WO2019139893A1 - Frein doté d'un commutateur à lames pour indiquer une condition de fonctionnement du frein - Google Patents

Frein doté d'un commutateur à lames pour indiquer une condition de fonctionnement du frein Download PDF

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Publication number
WO2019139893A1
WO2019139893A1 PCT/US2019/012676 US2019012676W WO2019139893A1 WO 2019139893 A1 WO2019139893 A1 WO 2019139893A1 US 2019012676 W US2019012676 W US 2019012676W WO 2019139893 A1 WO2019139893 A1 WO 2019139893A1
Authority
WO
WIPO (PCT)
Prior art keywords
brake
reed switch
field shell
armature plate
plate
Prior art date
Application number
PCT/US2019/012676
Other languages
English (en)
Inventor
Stephen E. NYQUIST
Bradley Lyn UFFELMAN
Original Assignee
Warner Electric Technology Llc
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
Priority claimed from US15/868,440 external-priority patent/US20180135713A1/en
Application filed by Warner Electric Technology Llc filed Critical Warner Electric Technology Llc
Publication of WO2019139893A1 publication Critical patent/WO2019139893A1/fr

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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
    • F16D65/00—Parts or details
    • F16D65/14—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position
    • F16D65/16—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake
    • F16D65/18—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake adapted for drawing members together, e.g. for disc brakes
    • 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
    • F16D65/00—Parts or details
    • F16D65/14—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position
    • F16D65/16—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake
    • F16D65/18—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake adapted for drawing members together, e.g. for disc brakes
    • F16D65/186—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake adapted for drawing members together, e.g. for disc brakes with full-face force-applying member, e.g. annular
    • 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
    • F16D66/00—Arrangements for monitoring working conditions, e.g. wear, temperature
    • F16D66/02—Apparatus for indicating wear
    • F16D66/021—Apparatus for indicating wear using electrical detection or indication means
    • F16D66/022—Apparatus for indicating wear using electrical detection or indication means indicating that a lining is worn to minimum allowable thickness
    • F16D66/025—Apparatus for indicating wear using electrical detection or indication means indicating that a lining is worn to minimum allowable thickness sensing the position of parts of the brake system other than the braking members, e.g. limit switches mounted on master cylinders
    • 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
    • F16D66/00—Arrangements for monitoring working conditions, e.g. wear, temperature
    • F16D66/02—Apparatus for indicating wear
    • F16D66/021—Apparatus for indicating wear using electrical detection or indication means
    • F16D66/026—Apparatus for indicating wear using electrical detection or indication means indicating different degrees of lining wear
    • F16D66/027—Sensors therefor
    • 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
    • F16D66/00—Arrangements for monitoring working conditions, e.g. wear, temperature
    • F16D66/02—Apparatus for indicating wear
    • F16D66/021—Apparatus for indicating wear using electrical detection or indication means
    • F16D66/028—Apparatus for indicating wear using electrical detection or indication means with non-electrical sensors or signal transmission, e.g. magnetic, optical
    • 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
    • F16D66/00—Arrangements for monitoring working conditions, e.g. wear, temperature
    • F16D2066/003—Position, angle or speed
    • 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
    • F16D2121/00—Type of actuator operation force
    • F16D2121/18—Electric or magnetic
    • F16D2121/20—Electric or magnetic using electromagnets
    • F16D2121/22—Electric or magnetic using electromagnets for releasing a normally applied brake

Definitions

  • This disclosure relates to a brake.
  • the instant disclosure relates to a brake that employs an electromagnetic or magnetic circuit to disengage the brake and in which a reed switch is oriented in a particular manner adjacent an air gap in the circuit to indicate an operating condition of the brake.
  • One conventional type of brake used in industrial applications includes a friction plate or disc that is coupled to a rotating member. Springs bias a non-rotating armature plate into engagement with the friction plate in order to engage the brake. A conductor and/or magnets are then used to create an electromagnetic or magnetic circuit to draw the armature plate away from the friction plate when it is desired to disengage the brake.
  • a brake is provided.
  • a brake is provided that employs an
  • a brake in accordance with one embodiment of the invention includes a friction plate configured for coupling to a shaft for rotation with the shaft about an axis of rotation, a pressure plate disposed about the axis on a first side of the friction plate and fixed against rotation and an armature plate disposed about the axis on a second side of the friction plate.
  • the brake further includes a field shell disposed about the axis on an opposite side of the armature plate relative to the friction plate.
  • the brake further includes a spring biasing the armature plate in a first axial direction towards the friction plate and away from the field shell to engage the brake.
  • the brake further includes a conductor disposed within the field shell. Current supplied to the conductor creates an electromagnetic circuit including the armature plate and the field shell.
  • the electromagnetic circuit urges the armature plate in a second axial direction away from the friction plate and towards the field shell to disengage the brake.
  • the brake further includes a reed switch extending across an air gap between first and second members of the electromagnetic circuit, a state of the reed switch indicative of an operating condition of the brake.
  • a brake in accordance with another embodiment of the invention includes a friction plate configured for coupling to a shaft for rotation with the shaft about an axis of rotation, a pressure plate disposed about the axis on a first side of the friction plate and fixed against rotation and an armature plate disposed about the axis on a second side of the friction plate.
  • the brake further includes a field shell disposed about the axis on an opposite side of the armature plate relative to the friction plate.
  • the brake further includes a spring biasing the armature plate in a first axial direction towards the friction plate and away from the field shell to engage the brake.
  • the brake further includes a conductor disposed within the field shell. Current supplied to the conductor creates an electromagnetic circuit including the armature plate and the field shell.
  • the electromagnetic circuit urges the armature plate in a second axial direction away from the friction plate and towards the field shell to disengage the brake.
  • the brake further includes a reed switch extending across an air gap between first and second members of the electromagnetic circuit, a state of the reed switch indicative of an operating condition of the brake. During proper operation of the brake, the reed switch undergoes a first transition from a first state to a second state when the brake is engaged and current begins flowing through the conductor and subsequently undergoes a second transition from the second state back to the first state once the brake is disengaged.
  • a brake in accordance with another embodiment of the invention includes a friction plate configured for coupling to a shaft for rotation with the shaft about an axis of rotation, a pressure plate disposed about the axis on a first side of the friction plate and fixed against rotation and an armature plate disposed about the axis on a second side of the friction plate.
  • the brake further includes a field shell disposed about the axis on an opposite side of the armature plate relative to the friction plate, the field shell including first and second components.
  • the brake further includes a spring biasing the armature plate in a first axial direction towards the friction plate and away from the field shell to engage the brake.
  • the brake further includes a permanent magnet disposed between the first and second components of the field shell and forming a magnetic circuit with the first and second components of the field shell and the armature plate.
  • the magnetic circuit urges the armature plate in a second axial direction away from the friction plate and towards the field shell to disengage the brake.
  • the brake further includes a reed switch extending across an air gap between first and second members of the magnetic circuit, a state of the reed switch indicative of an operating condition of the brake.
  • a brake in accordance with the present teachings is advantageous relative to conventional brakes because it provides an effective, low cost indication of the operation of the brake.
  • a user of the brake and/or the system in which the brake is installed is capable of readily identifying a malfunction of the brake without a significant expenditure of time.
  • Figure 1 is a diagrammatic view of a brake in accordance with one embodiment of the present invention and a system for controlling and monitoring the brake.
  • Figure 2 is a cross-sectional view of the brake of Figure 1.
  • Figure 3 is a perspective view of a brake in accordance with another embodiment of the present invention and a system for controlling and monitoring the brake.
  • Figure 4 is a cross-sectional view of the brake of Figure 3.
  • Figure 5 is a graph illustrating changes in a current level in a conductor and in a state of a switch in the brake of Figures 1-2 over time during proper operation of the brake.
  • Figure 6 is a graph illustrating changes in a current level in a conductor and in a state of a switch in the brake of Figures 1-2 over time during one type of failure in the brake.
  • Brake 10 provides a braking torque to a rotating body such as a shaft, gear, pulley, blade, etc. in order to slow or halt rotation of the rotating body.
  • brake 10 may be used in a wide variety of industrial and other applications requiring a brake.
  • Brake 10 may include a hub 12, a friction plate 14, a pressure plate 16, and armature plate 18, means, such as springs 20, for biasing armature plate 18 in one direction and means, such as field shell 22 and conductor 24, for urging armature plate 18 in another direction.
  • brake 10 may further include one or more reed switches 26. The state of each reed switch 26 is indicative of an operating condition of brake 10.
  • Hub 12 is configured for coupling to a rotating body such as a shah (not shown) and supports friction plate 14.
  • Hub 12 may be made from conventional plastics or metals.
  • Hub 12 is annular and is disposed about the rotating shaft and an axis 28 of rotation for the shaft.
  • Hub 12 may be coupled to the shaft in a variety of ways.
  • hub 12 may define a key or key way configured for alignment with a complementary key way or key in the shaft.
  • Hub 12 may alternatively include a plurality of splines or teeth configured to mesh with mating splines or teeth on the shaft.
  • a set screw 30 may be inserted through a radially extending aperture in hub 12 and engage the shaft.
  • Hub 12 may also form a unitary structure with the shaft.
  • the radially outer surface of hub 12 may define a plurality of flats for engagement with corresponding flats on friction plate 14.
  • Friction plate 14 is provided to transmit a braking torque to hub 12 and the shaft or other rotating body and is configured for coupling to the shaft (e.g. through hub 12) for rotation with the shaft about axis 28.
  • Friction plate 14 may be made from conventional metals or plastics and may be made by stamping, molding and/or machining. Friction plate 14 may be annular in shape and disposed about hub 12 and axis 28. Friction plate 14 is configured for rotation with hub 12 and may be rotationally coupled to hub 12 in a variety of ways that permit axial movement of friction plate 14 relative to hub 12 to enable proper operation of brake 10 and account for wear, vibration, runout or thermal expansion.
  • Friction plate 14 may have complementary, torque transmitting, shapes such as a key and key way, splines, single or double D-shape or hexagonal shape.
  • Friction plate 14 may also be coupled to hub 12 using leaf springs. In certain applications (typically low speed applications, applications with low to zero lash requirements and/or applications that permit light frictional drag during release of the brake), friction plate 14 may be combined with hub 12 as a unitary structure or coupled to hub 12 in a way that does not permit relative axial movement (e.g., an interference fit or through adhesives or other fasteners).
  • Friction plate 14 includes friction surfaces on opposed sides 32, 34 configured to engage pressure plate 16 and armature plate 18, respectively, during engagement of brake 10.
  • Pressure plate 16 is configured to engage friction plate 14 during application of brake 10 to transmit a braking torque to friction plate 14.
  • Pressure plate 16 provides a reaction surface against which armature plate 18 presses friction plate 14 during application of brake 10.
  • Pressure plate 16 may be made from conventional metals or plastics and may be made from steel (including stainless steel) in some embodiments.
  • Pressure plate 16 is disposed on side 32 of friction plate 14.
  • Pressure plate 16 may further be disposed about hub 12 and axis 28.
  • Pressure plate 16 is fixed against rotation and may be coupled to field shell 22 using a plurality of axially extending fasteners 36 such as bolts, pin, screws or the like.
  • Armature plate 18 is also configured to engage friction plate 14 during application of brake 10 to transmit a braking torque to friction plate 14.
  • Armature plate 18 may be made from metals or metal alloys or other materials having relatively low magnetic reluctance such as iron or steel.
  • Armature plate 18 is disposed on side 34 of friction plate 14.
  • Armature plate 18 may further be disposed about hub 12 and axis 28. Armature plate 18 is fixed against rotation, but is axially movable towards and away from friction plate 14 and pressure plate 16 to permit engagement and disengagement of brake 10.
  • Armature plate 18 may include a plurality of bores extending through armature plate 18 or a plurality of recesses in the radially outer surface of armature plate 18 configured to permit fasteners 36 to pass through armature plate 18. In this manner, fasteners 36 limit or prevent rotation of armature plate 18 about axis 28, but armature plate 18 is permitted to move along axis 28.
  • Springs 20 provide a means for biasing armature plate 18 in one direction along axis 28 towards friction plate 14 and pressure plate 16 to engage brake 10.
  • Springs 20 may be disposed between field shell 22 and armature plate 18. It should be understood that brake 10 may include either a single annular spring 20 or a plurality of springs 20 disposed in an annular array about axis 28. In the latter case, springs 20 may be spaced equally circumferentially spaced about axis 28.
  • Field shell 22, together with conductor 24, provide a means for urging armature plate 18 in the opposite direction along axis 28 away from friction plate 14 and pressure plate 16 to disengage brake 10.
  • Field shell 22 may also provide structural support and orient other components of brake 10 including pressure plate 16 and springs 20.
  • Field shell 22 may be annular in shape and disposed about axis 28 and may be disposed on a side of armature plate 18 opposite friction plate 14.
  • Field shell 22 may be made from materials having a relatively low magnetic reluctance such as ferromagnetic materials.
  • Field shell 22 may define a radially extending end wall 38 and axially extending, radially aligned, inner and outer walls 40, 42 that extend axially from end wall 38 towards armature plate 18.
  • Inner wall 40 may define one or more closed bores 44 configured to receive one end of each spring 20.
  • Outer wall 42 may also define one or more closed bores 46 configured to receive fasteners 36.
  • Conductor 24 may comprise a conventional wound coil or similar conductor and is configured to be received within field shell 22 between walls 40, 42. Current supplied to conductor 24 creates an electromagnetic circuit that includes armature plate 18 and field shell 22. This circuit urges armature plate 18 towards field shell 22 and away from friction plate 14 against the force of springs 20 to disengage brake 10.
  • one or more reed switches 26 are provided that indicates an operating condition of brake 10.
  • three reed switches 26 are provided and are equally circumferentially spaced about a circumference of brake 10.
  • Each switch 26 extends across an air gap between components of the electromagnetic circuit.
  • each switch 26 is disposed radially outwardly of armature plate 18 and field shell 22 and extends across the air gap between armature plate 18 and field shell 22 (and particularly, outer wall 42 of field shell 22).
  • switches 26 detects flux leakage from the electromagnetic circuit between armature plate 18 and field shell 22 when current has been supplied to conductor 24, but armature plate 18 has failed to disengage from friction plate 14.
  • switches 26 will remain in an open state.
  • Each switch 26 may be mounted within a housing 48 that may be coupled to brake 10.
  • housing 48 has a generally rectangular, box-like shape with a mounting flange 50 extending therefrom that is configured to receive a fastener 52 used to couple the housing 48 to brake 10.
  • Housing 48 may be made from aluminum and helps to orient reed switch 26 relative to brake 10 and the air gap between armature plate 18 and field shell 22 (it should be understood, however, that switch 26 could be oriented relative to brake 10 using a variety of structures and/or coupling methods in place of housing 48).
  • each switch 26 is oriented such that a longitudinal axis 54 of the switch 26 extends in a direction other than parallel to axis 28.
  • the longitudinal axis 54 of switch 26 is an axis that extends through and within a hermetically sealed glass chamber 56 of the switch 26 between the opposite longitudinal ends 58, 60 of chamber 56.
  • the longitudinal ends 58, 60 of the chamber also define the points at which the ferromagnetic reeds 62, 64 of switch 26 enter the chamber 56.
  • the longitudinal axis 54 of switch 26 will also intersect a plane containing axis 28 (the plane lying perpendicular to the drawing) at an angle Q between zero and ninety degrees. In accordance with one embodiment, axis 54 intersects the plane at an angle Q of about eighty degrees.
  • axis 54 also extends in a direction other than parallel to a direction of magnetic force at a point in the air gap where the magnetic force is greatest. Referring to Figure 2, the magnetic force between armature plate 18 and wall 42 of field shell 22 will be greatest along the shortest path between armature plate 18 and wall 42 which is parallel to axis 28.
  • each switch 26 Orienting each switch 26 such that its longitudinal axis 54 is at an angle relative to the axis 28 enables more robust and reliable switching.
  • the orientation reduces the sensitivity of switch 26 such that switch 26 only closes when there is a relatively high level of flux leakage proximate the air gap between armature plate 18 and field shell 22.
  • switch 26 does not close when current is not supplied to conductor 24.
  • Switch 26 also does not close when current is supplied to conductor 24 and armature plate 18 properly disengages from friction plate 14 and engages field shell 22-despite the existence of some flux leakage across the relatively small remaining air gap between armature plate 18 and field shell 22.
  • Switch 26 only closes when current is supplied to conductor 24, but armature plate 18 improperly fails to disengage from friction plate l4-resulting in a relatively high level of flux leakage across the relatively large air gap between armature plate 18 and field shell 22. In this manner, switch 26 is able to indicate an improper operating condition of brake 10 while not generating false positives.
  • the orientation of switch 26 also allows unwanted and inherent residual magnetism to drain from switch 26 to field shell 22 and other ferromagnetic components of the brake 10 when current is not being supplied to conductor 24 thereby preventing the contacts of switch 26 from inadvertently sticking and remaining closed. Further, the orientation of switch 26 accomplishes these results while allowing the switch 26 to be mounted close to the radially outer surface of field shell 22 and brake 10 in general thereby reducing the space required for switch 26 and the packaging of brake 10 while providing protection for switch 26.
  • System 88 may include a power circuit 90, a controller 92, and one or more input/output devices or interfaces such as a display 94.
  • Power circuit 90 controls delivery of current from a power source such as a power grid or an energy storage device (e.g., a battery or capacitor) to conductor 24 in brake 10.
  • Circuit 90 may include conventional switches and other circuit components used to control the flow and level of current to and from conductor 24.
  • Controller 92 controls the operation of power circuit 90 and, therefore, brake 10 and monitors the performance of brake 10 through reed switches 26.
  • Controller 92 may comprise a programmable microprocessor or microcontroller or may comprise an application specific integrated circuit (ASIC).
  • Controller 92 may include a central processing unit (CPU).
  • Controller 92 may also include a memory and an input/output (I/O) interface through which controller 92 may receive a plurality of input signals including those generated by reed switches 26 and display 94 and transmit a plurality of output signals including those used to control power circuit 90 and display 94.
  • Display 94 provides a visual indication of an operation condition of brake 10.
  • Display 94 may include a graphical user interface (GUI) that provides information output by controller 92 regarding the performance of brake 10 and that allows entry of commands to be input to controller 92 for use in controlling brake 10 (through, e.g., a touch screen component of display 94 or another input device such as a keyboard or mouse). It should be understood that a variety of input/output devices may be employed to indicate the operating condition of brake 10 including, for example, audio, visual or haptic alarms.
  • GUI graphical user interface
  • switches 26 will remain in an open state in the absence of any current in conductor 24.
  • springs 20 urge armature plate 18 into engagement with friction plate 14 to engage brake 10.
  • controller 92 directs power circuit 90 to provide current to conductor 24 and the level of current in conductor 24 begins to increase. Because armature plate 18 is still engaged with friction plate 14 and spaced from field shell 20 across a relatively large air gap, significant flux leakage occurs across the air gap between armature plate 18 and field shell 20. The flux leakage briefly causes switch 26 to transition from the open state to a closed state. The absence of this transition is indicative of a lack of current in conductor 24 (e.g.
  • Controller 92 may detect the absence of this transition in reed switches 26 (e.g., due to the failure of the switches 26 to transition from the open state to the close state within a
  • armature plate 18 and field shell 20 overcomes the biasing force of springs 20 and causes armature plate 18 to disengage from friction plate 14 and to engage field shell 20 thereby disengaging brake 10— and reducing the size of the air gap between armature plate 18 and field shell 20.
  • Flux leakage from the air gap between armature plate 18 and field shell 20 decreases as a result of the reduced air gap thereby causing reed switches 26 to transition from the closed state back to the open state.
  • brake 10 fails to disengage due to, for example, wear on armature plate 18 and field shell 20 that increases the distance between armature plate 18 and field shell 20 or the presence of foreign objects that prevent movement of armature plate 18, one or more of switches 26 will fail to transition back to the open state and will remain in the closed state.
  • Controller 92 may detect the absence of this transition in reed switches 26 (e.g., due to the failure of the switches 26 to transition from the closed state back to the open state within a predetermined period of time) and generate a signal indicative of a failure to disengage by the brake. This signal may again, for example, cause a change in display 94 and thereby provide an indication to an operator of a failure in brake 10.
  • FIG. 3-4 a brake 66 in accordance with another embodiment of the present teachings is illustrated.
  • Many components of brake lO-including hub 12, friction plate 14, pressure plate 16 armature plate 18, springs 20 and conductor 24— may also be used within brake 66. Therefore, the same numbers are used in Figures 3-4 to represent structure that may be common to brakes 10 and 66.
  • Brake 66 differs from brake 10 in the structure of the included field shell 68, the addition of one or more magnets 70, and the resulting operation of brake 66.
  • Field shell 68 together with magnets 70, provide a means for urging armature plate 18 in the opposite direction along axis 28 away from friction plate 14 and pressure plate 16 in order to disengage brake 66.
  • Field shell 68 may also provide structural support and orient other components of brake 66 including pressure plate 16 and springs 20.
  • Field shell 68 may be annular in shape and disposed about axis 28 and may be disposed on a side of armature plate 18 opposite friction plate.
  • Field shell 68 may be made from materials having a relatively low magnetic reluctance such as ferromagnetic materials.
  • Field shell 68 may include two components 72, 74.
  • Component 72 may define a radially extending end wall 76 an axially extending, radially inner wall 78 that extends from end wall 76 towards armature plate 18.
  • Wall 78 may define one or more closed bores 80 configured to receive one end of each spring 20.
  • Component 74 is disposed radially outwardly of wall 78 of component 72.
  • Component 74 may define a radially extending wall 82 that is axially spaced from wall 76 of component 72 and an axially extending, radially outer wall 84 that extends from end wall 82 towards armature plate 18.
  • Outer wall 84 may also define one or more closed bores 86 configured to receive fasteners 36.
  • Walls 76, 82 are axially spaced and sized to receive magnet 70 therebetween.
  • Walls 78, 84 are radially spaced and sized to receive conductor 24 therebetween.
  • Magnets 70 are provided to establish a magnetic circuit between armature plate 18, field shell 68 and magnets 70 in order to urge armature plate 18 in an axial direction away from friction plate 14 and pressure plate 16 and towards field shell 68 to release brake 66.
  • Magnets 70 may comprise neodymium iron boron (Nd-Fe-B) magnets or other known permanent magnets.
  • Magnets 70 may be disposed axially between walls 76, 82 of components 72, 74 of field shell 68 and may be secure therein using an adhesive. Magnets 70 may be equally circumferentially spaced from one another about the circumferential extent of brake 66.
  • brake 66 is a bi-stable brake in which supplying a short duration current to conductor 24 causes the brake 66 to move between an engaged and disengaged state and to remain in that state until current is supplied to conductor 24 again. If, for example, brake 66 is engaged with armature plate 18 engaging friction plate 14 under the force exerted by springs 20, current of a first polarity may be provided to conductor 24 to increase the force of the magnetic circuit comprising armature plate 18, field shell 68 and magnets 70 and cause armature plate 18 to move away from friction plate 14 towards field shell 68 and engage field shell 68 to release brake 66.
  • the current supply can be interrupted and armature plate 18 will remain engaged with field shell 68 under the force exerted by the magnetic circuit.
  • Current of an opposite polarity may then be provided to conductor 24 when it is desired to reapply brake 66.
  • the current weakens the magnetic attraction of the magnetic circuit and allows springs 20 to urge armature plate 18 away from field shell 68 towards friction plate 14 to engage brake 66.
  • one or more reed switches 26 are again provided to indicate an operating state of brake 66.
  • three reed switches 26 are provided and are equally circumferentially spaced about a circumference of brake 66.
  • Switches 26 extends across an air gap between members of the magnetic circuit.
  • switches 26 are disposed radially outwardly of components 72, 74 of field shell 68 and extends across the air gap between components 72, 74.
  • switches 26 detects flux leakage from the magnetic circuit comprising armature plate 18, field shell 68 and magnets 70.
  • switches 26 are again oriented such that a longitudinal axis 54 of each switch 26 extends in a direction other than parallel to axis 28 of brake 66.
  • the longitudinal axis 54 of switch 26 will also intersect a plane containing axis 28 (the plane lying perpendicular to the drawing) at an angle Q between zero and ninety degrees.
  • the preferred angle in a given application will depend on several factors including the size of brake 66, available mounting envelope for switch 26, anticipated vibration, the number of turns in a coil conductor 24 and current level, the operating environment for brake 66 (including nearby electromagnetic or magnetic devices and ferromagnetic structures) and the brake's magnetic iron circuit relative to electromagnet flux imbalance.
  • axis 54 also extends in a direction other than parallel to a direction of magnetic force at a point in the air gap where the magnetic force is greatest.
  • the magnetic force between components 72, 74 of field shell 68 will be greatest along the shortest path between components 72, 74 which is parallel to axis 28.
  • each switch 26 Orienting each switch 26 such that its longitudinal axis 54 is at an angle relative to the axis 28 again enables more robust and reliable switching.
  • the orientation again reduces the sensitivity of switch 26 such that switch 26 only closes when there is a relatively high level of flux leakage proximate the air gap between components 72, 74 of field shell 68.
  • switch 26 only closes when current is supplied to conductor 24, but armature plate 18 improperly fails to disengage from friction plate 14— resulting in a relatively high level of flux leakage across the relatively large air gap between components 72, 74. In this manner, switch 26 is able to indicate an improper operating condition of brake 66 while not generating false positives.
  • the orientation of switch 26 also allows unwanted and inherent residual magnetism to drain from switch 26 to field shell 68 and other ferromagnetic components of the brake 10 when current is not being supplied to conductor 24 thereby preventing the contacts of switch 26 from inadvertently sticking and remaining closed.
  • switch 26 accomplishes these results while allowing the switch 26 to be mounted close to the radially outer surface of field shell 68 and brake 66 in general thereby reducing the space required for switch 26 and the packaging of brake 66 while providing protection for switch 26.
  • a brake 10 or 66 in accordance with the present teachings is advantageous relative to conventional brakes because it provides an effective, low cost indication of the operation of the brake. As a result, a user of the brake and/or the system in which the brake is installed is capable of readily identifying a malfunction of the brake without a significant expenditure of time.

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

Abstract

L'invention concerne un frein (10) qui utilise un circuit magnétique ou électromagnétique pour libérer le frein et dans lequel un commutateur à lames (26) est utilisé pour indiquer une condition de fonctionnement du frein. Le commutateur à lames (26) est positionné dans un entrefer entre deux éléments (18, 22) du circuit magnétique ou électromagnétique. L'état du commutateur à lames change en réponse à une fuite de flux au niveau de l'entrefer et peut être utilisé pour surveiller d'éventuelles défaillances du fonctionnement du frein, comprenant une défaillance de fonctionnement en raison d'un manque de courant ou la défaillance du frein à se libérer en raison d'une obstruction.
PCT/US2019/012676 2018-01-11 2019-01-08 Frein doté d'un commutateur à lames pour indiquer une condition de fonctionnement du frein WO2019139893A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US15/868,440 2018-01-11
US15/868,440 US20180135713A1 (en) 2015-02-12 2018-01-11 Brake With a Reed Switch for Indicating an Operating Condition of the Brake

Publications (1)

Publication Number Publication Date
WO2019139893A1 true WO2019139893A1 (fr) 2019-07-18

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PCT/US2019/012676 WO2019139893A1 (fr) 2018-01-11 2019-01-08 Frein doté d'un commutateur à lames pour indiquer une condition de fonctionnement du frein

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Country Link
WO (1) WO2019139893A1 (fr)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006009876B3 (de) * 2006-03-03 2007-10-18 Kendrion Binder Magnete Gmbh Elektromagnetisch öffnende Federdruckbremse mit einer Lüfteinrichtung und einem Mikroschalter
WO2016130738A1 (fr) * 2015-02-12 2016-08-18 Warner Electric Technology Llc Frein avec un commutateur à lames pour indiquer une condition de fonctionnement du frein

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006009876B3 (de) * 2006-03-03 2007-10-18 Kendrion Binder Magnete Gmbh Elektromagnetisch öffnende Federdruckbremse mit einer Lüfteinrichtung und einem Mikroschalter
WO2016130738A1 (fr) * 2015-02-12 2016-08-18 Warner Electric Technology Llc Frein avec un commutateur à lames pour indiquer une condition de fonctionnement du frein

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