WO2008110738A1

WO2008110738A1 - Magnetic torque coupling having an inner rotor mounted for axial movement relative to an outer rotor

Info

Publication number: WO2008110738A1
Application number: PCT/GB2007/000838
Authority: WO
Inventors: Michael Charles Baker
Original assignee: Moog Controls Limited
Priority date: 2007-03-12
Filing date: 2007-03-12
Publication date: 2008-09-18

Abstract

The invention broadly provides a torque coupling (20) arranged to act between a variable-speed rotating shaft (21) and an energy-storage device (22), comprising: an inner rotor (23) mounted for rotation with the shaft and mounted for movement along the axis of the shaft; an outer rotor (25) surrounding the shaft, adapted to surround the inner rotor, and operatively connected to the energy-storage device, the inner rotor being rotationally coupled to the outer rotor when the inner rotor is arranged within the outer rotor and being rotationally uncoupled from the outer rotor when the inner rotor is arranged axially beyond the outer rotor; and an actuator (A) operatively arranged to selectively move the inner rotor axially along the shaft axis relative to the outer rotor; whereby the inner rotor may be selectively moved to a position relative to the outer rotor to permit the transfer of energy between the shaft and the energy-storage device.

Description

MAGNETIC TORQUE COUPLING HAVING

AN INNER ROTOR MOUNTED FOR AXIAL

MOVEMENT RELATIVE TO AN OUTER ROTOR

Technical Field

The present invention relates generally to torque couplings that are adapted to selectively transfer torque from one member to another, and, more particularly, to an improved magnetic torque coupling having a shaft-mounted inner rotor mounted for axial movement relative to an outer rotor to selectively permit the transfer of energy between a variable-speed rotating shaft and an energy-storage device, such as a flywheel.

Background Art

In some cases, it is desired to selectively transfer energy between (i.e., both to and from) a variable-speed rotating shaft to an energy-storage device.

For example in a Formula 1 car, the vehicle is quickly decelerated as the vehicle is braked during an approach to a turn. During such deceleration, the angular speed of the drive shaft to the ground wheels decreases. Such braking can be used to transfer energy to an energy-storage device, such as a flywheel. Once the vehicle has passed around the turn, it may be desired to quickly accelerate the vehicle to some higher speed. Hence, in this situation, it may be desired to transfer energy back from the flywheel to the drive shaft.

Upon information and belief, various regenerative braking techniques have been known on locomotives and on electrically-powered cars. Many locomotives utilize a fossil fuel engine (e.g., a diesel engine, a gas turbine or the like) to power one or more electric motors. These motors can function as generators in reverse. Hence, the motor can be used as an electric motor when used to accelerate an opposing load, and can be used as a generator when used to brake an aiding load. These motors may be associated with an energy-storage device, such as a battery. Hence, for example, when it is desired to accelerate an stationary or slowly-moving load, power may be supplied by the engine and may also be drawn from the battery. On the other hand, when it is desired to decelerate a moving load, the motor may be operated as a generator to supply energy to the battery. These applications appear to hinge on the fact that the electric motor may be operated either as a motor (i.e., may convert supplied electrical energy into rotational torque), or as a generator (i.e., may convert rotational torque into electrical energy). In some applications, it would be desirable to provide a torque coupling between a variable-speed rotating shaft and an energy-storage device, such as a flywheel. It might also be desirable to rotationally couple an inner rotor connected to the shaft with a non-contacting outer rotor that is associated with the flywheel. It might also be desirable to provide a measure of proportionality between a magnetically-coupled condition and a magnetically- uncoupled condition.

Devices of this nature have been attempted in a conventional motor-generator environment. For example, U.S. Pat. No. 6,492,753 appears to disclose a type of brushless permanent magnet motor having a rotor mounted for both axial and rotative movement relative to a stator. The rotor may be moved axially away from the stator to reduce the torque coupling therebetween, allegedly to enable the motor to operate at higher speeds. Other patents involving variations on this them are shown and described in U.S. Pats. No. 5,627,419, 6,492,753, 6,943,478 and 7,042,128.

Disclosure of the Invention

With parenthetical reference to the corresponding parts, portions or surfaces of the disclosed embodiments, merely for purposes of illustration and not by way of limitation, the present invention broadly provides an improved torque coupling that is adapted to act between a variable-speed rotating shaft (e.g., the drive shaft of a vehicle) and an energy-storage device (e.g., a capacitor, battery, flywheel, spring, accumulator, etc.), either directly or through an intermediate energy-conversion device.

In one aspect, the invention broadly provides a torque coupling (20) arranged to act between a variable-speed rotating shaft (21) and an energy-storage device (22), comprising: an inner rotor (23) mounted for rotation with the shaft and mounted for movement along the axis of the shaft; an outer rotor (25) surrounding the shaft, adapted to surround the inner rotor, and operatively connected to the energy-storage device, the inner rotor being rotationally coupled to the outer rotor when the inner rotor is arranged within the outer rotor and being rotationally uncoupled from the outer rotor when the inner rotor is arranged axially beyond the outer rotor; and an actuator (A) operatively arranged to selectively move the inner rotor axially along the shaft axis relative to the outer rotor; whereby the inner rotor may be selectively moved to a position relative to the outer rotor to permit the transfer of energy between the shaft and the energy-storage device. The energy-storage device may be a flywheel operatively arranged to rotate about the shaft axis. The flywheel and the outer rotor may be arranged to rotate together at proportional angular speeds, or may be arranged to rotate together at the same angular speed.

The torque coupling may be adapted to selectively transfer energy from the shaft to the flywheel when the rotational speed of the shaft is decelerating. Alternatively, the torque coupling may be adapted to selectively arranged to transfer energy from the flywheel to the shaft when it is desired to accelerate the rotational speed of the shaft.

The extent of rotational coupling between the inner and outer rotors may be a function of the axial position of the inner rotor along the shaft relative to the outer rotor.

The actuator may be fluid-powered, electrical, mechanical, etc.

In the preferred embodiment, the inner rotor is magnetically coupled to the outer rotor when the inner rotor is arranged within the outer rotor, and is magnetically uncoupled from the outer rotor when the inner rotor is arranged axially beyond the outer rotor. One of the rotors may have a rotating magnetic field, and the other of the rotors may have a plurality of shorted electrical conductors. Preferably, the inner rotor does not physically contact the outer rotor. The inner rotor may be mounted to the shaft by a spline connection.

The inner and outer rotors do not ever function as a motor or as a generator because they do not have any external electrical connections.

The rotational speed of one of the rotors may be urged to move toward the rotational speed of the other of the rotors when the inner rotor is moved from an axial position beyond the outer rotor toward an axial position within the outer rotor.

The torque coupling may further include drive means for supplying energy to the energy-storage device other than from the shaft.

In another aspect, the invention provides a torque coupling (50) arranged to act between a variable-speed rotating shaft (52) and an energy-storage device (58), comprising: an inner rotor (51) mounted for rotation with the shaft and mounted for movement along the axis of the shaft; a first outer rotor (54) surrounding the shaft, adapted to surround the inner rotor, and connected to the energy-storage device by a first ratio; a second outer rotor (55) surrounding the shaft in axially-spaced relation to the first outer rotor, adapted to surround the inner rotor, and connected to the energy-storage device by a second ratio; and an actuator (A) operatively arranged to selectively move the inner rotor axially along the shaft between one extreme position at which the inner rotor is positioned within the first outer rotor and another extreme position at which the inner rotor is positioned within the second outer rotor, the inner rotor being rotationally coupled to the first outer rotor when the inner rotor is positioned within the first outer rotor, being rotationally uncoupled from either outer rotor when the inner rotor is positioned between the outer rotors, and being rotationally coupled to the second outer rotor when the inner rotor is positioned within the second outer rotor; whereby the inner rotor may be selectively moved to a position relative to the outer rotors to permit the transfer of energy between the shaft and the energy-storage device.

The energy-storage device may be a flywheel operatively arranged to rotate about the shaft. The flywheel and the first outer rotor may be arranged to rotate together at the same angular speed, or at different angular speeds. The first and second ratios may be the same. The first and second outer rotors may be connected by a bevel gear, and may rotate in opposite directions.

The torque coupling may further include a ball-screw actuator (100), or some other type of rotary-to-linear motion conversion device, connected to the shaft, such that the actuator rod is arranged to be moved in one direction when the inner rotor is arranged within the first outer rotor, and such that the actuator is arranged to be moved in the opposite direction when the inner rotor is arranged within the second outer rotor.

The extent of rotational coupling between the inner rotor and the first outer rotor may be a function of the axial position of the inner rotor along the shaft relative to the first outer rotor. Similarly, the extent of rotational coupling between the rotor and second outer rotor may be a function of the axial position of the inner rotor along the shaft relative to the second outer rotor.

The actuator may be fluid-powered, electrical, mechanical, etc.

The inner rotor may be magnetically coupled to the first outer rotor when the inner rotor is arranged within the first outer rotor, and may be magnetically uncoupled from the first outer rotor when the inner rotor is arranged axially beyond the first outer rotor. Similarly, the inner rotor may be magnetically coupled to the second outer rotor when the inner rotor is arranged within the second outer rotor, and may be magnetically uncoupled from the second outer rotor when the inner rotor is arranged axially beyond the second outer rotor. The inner rotor may be magnetically uncoupled from both of the outer rotors when the inner rotor is arranged between the outer rotors.

One of the inner and outer rotors may have a rotating magnetic field, and the other of the inner and outer rotors may have a plurality of shorted electrical conductors. However, the inner rotor and outer rotors never function as a motor or as a generator because they have no external electrical connections.

The rotational speed of one of the inner rotor and either outer rotor may be urged to move toward the rotational speed of the other of the inner rotor and either outer rotor when the inner rotor is moved from an axial position beyond either outer rotor toward an axial position within such outer rotor.

In another aspect, the invention provides a torque coupling arranged to act between a variable-speed rotating shaft and a motor, comprising: an inner rotor mounted for rotation with the shaft and mounted for movement along the axis of the shaft; an outer rotor surrounding the shaft, adapted to surround the inner rotor, and operatively connected to the motor, the inner rotor being rotationally coupled to the outer rotor when the inner rotor is arranged within the outer rotor and being rotationally uncoupled from the outer rotor when the inner rotor is arranged axially beyond the outer rotor; and an actuator operatively arranged to selectively move the inner rotor axially along the shaft axis relative to the outer rotor; whereby the inner rotor may be selectively moved to a position relative to the outer rotor to permit the transfer of energy between the shaft and the motor.

In still another aspect, the invention provides a torque coupling (50) arranged to act between a variable-speed rotating shaft (52) and an energy-storage device (58), comprising: an inner rotor (51) mounted for rotation with the shaft and mounted for movement along the axis of the shaft; a first outer rotor (54) surrounding the shaft, adapted to surround the inner rotor, and connected to the energy-storage device by a first ratio; a second outer rotor (55) surrounding the shaft in axially-spaced relation to the first outer rotor, adapted to surround the inner rotor, and connected to the energy-storage device by a second ratio; and an actuator (A) operatively arranged to selectively move the inner rotor axially along the shaft between a first position at which the inner rotor is positioned within the first outer rotor, a second position at which the inner rotor is positioned within the second outer rotor, and a third position at which the inner rotor is positioned axially beyond the first and second outer rotors, the inner rotor being rotationally coupled to the first outer rotor when the inner rotor is positioned within the first outer rotor, being rotationally coupled to the second outer rotor when the inner rotor is positioned within the second outer rotor, and being rotationally uncoupled from either outer rotor when the inner rotor is positioned axially beyond the first and second outer rotors; whereby the inner rotor may be selectively moved to the first position to permit the transfer of energy between the shaft and the energy-storage device at the first ratio, or moved to the second position to permit the transfer of energy between the shaft and the energy-storage device at the second ratio, or moved to the third position to prevent the transfer of energy between the shaft and the energy-storage device.

Accordingly, the general object of the invention is to provide an improved torque coupling that is arranged to act between a variable-speed rotating shaft and an energy-storage device.

Another more specific object is to provide an improved torque coupling that is adapted for use in Formula 1-type racing cars.

These and other objects and advantages will become apparent from the foregoing and ongoing written specification, the drawings and the appended claims.

Brief Description of the Drawings

Fig. 1 is fragmentary longitudinal vertical sectional view of a first form of the improved torque coupling.

Fig. 2 is a fragmentary transverse vertical sectional view of the torque coupling shown in Fig. 1, this view being taken generally on line 2-2 of Fig. 1.

Fig. 3 is a fragmentary transverse vertical sectional view of a variant form of torque coupling shown in Fig. 2, this form having an increased number of shorted conductors.

Fig. 4 is a fragmentary longitudinal vertical sectional view of a second form of torque coupling, this view showing the inner rotor as having been axially displaced beyond the outer rotor to magnetically uncouple the inner and outer rotors.

Fig. 5 is a view similar to Fig. 4, but showing the inner rotor as having been axially displaced rightwardly from the position shown in Fig. 4 to a position at which the inner rotor is arranged within the outer rotor to magnetically couple the inner and outer rotors.

Fig. 6 is fragmentary longitudinal vertical sectional view of a third form of the improved torque coupling, this view showing the use of an auxiliary lay shaft for trickle- charging the flywheel, when the inner rotor is located axially beyond the outer rotor. Fig. 7 is a fragmentary longitudinal vertical sectional view of a fourth form of the improved torque coupling, this view showing the coupling as having two axially-spaced outer rotors, with a flywheel being mounted on the rightward outer rotor.

Fig. 8 is a fragmentary longitudinal vertical sectional view of a fifth form of the improved torque coupling, this view showing the inner rotor has being selectively movable relative to three axially-spaced outer rotors, with each outer rotor having its own individual gearing relationship with a lay shaft, thereby to provide a multi-ratio gear box.

Fig. 9 is a fragmentary longitudinal vertical sectional view of a sixth form of the improved torque coupling, this view having two oppositely-rotating outer rotors connected by a bevel gear, for controlling the direction of movement of a ball-screw actuator.

Fig. 10 is a fragmentary longitudinal vertical sectional view of a seventh form of the improved torque coupling, this embodiment having a flywheel mounted on the outer rotor.

Description of the Preferred Embodiments

At the outset, it should be clearly understood that like reference numerals are intended to identify the same structural elements, portions or surfaces consistently throughout the several drawing figures, as such elements, portions or surfaces may be further described or explained by the entire written specification, of which this detailed description is an integral part. Unless otherwise indicated, the drawings are intended to be read (e.g., cross-hatching, arrangement of parts, proportion, degree, etc.) together with the specification, and are to be considered a portion of the entire written description of this invention. As used in the following description, the terms "horizontal", "vertical", "left", "right", "up" and "down", as well as adjectival and adverbial derivatives thereof (e.g., "horizontally", "rightwardly", "upwardly", etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms "inwardly" and "outwardly" generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate.

Referring now to the drawings, the present invention broadly provides an improved torque coupling which is operatively arranged to act between a variable-speed rotating shaft and an energy-storage device, such as (but not limited to), a flywheel, a battery, a spring, a capacitor, an accumulator, and the like.

The present application discloses a number of different forms of the improved torque coupling. Each has its own individual characteristics and advantages. For the reader's convenience, these different embodiments will be dealt with seriatim herebelow. First Embodiment (Figs. 1-3)

Referring now to Fig. 1, an improved torque coupling device is generally indicated at 20. This coupling device is adapted to act between a variable-speed rotating shaft, indicated at 21, and an energy-storage device, indicated generically by box 22. The improved torque coupling includes an inner rotor, generally indicated at 23, that is mounted for rotation with the shaft and is mounted for axial sliding movement along the shaft. As best shown in Figs. 2 and 3, a spline connection, indicated at 24, is arranged to facilitate this operative connection between the inner rotor and the shaft.

The invention further includes an outer rotor, generally indicated at 25, that surrounds the shaft. The outer rotor is adapted to surround the inner rotor, and is operatively connected to the energy-storage device, such as by a ring gear. More particularly, the invention further includes a suitable actuator that is coupled to the inner rotor 23 by a rod 26. Hence, this actuator may selectively extend the rod such that the inner rotor is physically arranged within the outer rotor (as shown in Fig. 1), or may selectively retract the rod to withdraw the inner rotor from the outer rotor. In this latter position, the outer rotor will be physically located axially beyond the outer rotor. When the inner rotor is physically located within the outer rotor, the inner and outer rotors are magnetically coupled, and energy may be transferred between the shaft and the energy storage device. More particularly, if the energy-storage device is, for example, a flywheel, rotary motion of the shaft may be transmitted to increase the angular velocity of the flywheel. Conversely, if it is desired to accelerate the shaft, energy from the flywheel may be selectively transferred to the shaft.

Fig. 2 is a transverse vertical sectional view taken generally on line 2-2 of Fig. 1. This embodiment clearly shows the spline connection 24 between the shaft and the inner rotor, and further shows eight permanent magnets, severally indicated at M circumferentially mounted on the outer rotor and circumferentially spaced about the inner rotor. The inner rotor is shown as having a plurality of electrically-shorted conductors, severally indicated at 28. Hence, when the inner rotor is physically located within the outer rotor, as shown in Fig. 1, the inner and outer rotors are magnetically coupled. However, when the inner rotor is moved to a position axially beyond the outer rotor, the inner and outer rotors will be magnetically uncoupled.

Fig. 3 is a view of a modified inner rotor having additional conductors 28 to increase the torque transmitted between the inner and outer rotors. Second Embodiment (Figs. 4-5)

Referring now to Figs. 4-5, an improved torque motor, this time generally indicated at 30, is shown as having an inner rotor 31, an outer rotor 32, and an actuator A arranged to move the inner rotor along the axis of the shaft via a connecting rod 33. The outer rotor is again shown as having a plurality of circumferentially spaced magnets, severally indicated at M.

In this form, the energy-storage device is in the form of annular flywheel 34 that is mounted fast to the outer rotor 32 for rotation therewith. Thus, when the inner rotor is moved to a position along the shaft at which it is located axially beyond the outer rotor, as shown in Fig. 4, the inner and outer rotors will be magnetically and rotationally uncoupled. On the other hand, when the actuator draws the inner rotor within the outer rotor, as shown in Fig. 5, the inner and outer rotors will be magnetically and rotationally coupled, and energy may be transferred between the energy-storage device, in this case flywheel 35, and the shaft.

Third Embodiment (Fig. 6)

Referring now to Fig. 6, a third embodiment of the improved torque coupling is generally indicated at 40. This arrangement is shown as having an inner rotor 41 mounted on a shaft 42 by means of a spline connection 43. The energy-storage device is depicted as being a flywheel 44 which is mounted on the outer rotor 45 for rotation thereabout. A lay shaft 46, driven by a suitable motor, is connected to the outer rotor via gears 48 and 49 respectively. This arrangement allows the auxiliary motor to trickle-charge energy to rotate the outer rotor and flywheel at a relatively high speed around the shaft axis. Hence, such energy can then be built-up and stored in the flywheel, and will be available for immediate use. To store such energy, the actuator would first displace the inner rotor to an axially-extended position beyond the outer rotor, so that the inner and outer rotors would be uncoupled. Thereafter, the motor would rotate shaft 46 which, in turn, would rotate flywheel 44 and outer rotor 45 by meshing gears 48, 49. Thus, energy can be supplied to the flywheel. With such energy stored in the flywheel, the actuator can then physically move the inner rotor within the outer rotor to magnetically couple the two rotors and to allow energy to be transferred from the flywheel to the shaft. Fourth Embodiment (Fig. 7)

Fig. 7 illustrates a fourth embodiment of the improved device. In this case, the improved torque coupling is generally indicated at 50, and includes an inner rotor 51 rotation- ally coupled to, but slidable along, shaft 52 via a spline connection 53 therebetween. Two axially-spaced outer rotors, 54, 55 surround the shaft. The actuator A is connected to the inner rotor via a rod 56, and may selectively move the inner rotor between three discrete positions. The first position is when the inner rotor is physically arranged within the first or leftward outer rotor 54, as shown in Fig. 7. In this connection, the inner and left outer rotor are magnetically coupled.

The actuator may selectively move the inner rotor to an intermediate position between the two outer rotors. In this position, the inner and both outer rotors will be magnetically uncoupled.

The actuator may further move the inner rotor rightwardly to a position at which the inner rotor is physically located within the rightward or second outer rotor 55. In this position, the inner rotor will be magnetically coupled to the second outer rotor, but not the first.

This arrangement also shows the energy-storage device as being a flywheel 58 which is mounted on second outer rotor 55. A driven lay shaft 59 is connected to the first outer rotor 54 by meshing gears 60, 61. The lay shaft is also connected to second outer rotor 55 via meshing gears 62, 63. Here again, if desired, the device may be trickle-charged to accelerate the flywheel. Alternatively, if embodied in a Formula 1 vehicle, for example, energy may be transferred from the shaft to the flywheel during braking of the vehicle, and may be supplied from the flywheel back to the shaft during subsequent acceleration.

Fifth Embodiment (Fig. 8)

Fig. 8 illustrates yet another embodiment of the improved torque motor, this embodiment being generally indicated at 70. As before, this arrangement has an inner rotor 71 rota- tionally coupled to, but slidable along, a shaft 72 via a spline connection 73. In this arrangement, however, three axially-spaced outer rotors surround the shaft. The first of these is indicated at 74, the second at 75, and the third at 76. Each of these three outer rotors has a ring gear, indicated at 78, 79 and 80, respectively. Each ring gear has its own individual gear ratio for connection with a energy-storage device (not shown). Thus, the actuator A is arranged to move the inner rotor 71 relative to the outer rotors via a connecting rod 81. When the inner rotor is located within the leftward outer rotor 74 (as shown in Fig. 8), it will be magnetically coupled thereto, but magnetically uncoupled from second and third rotors 75, 76, respectively.

If the inner rotor is shifted rightwardly to a position within intermediate outer rotor 75, the inner rotor will be magnetically coupled to rotor 75, but will be magnetically uncoupled from leftward and rightward outer rotors 74, 76.

If the inner rotor is shifted further rightwardly to a position within rightward outer rotor 76, the inner rotor will be magnetically coupled to right outer rotor 76, but magnetically uncoupled from outer rotors 74 and 75. As noted before, each of these outer rotors is connected to a lay shaft 82 via different gear trains. More particularly, gear 83 is arranged to mesh with gear 78, gear 84 is arranged to mesh with gear 79, and gear 85 is arranged to mesh with gear 80. Thus, this arrangement provides a multi-ratio gear box.

Sixth Embodiment (Fig. 9)

Fig. 9 depicts yet another form of the improved torque coupling. In this form, the coupling, generally indicated at 90, is shown as having an inner rotor 91 mounted for rotation with, and axial sliding movement along, to a shaft 92 via a spline connection 93. This arrangement has two axially-spaced outer rotors 94, 95, with flywheel 96 coupled to right outer rotor 95. These two outer rotors are arranged to rotate in opposite angular directions by means of an intermediate bevel gear 98 engaging teeth on the proximate surfaces of outer rotors 94, 95. Actuator A is connected to the inner rotor via a rod 99, and is arranged to selectively move the inner rotor between a position at which the inner rotor is located within left outer rotor 94 (as shown in Fig. 9), an intermediate position at which the inner rotor is located between the two outer rotors, and a rightward position in which the inner rotor is physically located within right outer rotor 95. The left end of shaft 92 is connected to a ball-screw actuator 100 that is operatively arranged to move an eye 101 via an extendable and retractable rod 102. Thus, the ball screw may be extended by positioning with the inner rotor within one of the outer rotors, and may be retracted by selectively moving the inner rotor to a position within the other of the outer rotors. This arrangement also shows an auxiliary driven lay shaft 103 having a gear 104 arranged in meshing engagement with a ring gear 105 mounted on the right outer rotor. This arrangement allows energy to be trickled-charged to the flywheel, in the manner heretofore described.

If desired, other types of rotary-to-linear motion conversion devices might be used. Seventh Embodiment (Fig. 10)

Fig. 10 shows yet another form of the improved torque coupling. In this case, the torque coupling is generally indicated at 110, and is shown as including an inner rotor 111 mounted for rotation with, but sliding movement relative to, a shaft 112 via a spline connection 113. An actuator A is connected to the inner rotor via by shaft 114. Thus, actuator A may selectively move the inner rotor between a position within the outer rotor 116 (as shown in Fig. 10), and a position axially beyond outer rotor 115. A flywheel 116 is shown as being mounted on the outer rotor for rotation therewith. In this form, the flywheel is the energy- storage device, and energy may be selectively transferred between the drive shaft and the flywheel depending on the polarity of the energy flow.

Therefore, the present invention broadly provides an improved torque coupling that is operatively arranged to act between a variable-speed rotating shaft and an energy-storage device. The improved device has an inner rotor arranged for rotation with the shaft and mounted for axial movement along the shaft, and an outer rotor operatively connected to an energy-storage device. The inner rotor will be rotationally coupled to the outer rotor when the inner rotor is arranged within the outer rotor, and will rotationally uncoupled from the outer rotor when the inner rotor is arranged axially beyond the outer rotor. The improved torque coupling further includes an actuator that is operatively arranged to selectively move the inner rotor axially along the shaft axis relative to the outer rotor.

The various embodiments illustrate individual features, details and capabilities of the invention as previously described.

Modifications

The present invention expressly contemplates that many changes and modifications may be made. For example, the variable-speed rotating shaft may possibly be the drive shaft of a vehicle. However, this is merely illustrative and exemplary, and is not intended to be limitative of the scope of the appended claims. The energy-storage device may be a capacitor, a flywheel, an accumulator, a battery, or some other device. The connection to the energy-storage device may be either direct (as in the case of mechanical coupling to a flywheel) or indirect through some intermediate energy-conversion device. While a spline connection is presently-preferred for rotationally coupling the inner rotor to the shaft, but allowing the inner rotor to move along the shaft, other types of arrangements might alternatively be employed. While the various embodiments have been illustrated and describe as having inner and outer rotors that do not physically contact one another, the present invention does envision and contemplate that the invention could employ a mechanical friction clutch in which the various clutch portions do selectively and physically contact one another.

Therefore, while several presently-preferred forms of the improved torque coupling have been shown and described, and various modifications thereof discussed, persons skilled in this art will readily appreciate that various additional changes and modifications may be made without departing from the spirit of the invention, as defined and differentiated by the following claims.

Claims

ClaimsWhat is claimed is:

1. A torque coupling arranged to act between a variable-speed rotating shaft and an energy-storage device, comprising: an inner rotor mounted for rotation with said shaft and mounted for movement along the axis of said shaft; an outer rotor surrounding said shaft, adapted to surround said inner rotor, and opera- tively connected to said energy-storage device, said inner rotor being rotationally coupled to said outer rotor when said inner rotor is arranged within said outer rotor and being rotation- ally uncoupled from said outer rotor when said inner rotor is arranged axially beyond said outer rotor; and an actuator operatively arranged to selectively move said inner rotor axially along said shaft axis relative to said outer rotor; whereby said inner rotor may be selectively moved to a position relative to said outer rotor to permit the transfer of energy between said shaft and said energy-storage device.

2. A torque coupling as set forth in claim 1 wherein said energy-storage device is a flywheel operatively arranged to rotate about said shaft axis.

3. A torque coupling as set forth in claim 2 wherein said flywheel and said outer rotor are arranged to rotate together at proportional angular speeds.

4. A torque coupling as set forth in claim 3 wherein said flywheel and outer rotor are arranged to rotate together at the same angular speed.

5. A torque coupling as set forth in claim 3 wherein said torque coupling is adapted to selectively transfer energy from said shaft to said flywheel when the rotational speed of said shaft is decelerating.

6. A torque coupling as set forth in claim 3 wherein said torque coupling is adapted to selectively arranged to transfer energy from said flywheel to said shaft when it is desired to accelerate the rotational speed of said shaft.

7. A torque coupling as set forth in claim 1 wherein the extent of rotational coupling between said inner and outer rotors is a function of the axial position of said inner rotor along said shaft relative to said outer rotor.

8. A torque coupling as set forth in claim 1 wherein said actuator is fluid-powered.

9. A torque coupling as set forth in claim 1 wherein said inner rotor is magnetically coupled to said outer rotor when said inner rotor is arranged within said outer rotor, and is magnetically uncoupled from said outer rotor when said inner rotor is arranged axially beyond said outer rotor.

10. A torque coupling as set forth in claim 9 wherein one of said rotors has a rotating magnetic field, and the other of said rotors has a plurality of shorted electrical conductors.

11. A torque coupling as set forth in claim 1 wherein said inner rotor does not physically contact said outer rotor.

12. A torque coupling as set forth in claim 1 wherein said inner rotor is mounted to said shaft by a spline connection.

13. A torque coupling as set forth in claim 10 wherein said inner and outer rotors do not ever function as a motor.

14. A torque coupling as set forth in claim 10 wherein said inner and outer rotors do not ever function as a generator.

15. A torque coupling as set forth in claim 1 wherein the rotational speed of one of said rotors is urged to move toward the rotational speed of the other of said rotors when said inner rotor is moved from an axial position beyond said outer rotor toward an axial position within said outer rotor.

16. A torque coupling as set forth in claim 1 and further comprising drive means for supplying energy to said energy-storage device other than from said shaft.

17. A torque coupling arranged to act between a variable-speed rotating shaft and an energy-storage device, comprising: an inner rotor mounted for rotation with said shaft and mounted for movement along the axis of said shaft; a first outer rotor surrounding said shaft, adapted to surround said inner rotor, and connected to said energy-storage device by a first ratio; a second outer rotor surrounding said shaft in axially-spaced relation to said first outer rotor, adapted to surround said inner rotor, and connected to said energy-storage device by a second ratio; and an actuator operatively arranged to selectively move said inner rotor axially along said shaft between one extreme position at which said inner rotor is positioned within said first outer rotor and another extreme position at which said inner rotor is positioned within said second outer rotor, said inner rotor being rotationally coupled to said first outer rotor when said inner rotor is positioned within said first outer rotor, being rotationally uncoupled from either outer rotor when said inner rotor is positioned between said outer rotors, and being rotationally coupled to said second outer rotor when said inner rotor is positioned within said second outer rotor; whereby said inner rotor may be selectively moved to a position relative to said outer rotors to permit the transfer of energy between said shaft and said energy-storage device.

18. A torque coupling as set forth in claim 17 wherein said energy-storage device is a flywheel operatively arranged to rotate about said shaft.

19. A torque coupling as set forth in claim 18 wherein said flywheel and said first outer rotor are arranged to rotate together at the same angular speed.

20. A torque coupling as set forth in claim 18 wherein said flywheel and second outer rotor are arranged to rotate together at different angular speeds.

21. A torque coupling as set forth in claim 17 wherein said first and second ratios are the same.

22. A torque coupling as set forth in claim 21 wherein said first and second outer rotors are connected by a bevel gear.

23. A torque coupling as set forth in claim 22 and further comprising a ball screw actuator connected to said shaft, wherein said actuator is arranged to be moved in one direction when said inner rotor is arranged within said first outer rotor, and wherein said actuator is arranged to be moved in the opposite direction when said inner rotor is arranged within said second outer rotor.

24. A torque coupling as set forth in claim 17 and further comprising drive means for supplying energy to said energy-storage device other than from said shaft.

25. A torque coupling as set forth in claim 18 wherein said torque coupling is adapted to selectively transfer energy from said shaft to said flywheel when the rotational speed of said shaft is decelerating.

26. A torque coupling as set forth in claim 18 wherein said torque coupling is adapted to selectively arranged to transfer energy from said flywheel to said shaft when it is desired to accelerate the rotational speed of said shaft.

27. A torque coupling as set forth in claim 17 wherein the extent of rotational coupling between said inner rotor and said first outer rotor is a function of the axial position of said inner rotor along said shaft relative to said first outer rotor.

28. A torque coupling as set forth in claim 17 wherein the extent of rotational coupling between said rotor and second outer rotor is a function of the axial position of said inner rotor along said shaft relative to said second outer rotor.

29. A torque coupling as set forth in claim 17 wherein said actuator is fluid-powered.

30. A torque coupling as set forth in claim 17 wherein said inner rotor is magnetically coupled to said first outer rotor when said inner rotor is arranged within said first outer rotor, and is magnetically uncoupled from said first outer rotor when said inner rotor is arranged axially beyond said first outer rotor.

31. A torque coupling as set forth in claim 17 wherein said inner rotor is magnetically coupled to said second outer rotor when said inner rotor is arranged within said second outer rotor, and is magnetically uncoupled from said second outer rotor when said inner rotor is arranged axially beyond said second outer rotor.

32. A torque coupling as set forth in claim 17 wherein said inner rotor is magnetically uncoupled from both of said outer rotors when said inner rotor is arranged between said outer rotors.

33. A torque coupling as set forth in claim 17 wherein one of said inner and outer rotors has a rotating magnetic field and the other of said inner and outer rotors has a plurality of shorted electrical conductors.

34. A torque coupling as set forth in claim 33 wherein said inner rotor and outer rotors do not ever function as a motor.

35. A torque coupling as set forth in claim 33 wherein said inner rotor and said outer rotors do not ever function as a generator.

36. A torque coupling as set forth in claim 17 wherein said inner rotor is arranged to physically contact one of said outer rotors when said inner rotor is arranged within such outer rotor.

37. A torque coupling as set forth in claim 17 wherein the rotational speed of one of said inner rotor and either outer rotor is urged to move toward the rotational speed of the other of said inner rotor and either outer rotor when said inner rotor is moved from an axial position beyond either outer rotor toward an axial position within such outer rotor.

38. A torque coupling arranged to act between a variable-speed rotating shaft and a motor, comprising: an inner rotor mounted for rotation with said shaft and mounted for movement along the axis of said shaft; an outer rotor surrounding said shaft, adapted to surround said inner rotor, and opera- tively connected to said motor, said inner rotor being rotationally coupled to said outer rotor when said inner rotor is arranged within said outer rotor and being rotationally uncoupled from said outer rotor when said inner rotor is arranged axially beyond said outer rotor; and an actuator operatively arranged to selectively move said inner rotor axially along said shaft axis relative to said outer rotor; whereby said inner rotor may be selectively moved to a position relative to said outer rotor to permit the transfer of energy between said shaft and said motor.

39. A torque coupling arranged to act between a variable-speed rotating shaft and an energy-storage device, comprising: an inner rotor mounted for rotation with said shaft and mounted for movement along the axis of said shaft; a first outer rotor surrounding said shaft, adapted to surround said inner rotor, and connected to said energy-storage device by a first ratio; a second outer rotor surrounding said shaft in axially-spaced relation to said first outer rotor, adapted to surround said inner rotor, and connected to said energy-storage device by a second ratio; and an actuator operatively arranged to selectively move said inner rotor axially along said shaft between a first position at which said inner rotor is positioned within said first outer rotor , a second position at which said inner rotor is positioned within said second outer rotor, and a third position at which said inner rotor is positioned axially beyond said first and second outer rotors, said inner rotor being rotationally coupled to said first outer rotor when said inner rotor is positioned within said first outer rotor, being rotationally coupled to said second outer rotor when said inner rotor is positioned within said second outer rotor, and being rota- tionally uncoupled from either outer rotor when said inner rotor is positioned axially beyond said first and second outer rotors; whereby said inner rotor may be selectively moved to said first position to permit the transfer of energy between said shaft and said energy-storage device at said first ratio, or moved to said second position to permit the transfer of energy between said shaft and said energy-storage device at said second ratio, or moved to said third position to prevent the transfer of energy between said shaft and said energy-storage device.