical cavities 28 axially extend from radially extending wall 24 and are located concentrically within and spaced from annular cavity 26 and are located intermediate and spaced from annular cavity 26 and cylindrical bore 20.
• a plurality of threaded cylindrical cavities 30 axially extend from radially extending wall 24 and are located intermediate and spaced from annular cavity 26 and cylindrical bore 20 and are circumferentially intermediate plurality of cylindrical cavities 28.
• Each of threaded cylindrical cavities 30 include a relieved boss 32 formed in radially extending wall 24 and intersecting with annular cavity 26.
• Elongated bores 37 axially extend between ends 16 and 18 and intermediate and spaced from outer surface 14 and cylindrical wall 22 and annular cavity 26.
• Housing 12 includes an output flange 34 of an annular shape having a diametric extent corresponding to outer surface 14.
• Output flange 34 has first and second spaced, parallel, planar surfaces. The second surface of output flange 34 abuts with first end 16 and is secured to housing 12 by a plurality of bolts 36 extending axially through elongated bores 37 and threadably engaged with threaded bores 38 formed in output flange 34.
• Output flange 34 includes a cylindrical bore 40 of a diametric size intermediate and spaced from central bore 20 and annular cavity 26.
• An operational cavity is defined between output flange 34 and radially extending wall 24 and having a minimum radial extent defined by cylindrical wall 22.
• Annular cavity 26, cylindrical cavities 28 and threaded cylindrical cavities 30 extend axially in housing 12 opposite to output flange 34.
• Apparatus 10 also includes a rotor 46 received in the operational cavity.
• Rotor 46 includes a hub 48 such as for slidable fixed receipt on a rotatable shaft such as by way of a keyway as shown.
• Rotor 46 includes an annular shaped friction facing 50 having an inner radial extent 50a greater than cylindrical bore 40 and an outer radial extent 50b less than cylindrical wall 22 and abutting with the second surface of output flange 34.
• a disk 52 integrally extends between inner radial extent 50a and hub 48.
• Rotor 46 is formed as a single piece of homogenous material.
• Disk 52 is of an axial thickness considerably less than hub 48 and friction facing 50 to allow flexible movement of friction facing 50 relative to hub 48.
• rotor 46 can take other forms and types suitable for providing rotatable engagement and disengagement.
• rotor 46 can be of a design which minimizes or eliminates flexible movement.
• different manners of engagement and disengagement of rotor 46 can be utilized such as, but not limited to, having toothed interfacing surfaces.
• rotor 46 can be of any form or type allowing rotor 46 to be freely rotatable relative to housing 12 or to be rotatably fixed relative to housing 12.
• Apparatus 10 further includes an actuation plate 60 of an annular shape. Friction facing 50 is intermediate actuation plate 60 and the second surface of output flange 34.
• Actuation plate 60 has an outer radial extent slightly less than and for moveable receipt in cylindrical wall 22.
• Actuation plate 60 has an inner radial extent generally coextensive with cylindrical bore 20 and greater than hub 48.
• a plurality of bores 62 extend through actuation plate 60 at circumferentially spaced locations corresponding to threaded cylindrical cavities 30.
• a plurality of threaded bores 64 extends through actuation plate 60 at circumferentially spaced locations corresponding to annular cavity 26.
• Apparatus 10 also includes a flexible plate 70 including an annular portion 72 of a size for receipt in annular cavity 26.
• Tabs 78 extend radially outwardly of annular portion 72. Fasteners 76 extend through tabs 78 towards output flange 34 and are threadably received in threaded bores 64 for securing flexible plate 70 to actuation plate 60. Tabs 74 extend radially inwardly of annular portion 72 and are received in relieved bosses 32. Fasteners 80 axially extend through tabs 74 away from output flange 34 and are threadably received in threaded cylindrical cavities 30 for securing flexible plate 70 to housing 12.
• actuation plate 60 is moveably connected to housing 12 by flexible plate 70.
• apparatus 10 includes a plurality of springs 86 located in cylindrical cavities 28 for biasing actuation plate 60 away from radially extending wall 24 and towards friction facing 50 to sandwich friction facing 50 intermediate output flange 34 of housing 12 and actuation plate 60.
• Apparatus 10 further includes a mechanism 90 for moving actuation plate 60 against the bias of springs 86 towards radially extending wall 24.
• mechanism 90 is an electromagnet positioned within annular cavity 26 and suitably secured therein such as by adhesive.
• Mechanism 90 is located in housing 12 on an opposite side of actuation plate 60 than output flange 34 and draws actuation plate 60 towards and against the bias of springs 86.
• actuation plate 60 is formed of magnetic material, such that when mechanism 90 is energized, actuation plate 60 is drawn towards and moves against the bias of springs 86 to abut with radially extending wall 24.
• mechanism 90 is not energized, actuation plate 60 is not drawn toward radially extending wall 24 and moves by the bias of springs 86 away from radially extending wall 24.
• flexible plate 70 has sufficient flexibility to allow actuation plate 60 and flexible plate 70 secured thereto by tabs 78 to move axially away from housing 12 to sandwich friction facing 50 intermediate output flange 34 of housing 12 under the bias of springs 86 and relative to housing 12 and flexible plate 70 secured thereto by tabs 74.
• mechanism 90 for moving actuation plate 60 can take other forms and types including, but not limited to, other forms and types of electromagnetic, pneumatic, hydraulic and/or manual actuation.
• fasteners 76 are extended into tabs 78 and threaded to bores 64 for securing flexible plate 70 to actuation plate 60.
• Springs 86 are positioned in cylindrical cavities 28.
• mechanism 90 is positioned in and suitably secured within annular cavity 26.
• Fasteners 80 are extended into tabs 74 and threaded into threaded cylindrical cavities 30 to secure flexible plate 70 and actuation plate 60 to housing 12 and sandwiching springs 86 between actuation plate 60 and the closed ends of cylindrical cavities 28.
• Rotor 46 is positioned in the cylindrical cavity defined by cylindrical wall 22.
• Output flange 34 is placed to abut first end 16 and housing 12, and bolts 36 are extended axially through bores 37 of housing 12 radially outward of the operational cavity and threaded into threaded cylindrical bores 38 extending axially from the second surface to the first surface of output flange 34.
• actuation plate 60 when mechanism 90 is energized, actuation plate 60 is drawn against the bias of springs 86 to abut with radially extending wall 24. Thus, the axial spacing between actuation plate 60 and output flange 34 is greater than the axial thickness of friction facing 50. Thus, rotor 46 and the shaft rotatably fixed thereto are free to rotate relative to housing 12.
• actuation plate 60 moves under the bias of springs 86 away from radially extending wall 24 to engage rotor 46 and sandwich friction facing 50 between output flange 34 and actuator plate 60, thereby rotatably fixing rotor 46 to housing 12.
• apparatus 10 functions as a brake to stop rotation of rotor 46 and the shaft received therein.
• actuation plate 60 moves away from radially extending wall 24, rotor 46 is flexed to axially move friction facing 50 to contact with output flange 34 and actuation plate 60.
• Flexible plate 70 fastened to housing 12 by fasteners 80 and to actuation plate 60 by fasteners 76 is rotatably fixed to housing 12 but allows axial movement and actuation without the addition of backlash. Further, disengaging friction facing 50 from output flange 34 and actuator plate 60 occurs without an externally applied force to rotor 46, resulting in zero torsional drag on the rotatable shaft received in hub 48 of rotor 46.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Mechanical Engineering (AREA)
• Braking Arrangements (AREA)

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• 2022
  • 2022-04-04 WO PCT/US2022/023230 patent/WO2022216569A1/en active Application Filing
  • 2022-04-04 EP EP22719130.1A patent/EP4320364A1/de active Pending

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