Electromagnetic system for controlling the operating mode of a non friction coupling assembly and coupling and magnetic control assembly having same

Abstract

An electromagnetic system for controlling the operating mode of a non-friction coupling assembly and a coupling and magnetic control assembly are provided. Magnetic circuit components include a ferromagnetic or magnetic element received within a pocket of a coupling member. The element controls the operating mode of the coupling assembly. A stationary electromagnetic source includes at least one excitation coil which generates a magnetic field between poles of the source when the at least one coil is supplied with current. Ferromagnetic or magnetic first and second inserts are received and retained within first and second spaced passages, respectively, of the coupling member. The electromagnetic source, the element, the inserts and air gaps between the various magnetic circuit components make up a closed loop path containing magnetic flux so that the element moves between first and second positions of the element when the at least one coil is supplied with current.

Claims

1. An electromagnetic system for controlling the operating mode of a non-friction coupling assembly including first and second coupling members supported for a rotation relative to one another about a common axis, the first and second coupling members including coupling first and second faces, respectively, in close-spaced opposition with one another, the second coupling member having a third face spaced from the second face, the second face having a pocket, the first face having a set of locking formations, and the third face having first and second spaced passages in communication with the pocket, the system comprising: magnetic circuit components including: a ferromagnetic or magnetic element received within the pocket in a first position and projecting outwardly from the pocket in a second position, the element controlling the operating mode of the coupling assembly; a stationary electromagnetic source including at least one excitation coil which generates a magnetic field between first and second poles of the electromagnetic source when the at least one coil is supplied with current; and ferromagnetic or magnetic first and second inserts received and retained within the first and second spaced passages, respectively, of the second coupling member, the first and second inserts being in close-spaced opposition across first and second air gaps respectively, with the first and second poles, respectively, of the electromagnetic source, the first and second inserts being in close-spaced opposition across third and fourth air gaps, respectively, with first and second spaced portions, respectively, of the element, wherein the electromagnetic source, the inserts, the air gaps, and the element make up a closed loop path containing magnetic flux so that the element moves between the first and second positions when the at least one coil is supplied with current.

2. The system as claimed in claim 1, wherein the first and third faces are oriented to face axially in a first direction along the rotational axis and the second face is oriented to face axially in a second direction opposite the first direction along the rotational axis.

3. The system as claimed in claim 1, wherein the electromagnetic source further includes an annular ring housing having an annular recess in which the at least one coil is located, the housing being axially symmetric about the rotational axis and wherein the magnetic field is a generally circular magnetic field.

4. The system as claimed in claim 3, wherein the housing has a generally C-shaped cross-section.

5. The system as claimed in claim 1, wherein the element is a locking element which prevents relative rotation of the first and second coupling members with respect to each other in at least one direction about the axis.

6. The system as claimed in claim 5, wherein the locking element is an injection molded strut.

7. The system as claimed in claim 1, further comprising a return biasing member to urge the element to a return position which corresponds to either the first position or the second position of the element.

8. The system as claimed in claim 1, wherein the first, second and third faces are generally annular and extend generally radially with respect to the axis.

9. The system as claimed in claim 1, wherein the coupling assembly is a clutch assembly and the first and second faces are clutch faces.

10. The system as claimed in claim 1, wherein the at least one coil has a circumference and wherein the inserts comprise magnetic pole pieces which cover substantially the entire circumference of the at least one coil.

11. The system as claimed in claim 1, wherein the second coupling member is made of non-ferrous/non-magnetic material.

12. The system as claimed in claim 1, wherein a plurality of coils generate the magnetic field.

13. A coupling and magnetic control assembly comprising: first and second coupling members supported for a rotation relative to one another about a common axis, the first and second coupling members including coupling first and second faces, respectively, in close-spaced opposition with one another, the second coupling member having a third face spaced from the second face, the second face having a pocket, the first face having a set of locking formations, and the third face having first and second spaced passages in communication with the pocket; and magnetic circuit components including: a ferromagnetic or magnetic element received within the pocket in a first position and projecting outwardly from the pocket in a second position, the element controlling the operating mode of the coupling assembly; a stationary electromagnetic source including at least one excitation coil which generates a magnetic field between first and second poles of the electromagnetic source when the at least one coil is supplied with current; and ferromagnetic or magnetic first and second inserts received and retained within the first and second spaced passages, respectively, of the second coupling member, the first and second inserts being in close-spaced opposition across first and second air gaps, respectively, with the first and second poles, respectively, of the electromagnetic source, the first and second inserts being in close-spaced opposition across third and fourth air gaps, respectively, with first and second spaced portions, respectively, of the element, wherein the electromagnetic source, the inserts, the air gaps, and the element make up a closed loop path containing magnetic flux so that the element moves between the first and second positions when the at least one coil is supplied with current.

14. The assembly as claimed in claim 13, wherein the first and third faces are oriented to face axially in a first direction along the rotational axis and the second face is oriented to face axially in a second direction opposite the first direction along the rotational axis.

15. The assembly as claimed in claim 13, wherein the electromagnetic source further includes an annular ring housing having an annular recess in which the coil is located, the housing being axially symmetric about the rotational axis and wherein the magnetic field is a generally circular magnetic field.

16. The assembly as claimed in claim 15, wherein the housing has a generally C-shaped cross-section.

17. The assembly as claimed in claim 13, wherein the element is a locking element which prevents relative rotation of the first and second coupling members with respect to each other in at least one direction about the axis.

18. The assembly as claimed in claim 17, wherein the locking element is an injection molded strut.

19. The assembly as claimed in claim 17, further comprising a return biasing member to urge the element to a return position which corresponds to either the first position or the second position of the element.

20. The assembly as claimed in claim 13, wherein the first, second and third faces are generally annular and extend generally radially with respect to the rotational axis.

21. The assembly as claimed in claim 13, wherein the coupling assembly is a clutch assembly and the first and second faces are clutch faces.

22. The assembly as claimed in claim 13, wherein the at least one coil has a circumference and wherein the inserts comprise magnetic pole pieces which cover substantially the entire circumference of the at least one coil.

23. The assembly as claimed claim 13, wherein the second coupling member is made of non-ferrous/non-magnetic material.

24. The assembly as claimed in claim 13, wherein a plurality of coils generate the magnetic field.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side sectional schematic view of a coupling and magnetic control assembly constructed in accordance with at least one embodiment of the present invention and showing magnetic flux lines when a coil of a stationary electromagnetic source is supplied with current;

(2) FIG. 2 is a perspective, schematic view of a portion of the assembly of FIG. 1 and particularly showing various air gaps between various magnetic circuit components;

(3) FIG. 3 is a top plan view, partially broken away, of the second coupling member or pocket plate to show where the magnetic pole pieces are to be fit or inserted within the plate;

(4) FIG. 4 is a bottom view, partially broken away, of the pocket plate and further illustrating where the circular magnetic field generated by the electromagnetic source points up and down with respect to the pole pieces;

(5) FIG. 5 is a side perspective schematic view of the electromagnetic source which is capable of generating the circular magnetic fields of FIG. 4 when a coil contained in an annular recess of the annular housing of the source is energized by current;

(6) FIG. 6 is a view, partially broken away and in cross section, of the coupling and magnetic control assembly constructed in accordance with a second embodiment of the present invention;

(7) FIG. 7 is an enlarged view of a portion of the assembly of FIG. 6 showing a scale and magnetic field lines due to coil currents in an electromagnetic source of the assembly;

(8) FIG. 8 is a schematic view, partially broken away, of the pocket plate and locking member of FIG. 6 with a biasing spring and pole pieces shown by phantom lines;

(9) FIG. 9 is a view, similar to the view of FIG. 8, but without the magnetic circuit components or the spring of FIG. 8;

(10) FIG. 10 is a perspective schematic view of the notch plate of FIG. 6;

(11) FIG. 11 is perspective schematic view of the assembly of FIG. 6 but without an electromagnetic source;

(12) FIG. 12 is a perspective schematic view of the electromagnetic source of FIG. 6;

(13) and

(14) FIG. 13 is a perspective, schematic view of the assembly of FIG. 6 without the notch plate of FIG. 10 and without the pocket plate and return spring.

DETAILED DESCRIPTION

(15) 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.

(16) Referring now to FIGS. 1-5, there is illustrated a planar, coupling and magnetic control assembly, generally indicated at 11. The assembly 11 includes a first coupling member, generally indicated at 10, which may comprise a notch plate or member having a first coupling face 12.

(17) The assembly 11 may include a non-ferrous, non-magnetic pocket plate or second member, generally indicated at 14, which includes a second coupling face 16 in close-spaced opposition with the first coupling face 12, when the members 10 and 14 are assembled and held together by a locking or snap ring 18. At least one of the members 10 and 14 is mounted for rotation about a common axis 20 (FIG. 5).

(18) The second coupling member 14 also includes third face 22 spaced from the second face 16. The third face 22 has first and second spaced passages 25 and 23 which extend through the second coupling member 14 in communication with a pocket 24 formed in the second face 16.

(19) The pocket 24 preferably is a T-shaped recess or pocket 24 as best shown in FIG. 3. The recess 24 defines a load bearing first shoulder. The first coupling face 12 of the notch plate 10 has a plurality of recesses or notches (not shown in the first embodiment, but shown in the second embodiment of the notch plate 110 in FIG. 10). Each notch of the notches defines a load-bearing second shoulder. While only a single pocket 24 is shown, it is to be understood that a plurality of pockets 24 (and struts 26) are preferred.

(20) An electromagnetic system for controlling the operating mode of the coupling assembly includes a plurality of magnetic circuit components including a ferro-magnetic element or a locking strut, generally included at 26, extendable between the coupling faces 12 and 16 of the member 10 and the member 14, respectively, when the members 10 and 14 are assembled and held together.

(21) The element 26 may comprise a ferromagnetic locking element or strut movable between first and second positions. The first position (not shown) is characterized by abutting engagement of the locking element 26 with a load-bearing shoulder (not shown) of the member 10 and the shoulder of the pocket 24 formed in an end wall of the second member 14. The second position (solid lines in FIGS. 1 and 2) is characterized by non-abutting engagement of the locking element 26 with a load-bearing shoulder of at least one of the members 10 and 14. A return biasing member or spring (not shown in the first embodiment, but shown in the second embodiment at 129) may be positioned under each of the struts 26 to urge its strut 26 to a return position which corresponds to the uncoupling position of the strut 26.

(22) The electromagnetic system also includes a stationary electromagnetic source, generally indicated at 31, including at least one excitation coil 33 which is at least partially surrounded by a generally C-shaped (in cross-section) annular ring housing part 35. Instead of a single coil a plurality of similar coils could be provided to feed MMF into the core plates. In this embodiment, the coils would each wrap around a section of the core with the axes of the coils pointing in the direction of the field through the core. When the at least one coil 33 is energized (supplied with current), an axial symmetric, generally circular magnetic field (indicated by phantom lines in FIG. 1) loops out of the housing part 35 at a north pole of the housing part 35, through a magnetic insert or pole piece 37, into a first portion of the strut 26, out a second portion of the strut, through another insert or pole piece 39 and back into the housing part 35 at a south pole of the housing part 35.

(23) The pole pieces 37 and 39 are inserted into the bottom of the pocket 24 through the third face 22 and are received and retained within the first and second passages 25 and 23, respectively, and are in close-spaced opposition with the north and south poles, respectively, of the housing part 35.

(24) The electromagnetic source 31, the element 26, the inserts 37 and 39, the air gaps between the inserts 37 and 39 and the element 26 and the air gaps between the source 31 and the inserts 37 and 39 make up a closed loop path containing magnetic flux so that the element 26 moves between its coupling and uncoupling positions when the coil 33 is supplied with current. The pole pieces 37 and 39 direct the magnetic field into the strut 26 to attract (or repel) the strut 26 and move the strut 26 into an engaged (or disengaged) position.

(25) Referring now to FIG. 4, there is illustrated by phantom lines 41 an outwardly pointing (out of the page), circular magnetic field at the third face 22 in which the insert 39 is located. Phantom lines 43 illustrate an inwardly pointing (into the page), circular magnetic field in which insert 37 is located at the third face 22 of the second coupling member 14. The source 31 of FIG. 5 directs a magnetic field at the back of the pocket plate 14 when the coil 33 is energized. The resulting magnetic field permeates into the pole pieces 37 and 39 and the strut 26.

(26) The number of Amp-turns required to generate a mechanical force to move the strut 26 between coupling and uncoupling positions is a function of the size of the “Air Gaps” of FIG. 2. Consequently, the air gaps should be made as small as possible to avoid leakage of magnetic flux in order to minimize the number of Amp-turns required to generate the force necessary to move the strut 26 especially at high clutch member RPM (greater than 5 k RPM).

(27) Referring now to FIGS. 6-13, there is illustrated a second embodiment of a planar, coupling and magnetic control assembly, generally indicated at 111. The assembly 111 includes a first coupling member, generally indicated at 110, which may comprise a notch plate or member having a first coupling face 112. The parts or components of the second embodiment which are the same or similar to the parts or components of the first embodiment in either structure or function have the same reference number but one preceded by the number “1”.

(28) The assembly 111 may include a non-ferrous, non-magnetic pocket plate or second member, generally indicated at 114, which includes a second coupling face 116 in close-spaced opposition with the first coupling face 112, when the members 110 and 114 are assembled and held together by a locking or snap ring 118. At least one of the members 110 and 114 is mounted for rotation about a common axis 120 (FIGS. 10 and 12).

(29) The second coupling member 114 also includes third face 122 spaced from the second face 116. The third face 122 has first and second spaced passages 125 and 123 which extend through the second coupling member 114 in communication with a pocket 124 formed in the second face 116.

(30) The pocket 124 preferably is a T-shaped recess or pocket 124 as best shown in FIGS. 8 and 9. The recess 124 defines a load bearing first shoulder. The first coupling face 112 of the notch plate 110 has a plurality of recesses or notches 113. Each notch 113 of the notches defines a load-bearing second shoulder. While only a single pocket 124 is shown in FIGS. 6-9, it is to be understood that a plurality of pockets 124 (and struts 126) are preferred as shown in FIG. 13.

(31) An electromagnetic system for controlling the operating mode of the coupling assembly 111 includes a plurality of magnetic circuit components including a ferro-magnetic element or a locking strut, generally included at 126, extendable between the coupling faces 112 and 116 of the member 110 and the member 112, respectively, when the members 110 and 114 are assembled and held together. Each of the struts 126 may include a pivot pin 127 about which the strut 126 pivots and a bearing 128 to rotatably support the pin 127.

(32) The element 126 may comprise a ferromagnetic locking element or strut movable between first and second positions. The first position (shown in FIGS. 8 and 13) is characterized by abutting engagement of the locking element 126 with a load-bearing shoulder of a notch 113 of the member 110 and the shoulder of the pocket 124 formed in an end wall of the second member 114. The second position (solid lines in FIGS. 6 and 7) is characterized by non-abutting engagement of the locking element 126 with a load-bearing shoulder of at least one of the members 110 and 114. A biasing member or spring 129 (FIG. 8) may be positioned under each of the struts 126 to urge its strut 126 to a return position which corresponds to the uncoupling position of the strut 126.

(33) The electromagnetic system also includes a stationary electromagnetic source, generally indicated at 131, including at least one excitation coil 133 which is at least partially surrounded by an annular ring housing part 135. The housing part 135 includes first and second pieces 136 and 138 which are secured together. The coil 133 is held within a bobbin 134. When the coil 133 is energized (supplied with current), an axial symmetric, generally circular magnetic field 201 loops out of the housing part 135 at a north pole of the housing part 135, through a magnetic insert or pole piece 137, into a first portion of the strut 126, out a second portion of the strut 126, through another insert or pole piece 139 and back into the housing part 135 at a south pole of the housing part 135.

(34) As shown in FIGS. 11 and 13, the pole pieces 137 and 139 may be segmented and secured to the third face 122 of the pocket plate 114 by screws 142. The pole pieces 137 and 139 are received and retained within the first and second passages 125 and 123, respectively, and are in close-spaced opposition with the north and south poles, respectively, of the housing part 135.

(35) The electromagnetic source 131, the element 126, the inserts 137 and 139, the air gaps between the inserts 137 and 139 and the element 126 and the air gaps between the source 131 and the inserts 137 and 139 make up a closed loop path containing magnetic flux so that the element 126 moves between its coupling and uncoupling positions when the coil 133 is supplied with current. The pole pieces 137 and 139 direct the magnetic field into the strut 126 to attract (or repel) the strut 126 and move the strut 126 into an engaged (or disengaged) position.

(36) The above-noted electromagnetic systems reduce the frictional losses that are generally present in prior art actuation systems that act on locking elements within a rotating clutch member. This is made possible because the actuation system has no moving parts and it has no physical contact with the clutch member. Reducing the frictional losses provides a way to reduce the power consumption requirements of the actuation system.

(37) In summary, the above-described clutch actuation system uses a stationary electromagnetic coil to produce a magnetic field that interacts with locking elements while they are moving with its rotating clutch member. The coil sits inside a core/housing which is axially symmetric with a generally C-shaped cross section. The coil produces an axially symmetric magnetic field that loops out of one side of the C-shaped core and into the other side (like a horseshoe magnet revolved about an axis). The open end of the housing/core faces axially toward a non-magnetic clutch member that houses the locking elements and is free to rotate independently of the coil. The clutch member includes magnetic pole pieces that provide a low reluctance path for the magnetic flux from the coil to reach the locking element. At each controllable locking element, there is an individual magnetic circuit which takes the flux from a portion of the bulk field from the main core and directs it through one pole piece, through the locking element, and through the other pole piece to return back to the main core. The bulk field source is axially symmetric so that the individual magnetic circuits have a constant MMF (i.e. magnetomotive force) source regardless of their orientation relative to the main core; that is what enables the stationary coil to actuate locking elements in a rotating clutch member.

(38) Obviously, the main core or coil housing may have a different shaped cross-section besides a generally C-shape.

(39) Also, the flux path in the individual magnetic circuit components may be such that the flux lines that cross the air gaps between the main core and the pole pieces are oriented in the radial direction to reduce attractive forces between the main core and the clutch member.

(40) Also, a lever may be coupled (not shown) to the strut so that the magnetic force pulls on the lever to control the strut instead of pulling on the strut directly as shown herein. This action could engage or disengage the strut.

(41) 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.