ELECTRIC ACTUATOR MODULE FOR SELECTABLE CLUTCH

Abstract

A clutch module which includes a first rotating member including at least one strut actuation module and a second engaged member including cam surfaces thereon for engagement by said strut actuation module. The strut actuation module includes a frame with a strut pivotally movable with respect to the frame. The strut includes an engagement end and a base end including a first side and a second side thereof. A pin or post portion extends from the frame and has an insulated bobbin with an energizable coil surrounding the bobbin. A U-shaped member including a pair of actuation legs is attached to the pin member and forms a magnetic gap between the base end of the strut and peripheral ends of the legs, such that when the coil is energized the peripheral ends of the legs are polarized in a first polarity and the frame and the strut are polarized with an opposite polarity thereby biasing the strut toward the peripheral ends and pivoting the actuation end into engagement with a cam surface of the engagement member.

Description

FIELD OF THE INVENTION

The present disclosure relates generally to an actuation member. More particularly, the present disclosure relates to a transmission for use in a drive train of a vehicle (such as an automobile truck, van, utility, industrial equipment, fleet, cargo or the like) including an actuation member for use in selectively a clutch in the transmission.

BACKGROUND OF THE INVENTION

A selectable one way clutch (OWC) to be used in automatic transmissions replaces the friction discs OWC actuated by oil pressure with a strut-based selectable OWC actuated by an electromagnetic module controlled by the transmission ECU. This reduces the drag losses associated with the friction disc clutch of prior designs when it is open and over-running continuously while the transmission is running and may also offer cost reductions associated with the removal of the components of the friction discs clutch (friction discs, pressure plates, end plate, piston and seals).

In one prior art embodiment of a clutch for a transmission, a coil is wound around a steel magnetic pole, which when electrically energized, acts to close the gap (such as an air gap) between the end poles (i.e., north and south) and the one-way clutch strut end. In this design, the pole ends are magnetized, which work to attract the end portion of the strut, which is not magnetized.

In the above concept, the clutch housing does not play any role in the magnetic circuit; it only controls the relative position of the coil and struts. When an electrical charge is applied, the mechanism pulls the strut from the open position and toward the closed position. The pole is magnetized and the strut is not magnetized so the housing is not part of the magnetic circuit or path.

While this arrangement is one method of actuating a strut, it requires single pole magnetic attraction which is not as robust or reliable of a lock up as might be desired depending on the application. Therefore, it is desirable in the art to provide a more robust actuation of a strut in a clutch.

SUMMARY OF THE INVENTION

In accordance with the present invention there is provided a clutch actuation module assembly. A clutch module which includes a first rotating member including at least one strut actuation module and a second engaged member including cam surfaces thereon for engagement by the strut actuation module is provided. The strut actuation module includes a frame with a strut pivotally movable with respect to the frame. The strut includes an engagement end and a base end including a first side and a second side thereof. A pin or post portion extends from the frame and has an insulated bobbin with an energizable coil surrounding the bobbin. A U-shaped member including a pair of actuation legs is attached to the pin member and forms a magnetic gap between the base end of the strut and peripheral ends of the legs, such that when the coil is energized the peripheral ends of the legs are polarized in a first polarity and the frame and the strut are polarized with an opposite polarity thereby biasing the strut toward the peripheral ends and pivoting the actuation end into engagement with a cam surface of the engagement member.

In alternate embodiments bi-directional strut arrangements are provided.

In accordance with the present invention there is provided an improved device and control strategy for an OWC clutch for use in a transmission in a vehicle wherein the housing of the clutch actuator is included as part of the magnetic circuit for actuating the mechanism to create a stronger magnetic actuator device and to provide greater accuracy and control while reducing the power consumption and other negative drawbacks of the known mechanisms and controls.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is an assembly view of the clutch showing a sectional view of a strut actuation module in accordance with the present invention;

FIG. 2 is a detailed sectional view of the actuation module of FIG. 1 of the present invention;

FIG. 3 is a sectional view of the actuation module of FIG. 2 taken along line 3-3 of FIG. 2;

FIG. 4 is a detailed sectional view of the actuation module of FIG. 2;

FIG. 5 is an assembly view of the clutch showing a spaced plurality of actuation modules in section in accordance with the present invention;

FIG. 6 is a detailed sectional view of an alternate embodiment of an actuation module showing a pair of actuated strut assemblies on a common frame;

FIG. 7 is a detailed sectional view of an alternate embodiment of an actuation module showing a pair of actuated strut assemblies on a common frame and demonstrating using a common coil to actuate the struts;

FIG. 8 is a sectional view of the actuation module of FIG. 7;

FIG. 9 is a detailed section view showing a pair of actuation modules operating in a bi-directional clutch;

FIG. 10 is an alternate embodiment of a bi-directional actuation module showing a pair of coils operating a pivotal strut;

FIG. 11 is a sectional view of the bi-directional actuation module of FIG. 10;

FIG. 12 is a sectional view of an alternate embodiment of a bi-directional module using a mechanical actuation;

FIG. 13 is a perspective view of the strut member of FIG. 12.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance with the present invention there is provided a clutch module generally shown at 10 for example for a transmission (not shown) which is controlled using an on-off relay to actuate a clutch mechanism.

Referring to the drawings, FIGS. 1-4, there are provided a clutch module 10 which includes a first rotating member 12 including at least one strut actuation module generally indicated as 14 and a second engaged member 16 including cam surfaces 17 thereon for engagement by said strut actuation module 14. The members 12 and 14 include engagement teeth or splines 12(a) and 14(a) respectively. The strut actuation module 14 includes a frame 18 with a strut 20 pivotally movable with respect to frame 18 about a pivot 22. The strut 20 includes an engagement end 26 and a base end 24 and including a first side 28 and a second side 30 thereof. A pin or post portion 32 extends from said frame 18 and has an insulated bobbin 34 with an energizable coil 36 surrounding the bobbin 34. A U-shaped member 37 is secured magnetically and mechanically to said post 32 by way of a screw or other fastener 39. The U-shaped member 37 includes a pair of actuation legs 38 and 40. A biasing spring 42 (such as the accordion spring shown) is provided in a bore 44 in the frame 18. At rest the biasing spring biases the strut 20 out of engagement with the cam surfaces 17 to provide a normally disengaged freewheeling condition. The peripheral ends 46 and 48 form a magnetic gap between said base end 24 of said strut 20 and peripheral ends 46 and 48 of said legs 38 and 40.

When the coil 36 is energized the peripheral ends 46 and 48 of said legs 38 and 40 are polarized in a first polarity and said frame 18 and said strut 20 are polarized with an opposite polarity thereby biasing said strut 20 toward said peripheral ends 46 and 48 and pivoting said engagement end 26 into engagement with a cam surface 17 of said engagement member 16.

Typically the actuation module is contained in a metallic housing. Thus in the present invention, the housing can be used as an integral component of a magnetic circuit for controlling the clutch. When the coil is powered, the housing is magnetized and will take a particular polarity (i.e., either north or south as may be desired) that is opposite from a polarity of the magnetic poles of an actuator, in this instance the U-shaped member 37 coupled to the clutch mechanism. Since the housing is in contact with struts, the struts will be magnetized with the same polarity as the housing. In this application, the attraction force between the strut ends and the magnetic poles of the U-shaped member 37 (i.e., across the air gap between them) is greatly increased as compared with the case where the struts carry a neutral charge from a magnetic perspective.

While the strut 20 is shown to be pivotal about a pin it is to be appreciated by those skilled in the art that the strut can be configured as being pivotable in a suitable housing in the member 12.

As can be seen in FIG. 6, all of the coils 36 and 36a (e.g., two in the embodiment shown) will work together to magnetize the housing, therefore increasing the magnetic field intensity and generating a greater magnetic force in the struts and attracting them toward the closed position from the open position.

Referring now to FIG. 7 there is provided an alternate embodiment of and actuation module 110. Strut actuation module 110 includes a pair of pivotal engagement struts 112 and 114 which pivot on pins 116 and 118 respectively, and are attached to frame 120. A U-shaped member 122 is provided which includes a front U-shaped member 124 and a rear U-shaped member 126 which are magnetically and electrically coupled to one another through connection leg 128. Front and Rear U-shaped members 124 and 126 include a pair of outer peripheral end portions 130 and 132 which engaged the struts 112 and 114 on the front and rear sides of the struts. A single central bobbin and coil 134 energizes the U-shaped members for providing the actuation of the multiple struts. It will be readily appreciated that while two struts are shown this invention could be configured to actuate more than just two struts if desired. As shown in FIG. 8 biasing springs are provided for biasing the struts 112 and 114 into a freewheeling position.

FIG. 9 shows the use of mirror image strut actuation modules 14 and 14′ of the type shown in FIGS. 1-4 and discussed above. Where the mirror image parts are labeled with prime numbers. The engaged member 16′ in this embodiment includes bi-directional cam members 17′. In operation, either actuation member or sets of members 14 or 14′ can be energized depending on the direction which is desired for engaging and rotating the engaged member 16′.

Referring now to FIGS. 10 and 11 there is show a second embodiment of a bi-directional arrangement 210. In this embodiment a symmetrical strut member 212 is pivotally attached by a pin 214 to a frame 216. A pair of U-shaped members 218 and 220 with separate coil and bobbin assemblies 222 and 224 are used to selectively actuate the strut from a first position for actuation engaging cams and rotating the member 226 in a first direction or the other coil is used for actuation and engaging cams for rotating the member in a second direction. Biasing springs 228 and 230 are provided for biasing the strut 212 to a free-wheeling position.

Referring now to FIGS. 12 and 13. There is provided an alternate embodiment of a two way clutch actuation module 310. In this embodiment a strut 311 is provided which is pivotal about pin 312 by way of an actuation arm 314 which is engaged by a corresponding orifice 316 in an actuation slider 318 with slides in a track 320 in frame 322. In this embodiment the slider may be powered by any number of mechanisms such as hydraulics, pneumatics, a solenoid, a servo, a ball screw arrangement, stepper motor, or the like for moving the sliding member back and forth in the track for actuation of the strut in an opposite direction.

In a further alternate embodiment a bi-directional actuation module may be provided by using a permanently magnetized symmetrical strut member with a U shaped member which has legs on either side of the pivot. In this embodiment frame includes a pin portion extending from the frame and having and insulated bobbin with an energizable coil surrounding the bobbin. The U-shaped member includes a pair of actuation legs attached to said pin member and extends between a first polarized end of said strut and a second peripheral end of said leg being adjacent to a second polarized end of said strut. In this embodiment when the coil is energized the peripheral ends of said legs are polarized for moving said strut to a first position and when energized in an opposite direction the legs are polarized for moving the strut in an opposite direction.

It is understood that the above description is intended to be illustrative and not restrictive. Many embodiments as well as many applications besides the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the invention should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. The omission in the following claims of any aspect of subject matter that is disclosed herein is not a disclaimer of such subject matter, nor should it be regarded that the inventors did not consider such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A clutch module comprising: A first rotating member including at least one strut actuation module;A second engaged member including cam surfaces thereon for engagement by said strut actuation module;said strut actuation module including a frame with a strut pivotally moveable with respect to said frame, said strut including an engagement end and a base end including a first side and a second side thereof, a pin/post portion extending from said frame and having and insulated bobbin with an energizable coil surrounding said bobbin, a U-shaped member including a pair of actuation legs attached to said pin member and forming a magnetic gap between said base end of said strut and peripheral ends of said legs, such that when said coil is energized the peripheral ends of said legs are polarized in a first polarity and said frame and said strut are polarized with an opposite polarity thereby biasing said strut toward said peripheral ends and pivoting said actuation end into engagement with a cam surface of said engagement member.

2. The clutch module of claim 1 further wherein the strut is pivotable around a pin secured to the frame.

3. The clutch module of claim 1 wherein the strut is pivotable in a pocket formed in the first driven member.

4. The clutch module of claim 1 further comprising a plurality of said actuation modules.

5. The clutch module of claim 4 wherein said plurality of actuation modules are positioned together on a single frame member for increasing the magnetic force.

6. The clutch module of claim 5 where a single coil is used to operate a plurality of struts.

7. The clutch module of claim 1 wherein a plurality of first cam surfaces are formed on said second engaged member for engagement of said engaged member in a first direction and a second plurality of cam surfaces are formed on said engaged member for engagement of said engaged member in a second direction and further comprising at least one actuation module for selectively engaging said first or second cam surfaces.

8. The clutch module of claim 7 wherein said strut of said actuation module is pivotal in a first direction for engaging said one of said first plurality of cam surfaces and pivotal in a second direction for engaging one of said second plurality of cam surfaces.

9. The clutch module of claim 7 wherein a first coil is used for pivoting said strut in a first direction and a second coil is used for pivoting said strut in a second direction.

10. A bi-directional clutch module comprising: A first rotating member including at least one strut actuation module;A second engaged member including a plurality of first cam surfaces formed on said second engaged member for engagement of said engaged member in a first direction and a second plurality of cam surfaces are formed on said engaged member for engagement of said engaged member in a second direction and when said at least one actuation module is configured for selectively engaging said first or second cam surfaces.said strut actuation module including frame with a strut pivotally moveable with respect to said frame, said strut of said actuation module is pivotal in a first direction for engaging said one of said first plurality of cam surfaces and pivotal in a second direction for engaging one of said second plurality of cam.

11. The bi-directional clutch module of claim 11 wherein said strut further comprises a control arm extending from a lower portion of said strut said frame including and actuation portion for engaging said control arm and pivoting said strut from a first position for engaging said engaged member for rotation in a first direction and a second position for freewheeling of the clutch and a third position for engaging said engaged member for rotation in a second direction.

12. The bidirectional clutch module of claim 12 wherein the actuation portion includes a slide situated in a track said slide having a central orifice for engaging said arm.

13. The bi-directional clutch module of claim 12 wherein said slide is actuated by hydraulics, pneumatics, a solenoid, a servo, a ball screw arrangement, stepper motor, or the like for moving the sliding member back and forth in the track for actuation said strut.

14. The bi-directional clutch module of claim 13 wherein said strut has a permanent magnetic characteristic and said frame includes a pin portion extending from said frame and having and insulated bobbin with an energizable coil surrounding said bobbin, a U-shaped member including a pair of actuation legs attached to said pin member and between said a first polarized end of said strut and a second peripheral end of said leg being adjacent to a second polarized end of said strut, such that when said coil is energized the peripheral ends of said legs are polarized for moving said strut to a first position and when energized in an opposite direction the legs are polarized for moving the strut in an opposite direction.