Actuating assembly for an actuatable device in a motor vehicle drivetrain

An actuating assembly includes a body; a plunger axially movable with respect to the body; a linear actuator configured for being activated to axially move the plunger in a first direction into engagement with the body such that the plunger and body are rotationally fixed with respect to each other; a barrel movable with respect to the body for contacting the plunger and the body depending on an axial position of the plunger; and a spring for biasing the barrel toward the plunger. The barrel is configured such that the spring forces the barrel into circumferential engagement with the body in two different axial positions of the barrel with respect to the body when the linear actuator is inactive depending on a rotational orientation of the barrel.

The present disclosure relates generally to motor vehicle drivetrains and more specifically to actuating assemblies for actuatable devices in motor vehicle drivetrains.

BACKGROUND

Disconnect clutches and valves are actuatable devices used in automotive drivetrains that can be actuated by an actuating assembly.

SUMMARY OF THE INVENTION

An actuating assembly for an automotive drivetrain is provided. The actuating assembly includes a body; a plunger axially movable with respect to the body; a linear actuator configured for being activated to axially move the plunger in a first direction into engagement with the body such that the plunger and body are rotationally fixed with respect to each other; a barrel movable with respect to the body for contacting the plunger and the body depending on an axial position of the plunger; and a spring for biasing the barrel toward the plunger, the barrel being configured such that the spring forces the barrel into circumferential engagement with the body in two different axial positions of the barrel with respect to the body when the linear actuator is inactive depending on a rotational orientation of the barrel.

In some examples, the actuating assembly is configured such that, depending on the axial position of the plunger and a rotational orientation of the barrel, the spring forces the barrel into each of: a first orientation in which the barrel circumferentially engages the plunger; a second orientation in which a first surface of the barrel circumferentially engages the body and the barrel is in a first axial position of the two different axial positions; and a third orientation in which a second surface of the barrel circumferentially engages the body and the barrel is in a second axial position of the two different axial positions.

In some examples, the barrel is axially closer to the engagement surface of the plunger in the second orientation than in the third orientation.

In some examples, the barrel includes barrel ramps and the plunger includes plunger ramps, the barrel ramps axially contacting the plunger ramps in the first orientation.

In some examples, the body includes tabs having tab ramp surfaces, the tab ramp surfaces axially contacting the barrel ramps in the third orientation.

In some examples, the barrel includes barrel slots, the tabs being received in the barrel slots in the second orientation.

In some examples, the barrel slots are formed in some of the barrel ramps.

In some examples, the plunger includes plunger slots receiving the tabs to rotationally fix the plunger and the body with respect to each other.

In some examples, the linear actuator is configured for actuating the plunger solely in the first direction.

In some examples, the barrel is a different circumferential position with respect to the body in each of the two different axial positions.

In some examples, the two different axial positions are directly rotationally adjacent each other.

In some examples, the plunger includes a first plunger surface configured for circumferentially engaging a first body surface of the body to rotationally connect the plunger with the body.

In some examples, the first plunger surface is on at least one slot on of the plunger and the first body surface is on at least one tab of the body, the at least one tab of the body entering into the at least one slot of the plunger to rotationally connect the plunger with the body.

In some examples, the plunger includes a second plunger surface configured for circumferentially engaging a first barrel surface of the barrel when the solenoid is activated.

In some examples, the second plunger surface is on at least one stop edge of a plunger ramp of the plunger and the first barrel surface is on at least one stop edge of a barrel ramp of the barrel.

In some examples, the barrel includes a second barrel surface configured for circumferentially engaging a second body surface to rotationally connect the barrel with the body in a first of the two different axial positions of the barrel.

In some examples, the second barrel surface is on at least one slot of the barrel and the second body surface is on axial end of at least one tab of the body, the at least one tab of the body entering into the at least one slot of the barrel to rotationally connect the barrel with the body.

In some examples, the first barrel surface is configured for circumferentially engaging the first body surface to rotationally connect the barrel with the body in a second of the two different axial positions of the barrel.

A method of constructing an actuating assembly for an automotive drivetrain is also provided including rotationally fixing a plunger to a body such that the plunger is axially movable by a linear actuator with respect to the body in a first direction when the linear actuator is activated; resiliently preloading a barrel for axial movement with respect to the body and the plunger such that depending on an axial position of the plunger and a rotational orientation of the barrel, the barrel is forceable into each of: a first orientation in which the barrel circumferentially engages an engagement surface of the plunger; a second orientation in which a first surface of the barrel circumferentially engages the body and the barrel is in a first axial position; and a third orientation in which a second surface of the barrel circumferentially engages the body and the barrel is in a second axial position axially closer to the engagement surface of the plunger in the second orientation than in the third orientation.

DETAILED DESCRIPTION

The present disclosure provides a bi-stable actuating assembly that enables a single-acting linear actuator—i.e., one that actuates in only a single direction (push-only or pull-only)—to actuate a plunger into either of two stable positions, then hold the plunger in the respective stable position without the need for continued application of the linear actuator force. In an example where the actuator is an electrical solenoid, the plunger is held in respective stable position without the need for continued application of the electrical energization of the solenoid.

In general, in a solenoid-actuated device offering two different positions, one of those positions would require the solenoid to be continuously energized. If continuous energization in one position is not acceptable, then a bi-stable mechanism, de-energized in each of its two stable positions (after the initial, momentary energization required to move the device to that position), two solenoids can used in combination with mechanical detents in the mechanism.

This present disclosure enables a single, single-acting solenoid to switch a device between two stable positions, and then remain de-energized in either of those two positions.

FIGS.1and2illustrate different exploded views of an actuating assembly10for an actuatable device in an automotive drivetrain. The actuatable device can be a clutch or a hydraulic valve. Actuating assembly10can include a body12, a plunger14axially movable with respect to the body12, a linear actuator18configured for being activated to axially move the plunger14in a first direction into engagement with the body12and a barrel20movable with respect to the body12for contacting the plunger14. The linear actuator18, which is shown schematically, is configured for actuating the plunger14solely in the first direction. For example, linear actuator18can be a solenoid. Actuating assembly10can also include a spring22for biasing the barrel20toward the plunger14. The barrel20is configured such that the spring22forces the barrel20into circumferential engagement with the body12in two different axial positions of the barrel20with respect to the body12when the linear actuator18is inactive. As explained further below, the barrel20is in a different circumferential position with respect to the body12in each of the two different axial positions, and the two different axial positions are directly rotationally adjacent to each other.

The plunger14includes a first plunger surface14aconfigured for circumferentially engaging a first body surface12aof the body12to rotationally connect the plunger14with the body12. In the example shown inFIG.1, the first plunger surface14ais formed on circumferentially facing edges of at least one slot24on of the plunger14and the first body surface12ais formed on circumferentially facing edges of at least one tab26of the body12. The at least one tab26enters into the at least one slot24to rotationally connect the plunger14with the body12. More specifically,FIG.1shows that plunger14includes a plurality of circumferentially spaced apart slots24and body12includes a plurality of circumferentially spaced apart tabs26, with each of tabs26entering into one of slots24.

Plunger14also includes a second plunger surface14bconfigured for circumferentially engaging a first barrel surface20aof the barrel20when the linear actuator18is activated. The second plunger surface14bis on at least one stop edge of a plunger ramp28and the first barrel surface20ais on at least one axially extending stop edge of a barrel ramp30.

The barrel20also includes second barrel surfaces20b,20cconfigured for circumferentially engaging first body surface12aand a second body surface12bto rotationally connect the barrel20with the body12in a first axial position of the two different axial positions of the barrel20. The second barrel surfaces20b,20care on at least one slot32of the barrel and the second body surface12bon an axial end of at least one tab26. Surfaces20bare on circumferentially facing and axially extending portions of slots32and surfaces20care ramped surfaces extending between two surfaces20b. Surfaces20c,12bare ramp surfaces tapered such that surfaces20c,12bextend circumferentially to a greater extent than surfaces20c,12b, respectively, extend axially. The at least one tab26enters into the at least one slot32of the barrel20to rotationally connect the barrel20with the body12. The first barrel surface20ais also configured for circumferentially engaging the second body surface12bto rotationally connect the barrel20with the body12in a second axial position of the two different axial positions of the barrel20.

More specifically, barrel20includes a plurality of ramps30that are directly circumferentially adjacent to each other. Some of ramps30—every other ramp30in the example shown inFIG.1, are each intersected by one of slots32. Each ramp30has a shape that is complementary to each of ramps28of plunger14to allow for the engagement surface34of plunger14, which is formed by a plurality of axially and circumferentially extending ramp surfaces34a, to axially rest flush against plunger engaging surface36of barrel20, which is formed by a plurality of axially and circumferentially extending ramp surfaces36a.

Actuating assembly10can further include a retainer40for holding spring22axially in place, and an armature42formed as a single piece with plunger14, allowing the linear actuator18in the form of the solenoid to actuate plunger14in the first direction D1by pulling the plunger toward the linear actuator18.

Body12and the retainer40, which is in the form of a C-shaped retaining ring inFIGS.1and2, can both for example be rigidly mounted inside of a tubular rotor, and a shaft can run through the middle of actuating assembly10. A disconnect clutch, when actuated by actuating assembly10, can alternately couple and de-couple the tubular rotor to and from the shaft. A spring44, which is shown schematically, can urge the armature42gently toward body12, attempting to create space between a face of the disconnect clutch and the armature42.

Linear actuator18is located on the opposite end of body12from the armature42, and can forcefully pull the armature42and plunger14toward the body12when the coil of linear actuator18is electrically energized, in the same direction as the push of the spring44, which generates a weaker axial force than spring22.

Spring22, with one end anchored against the retainer40, presses against barrel20, which is axially slidable in the body12and is also free to rotate inside the body12unless barrel surfaces20aor20bare engaged with the tabs26. Depending upon the axial position of the plunger14and the angular orientation of the rotating barrel20, the force of the spring22pushes the rotating barrel20into the body12until the travel of barrel20is stopped by either the plunger14or the body12. The actuating assembly10is configured such that, depending on the axial position of the plunger14and a rotational orientation of the barrel20, the barrel20is resiliently preloaded for axial movement with respect to the body12and the plunger14such that depending on an axial position of the plunger14and a rotational orientation of the barrel20, the barrel20is forceable into each of:a first orientation in which the barrel20circumferentially engages the plunger14;a second orientation in which first barrel surface20acircumferentially engages the body12and the barrel20is in a first axial position; anda third orientation in which a second barrel surface20bcircumferentially engages the body12and the barrel20is in a second axial position different from the first axial position. The barrel20is axially closer to the engagement surface34of plunger14in the second orientation than in the third orientation.

In the first orientation, the force of the spring22pushes the rotating barrel20into the body12until the travel of barrel20is stopped by the ramp surfaces12bat the ends of the tabs26contacting the bottom ramp surfaces20cof slots32the rotating barrel20. In the second orientation, the force of the spring22pushes the rotating barrel20into the body12until the travel of barrel20is stopped by the ramp surfaces12bat the ends of the tabs26contacting the surfaces20aof ramps30of the rotating barrel20. In the third orientation, the force of the spring22pushes the rotating barrel20into the body12until the travel of barrel20is stopped by the surfaces14bon ramps28on the face of the plunger14contacting surfaces20aof ramps30of the rotating barrel20.

The function in actuating assembly10is initiated when linear actuator18is activated by the solenoid coil being energized, and the armature42is pulled toward the body12. The plunger14moves with the armature42, and maintains a constant angular orientation with respect to the body12due to the slots24of plunger14riding on the tabs26of body12.

If the linear actuating assembly10is inactive due to for example the solenoid coil not being energized, then the actuating assembly10is the first axial position—i.e., an extended stable position in which the clutch disengaged—and the ramp surfaces12bat the ends of the tabs26contact against the bottom ramp surfaces20cof slots32the rotating barrel20.

In this case, when the linear actuating assembly10is active due to for example the solenoid coil being energized, the force of the linear actuating assembly10overcomes the force of spring22and the ramps28on the face of the plunger14move into contact with surfaces20aof ramps30of the rotating barrel20.

Once plunger14, which is not free to rotate with respect to the body12, has pushed rotating barrel20far enough for the ends of the tabs26to be moved out of slots24, rotating barrel20is free to rotate, and will do so due to low-friction contact between barrel ramp surfaces36aand plunger ramp surfaces34a. This relative rotation will stop when rotating barrel20has rotated far enough for the stop surfaces20aat the ends of ramps30to contact stop surfaces14bat the ends of ramps28. This marks the point of maximum required axial travel, and the activation of linear actuator18, for example by the flow of electricity to the solenoid coil, can be cut off at this point.

After the linear actuator18has been deactivated, spring22pushes rotating barrel20away from the linear actuator18, moving armature42and plunger14along with barrel20, until ramps30come into contact with ramps28at the ends of the tabs26. When this contact initially occurs, the stop surfaces20aare about half of a ramp length away from the edges of tabs26, so the force of spring22pushes rotating barrel20down the contacting ramps28,30until the barrel20has rotated far enough for stop surfaces20ato contact the edges of tabs26. At this point, actuating assembly10is now locked into the second axial position—i.e., a retracted stable position in which the clutch engaged and the ramp surfaces12bat the ends of the tabs26contact against the surfaces20aof ramps30of the rotating barrel20.

When actuating assembly10is in this retracted stable position, and the linear actuator18is activated, the linear actuator18overcomes the force of spring22, but has to travel less of an axial distance than during the initial activation of the linear actuator18described in the preceding paragraphs. In particular, thr amount of axial travel required to free the rotating barrel20from the ends of tabs26is much less than in the initial activation of the linear actuator18, because in this arrangement, the ends of tabs26have been resting against ramps30, instead of against the bottoms of slots24. Further, at the end of this cycle (after the deactivation of the linear actuator18), the amount of axial travel required to seat the rotating barrel20into the extended stable position is much greater than in the initial activation of the linear actuator18. This is because tabs26move into slots24, and spring22then keeps pushing the rotating barrel20, along with armature42and plunger14, away from the linear actuator18until the ramp surfaces12bat the ends of tabs26have seated at the bottoms of slots24in the rotating barrel20.

Instead of using actuating assembly10with a clutch, actuating assembly10can also be used for control of 2-position hydraulic or pneumatic spool valves. The current state of the art is for these valves to utilize two electrical solenoids, one mounted at each end of the valve housing, each with its own set of wires. Each solenoid will push (or pull) the spool in one direction, opposite to that of the other solenoid.

This system could be replaced with a less expensive arrangement, in which only a spring (instead of a solenoid) is installed at one end of the housing, to push the spool toward a single solenoid mounted at the opposite end of the housing. To shift the spool in the valve, this solenoid, in combination with the present disclosure, would be momentarily energized, to overcome the preload force of the spring, pushing the spool slightly past its farthest stable position, and then be shut off. The spring force would then move the spool back toward the solenoid, and the device of the present disclosure would lock it into one of its two stable, pre-defined axial positions.

Actuating assembly10can also be used with a 2-position rotary valve, such as a ball or butterfly valve. The arrangement can be similar to the configuration described above for use with the spool valve. However, in this application, actuating assembly10can act upon a bellcrank attached to the valve's pivot rod, the solenoid would be mounted to some sort of bracket on the valve's housing, and a torsion spring could be used to bias the valve toward the solenoid's de-energized position.

Actuating assembly10can also be applied to mechanisms utilizing other types of solenoids (not just electrical). For example, vacuum solenoids, in either a push-type or pull-type configuration, of the type commonly used in automotive applications, can also be used in actuating assembly10.

In the preceding specification, the disclosure has been described with reference to specific exemplary embodiments and examples thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of disclosure as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative manner rather than a restrictive sense.

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