Multi-speed automatic gearbox with multiple clutches

Abstract

A multi-speed automatic gearbox is provided that includes multiple clutches. The gearbox includes an outer cover, with an input powered by a motor, an output, and a plurality of gears located within the outer cover between the input and the output. A first clutch may be mounted between the outer cover and the input, and a second clutch may around the circumference or exterior of the outer cover. In a first configuration, the first clutch is engaged and the second clutch is disengaged, resulting in the rotation of the input, the outer surface, and the output at a ratio of 1:1. In a second configuration, the second clutch is engaged and the first clutch is disengaged, resulting in rotation of the input and the output at a ratio of N:1.

Description

Multi-Speed Automatic Gearbox with Multiple ClutchesCROSS-REFERENCE(S) TO RELATED APPLICATION(S)

[0001] This present application claims priority on U.S. Provisional Patent Application Serial No. 63 / 679,253, filed on August 5, 2024 and entitled MultiSpeed Automatic Gearbox with Multiple Clutches, the entire contents of which are hereby expressly incorporated by reference into the present application.BACKGROUND OF THE INVENTION1. Field of the Invention

[0002] The present invention relates in general to the field of multi-speed gearboxes. More specifically, the present invention is directed to a multi-speed gearbox that includes clutches and has improved transmission capabilities. Even more specifically, the present invention is directed to a multi-speed gearbox having two or more clutches used to enhance humanoid products used to mimic muscle performance.2. Discussion of the Related Art

[0003] A variety of different humanoid products are known in the art, such as prosthetic devices and limbs that are used to imitate human body parts. For instance, prosthetic hands, arms, feet, and legs are routinely used by individuals. While these products are helpful for many individuals, prosthetic devices generally do not operate at the same level as a corresponding body part. More specifically, there has been an inability to bridge the gap between existing actuators and transmissions to match the performance of human muscle-tendon in the five performance attributes of size, weight, strength, speed, and dexterity simultaneously.

[0004] Brushless DC motors (BLDCs) have improved performance because of their ability to achieve larger power densities and specific powers than human muscle.However, a BLDC is typically coupled with transmission options to produce required torque. Output of a BLDC when coupled with a fixed reduction ratio transmission still does not match human muscle for the five attributes listed above. Furthermore, the size and weight of the transmission devices reduces the performance of the device. Additional issues occur based on the balance between a device having a reasonable size and weight while still achieving sufficient torque, speed, and dexterity.

[0005] What is needed is prosthetic devices having enhanced functional capabilities. What is further needed is prosthetic devices that more closely mimic operation of human body parts. What is further needed is supporting mechanical components, such as a multi-speed gearbox, that enables a prosthetic device to function like human body parts. Additionally, a multi-speed gearbox having multiple clutches that works with a prosthetic device to match muscle-tendon attributes related to size, weight, strength, speed, and dexterity is desired.SUMMARY AND OBJECTS OF THE INVENTION

[0006] By way of summary, the present invention is directed to an inventive gearbox having multiple clutches. For instance, the gearbox may include a first clutch having a first clutch component that engages and disengages with a second clutch component, and a second clutch having a third clutch component that engages and disengages with a fourth clutch component.

[0007] According to one aspect of the invention, the gearbox includes a housing, an input such as an input shaft, an output such as an output shaft extending from the housing, a plurality of gears located within the housing between the input and the output, and first and second clutches. The first clutch includes a first clutch component, such as a pad, and a second clutch component, such as a pad. In one embodiment, the first clutch component is associated with the input, and the second clutch component is associated with the housing. Similarly, the first and second clutch components may be associated with other components of the gearbox. The second clutch includes third and fourth clutch components, suchas pads. In one embodiment, the third and fourth clutch components are associated with the housing, although they could similarly be associated with other components of the gearbox.[0008J The gearbox is movable between first and second configurations. In the first configuration, the first clutch is activated meaning that the first clutch pad and the second clutch pad are engaged with one another, while the second clutch is deactivated meaning that the third clutch pad and the fourth clutch pad are disengaged. While in the first configuration, the input, the housing, and the output all rotate at the same rate, meaning that the rotational ratio is 1: 1. In the second configuration, the second clutch is activated meaning that the third clutch pad and the fourth clutch pad are engaged with one another, while the first clutch is deactivated meaning that the first clutch pad and the second clutch pad are disengaged. While in the second configuration, the input and the output have a rotational ratio of N: 1, where N is not equal to 1.

[0009] According to another aspect of the present invention, a method of operating the claimed gearbox is provided.

[0010] Additionally, multiple gearboxes may be used together. For instance, two gearboxes may be used together, with the output of the first gearbox serving as or being connected to the input of the second gearbox. This results in a four- speed gearbox. Similarly, three gearboxes may be used together, with the output of the second gearbox serving as or being connected to the input of the third gearbox. This results in an eight-speed gearbox.

[0011] These, and other aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the presentinvention without departing from the spirit thereof, and the invention includes all such modifications.BRIEF DESCRIPTION OF DRAWING

[0012] A clear conception of the advantages and features constituting the present invention, and of the construction and operation of typical mechanisms provided with the present invention, will become more readily apparent by referring to the exemplary, and therefore non-limiting, embodiments illustrated in the drawings accompanying and forming a part of this specification, wherein like reference numerals designate the same elements in the several views, and in which:

[0013] FIG. 1 is a sectional view of an inventive gearbox;

[0014] FIG. 2 is a sectional view of the inventive gearbox of FIG. 1 in a first mode of operation;

[0015] FIG. 3 is a sectional view of the inventive gearbox of FIG. 1 in a second mode of operation;

[0016] FIG. 4 is an exploded view of the inventive gearbox of FIGS. 1-3; and

[0017] FIG. 5 is a perspective view of the inventive gearbox in use with a prosthetic leg device.

[0018] In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the word connected, attached, or terms similar thereto are often used. They are not limited to direct connection but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art.DESCRIPTION OF PREFERRED EMBODIMENTS

[0019] The present invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments described in detail in the following description.

[0020] The present invention is directed to a multi-speed gearbox 20 is provided that includes at least one gear stage that is used to manipulate any type of prosthetic device or limb. The present invention is directed to a multi-speed gearbox 20 that enables a motor-transmission to match muscle-tendon in one or more of the following human muscle-tendon performance metrics of size, weight, strength, speed, and dexterity. FIG. 5 shows the multi-speed gearbox 20 in use with a prosthetic leg device, although the gearbox 20 could similarly be used with other different prosthetic devices.

[0021] An embodiment of the multi-speed gearbox will now be provided. As shown in the figures, the gearbox 20 includes an outer cover 22 that serves as a housing with an internal cavity 24, an input 26 extending into the internal cavity 24 and powered by a motor 28, and an output 30 extending from the outer cover 22. In the illustrated embodiment, the input 26 is an input shaft 32 and the motor 28 includes a rotor 34 on the shaft 32 and a stator 36. Additionally, a slip ring 37 that includes a slip ring ground 38 and a slip ring rotor 40 may be mounted to the input shaft 32.

[0022] In terms of the actual gears contained within the gearbox 20, any number of different gear configurations could be used. By way of example and not limitation, the gearbox may contain traditional planetary gears, compound planetary gears, cycloidal gears, ravigneaux gears, and the like, although no specific gear configurations are shown within the gearbox 20. Regardless of the gear configuration, multiple clutches (described below) are used to move the gearbox 20 between a first gear ratio of N: 1 of the input shaft 32 to the output 30 to a second configuration of 1 : 1.

[0023] Each gear stage includes two independently controlled active clutches, as shown a first controlled active clutch 42 and a second controlled active clutch 44. While one example of where the two clutches may be located is shown and described, one having ordinary skill in the art should appreciate that the clutches could similarly be located in other locations and in connection with other components of the gearbox to achieve the same end results.

[0024] In the illustrated embodiment, the first controlled active clutch 42, or 1: 1 clutch, includes an input side clutch component 46, as shown a pad, that is secured to the input shaft 32. Additionally, the first controlled active clutch 42 includes a gearbox side clutch component 48, as shown a pad, that is secured to the outer cover 22 of the gearbox 20. Of course, the first controlled active clutch 42 components could be mounted elsewhere. In the illustrated embodiment, the clutch 42 connects the input shaft 32 and motor rotor 34 to the gearbox 20 when it is turned on. Because the input side clutch component 46 rotates with the input shaft 32, it must receive power through the slip ring 37 or similar device that passes power from ground through to the input side clutch component 46. As shown, an opening is formed in the input shaft 32, with wires extending from the slip ring 37 to the component 46. The first controlled active clutch 42 may be an electrostatic clutch due to its lightweight, compact size, and minimal power consumption, but of course other clutches could similarly be used.

[0025] In the illustrated embodiment, the second controlled active clutch 44, or N: 1 clutch, includes a first clutch component 50 that is secured to the exterior of the outer cover 22 of the gearbox 20. Additionally, the second controlled active clutch 42 includes a second clutch component 52 that is grounded. In the illustrated embodiment, the second controlled active clutch 44 is an electrostatic clutch, but this clutch could be a solenoid with a tooth that interferes with the exterior (i.e. a dog clutch), a traditional electromagnetic brake / clutch, or any other type of clutch as known to those having ordinary skill in the art.

[0026] In a first configuration, shown in FIG. 2, the first controlled active clutch 42 is powered on, meaning that the input side clutch component 46 and the gearbox side clutch component 48 are engaged as designated be reference 54, whereas the second controlled active clutch 44 is powered off, meaning that the first clutch component 50 and the second clutch component 52 are disengaged. In this configuration, the clutch 42 and the inherent kinematics of the gearbox 20 force the input shaft 32 and gearbox 20 outer cover 22 to rotate together at the same speed. As a result, the output 30 of the gearbox 20 must also rotate at the same speed. In this configuration, the gearbox 20 rotates as a single rigid body (and thus at a 1: 1 ratio). This is designated by the three arrows in FIG. 2, where the input 26, the outer cover housing 22, and the output 30 all rotate together. The user may also place the two clutch components in alternative locations that prevent two gears or other bodies from rotating relative to each other, thereby achieving the desired 1 : 1 ratio.

[0027] In a second configuration, shown in FIG. 3, the second controlled active clutch 44 is powered on, meaning that the first clutch component 50 and the second clutch component 52 are engaged as designated by reference 56, whereas the first controlled active clutch 42 is powered off, meaning that the input side clutch component 46 and the gearbox side clutch component 48 are disengaged. When this occurs, rotation of the exterior of the gearbox 20 is prevented relative to the ground. When the second controlled active clutch 44 is powered on and the first controlled active clutch 42 is powered off, it is meant to prevent the outer cover 22 of the gearbox 20 from rotating relative to ground. When the second controlled active clutch 44 is powered on and the outer cover 22 does not rotate, the gearbox 20 perfonns as a traditional gearbox would, providing a N: 1 ratio, where N is the nominal reduction ratio of the gearbox 20. The input shaft 32 is rotated to cause the internal gears (not shown) to rotate, in turn causing the output 30 to rotate at the N ratio. The second configuration operates with minimal lost power, making it more efficient than similar gearboxes of the priorart. This power savings is critical in cases where high power output is needed in both the first configuration and the second configuration. In fact, by including the first and second controlled active clutches 42, 44, efficiency of the gearbox 20 in the second configuration (N : 1 mode) can be up to ~90%-95%. This is consistent with the efficiency that is typically achieved in the first configuration (1: 1 mode). This has tremendous benefits in applications that require high power output in both 1 : 1 and N : 1 mode.

[0028] Although both pads of an electrostatic clutch do not need to be powered, it is preferred that they are both powered. Doing so dramatically improves the force holding capacity per unit area of the clutch. Thus, in certain embodiments, both clutches include inductive coupling / charging circuitry so that the moving clutch pads (i.e. the gearbox side clutch 48 of the first controlled active clutch 42 and the first clutch component 50 of the second controlled active clutch 44) are powered when either of the respective clutches are turned on.

[0029] While the figures show a single gear box 20, it should be noted that multiple gearboxes may be used together. For instance, first and second gear boxes could be used to create a 4-speed gear box, where the output of the first gear box serves as the input of the second gear box. Similarly, three gear boxes could be used to create an 8-speed gear box, where the output of the first gear box serves as the input of the second gear box, and the output of the second gear box serves as the input of the third gear box. In certain instances, additional gear boxes may be used together to achieve desired results.

[0030] Regardless of whether a single gear box is utilized, or multiple gearboxes are utilized, the output is used to drive any variety of different transmission components or mechanisms, whether in series or in parallel, including for instance various linkages, screws, cables, and other components. Additionally, the gearbox may be use with additional motor and gearbox combinations.

[0031] Turning briefly to FIG. 5, one exemplary practical application of the gear box 20 in use with a leg prosthetic assembly 58 is shown. The leg prostheticassembly 58 may include a body 60, a first adapter 62 located at a top end of the body 60 and engageable with the user’s body, a second adapter 64 located at a bottom end of the body 60, and an ankle / foot prosthetic 66 that is connected to the second adapter 64. In this configuration, the gear box 20 facilitates movement of the leg prosthetic assembly 58 similar to that of a human leg. As emphasized throughout, the gear box 20 could be used with other prosthetic devices to simulate other human body parts.

[0032] While the above description is primarily in connection with use of a gearbox with humanoid / prosthetic devices, it should be noted that there are virtually innumerable uses for the present invention, all of which need not be detailed here. All the disclosed embodiments can be practiced without undue experimentation.

[0033] Although the best mode contemplated by the inventors of carrying out the present invention is disclosed above, practice of the present invention is not limited thereto. It will be manifest that various additions, modifications and rearrangements of the features of the present invention may be made without deviating from the spirit and scope of the underlying inventive concept. In addition, the individual components need not be fabricated from the disclosed materials but could be fabricated from virtually any suitable materials.

[0034] Moreover, the individual components need not be formed in the disclosed shapes, or assembled in the disclosed configuration, but could be provided in virtually any shape, and assembled in virtually any configuration to improve the operating characteristics of the gearbox. Furthermore, all the disclosed features of each disclosed embodiment can be combined with, or substituted for, the disclosed features of every other disclosed embodiment except where such features are mutually exclusive.

[0035] It is intended that the appended claims cover all such additions, modifications and rearrangements. Expedient embodiments of the present invention are differentiated by the appended claims.

[0036] Although the best mode contemplated by the inventors of carrying out the present invention is disclosed above, practice of the present invention is not limited thereto. It will be manifest that various additions, modifications and rearrangements of the features of the present invention may be made without deviating from the spirit and scope of the underlying inventive concept.

[0037] Moreover, the individual components need not be assembled in the disclosed configuration, but could be provided in virtually any configuration. Furthermore, all the disclosed features of each disclosed embodiment can be combined with, or substituted for, the disclosed features of every other disclosed embodiment except where such features are mutually exclusive.

[0038] It is intended that the appended claims cover all such additions, modifications and rearrangements. Expedient embodiments of the present invention are differentiated by the appended claims.

Claims

CLAIMSWhat is claimed is:

1. A gearbox comprising: a housing; an input extending through the housing; an output extending through the housing; a plurality of gears locating within the housing between the input and the output; a first clutch comprising: a first clutch component; a second clutch component; and a second clutch comprising: a third clutch component; and a fourth clutch component2. The gearbox of claim 1, wherein the housing is movable between: a first configuration where: the first clutch is activated and the first clutch component and the second clutch component are engaged with one another; and the second clutch is deactivated and the third clutch component is disengaged with the fourth clutch component; and a second configuration where: the second clutch is activated and the third clutch component and the fourth clutch component are engaged with one another; and the first clutch is deactivated and the first clutch component is disengaged with the second clutch component.

3. The gearbox of claim 2, wherein in the first configuration, the input and the output rotate at a ratio of 1 : 1.

4. The gearbox of claim 2, wherein in the first configuration, the input and the output rotate at a ratio of N: 1, wherein N is not equal to 1.

5. The gearbox of claim 2, wherein the input is an input shaft; and wherein the first clutch component is associated with the input shaft.

6. The gearbox of claim 5, further comprising a slip ring associated with the input shaft; wherein the slip ring powers the first clutch.

7. The gearbox of claim 1, wherein the plurality of gears is selected from a group consisting of traditional planetary gears, compound planetary gears, cycloidal gears, and ravigneaux gears.

8. The gearbox of claim 1 , wherein the first clutch component is associated with the input; wherein the second clutch component is associated with the housing; wherein the third clutch component is associated with the housing; and wherein the fourth clutch component is associated with an external component.

9. The gearbox of claim 1, wherein the first clutch component is associated with a carrier and the second clutch component is associated with the housing.

10. The gearbox of claim 1, wherein the first clutch component is associated with a first internal gear and the second clutch component is associated with a second internal gear.

11. A method of operating a gearbox, comprising the steps of: engaging a first clutch component of a first clutch with a second clutch component of the first clutch; rotating an input and an output associated with a housing at a rotational ratio of 1: 1; disengaging the first clutch component from the second clutch component; engaging a third clutch component of a second clutch with a fourth clutch component of the second clutch; rotating the input and the output at a rotational ratio of N: l, where N is not equal to 1.

12. The method of claim 11, further comprising the steps of: moving a housing between: a first configuration where: the first clutch component and the second clutch component are engaged; and the third clutch component and the fourth clutch component are disengaged; and a second configuration where: the first clutch component and the second clutch component are disengaged; and the third clutch component and the fourth clutch component are engaged;13. The method of claim 11, wherein in the first configuration, an input shaft and an output shaft rotate at a ratio of 1 : 1 ; and wherein in the second configuration, an input shaft and an output shaft rotate at a ratio of N: 1, wherein N is not equal to 1.

14. The method of claim 11, further comprising the step of providing power to the first clutch using a slip ring.

15. The method of claim 14, wherein the slip ring is mounted to an input shaft.

16. The method of claim 11, wherein the first clutch and the second clutch are one of electromagnetic clutches and electrostatic clutches.

17. The method of claim 11, further comprising the step of rotating a plurality of gears located within the housing.

18. The method of claim 11, wherein the first clutch component is associated with the input and the second clutch component is associated with the housing.

19. A gearbox assembly comprising: a first gearbox comprising: a housing; a first input extending through the housing; a first output extending through the housing; a plurality of gears locating within the housing between the input and the output; a first clutch comprising: a first clutch component associated with the input;a second clutch component associated with the housing; and a second clutch having a third clutch component and a fourth clutch component associated with the housing; and a second gearbox comprising: the first output serves as a second input; a second output; a third clutch; and a fourth clutch.

20. The gearbox assembly of claim 19, further comprising a third gearbox where the second output serves as a third input, and wherein the assembly is an eight-speed gear box.

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