TECHNICAL FIELD

[0001] This invention relates to struts for coupling apparatus such as controllable or selectable one-way clutches (OWCs).

OVERVIEW

[0002] A typical one-way clutch (OWC) consists of an inner ring, an outer ring and a locking device between the two rings. The one-way clutch is designed to lock in one direction and to allow free rotation in the other direction. Two types of one-way clutches often used in vehicular, automatic transmissions include:

• Roller type which consists of spring loaded rollers between the inner and outer race of the one-way clutch. (Roller type is also used without springs on some applications); and

• Sprag type which consists of asymmetrically shaped wedges located between the inner and outer race of the one-way clutch.

[0003] The one-way clutches are typically used in the transmission to prevent an interruption of drive torque (i.e., power flow) during certain gear shifts and to allow engine braking during coasting.

[0004] Controllable or selectable one-way clutches (i.e. , OWCs) are a departure from traditional one-way clutch designs. Selectable OWCs add a second set of locking members in combination with a slide plate. The additional set of locking members plus the slide plate adds multiple functions to the OWC. Depending on the needs of the design, controllable OWCs are capable of producing a mechanical connection between rotating or stationary shafts in one or both directions. Also, depending on the design, OWCs are capable of overrunning in one or both directions. A controllable OWC contains an externally controlled selection or control mechanism. Movement of this selection mechanism can be between two or more positions which correspond to different operating modes.

[0005] U.S. Patent No. 5,927,455 discloses a bi-directional overrunning pawl-type clutch,

U.S. Patent No. 6,244,965 discloses a planar overrunning coupling, and U.S. Patent No. 6,290,044 discloses a selectable one-way clutch assembly for use in an automatic transmission.

[0006] U.S. Patent Nos. 7,258,214 and 7,344,010 disclose overrunning coupling assemblies, and U.S. Patent No. 7,484,605 discloses an overrunning radial coupling assembly or clutch.

[0007] A properly designed controllable OWC can have near-zero parasitic losses in the

"off state. It can also be activated by electro -mechanics and does not have either the complexity or parasitic losses of a hydraulic pump and valves.

[0008] Other related U.S. patent publications include: 201 1/0215575; 2011/0140451;

2011/0233026; 2011/0177900; 2010/0044141; 2010/0071497; 2010/01 19389; 2010/0252384; 2009/0133981 ; 2009/0127059; 2009/0084653; 2009/0194381 ; 2009/0142207; 2009/0255773; 2009/0098968; 2010/0230226; 2010/0200358; 2009/021 1863; 2009/0159391 ; 2009/0098970; 2008/0223681 ; 2008/01 10715; 2008/0169166; 2008/0169165; 2008/0185253; 2007/0278061; 2007/0056825; 2006/0138777; 2006/0185957; 2004/01 10594; and the following U.S. patents: 7,942,781; 7,806,795; 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, 193,038; 4,050,560; 4,340, 133; 5,597,057; 5,918,715; 5,638,929; 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; 5,924,510 and 5,918,715.

[0009] A linear motor is an electric motor that has had its stator and rotor "unrolled" so that instead of producing a torque (rotation) it produces a linear force along its length. The most common mode of operation is as a Lorentz-type actuator, in which the applied force is linearly proportional to the current and the magnetic field. U.S. published application 2003/0102196 discloses a bi-directional linear motor. [0010] Metal injection molding (MIM) is a metalworking process where finely -powdered metal is mixed with a measured amount of binder material to comprise a 'feedstock' capable of being handled by plastic processing equipment through a process known as injection mold forming. The molding process allows complex parts to be shaped in a single operation and in high volume. End products are commonly component items used in various industries and applications. The nature of MIM feedstock flow is defined by a physics called rheology. Current equipment capability requires processing to stay limited to products that can be molded using typical volumes of 100 grams or less per "shot" into the mold. Rheology does allow this "shot" to be distributed into multiple cavities, thus becoming cost-effective for small, intricate, high-volume products which would otherwise be quite expensive to produce by alternate or classic methods. The variety of metals capable of implementation within MIM feedstock are referred to as powder metallurgy, and these contain the same alloying constituents found in industry standards for common and exotic metal applications. Subsequent conditioning operations are performed on the molded shape, where the binder material is removed and the metal particles are coalesced into the desired state for the metal alloy.

[0011] A clevis fastener is a three piece fastener system consisting of a clevis, clevis pin, and tang. The clevis is a U-shaped piece that has holes at the end of the prongs to accept the clevis pin. The clevis pin is similar to a bolt, but is only partially threaded or unthreaded with a cross-hole for a cotter pin. The tang is the piece that fits between the clevis and is held in place by the clevis pin. The combination of a simple clevis fitted with a pin is commonly called a shackle, although a clevis and pin is only one of the many forms a shackle may take.

[0012] Clevises are used in a wide variety of fasteners used in the farming equipment, sailboat rigging, as well as the automotive, aircraft and construction industries. They are also widely used to attach control surfaces and other accessories to servos in model aircraft. As a part of a fastener, a clevis provides a method of allowing rotation in some axes while restricting rotation in others.

[0013] For purposes of this application, the term "coupling" should be interpreted to include clutches or brakes wherein one of the plates is drivably connected to a torque delivery element of a transmission and the other plate is drivably connected to another torque delivery element or is anchored and held stationary with respect to a transmission housing. The terms "coupling," "clutch" and "brake" may be used interchangeably.

SUMMARY OF EXAMPLE EMBODIMENTS

[0014] In one embodiment, a strut for a controllable one-way clutch is provided. The strut includes a member-engaging first end surface. The strut further includes a member-engaging second end surface diametrically opposite the first end surface. The strut still further includes a main body portion between the end surfaces. The strut further includes a projecting leg portion which extends from the main body portion to provide an attachment location for a free end of a rod which reciprocates.

[0015] The leg portion may have an aperture adapted to receive a pivot pin to allow rotational movement of the strut in response to reciprocating movement of the rod which is adapted to be coupled to the strut via the pivot pin.

[0016] The aperture may be an oblong aperture to receive the pivot pin to allow both rotational and translational movement of the strut in response to reciprocating movement of the rod.

[0017] The strut may further include a projecting second leg portion which extends from the main body portion to provide a second attachment location for the free end of the rod.

[0018] The second leg portion may have a second aperture adapted to receive the pivot pin to allow rotational movement of the strut in response to reciprocating movement of the rod which is adapted to be coupled to the strut via the pivot pin and wherein the strut is a clevis-shaped strut.

[0019] The second aperture may be an oblong aperture to allow both rotational and translational movement of the strut in response to reciprocating movement of the rod.

[0020] The strut may further include a pair of oppositely projecting ears which extend laterally from the main body portion proximate the first end surface.

[0021] The strut may be an injection molded strut.

[0022] The end surfaces may be canted. [0023] In another embodiment, an injection molded strut for a controllable one-way clutch is provided. The strut includes a member-engaging first end surface. The strut further includes a member-engaging second end surface diametrically opposite the first end surface. The strut still further includes a main body portion between the end surfaces. The main body portion includes a pair of spaced-apart side surfaces. The strut further includes a pair of spaced-apart leg portions. Each of the leg portions extends from the main body portion proximate one of the side surfaces to provide attachment locations for a free end of a rod which reciprocates.

[0024] Each of the leg portions may have an aperture adapted to receive a pivot pin to allow rotational movement of the strut in response to reciprocating movement of the rod which is adapted to be coupled to the strut via the pivot pin and wherein the strut is a clevis-shaped strut.

[0025] Each of the apertures may be an oblong aperture to receive the pivot pin to allow both rotational and translational movement of the strut in response to reciprocating movement of the rod.

[0026] The strut may further include a pair of oppositely projecting ears which extend laterally from the main body portion proximate the first end surface.

[0027] The strut may be a metal injection molded strut.

[0028] The end surfaces may be canted.

[0029] In another further embodiment, a clevis-shaped strut for a controllable one-way clutch is provided. The strut includes a member-engaging first end surface. The strut further includes a member-engaging second end surface diametrically opposite the first end surface. The strut still further includes a main body portion between the end surfaces. The main body portion includes a pair of spaced-apart side surfaces. The strut further includes a pair of spaced-apart, projecting leg portions, each of the leg portions extending from the main body portion proximate one of the side surfaces and having an aperture adapted to receive a pivot pin between the leg portions to allow rotational movement of the strut in response to reciprocating movement of a rod. A free end of the rod is adapted to be coupled to the strut via the pivot pin.

[0030] Each of the apertures may be an oblong aperture to receive the pivot pin to allow both rotational and translational movement of the strut in response to reciprocating movement of the rod. [0031] The strut may further include a pair of oppositely projecting ears which extend laterally from the main body portion proximate the first end surface.

[0032] The strut may be an injection molded strut such as a metal injection molded strut.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a perspective view, partially broken away and in cross-section, of an electromechanical assembly including a reciprocating rod and a first subassembly of a controllable coupling assembly wherein the reciprocating rod of the electromechanical assembly controls the operating mode of the coupling assembly;

[0034] Figure 2 is a different perspective view, partially broken away and in cross-section, of the assemblies of Figure 1 ;

[0035] Figure 3 is an enlarged front view, partially broken away and in cross-section, of the assemblies of Figures 1 and 2;

[0036] Figure 4 is an enlarged front view, partially broken away and in cross-section, of the assemblies of Figures 1 and 2 but showing a second reciprocating rod to control the operating mode of the coupling assembly;

[0037] Figure 5 is an exploded perspective view showing the first subassembly of the coupling assembly, first and second sets of rods of the electromechanical assembly and corresponding forward and reverse struts;

[0038] Figure 6 is an exploded perspective view showing a second subassembly of the coupling assembly, third and fourth sets of rods of a second electromechanical assembly and corresponding forward and reverse struts;

[0039] Figure 7 is a bottom perspective view of a clevis-shaped strut (either forward or reverse) and interconnected rod, partially broken away; and

[0040] Figure 8 is a top perspective view of the strut of Figure 7. DESCRIPTION OF EXAMPLE EMBODIMENTS

[0041] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0042] Referring now to Figures 1-4, there is illustrated an electromechanical assembly, generally indicated at 10, to control the operating mode of a coupling apparatus, generally indicated at 12, having drive and driven members 14 and 16, respectively, supported for rotation relative to one another about a common rotational axis 18. The drive member 14 may be a pocket plate and the driven member 16 may be a notch plate. The coupling apparatus or assembly 12 includes at least one (preferably two) forward strut 20 and at least one (preferably two) reverse strut 20 for selectively mechanically coupling the members 14 and 16 together and change the operating mode of the assembly 12. Preferably, the struts 20 are spaced at 90° intervals about the axis 18.

[0043] The assembly 10 includes a first subassembly 22 including a first stator 24 having at least one (preferably two) electromagnetically inductive first coil 26 to create a first magnetic flux when at least one first coil 26 is energized. The subassembly 22 may also include a second stator 28 having at least one (preferably two) electromagnetically inductive second coil 30 to create a second magnetic flux when the at least one second coil 30 is energized.

[0044] The assembly 10 also includes a second subassembly 32 adapted for coupling with one of the members 14 or 16 (preferably the member 14) of the coupling apparatus 12 to rotate therewith. The second subassembly 32 is supported for rotation relative to the first subassembly 22 by a bushing 33 about the rotational axis 18 when coupled to the coupling apparatus 12. The second subassembly 32 includes at least one (preferably two) bi-directionally movable first rod 34. Each first rod 34 has a free end 36 adapted for connection to a forward strut 20 of the coupling apparatus 12 for selective, small displacement forward strut movement. [0045] The second subassembly 32 also includes a first actuator 38 operatively connected to the at least one first rod 34 for selective bi-directional shifting movement along the rotational axis 18 between a first position of the first actuator 38 which corresponds to a first mode of the coupling apparatus 12 and a second position of the first actuator 38 which corresponds to a second mode of the coupling apparatus 12. When two first rods 34 are provided, the first rods are spaced 180° apart from one another. The first and second modes may be locked and unlocked (i.e. free wheeling) modes.

[0046] A first magnetic control force is applied to the first actuator 38 when the at least one first coil 26 is energized to cause the first actuator 38 to move between its first and second positions along the rotational axis 18.

[0047] The second subassembly 32 further includes at least one (preferably two) bi-directionally movable second rod 40. Each second rod 40 has a free end 42 adapted for connection to a reverse strut 20 of the coupling apparatus 12 for selective, small displacement reverse strut movement. The second subassembly 32 also includes a second actuator 44 operatively connected with the at least one second rod 40 for bi-directional shifting movement thereof along the rotational axis 18 between a first position of the second actuator 44 which corresponds to a third mode of the coupling apparatus 12 and a second position of the second actuator 44 which corresponds to a fourth mode of the coupling apparatus 12. When two second rods 40 are provided, the second rods are spaced 180° apart from each other but 90° apart from the first rods 34. The third and fourth modes may be locked and unlocked (i.e. free wheeling) modes.

[0048] A second control magnetic force is applied to the second actuator 44 when the at least one second coil 30 is energized to cause the second actuator 44 to move between its first and second positions along the rotational axis 18.

[0049] The second subassembly 32 includes a first pair of spaced biasing springs or members

46 and 48 for exerting corresponding biasing forces on the first actuator 38 in opposite directions along the rotational axis 18 when the first actuator 38 moves between its first and second positions along the rotational axis 18. Each face of each actuator 38 or 44 has clearance holes and spring pockets for the connecting rods 34 and 40, respectively, and their respective springs. When the actuators 38 and 44 move they push/pull their respective springs trapped between their faces and the ends of their corresponding rods 34 and 40.

[0050] The second subassembly 32 also includes a second pair of spaced biasing springs or members 50 and 52 for exerting corresponding biasing forces on the second actuator 44 in opposite directions along the rotational axis 18 when the second actuator 44 moves between its first and second positions along the rotational axis 18. Axial movement of the actuators 38 and 44 puts a biasing load onto the struts 20 via the springs 46, 48, 50 and 52 to either engage or disengage the struts 20. By reversing the current direction in the stators 24 and 28 their corresponding actuator 38 or 44 is moved back and forth from "off to "on."

[0051] The second subassembly 32 includes a hub 54 adapted for coupling with the one of the members 14 and 16 (preferably the member 14) of the coupling apparatus 12. The hub 54 is supported for rotation relative to the first subassembly 22 by the bushing 33 about the rotational axis 18. The hub 54 slidably supports the first and second actuators 38 and 44, respectively, during corresponding shifting movement along the rotational axis 18.

[0052] The second subassembly 32 includes a first pair of spaced stops 56 and 58 supported on the hub 54 to define the first and second positions of the first actuator 38. The second subassembly 32 also includes a second pair of spaced stops 60 and 62 supported on the hub 54 to define the first and second positions of the second actuator 44.

[0053] The second subassembly 32 also includes a set of spaced guide pins 64 sandwiched between inner surfaces 66 of the first and second actuators 38 and 44, respectively, and an outer surface 68 of the hub 54 and extending along the rotational axis 18. The inner surfaces 66 and the outer surface 68 have V-shaped grooves or notches formed therein to hold the guide pins 64. The actuators 38 and 44 slide on the guide pins 64 during shifting movement of the actuators 38 and 44 along the rotational axis 18. The guide pins 64 pilot the actuators 38 and 44 on the hub 54. The hub 54 also distributes oil to the guide pins 64.

[0054] Each of the stators 24 and 28 includes a ferromagnetic housing 70 having spaced apart fingers 72 and an electromagnetically inductive coil 26 or 30 housed between adjacent fingers 72. [0055] Each of the actuators 38 and 44 includes an annular inner part 74 and an annular outer part 76 connected thereto and having a magnetic annular ring 78 sandwiched between a pair of ferromagnetic backing rings 80. The magnetic control forces magnetically bias the fingers 72 and their corresponding backing rings 80 into alignment upon coil energization. These forces latch their respective actuator 38 or 40 in the "on" and "off positions. The rings 78 and 80 are acted upon by their respective stators 24 and 28 to move their respective actuators 38 and 40.

[0056] The second actuator 44 has at least one (preferably two) aperture 45 extending completely therethrough to allow each first rod 34 to move bi-directionally therethrough. A hollow cylindrical bushing 47 slidably supports each first rod 34 in the at least one aperture 45 during bi-directional shifting movement thereof.

[0057] Referring now to Figures 5 and 6, the coupling assembly or apparatus 12 comprises a controllable clutch assembly including first and second clutch subassemblies. The assembly 12 includes the drive or first clutch member 14, the driven or second clutch member 16 and a third or drive clutch member 82 all supported for rotation relative to one another about the common rotational axis 18. The first clutch member 14 has a coupling first face 84 oriented to face axially in a first direction along the rotational axis 18. The third clutch member 82 has a coupling third face 86 oriented to face axially in a second direction along the rotational axis 18. The second clutch member 16 has a coupling second face 88 opposed to the first face 84 and oriented to face axially in the second direction along the rotational axis 18. The second clutch member 16 also has a coupling fourth face 90 opposed to the third face 86 and oriented to face axially in the first direction along the rotational axis 18.

[0058] The first face 84 has a first set of pockets 92 spaced about the rotational axis 18.

Each pocket 92 of the first set has a strut 20 of a first set of struts 20 received thereby.

[0059] The second face 88 has a first set of locking formations 94 that are engaged by the struts 20 upon projecting outwardly from the first set of pockets 92 to prevent relative rotation of the first and second clutch members 14 and 16 with respect to each other in at least one direction about the axis 18. [0060] The third face 86 has a second set of pockets 96 spaced about the rotational axis 18.

Each pocket 96 of the second set has a strut 20 of a second set of struts 20 received thereby. Each strut 20 contained within the second set of pockets 96 is connected or coupled to its respective rod 97 of a second electromechanical assembly substantially identical in structure and operation to the first electromechanical assembly. Consequently, other than the rods 97, the second electromechanical assembly is neither shown nor described.

[0061] The fourth face 90 has a second set of locking formations 98 that are engaged by the second set of struts 20 upon projecting outwardly from the second set of pockets 96 to prevent relative rotation of the second and third clutch members 16 and 82 with respect to each other in at least one direction about the axis 18. The first and second clutch members 14 and 16, respectively, form the first clutch subassembly and the second and third clutch members 16 and 82, respectively, form the second clutch subassembly.

[0062] The first clutch member 14 has a first set of passages 100 spaced about the rotational axis 18 and in communication with their respective pockets 92 of the first set of pockets 92 to communicate an actuating force (preferably by the rods 34 and 40) to their respective strut 20 within its respective pocket 92 so that its respective strut 20 moves into contact with the first set of locking formations 94 to couple the first and second clutch members 14 and 16, respectively, for rotation with each other in at least one direction about the axis 18.

[0063] The third clutch member 82 has a second set of passages (now shown) spaced about the rotational axis 18 and in communication with their respective pockets 96 of the second set of pockets 96 to communicate an actuating force (preferably by the driven rods 97 as previously described) to their respective strut 20 within its respective pockets 96 so that its respective strut 20 moves into contact with the second set of locking formations 98 to couple the second and third clutch members 16 and 82, respectively, for rotation with each other in at least one direction about the axis 18.

[0064] Each strut 20 of the first and second sets of struts 20 has an end 106 that is pivotally movable outwardly of its respective pocket 92 or 96. [0065] The second clutch member 16 includes a housing 108 having an end wall 110 for housing the first and third clutch members 14 and 82, respectively.

[0066] Each of the subassemblies is independently controllable.

[0067] The first set of struts 20 includes at least one reverse strut 20 and at least one forward strut 20. A first element 1 12 is supported between the first and second clutch members 14 and 16, respectively. The first element 1 12 has at least one opening 114 extending completely therethrough to allow the forward and reverse struts 20 of the first set to extend therethrough and lock the first and second clutch members 14 and 16, respectively, together to prevent relative rotation between the first and second clutch members 14 and 16, respectively, in either direction about the axis 18.

[0068] The second set of struts 20 includes at least one reverse strut 20 and at least one forward strut 20. A second element 116 is supported between the second and third clutch members 16 and 82. The second element 116 has at least one opening 118 extending completely therethrough to allow the forward and reverse struts 20 of the second set to extend therethrough and lock the second and third clutch members 16 and 82, respectively, together to prevent relative rotation between the second and third clutch members 16 and 82, respectively, in either direction about the axis 18.

[0069] The first, second, third and fourth faces 84, 88, 86 and 90, respectively, are generally flat and face generally axially. The first, second, third and fourth faces 84, 88, 86 and 90, respectively, are generally annular and extend generally radially with respect to the rotational axis.

[0070] Referring now to Figures 7 and 8, there is illustrated one of the clevis-shaped struts

20 for the planar one-way clutch or apparatus 12. Each strut 20 comprises a member-engaging canted first end surface 120 and a member-engaging canted second end surface 122 diametrically opposite the first end surface 120. Each strut 20 also includes a main body portion 124 between the end surfaces 120 and 122. The main body portion includes a pair of spaced-apart side surfaces 126. Each strut 20 further includes a pair of spaced-apart, projecting leg portions 128. Each of the leg portions 128 extend from the main body portion 124 proximate one of the side surfaces 126. Each leg portion 128 has an aperture 130 adapted to receive a pivot pin 132 between the leg portions 128 to allow rotational movement of the strut 20 in responses to reciprocating movement of the rods 34, 40 or 97. A free end 134 of the rod 34, 40 or 97 is adapted to be coupled to the strut 20 via the pivot pin 132.

[0071] Each of the apertures 130 is preferably an oblong aperture 130 to receive the pivot pin

132 to allow both rotational and translational movement of the strut 20 in response to reciprocating movement of the rod 34, 40 or 97. Each strut 20 also includes a pair of oppositely projecting canted ears 136 which extend laterally from the main body portion 124 proximate the first end surface 120. Each strut 20 is preferably an injection molded strut such as a metal injection molded strut.

[0072] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.