CLUTCH AND CONTROL UNIT WITH ONE ROUTE SENSOR

Abstract

Clutch and control unit (10) comprising: a controllable coupling unit with a first and a second coupling element (12, 12', 58) rotatably mounted relative to each other about an axis of rotation (36), wherein the first coupling element (12, 12', 58) has a first coupling planar surface (18, 18') with a locking element pocket (20) which receives a locking element (22), wherein the second coupling element (58) has a second coupling planar surface (66) with an arrangement of locking structures (66); a control element (26), which is rotatable about the axis of rotation (36), which is made of an electrically conductive material and is installed for controlled switching movement between the first and the second coupling surface (18, 18', 34) relative to the locking element (22) for controlling the position of the locking element (22), wherein the control element (26) enables the locking element (22) to engage in one of the locking structures (66) in a first position of the control element (26) and the control element (26) holds the locking element (22) in the locking element pocket (20) in a second position of the control element (26) and the control element (26) includes a sensor opening; and a rotary position sensor designed to generate a magnetic field to induce eddy currents in the electrically conductive material of the control element (26), and which is at least partially axially aligned with the sensor opening, during the switching movement of the control element (26) between the first and second positions, wherein a switching movement of the control element (26) changes a magnetic field caused by the eddy currents, the sensor (100) provides a feedback signal of the position to the control (112) of the vehicle transmission, wherein the signal is correlated with the position of the control element (26).

Description

TECHNICAL FIELD

[0001] The invention relates generally to clutch and control units, each of which includes a contactless, inductive position sensor, and more particularly to such units that utilize inductive position sensors to directly sense the position of a control element. OVERVIEW

[0002] A typical overrunning clutch (OWC) consists of an inner ring, an outer ring, and a locking device between the two rings. The overrunning clutch is designed to lock in one direction and allow free rotation in the other. Two types of overrunning clutches commonly used in automatic transmissions include: Roller type, which consists of spring-loaded rollers between the inner and outer pulleys of the overrunning clutch. (Roller type is also used without springs in some applications); and Freewheel type consisting of asymmetrically shaped wedges arranged between the inner and outer running plates of the freewheel clutch.

[0003] Overrunning clutches are typically used in the transmission to prevent interruption of drive torque (i.e., energy flow) during certain gears and to enable engine braking when coasting.

[0004] Controllable or switchable overrunning clutches (i.e., OWC) are a departure from conventional overrunning clutch designs. Switchable overrunning clutches incorporate a second set of locking elements in combination with a sliding plate. The additional set of locking elements plus the sliding plate adds multiple functions to the overrunning clutch. Depending on the design needs, controllable overrunning clutches are capable of establishing a mechanical connection between a rotating or stationary shaft in one or both directions. Also depending on the design, overrunning clutches are capable of traveling disengaged in one or both directions. A controllable overrunning clutch incorporates an externally controlled selection or control mechanism. Movement of this selection mechanism can be between two or more positions corresponding to different modes of operation.

[0005] US Patent No. 5,927,455 discloses a bidirectional pawl type one-way clutch, US Patent No. 6,244,965 discloses a planar type one-way clutch, and US Patent No. 6,290,044 discloses a switchable one-way clutch assembly for use in an automatic transmission.

[0006] U.S. Patent Nos. 7,258,214 and 7,344,010 disclose one-way clutch units, and U.S. Patent No. 7,484,605 ​​discloses a radial one-way clutch unit or shift clutch.

[0007] A properly designed, controllable overrunning clutch can exhibit virtually zero reactive losses when disengaged. It can also be activated electromechanically and has neither the complexity nor the reactive losses of a hydraulic pump and valves.

[0008] DE 10 2011 121 626 A1 describes a powertrain system for a vehicle comprising an engine, a transmission, and an electrically actuated one-way clutch. This clutch can freewheel in a "neutral mode" or block one direction in a "locked mode." Furthermore, the system features a hydraulically actuated dual clutch with a spring that pushes the clutch into an engaged position before the engine starts.

[0009] US 2018 0066 716 A1 discloses a controllable clutch unit with locking elements for forward and reverse movement and multiple clutch surfaces that enable relative rotational movements around a common axis. A mechanism prevents a "lock-lock" condition in which the clutch inadvertently locks in both directions.

[0010] US 2015 0204 390 A1 discloses an electronic vehicle transmission that operates in an environment hostile to electrical components. The transmission contains an electromechanical component activated by an excitation coil and includes a mechanical interlock. Special wiring resists heat and protects the insulation from brittleness.

[0011] US 2015 0211 587 A1 describes a magnetic control system for a one-way clutch. It includes a control mechanism with a translator structure that moves between two positions, assisted by magnetic targets. A stationary sensor detects the magnetic flux changes, which is used as a position signal.

[0012] US 2016 0131 205 A1 presents an electromechanical control system for a selectable clutch equipped with a bidirectional actuator and a failsafe function. This function moves the control component to a safety position in the event of system failures to prevent unwanted clutch engagement.

[0013] Other related US patent publications include: 2016 / 0377126, 2015 / 0014116, 2011 / 0140451, 2011 / 0215575, 2011 / 0233026, 2011 / 0177900, 2010 / 0044141, 2010 / 0071497, 2010 / 0119389, 2010 / 0252384, 2009 / 0133981, 2009 / 0127059, 2009 / 0084653, 2009 / 0194381, 2009 / 0142207, 2009 / 0255773, 2009 / 0098968, 2010 / 0230226, 2010 / 0200358, 2009 / 0211863, 2009 / 0159391, 2009 / 0098970, 2008 / 0223681, 2008 / 0110715, 2008 / 0169166, 2008 / 0169165, 2008 / 0185253, 2007 / 0278061, 2007 / 0056825, 2006 / 0252589, 2006 / 0278487, 2006 / 0138777, 2006 / 0185957, 2004 / 0110594, and the following US patents no.9 874 252, 9 732 809, 8 888 637, 7 942 781, 7 806 795, 7 695 387, 7 690 455, 7 491 151, 7 484 605, 7 464 801, 7 349 010, 7 275 628, 7 256 510, 7 223 198, 7 198 587, 7 093 512, 6 953 409, 6 846 257, 6 814 201, 6 503 167, 6 328 670, 6 692 405, 6 193 038, 4 050 560, 4 340 133, 5 597 057, 5 918 715, 5 638 929, 5 342 258, 5 362 293, 5 678 668, 5 070 978, 5 052 534, 5 387 854, 5 231 265, 5 394 321, 5 206 573, 5 453 598, 5 642 009, 6 075 302, 6 065 576, 6 982 502, 7 153 228, 5 846 257, 5 924 510 and 5 918 715.

[0014] A linear motor is an electric motor that rolls its stator and rotor against each other, so that instead of generating torque (rotation), it generates a linear force along its length. The most common operating mode is a Lorenz drive, in which the applied force is linearly proportional to the current and the magnetic field. Published US application 2003 / 0102196 discloses a bidirectional linear traction motor.

[0015] Linear stepper motors are used for positioning applications requiring rapid acceleration and high-speed motion with low mass loading. Additional features of linear stepper motor systems include mechanical simplicity and precise no-load operation.

[0016] A linear stepper motor operates according to the same electromagnetic principles as a rotary stepper motor. The stationary part, or base plate, is a passive steel bar with teeth that extends over the desired travel distance. Permanent magnets, electromagnets with teeth, and bearings are incorporated into the moving elements, or driver. The driver moves in two directions along the base plate, assuming individual positions in response to the current state in the field windings. Generally, the motor is a two-phase motor, but a larger number of phases can be used.

[0017] The linear stepper motor is well-known in the art and operates according to established principles of magnetic theory. The stator or support plate element of the linear stepper motor consists of an elongated, rectangular steel bar with a multitude of parallel teeth extending over the distance to be traveled and functioning like a rail for the so-called driver element of the motor.

[0018] The support plate is completely passive during motor operation, with all magnets and electromagnets embedded in the driver or rotor component. The driver moves in two directions along the support plate, assuming individual positions in response to the state of the electric current in the field windings.

[0019] US patents assigned to the same assignee as the following application and related to the present application include 8 813 929, 8 888 637, 9 109 636, 9 121454, 9 186 977, 9 303 699, 9 435 387, 2012 / 0149518, 2013 / 0256078, 2013 / 0277164, 2014 / 0100071, 2015 / 0014116, 9 255 614, 2015 / 0001023, 9 371 868, 2016 / 0369855, 2016 / 0131206, 2016 / 0377126, 2016 / 0131205, 2016 / 0047439, 2018 / 0328419, 2018 / 0010651, 2018 / 0038425, 2018 / 0106304, 2018 / 0156332, 2018 / 0231105, 2019 / 0170198, 9 482 294, 9 482 297, 9 541 141, 9 562 574, 9 638 266, 8 286 722, 8 720 659 and 9 188 170. The complete disclosures of all commonly assigned patents identified above are hereby incorporated by reference.

[0020] In some of the above related patents, which are assigned to the assignee by assignment of the present application, a linear, electrically controllable, two-position mechanical diode is disclosed. This device is a dynamic one-way clutch because both running plates (i.e., recessed and pocket plates) rotate. The linear motor or actuator moves, which in turn moves pistons connected to struts through a magnetic field generated by a stator. The actuator includes a ring of permanent magnets that latches the clutch into two states, ON and OFF. Current is consumed only when transitioning from one state to the other. Once in the desired state, the magnet latches, and the current is interrupted.

[0021] US Patent Documents 2015 / 0000442, 2016 / 0047439 and US Patent No. 9,441,708 disclose magnetically latching, controllable, 3-position, 2-way, linear motor mechanical diodes.

[0022] Mechanical forces resulting from local or remote magnetic sources, i.e., electric currents and / or permanent magnet (PM) materials, can be determined by examining the magnetic fields generated or "excited" by the magnetic sources. A magnetic field is a vector field that, at any point in space, indicates the magnitude and direction of the influencing power of the local or remote magnetic sources. The strength or magnitude of the magnetic field at a point in a region of interest depends on the strength, size, and relative position of the exciting magnetic sources and the magnetic characteristics of the various media between the positions of the exciting sources and the given region of interest.Magnetic properties refer to material properties that determine "how easy" it is to magnetize a unit volume of the material, or "how low" an excitation level is required to magnetize a unit volume of the material—that is, to establish a certain level of magnetic field strength. In general, areas containing ferrous material are much easier to magnetize than areas containing air or plastic.

[0023] Magnetic fields can be represented or described as three-dimensional lines of force, which are closed curves and traverse regions in space and within material structures. When magnetic "action" (generation of measurable levels of mechanical force) occurs within a magnetic structure, these lines of force are recognized as connecting or linking the magnetic sources within the structure. Magnetic lines of force are connected / linked to a current source when they surround all or part of the current path in the structure. Lines of force are connected / linked to a permanent magnet source when they traverse the permanent magnet material, generally in the direction or opposite to the direction of permanent magnetization.Individual lines of force, or field lines, that do not intersect exhibit tensile stress levels at every point along the line's length, very similar to the tensile force in a stretched rubber band that is stretched to form a closed curve of field lines. This is the primary method of force generation via air gaps in the design of a magnetic machine.

[0024] One can generally determine the direction of pure force generation in parts of a magnetic machine by examining graphic representations of magnetic field lines within the structure. The more field lines (the more stretched rubber bands) there are in each direction across an air gap separating machine elements, the more tensile force is present between machine elements in that given direction.

[0025] The term "sensor" is used herein to describe a circuit or assembly that includes a sensing element or other components. In particular, the term "magnetic field sensor" is used herein to describe a circuit or assembly that includes a magnetic field sensing element and electronics connected to the magnetic field sensing element.

[0026] The term "magnetic field sensor" used here is used to describe a variety of electronic elements that can sense a magnetic field. Magnetic field sensors can be, but are not limited to, Hall-effect elements, magnetic reluctance elements, or magnetotransistors. As is known, there are different types of Hall-effect elements, for example, a planar Hall element, a vertical Hall element, and a circular vertical Hall element (CVH). Furthermore, there are different types of magnetic reluctance elements, for example, a maximum magnetic reluctance element (GMR), an anisotropic magnetic reluctance element (TMR), an indium antimonide (InSb) sensor, and a magnetic tunneling junction (MTJ).

[0027] As is known, some of the magnetic-field sensing elements described above tend to have an axis of maximum sensitivity parallel to a substrate supporting the magnetic-field sensing element, and others of the magnetic-field sensing elements described above tend to have an axis of maximum sensitivity perpendicular to a substrate supporting the magnetic-field sensing element. In particular, planar Hall elements tend to have sensitivity axes perpendicular to a substrate, while magnetoresistive Hall elements and vertical Hall elements (including circular vertical Hall sensors, CVHs) tend to have sensitivity axes parallel to a substrate.

[0028] Magnetic field sensors are used in a variety of applications, including, but not limited to, an angle sensor that senses the direction angle of a magnetic field, a current sensor that senses a magnetic field generated by a current carried by a current-carrying conductor, a magnetic switch that senses the proximity of a ferromagnetic object, a rotation detector that senses passing ferromagnetic particles, for example, magnetic regions of a ring magnet, and a magnetic field sensor that senses the magnetic field density of a magnetic field.

[0029] Modern motor vehicles utilize an engine-transmission system with gears of varying sizes to transfer the power generated by the vehicle's engine to the vehicle's wheels, based on the speed at which the vehicle is traveling. The engine-transmission system typically includes a clutch mechanism that can engage and disengage these gears. The clutch mechanism can be operated manually by the vehicle driver or automatically by the vehicle itself, based on the speed at which the driver desires to operate the vehicle.

[0030] In vehicles with automatic transmissions, the vehicle needs to sense the position of the shift clutch for smooth, efficient shifting between gears in the transmission and for overall effective transmission control. Therefore, vehicles with automatic transmissions can use a shift clutch position sensor to sense the linear position of the shift clutch to facilitate gear shifting and transmission control.

[0031] Current clutch position sensors use magnetic sensors. One advantage of using magnetic sensors is that the sensor does not need to be in physical contact with the object being sensed, thus avoiding mechanical wear between the sensor and the object. However, the effective accuracy of a clutch length measurement can be compromised if the sensor is not in physical contact with the sensed object due to a necessary gap or tolerance between the sensor and the object. Furthermore, current sensing systems addressing this problem use magnetic coils and certain application-specific integrated circuits, which are relatively expensive.

[0032] US Patent No. 8,324,890 discloses a transmission clutch position sensor that includes two Hall sensors located at opposite ends of a power flux compressor outside the transmission housing to sense a magnetic field generated by a magnet attached to the clutch piston. To reduce sensitivity to magnet-to-magnet gap tolerances, a ratio of the voltage from one Hall sensor to the sum of the voltages from both Hall sensors is used to correlate the piston and thus the clutch position. The following US and foreign patent documents are related to the present invention: GB 253 319, DE 1020 16118266, FR 3 025 878, and US 10 247 578.

[0033] For the purposes of this application, the term "clutch" shall be interpreted to include clutches or brakes, wherein one of the discs is drivably connected to a torque output element of the transmission, and the other disc is drivably connected to another torque output element, or is anchored or fixedly secured relative to a transmission housing. The terms "clutch," "clutch," and "brake" may be used interchangeably.

[0034] Notwithstanding the above, there is still a need to directly sense the position of a control element or shift disc because the sensing occurring at the shift disc actuator has the potential to inaccurately report the state of the clutch in case of damage to the actuator. SUMMARY OF EXEMPLARY EMBODIMENTS

[0035] An object of at least one embodiment of the present invention is to provide a clutch and control unit with a contactless, inductive displacement sensor which directly senses the control element position, eliminating the need to indirectly infer a state of the assembly.

[0036] In carrying out the above-mentioned object and other objects of at least one embodiment of the present invention, a clutch and control unit with a contactless, inductive displacement sensor is provided. The unit comprises a controllable clutch unit with first and second clutch elements that are rotatably mounted relative to one another about a rotation axis. The first clutch element has a first clutch face with a locking element pocket that receives a locking element. The first clutch face also has a sensor pocket that receives the sensor. The second clutch element has a second clutch face with an arrangement of locking structures.A control element made of electrically conductive material is installed for controlled small-displacement switching movement between the first and second clutch face relative to the locking element and the sensor for controlling the position of the locking element. The control element allows the locking element to engage one of the locking structures in a first position of the control element, wherein the control element holds the locking element in the locking element pocket in a second position of the control element. The sensor is designed to generate a magnetic field for inducing eddy currents in the electrically conductive material of the control element, wherein switching movement of the control element changes a magnetic field caused by the eddy currents. The sensor provides a position feedback signal for controlling the vehicle transmission, the signal being correlated with the position of the control element.

[0037] The control element can be rotatable about the rotation axis, wherein the sensor is a rotational position sensor.

[0038] The control element can be an electrically conductive switching disc.

[0039] The control element may include an opening that is at least partially axially aligned with the sensor during the switching movement between the first and second positions to change the magnetic field caused by the eddy currents.

[0040] The sensor may include a circuit board, with the control element being mounted directly on the board.

[0041] The sensor may include a transmitting coil with a resonant frequency that changes as the control element moves.

[0042] The first and second coupling elements may be a pocket plate and a recess plate, respectively.

[0043] The locking element can be a strut.

[0044] The control element may be an apertured control element.

[0045] In still further implementing the above-mentioned object and other objects of at least one embodiment of the present invention, a clutch and control unit with a contactless, inductive displacement sensor is provided. The unit comprises a controllable clutch unit with first and second clutch elements that are rotatably mounted relative to one another about a rotation axis. The first clutch element has a first clutch face with a plurality of locking element pockets. Each of the pockets receives a locking element. The first clutch face also has a sensor pocket that receives the sensor. The second clutch element has a second clutch face with an arrangement of locking structures.A control element is made of an electrically conductive material and is installed for controlled switching movement with small adjustment between the first and second clutch face relative to the locking elements and the sensor for controlling the position of the locking elements. The control element allows the locking elements to engage the locking structures in a first position of the control element, wherein the control element maintains the locking elements in their locking element pockets in a second position of the control element. The sensor is designed to generate a varying magnetic field to induce eddy currents in the electrically conductive material of the control element, wherein the switching movement of the control element changes a magnetic field caused by the eddy currents. The sensor provides a position feedback signal for controlling the vehicle transmission, wherein the signal is correlated with the position of the control element.

[0046] The control element can be rotatable about the rotation axis, wherein the sensor is a rotational position sensor.

[0047] The control element can be an electrically conductive switching disc.

[0048] The control element may include an opening that is at least partially aligned with the sensor during a switching movement between the first and second positions to change the magnetic field generated by the eddy currents.

[0049] The sensor may include a circuit board, with the control element being mounted directly on the board.

[0050] The sensor may include a transmitting coil with a resonant frequency that changes as the control element moves.

[0051] The first and second clutch elements may be a pocket plate or a recess plate.

[0052] Each of the locking elements can be a strut.

[0053] The control element may be a control element provided with an opening. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exploded perspective view of a prior art one-way clutch and clutch assembly modified in accordance with at least one embodiment of the present invention; Fig. 2 is a top plan view, partially broken away, of a pocket plate modified in accordance with at least one embodiment of the present invention; Fig. 3 is a side view, partially broken away, of the modified pocket plate of Fig. 2; and Fig. 4 is a top plan view, partially broken away, of the modified pocket plate of Fig. 2 and Fig. 3, which now includes an open switching disc, a sensor and a vehicle control unit. DETAILED DESCRIPTION

[0054] With reference again to the drawing figures, Fig. 1 is an exploded perspective view of a one-way clutch or clutch assembly, indicated generally at 10, modified in accordance with at least one embodiment of the present invention. It should be understood, however, that the present invention may be utilized in a wide variety of precisely modified switchable clutches, such as switchable clutches having three or more operating modes or states. Indeed, the present invention may be utilized with controllable mechanical diodes (CMDs) having an unlimited number of operating modes or mechanical states.

[0055] As described in U.S. Patent No. 8,602,187 and published in U.S. Patent Application No. 2014 / 0190785, both of which are assigned to the assignee, the unit 10 includes an annular, inverted pocket plate or first outer clutch member, indicated generally at 12. An outer, axially extending surface 14 of the plate 12 has outer profiles 16 for coupling the plate 12 to the inner surface of a transmission housing (not shown). A radially extending inner surface or clutch face 18 of the plate 12 is formed with spaced-apart pockets 20 in which inverted struts 22 are pivotally biased outwardly by coil springs 23 disposed in the pockets 20 below their respective struts 22. Preferably, twelve inverted struts 22 are provided. However, it should be understood that a larger or smaller number of inverted struts 22 may be provided.

[0056] The assembly 10 also includes a control or selector slide plate member, generally indicated at 26, having a plurality of spaced-apart apertures 28 extending completely therethrough to allow the inverted struts 22 to rotate within their pockets 20 and project through the aperture 28 to engage spaced-apart locking structures or ramped inverted recesses (not shown) formed in a radially extending surface or clutch face of a front or inner pocket plate or clutch member, generally indicated at 34, when the plate 26 is accurately angularly positioned about a common central first rotational axis 36 by an output member in the form of an actuating pin or arm 38. The pin 38 is connected or fixed to the plate 26 for movement therewith.

[0057] The pin 38 may extend through a recess or elongated slot formed through a wall or wall portion of an outer circumferential end wall 42 of the plate 12, as shown in U.S. Patent No. 8,602,187. The wall may be a common wall separating and shared by the first coupling member 12 and a housing of the control system. The elongated slot may extend between and communicate with an inner surface 72 of the housing and an inner surface of the wall 42 of the first coupling member 12 or plate. The pin 38 may move within the slot between different deployment positions to cause the plate 26 to translate or toggle between its control positions to alternatively cover or uncover the struts 22 (i.e., to engage or disengage the reversed struts 22, respectively).

[0058] The plate 34 consists of a wedge ring with internal wedges formed on its axially extending inner surface. A radially extending surface, or clutch face spaced from the other clutch face (not shown) of the plate 34, has a plurality of spaced-apart pockets 52 formed therein for receiving a plurality of forward struts 54 rotatably biased by respective coil springs 55. Preferably, fourteen forward struts 54 are provided. However, it should be understood that a greater or lesser number of forward struts 54 may be provided.

[0059] The unit 10 may also include a second outer clutch member or recess plate, indicated generally at 58, having a plurality of locking structures, cams, or recesses (not shown) formed in a radially extending surface or clutch face (not shown) thereof, by which the forward struts 54 lock the forward plate 58 to the recess plate in one direction about the axis 36, but allow freewheeling in the opposite direction about the axis 36. The recess plate 58 includes external keys 64 formed on an axially outer surface 66 of the plate 58 and received and retained in axially extending recesses 68 formed in the axially extending inner surface 18 of the outer circumferential end wall of the plate 12.

[0060] The unit 10 may further include a snap ring, indicated generally at 72, having end portions 74 mounted in an annular recess 76 formed in the inner surface 18 of the end wall of the plate 12 to hold the plates 12, 26, 34 and 58 together and limit axial movement of the plates relative to one another.

[0061] The pin 38 has a control position for disengaging the reverse struts 22. In one embodiment, a pin 38 is rotated 7° in a forward freewheeling direction about the axis 36 to rotate the indexing disc 26 and, in turn, allow the reverse struts 22 to move from their disengaged position in their pockets 20 to their engaged position with the recesses (not shown) of the plate 34.

[0062] As described above, a typical switchable one-way clutch consists of a recessed plate, a pocket plate, a shift disc, struts, springs, and a snap ring. The recessed plate and pocket plate rotate relative to each other. The struts, when engaged, prevent rotation in one direction, although the shift disc can prevent the struts from engaging. The position of the shift disc is typically controlled by a hydraulically actuated mechanism called a control lever.

[0063] The current method for determining the position of the switching disc is by sensing the position of the control lever. If the control lever were removed from the switching disc, there would no longer be a way to determine the position of the switching disc. The valve position was previously measured using Hall cells, but the valve position was only measured based on a prototype.

[0064] The importance of knowing the position of the shift disc is that if the part were to lock under improper conditions, the vehicle would suddenly be pulled into first gear. A vehicle pulled into first gear on the road could damage the engine due to extreme engine speeds. Monitoring the position of the shift disc can help protect against the risk of unwanted changes in the clutch condition. The sensor could also detect if the shift lever is damaged and restrict transmission shifting.

[0065] Due to the scenarios given above, there is a need for a more direct way to find the position of the openings in the switching disc.

[0066] An object of at least one embodiment of the present invention is to locate the indexing disc directly using an eddy current or inductive position sensor. As disclosed below, the location or position of an indexing disc 26' can be equated to changes in the output of an eddy current or inductive displacement sensor 100.

[0067] With reference now to Fig. 2, Fig. 3 and Fig. 4 shows a pocket plate 12' and a switching disc 26', the two being taken from the unit 10 of Fig. 1 to enable a contactless, inductive displacement sensor, generally indicated at 100, to directly sense the movement of a control element or switching disc. The sensor 100 may include a coil circuit board 116 upon which one or more coils 110 are mounted, and an electronics circuit board 114 housing the active electronics (not shown) of the sensor 100.

[0068] In Fig. 2, Fig. 3 and Fig. 4 parts shown, which are the same as the parts of Fig. 1 such as the struts 22 have the same reference number. In Fig. 2, Fig. 3 and Fig.Parts shown in Figure 4 that are part of the modified unit have the same reference number as the corresponding part of unit 10, but with a single-dash marking (i.e., a surface 14', splines 16', a clutch face 18', pockets 20', a plate 26, and openings 28'). New features or parts are given a new reference number, such as the sensor 100, an opening 102 formed through a wall of the pocket plate 12, and a circular opening 104 formed in the indexing disc 26'. The opening 104 is a dedicated opening in the indexing disc 26' to predetermine the sensor 100. The sensor 100 is installed below the indexing disc 26' in a sensor pocket 19' formed in the pocket plate 12'.The opening 102 has a size and shape that allows the coil circuit board 116 of the sensor 100 to be inserted through a side wall of the pocket plate 12' and into the sensor pocket 19' formed in the coupling face 18' of the pocket plate 12'. The electronic circuit board 114 typically remains outside the pocket plate 12'. The two circuit boards 114 and 116 can be stacked vertically and horizontally offset from each other.

[0069] The eddy current sensor 100 operates by generating varying magnetic fields in one or more coils 110 of the sensor 100 to induce closed eddy current circuits in the electrically conductive material of the switching disc 26'. The resulting circulation of electric current in the conductive material creates an electromagnet that opposes the magnetic field of the coil 110. The sensor 100 can measure the change in the magnetic field caused by the eddy currents, which change correlates with how close the electrically conductive material of the switching disc 26' is to the sensor 100. There is a coupling between the magnetic field of the coil and the eddy currents, similar to the coupling between the windings of a transformer, which creates a mutual inductance. The coupling is distance-dependent and, when coupled, changes the inductance of the coil 100 and the coupling system.The change in inductance is measured from the change in the resonant frequency of coil 100. When the current reaches a steady-state amplitude, the inductance of the system can be calculated from the measured time constant and the known resistance of the sensor electronics. The sensor 100 can be modeled as a lossy inductor in parallel with a capacitor.

[0070] With known inductance, capacitance and resistance of the sensor 100, the resonance frequency can be calculated.

[0071] The eddy current or inductive position sensor 100 outputs a value to a vehicle controller 112 for use in controlling the vehicle transmission that is relatively high when the sensor 100 is located below the air gap or opening 104 and relatively low when the sensor is located below a non-opening portion of the shift disc 26'.

Claims

[1] Coupling and control unit (10) comprising: a controllable coupling unit with a first and a second coupling element (12, 12', 58) which are rotatably mounted relative to one another about a rotation axis (36), wherein the first coupling element (12, 12', 58) has a first coupling planar surface (18, 18') with a locking element pocket (20) which receives a locking element (22), wherein the second coupling element (58) has a second coupling planar surface (66) with an arrangement of locking structures (66); a control element (26), which is rotatable about the rotation axis (36), which consists of an electrically conductive material and is installed for controlled switching movement between the first and second coupling face (18, 18', 34) relative to the locking element (22) for controlling the position of the locking element (22), wherein the control element (26) enables the locking element (22) to engage one of the locking structures (66) in a first position of the control element (26) and the control element (26) holds the locking element (22) in the locking element pocket (20) in a second position of the control element (26), and the control element (26) comprises a sensor opening; and a rotational position sensor configured to generate a magnetic field to induce eddy currents in the electrically conductive material of the control element (26) and at least partially axially aligned with the sensor opening during the switching movement of the control element (26) between the first and second positions, wherein a switching movement of the control element (26) changes a magnetic field caused by the eddy currents, the sensor (100) provides a feedback signal of the position to the controller (112) of the vehicle transmission, the signal being correlated with the position of the control element (26). [2] Clutch and control unit according to claim 1, wherein the control element (26) is an electrically conductive switching disc. [3] Coupling and control unit according to claim 1, wherein the sensor opening of the control element (26) is wedge-shaped. [4] Coupling and control unit according to claim 1, wherein the sensor (100) contains a printed circuit board, and wherein the control element (26) is received directly on the printed circuit board. [5] The clutch and control unit of claim 1, wherein the sensor (100) includes a transmitting coil having a resonant frequency that changes as the control member (26) moves. [6] A clutch and control unit according to claim 1, wherein the first clutch element (12) is a pocket plate and the second clutch element (58) is a recess plate. [7] Coupling and control unit according to claim 1, wherein the locking element (22) is a strut. [8] Coupling and control unit according to claim 1, wherein the control element (26) is a control element (26) provided with an opening (102). [9] Clutch and control unit comprising: a controllable clutch unit having a first and a second clutch element which are mounted so as to be rotatable relative to one another about a rotation axis (36), wherein the first clutch element has a first clutch face (18, 18') with a plurality of locking element pockets (20), each of the pockets receiving a locking element (22), wherein the second clutch element has a second clutch face (18, 18', 34) with an arrangement of locking structures (66);a selector plate rotatable about the rotation axis (36) and made of electrically conductive material and installed for controlled switching movement between the first and second clutch face surfaces (18, 18', 34) relative to the locking elements (22) to control the position of the locking elements (22), the selector plate allowing the locking elements (22) to engage the locking structures (66) in a first position of the selector plate and the selector plate to retain the locking elements (22) in their locking element pockets (20) in a second position of the selector plate, the selector plate having a sensor opening; and; a rotational position sensor configured to generate a variable magnetic field to induce eddy currents in the electrically conductive material of the selector plate and at least partially axially aligned with the sensor opening during switching movement of the switch plate between the first and second positions, wherein the switching movement of the switch plate changes a magnetic field caused by the eddy currents, the sensor (100) provides a position feedback signal to the controller (112) of the vehicle transmission, the signal being correlated with the position of the switch plate. [10] A clutch and control unit according to claim 9, wherein the pocket plate has a side wall and a sensor opening through the side wall through which a portion of the sensor extends. [11] Clutch and control unit according to claim 9, wherein the sensor opening of the selection plate is wedge-shaped. [12] A clutch and control unit according to claim 9, wherein the sensor (100) includes a circuit board, and wherein the selection plate is received directly on the circuit board. [13] A clutch and control unit according to claim 9, wherein the sensor (100) includes a transmitting coil having a resonant frequency that changes as the switching plate moves. [14] A clutch and control unit according to claim 9, wherein the first clutch element (12) is a pocket plate and the second clutch element (58) is a recess plate. [15] Clutch and control unit according to claim 9, wherein the locking element (22) is a strut. [16] A clutch and control unit according to claim 9, wherein the selector plate is an apertured selector plate. [17] Clutch and control unit according to claim 9, wherein the first clutch surface also has a sensor pocket (19') which receives the sensor (100). [18] Clutch and control unit according to claim 9, wherein the position sensor is a non-contact, inductive displacement sensor. [19] Clutch and control unit according to claim 1, wherein the first clutch surface also has a sensor pocket (19') which receives the sensor (100). [20] The clutch and control unit of claim 1, wherein the pocket plate has a side wall and a sensor opening through the side wall. [21] Clutch and control unit according to claim 1, wherein the position sensor is a non-contact, inductive displacement sensor. [22] A one-way clutch assembly rotatable about a longitudinal axis, comprising: a pocket plate comprising a pocket plate coupling surface extending radially with respect to the longitudinal axis, having the locking element pockets (20); a notch plate having a notch plate coupling surface extending radially with respect to the longitudinal axis, opposite the pocket plate coupling surface of the pocket plate and having an array of locking structures (66); Locking elements (22) in the locking element pockets (20) of the pocket plate coupling surface of the pocket plate, which can be selectively engaged with the locking structures (66) of the notch plate coupling surface of the notch plate; a rotatable selection plate rotatable about the longitudinal axis and mounted between the pocket plate and the notch plate for selectively controlling the movement of the locking elements (22) into and out of engagement with the locking structures (66) of the notch plate coupling surface of the notch plate, comprising a sensor opening; and a rotational position sensor at least partially aligned with the sensor opening of the selection plate to directly detect the rotational position of the selection plate. [23] One-way clutch assembly according to claim 22, wherein the rotational position sensor is received in a sensor pocket (19') of the pocket plate coupling surface of the pocket plate. [24] The one-way clutch assembly of claim 22, wherein the rotational position sensor extends through an opening in an outer circumferentially extending side wall of the pocket plate. [25] One-way clutch assembly according to claim 22, wherein the sensor opening is wedge-shaped.

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