Compact rotary clutch mechanism using laminated structure

Abstract

The compact rotating clutch may include multiple clutch units in a stacked configuration. Each clutch unit includes an electrode and a reinforcing structure capable of transmitting loads. An electrical connection may be established between the clutch units in the clutch to enable control of the clutch, which may operate in an engaged and disengaged state. Control of the clutch units may also enable slip or damped relative rotation between input and output elements connected to the clutch.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit under 35 U.S.C. § 119 of U.S. Provisional Patent Application No. 63 / 435,387, filed December 27, 2022, which is incorporated herein by reference.

[0002] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not applicable. [Background technology]

[0003] Rotating clutches are used to provide a resistive load between a rotating component and an adjacent component. Their usual purpose is to prevent relative rotation between components, as is typical of clutches used in automotive drivetrains. In some applications, they can also be used to provide a resistive load small enough to allow relative rotation between components. The purpose may be to dissipate energy, as in a brake, or in some cases to limit the amount of torque that can be applied before relative rotation occurs. This is sometimes done in some exercise and training equipment to ultimately adjust the resistance. Torque limiting is also useful as a mechanical fuse to prevent damage to expensive or sensitive components, such as gearboxes.

[0004] Conventional rotary clutches are typically mechanical, magnetic, pneumatic, or hydraulic. Mechanical clutches, when electronically controlled, require an auxiliary actuator to operate and can be quite large. Magnetic clutches require a large, heavy coil and a large, constant current input to operate the clutch. Hydraulic and pneumatic clutches require reservoirs, piping, seals, and / or compressors. These methods are typically used in applications where size, weight, mass, and power consumption are not critical design considerations. Examples include stationary assembly robots, revolving doors, and conveyor belt systems.

[0005] Growing areas such as mobile robots, exoskeletons, and lightweight, energy-efficient vehicles could greatly benefit from incorporating clutches. For example, studies have shown that power-saving clutches could achieve energy savings of up to 85% in walking robots, but their excessive size, weight, and difficulty in electronic control currently prevent their implementation. Some magnetic clutches are small enough to be applicable in these applications, but their weight and high power consumption offset their benefits. Robot designers are finding that even for functions where clutches are sometimes better suited, such as maintaining static joint posture, they can be performed just as effectively and at a lower cost using existing motors.

[0006] Electrostatic clutches can be a lightweight, compact, and energy-efficient solution. At a comparable performance level, electrostatic clutches are significantly lighter than electromagnetic clutches and can consume approximately 1 / 1000th of the power when in operation. Electrostatic clutches can offer advantages over existing solutions in one or more of the following areas: improved precision and accuracy of force limiting, compactness, reduced overall weight, improved energy efficiency, improved controllability and responsiveness, simplified configuration and reduced part count, reduced heat generation, and reduced cost. However, several challenges limit the miniaturization of rotating clutches and affect their performance.

[0007] Traditional electrostatic clutch designs employ an inner electrode that interacts with the shaft and an outer electrode that interacts with the housing. These electrodes have features or are attached to structural members that interact with the shaft or housing. Typical examples of these features include splines, gear teeth, or keyways. These elements introduce backlash into the system, occupy radial space, and limit torque transmission capabilities.

[0008] As mentioned above, markets where mass and power consumption are design considerations represent promising potential markets for electrostatic clutches. Many products in this field are highly specialized, employing frameless motors and custom gearboxes selected to fit into custom housings. It would be beneficial for electrostatic rotary clutches to be easily customized in terms of overall length and diameter, allowing for easy integration into these specialized assemblies. Furthermore, it would be beneficial to develop electrostatic clutches that overcome the limitations of conventional designs, allowing for implementation in a wide range of applications. Summary of the Invention

[0009] In one embodiment, the rotating clutch comprises multiple electrostatically attracted clutch units stacked on top of each other. Each clutch unit is modular and can be connected to as many other clutch units as needed to form a clutch. This clutch has advantages over conventional electrostatic clutches that use an external housing to provide an environmental seal and mechanically connect the clutch unit to the input or output of a device. This clutch configuration also allows for efficient manufacturing and assembly methods. End caps and adapters can be used to connect to a variety of input and output configurations, including keyed shafts and flanged attachments. Additionally, this clutch can be used in a frameless configuration.

[0010] In a rotating clutch, the amount of torque each pair of clutch electrodes can generate is largely dependent on the diameter of the clutch interface, i.e., the area where the clutch electrodes overlap to generate an attractive force. Because torque is proportional to the cube of the radius, increasing the diameter of the clutch interface is advantageous for performance, especially when it can be achieved without increasing the diameter of the entire clutch device. Furthermore, multiple clutch electrodes acting in parallel increase the amount of force or torque the clutch can generate. The clutch of the present disclosure increases the number of clutch electrodes that can be placed per unit length of the rotating clutch, thereby improving the torque-to-length ratio.

[0011] By using a stacked or laminated construction clutch unit, the clutch members form a type of one-piece housing, eliminating the need for a structural housing to transfer loads from the set of clutch members to the output. Advantages of this clutch include a reduction in the overall number of components, as well as the ability to easily and quickly customize the length and torque capacity of the clutch by selecting the number of clutch units in the stack. This clutch is also well-suited for applications where a frameless design is preferred. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating the principle of electrostatic adsorption.

[0013] [Figure 2] FIG. 2 is an assembly diagram of the closed clutch unit.

[0014] [Figure 3] FIG. 2 is an exploded view of the closed clutch unit.

[0015] [Figure 4] FIG. 10 is an exploded view of a closed clutch unit according to another embodiment.

[0016] [Figure 5]FIG. 1 is an assembly diagram of a rotary clutch body having a plurality of clutch units.

[0017] [Figure 6] 10A-10C illustrate an adapter and internal structural members with an enhanced mechanical interface.

[0018] [Figure 7] 1 is an assembly diagram of a clutch body with multiple clutch units, an internal clutch member adapter, and an electronics housing.

[0019] [Figure 8] FIG. 1 is an exploded view of a clutch body with multiple clutch units, an internal clutch adapter, and an electronics housing.

[0020] [Figure 9] FIG. 1 is an exploded view of an open clutch unit having planar outer clutch electrodes and spacers.

[0021] [Figure 10] FIG. 1 is a diagram showing an open clutch unit having an L-shaped cross section in the diametrical direction.

[0022] [Figure 11] 1 is a cross-sectional view of an embodiment of an open clutch unit having an L-shaped cross section.

[0023] [Figure 12] FIG. 1 is an assembled view of two open clutch units with outer clutch members of L-shaped cross section.

[0024] [Figure 13] A closed clutch element with a T-section outer clutch member structure.

[0025] [Figure 14] FIG. 10 shows a closed clutch element with an L-section outer clutch member structure.

[0026] [Figure 15] FIG. 10 shows two closed clutch units with steps in the outer clutch member structures to allow for self-alignment.

[0027] [Figure 16] FIG. 1 shows an open clutch unit with a T-section outer clutch member.

[0028] [Figure 17] FIG. 1 shows a clutch with shaped outer clutch members to transfer torque to corresponding recesses in a larger mechanical structure.

[0029] [Figure 18] FIG. 2 is an exploded view of a ball bearing with a clutch mechanism.

[0030] [Figure 19] 1 illustrates an embodiment of a frameless clutch body with multiple clutch units, slip rings, and electrical connectors.

[0031] [Figure 20] 10A and 10B are views showing a frameless clutch body according to another embodiment.

[0032] [Figure 21] 13A and 13B show a clutch body made up of multiple clutch units with surface mounts and keyway adapters according to another embodiment.

[0033] [Figure 22] 10 shows a closed clutch unit with two separate outer clutch member structures according to another embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0034] Disclosed herein is a clutch 100 including multiple clutch units 110 that cooperate to provide a load for resisting relative rotational motion between a mechanical input and output. FIG. 1 illustrates the basic structure of an electrostatic clutch. The electrostatic clutch shown in FIG. 1 includes a pair of clutch elements each including a counter electrode 102 and a dielectric member 103 separating the opposing electrodes 102. A controller 140 applies a voltage between the electrodes 102. The maximum resistance obtained before slippage occurs can be controlled by adjusting the voltage applied to the clutch. For simplicity, the term "clutch element" may refer to an element or a collection of elements that function as an electrode 102 and can transmit a mechanical load generated by electrostatic attraction. Examples of clutch elements include a single electrode 102, an electrode 102 with a carrier, or a rigid substrate coated with a conductive layer. The clutch element may also include a dielectric member. Furthermore, the term "clutch interface" refers to the overlapping area of ​​the input electrode 102 and the output electrode 102 where adhesion occurs in a connected state, and may also refer to the opposing surfaces of the clutch members that contact each other.

[0035] The rotary electrostatic attraction clutch 100 includes one or more clutch units 110. FIG. 2 shows a single clutch unit 110, which includes at least one clutch member associated with a mechanical input and one clutch member associated with a mechanical output. These clutch units 110 can be combined to form a clutch 100 capable of transmitting a greater mechanical load than a single unit 110 alone can transmit. The clutch 100 can be expanded to a clutch of any size and torque capability by combining it with any number of additional clutch units 110.

[0036] Referring again to FIG. 2 , the clutch unit 110 further includes a reinforcing structure 111, which may include an outer structure 111 and an inner structure 111. Each of these reinforcing structures 111 has a clutch member disposed therein. In the embodiment shown in FIG. 2 , the outer structure 111 is ring-shaped and has a plurality of holes formed around its outer periphery. These holes are used to fasten the clutch unit 110 to additional units 110 as well as to attach it to a larger mechanical structure. The reinforcing structure 111 may also include conductive regions for establishing electrical connections between adjacent units 111. The outer reinforcing structure 111 is connected to two clutch members or electrodes 102. These two outer clutch members surround the inner clutch member or electrode 102. In other words, the inner electrode 102 interacts with the first outer electrode 102 on one side and the second outer electrode 102 on the opposite side. In this embodiment, the inner clutch member includes a tooth-shaped profile as a mechanical interface with the splined shaft. The side view of FIG. 2 shows that the clutch unit 110 has a thin structure.

[0037] FIG. 3 is an exploded view of the clutch unit 110 shown in FIG. 2. The reinforcing structure 111 is similar in structure to a printed circuit board. For example, the reinforcing structure 111 is made of an FR4-grade glass fiber substrate with conductive pads on its surface. Vias establish electrical connection between the conductive areas on the upper and lower surfaces of the reinforcing structure 111. The outer and inner edges of the reinforcing structure 111 are made of glass fiber and are therefore insulated from the conductive pads. The clutch electrode 102 is bonded to the reinforcing structure 111 using an annular pressure-sensitive adhesive or similar connection mechanism. Electrical connection to the outer clutch electrode 102 is established by the conductive adhesive.

[0038] In this embodiment, the outer clutch electrodes 102 are electrically isolated from one another, allowing a potential difference to be applied therebetween. The inner clutch member is a single component that functions as both the reinforcing structure 111 capable of transmitting mechanical loads and the electrode 102. A dielectric member 103 separates the inner and outer clutch electrodes 102 and may be disposed on the outer set, the inner set, or both sets of clutch electrodes 102. In this embodiment, the inner clutch member is electrically isolated, and its only electrical connection to the clutch circuit or controller 140 is through the clutch interface located between the surfaces of the inner and outer electrodes 102. In this configuration, the clutch unit 110 acts as two capacitors in series, with the interface between each pair of outer and inner clutch electrodes 102 acting as one capacitor. The inner clutch electrode 102 experiences a potential intermediate that experienced by the outer electrodes 102.

[0039] In the embodiment shown in FIG. 2, there is one inner clutch electrode 102 and two outer electrodes 102, and the outer clutch electrodes 102 are flexible. These flexible electrodes 102 may be constructed from a single continuous piece of material, such as a thin sheet of stainless steel. Alternatively, the outer electrode 102 may be constructed from multiple materials, such as a polymer carrier, a thin coating of conductive material, and a dielectric coating 103 on the surface of the conductive material. In this embodiment, each unit 110 includes two outer electrodes 102 for the outer clutch member. This type of clutch unit 110, in which two outer electrodes 102 surround one or more inner electrodes 102, is referred to as a "closed" clutch unit 110. Each closed clutch unit 110 can function as a clutch either alone or in combination with additional clutch units 110.

[0040] As previously mentioned, each pair of electrodes 102 must include a dielectric member 103 disposed therebetween, with at least one of the electrodes 102 being flexible or semi-flexible. These general design characteristics can be achieved through a variety of configurations. The flexible electrodes 102 are disposed on a reinforcing structure 111, which may be constructed of machined metal, sheet metal, fiberglass, or other materials. Mechanical attachment of the flexible electrodes 102 to the reinforcing structure 111 can be achieved by pressure-sensitive adhesives, glue, thermal lamination, clamping between clutch units 110 or other components, laser sintering, welding, stitching, or other attachment methods. The attachment method may be applied to the entire flexible electrode 102 that overlaps the reinforcing structure 111, or only to the portion of the flexible electrode 102 that overlaps the reinforcing structure 111.

[0041] FIG. 4 illustrates an embodiment of a clutch 100 that includes two electrodes 102 forming an inner clutch member and two electrodes 102 forming an outer clutch member. In this embodiment, the outer clutch member includes a flexible electrode 102. These flexible electrodes 102 may be constructed from a single continuous member, such as a thin sheet of stainless steel. Alternatively, they may be constructed from multiple members, such as a polymer carrier, a thin coating of conductive material, and a dielectric coating 103 applied to the conductive material. In the embodiment shown in FIG. 4, an electrical connection is established between the outer electrode 102 and an outer reinforcing structure 111 using a conductive adhesive. The inner clutch member is constructed from a reinforcing structure 111 with toothed elements for interfacing with an overlying mechanical structure. The inner flexible electrode 102 is adhered to the inner structure 111 using a patterned pressure-sensitive adhesive. Additionally, an electrically conductive ring coated with a conductive adhesive is used to establish an electrical connection between the electrode 102 and a conductive region on the surface of the inner structure 111. The ring is in electrical contact with both the electrode 102 and the conductive region on the inner structure 111.

[0042] The conductive regions on the top and bottom surfaces of the reinforcing structure 111 are electrically connected by vias. Alternatively, this electrical connection between the inner electrodes 102 may be achieved by simple gluing, mechanical clamping, using any structural element that is conductive in bulk, using pass-throughs or cutouts, or by using a single folded electrode 102. For example, the inner electrode 102 may be one continuous piece of material folded around the inner structural member 111.

[0043] FIG. 5 illustrates one embodiment of a large clutch structure, a clutch body 115, that includes multiple clutch units 110. In this embodiment, the clutch units 110 are the units 110 shown in FIG. 4. In this embodiment, multiple clutch units 110 are stacked to form a rotating clutch capable of transmitting greater torque than a single clutch unit 110. While three clutch units 110 are shown in FIG. 5, any number of clutch units 110 may be used. Additionally, the clutch units 110 are separated by spacers 116 to prevent interference between the outer electrodes 102 of adjacent units. Electrical connections are established through tabs on the leftmost top cap. This top cap protects the flexible electrodes 102 of clutch unit 110b and serves as an electrical connection to the upper structure on which the clutch body 115 operates. Similarly, the rightmost bottom cap protects the lower clutch unit 110 from damage but does not provide any electrical connections.

[0044] The top cap, spacer 116, and clutch unit 110 all have patterned conductive areas that align with each other, allowing voltage to be transferred by mechanical contact between the top cap and top spacer 116. Vias in the spacer 116 transfer the voltage to its underside, which then transfers the voltage to the next clutch unit 110 by mechanical contact. This pattern is repeated until all clutch units 110 are electrically connected. In this embodiment, no separate electrical connection to the inner clutch members is required. The outer edges of the clutch unit 110 are non-conductive, and the assembled clutch body 115 is insulated by the clutch unit's own reinforcing structure 111 and the upper and lower end caps.

[0045] Mechanical attachment between the clutch units 110 is achieved by mechanically fastening them using holes formed in the clutch members with rivets, bolts, stakes, or other attachment mechanisms. This clutch 100 design contrasts with conventional designs in which the outer structural elements of the clutch members individually fit into housing or adapter components to transmit torque. Conventional housing members are often monolithic structures with fixed lengths. Furthermore, upon actuation into a connected state, each clutch member moves from its rest position within the housing, compressing the entire clutch member stack. In contrast, the clutch member outer reinforcing structure 111 or rigid outer electrode 102 of the present invention forms a composite structure capable of transmitting torque through the mechanical connection between the clutch units 110, while maintaining the relative position of the clutch units 110.

[0046] The individual clutch units 110 may be mechanically connected by various means. Multiple clutch units 110 may be stacked and connected by welding or laser sintering, with torque being transferred between the units 110 via the welds. In other embodiments, the clutch units 110 may be mechanically connected by adhesives such as adhesive varnishes, epoxies, or polymers. In still other embodiments, the clutch units 110 may be connected by additional mounting hardware. Rivets, stakes, or bolted connections may be used to connect and transfer torque between the clutch units 110. This connecting hardware may transfer torque through shear loads at the fastener body 115 or may clamp the clutch units 110 together and transfer most of the torque load through friction between interacting surfaces on adjacent clutch units 110. In embodiments that include connecting hardware, bolt circles or notches may be formed in each clutch unit 110. In some embodiments, most or all of the torque is transferred to the external mechanical structure by friction between the clutch member outer reinforcing structure 111 or the rigid outer electrode 102. The inner clutch member is connected to the splined shaft using a toothed connection.

[0047] As previously mentioned, the clutch body 115 is a composite structure formed by multiple clutch units 110 to function as the complete clutch 100. The clutch body 115 may be comprised of a single individual clutch unit 110, a stack of identical clutch units, or a stack of identical clutch units with additional components. Additionally, the clutch body 115 may include a mechanical input, a mechanical output, and means for establishing electrical connections to a larger electromechanical system.

[0048] FIG. 6 shows another form of inner reinforcing structure 111 that mechanically interfaces with a pin, which may be located on an external structure or an input / output element. In this embodiment, the notch is reinforced with a material different from the base material of the reinforcing structure 111. This reinforcement may be achieved by a plating process. In other embodiments, a separate component, such as a tube or molded insert, may be inserted into the reinforcing structure 111 and held in place by a press fit, adhesive, epoxy, or other means. This type of interface may be applied to connectors with spline, pin, hex, star, or any other shape.

[0049] Figure 7 shows yet another embodiment of the clutch 100, in which ten clutch units 110 are stacked together with end rings and end caps. The end caps hold the inner clutch member adapters 125 and protect the flexible electrodes from damage. The end rings are provided with electronics housings to which electrical connectors can be attached.

[0050] As a further example, FIG. 8 shows an exploded view of the embodiment shown in FIG. 7. The clutch 100 in this embodiment includes an adapter 125. The adapter 125 functions as a splined shaft and can be press-fit onto a circular shaft included in the higher mechanical structure 120 on which the clutch operates. The laminations and end rings of the clutch unit 110 are fastened together using stakes, rivets, bolts, or other fasteners. The adapter 125 may include set screws, split hub clamps, press fits, keyways, or other fasteners or features to allow the clutch 100 to be attached to the mechanical input 120. This embodiment of the clutch body 115 is "frameless," meaning that it does not include holes for bolt attachment to the higher mechanical structure 120.

[0051] In the embodiment shown in Figure 8, the electrical connector shown is a Zero Insertion Force (ZIF) connector designed to interface with a flexible or ribbon cable. The type of cable and connector is not critical other than that they be compact and appropriately sized for the current.

[0052] The connector of the inner clutch member is mechanically connected to the adapter. The clutch cap acts as a seal to protect the clutch 100 from foreign matter. End rings and secondary caps are used to protect the flexible electrodes 102 on the end clutch units 110. In this example embodiment, the stack of clutch units 110 is held together by rivets. In other embodiments, the bond between the clutch units 110 may be formed by epoxy bonding agents, polymer bonding agents, rubber bonding agents, varnish, laser welding, spot welding, wire welding, bolting, sintering, or other attachment means.

[0053] The adapter 125 shown in FIG. 8 has a rounded inner notch for press-fit onto the shaft. The notch may be keyed, splined, or otherwise shaped to interface with the clutch's mechanical input or the surrounding mechanical system 120. Some embodiments do not include the inner clutch member adapter 125. In some embodiments, the mechanical input 120 to the clutch 100 directly engages the inner clutch member of each clutch unit 110. In other embodiments, multiple inner clutch members are stacked using any of the coupling methods described above. A clutch 100 including one or more clutch units 110 may include components 130 at one or both ends of the clutch unit stack. These end components 130 may serve a variety of purposes, including, but not limited to, housing electronics or a controller 140, housing sensors, or electrically insulating the clutch unit 110. Additionally, these end components 130 may include, but are not limited to, flanges, through-holes, threaded holes, split-hub clamps, other clamping mechanisms, or other mechanisms for connecting to the input or output of the clutch 100. These end components 130 may include one or more electrode pairs, or none at all.

[0054] For electrostatic attraction to occur between opposing electrodes 102, they must be subjected to a potential difference. Therefore, when connected, the inner and outer electrodes 102 must remain electrically isolated from each other via the dielectric member 103. The electrostatic attraction effect can be stopped by shorting the inner and outer electrodes 102 and equalizing their potentials using a controller 140 using a relay, transistor, MOSFET, or other circuit. In some embodiments, the outer clutch member electrodes 102 are connected in series to the terminals of the power supply or controller 140. In other embodiments, each of the outer clutch member electrodes 102 is electrically connected in parallel to the terminals of the power supply or controller 140. In some embodiments, attraction and torque transmission can be activated by applying a positive voltage to all inner clutch member electrodes 102 and a negative voltage to all outer clutch member electrodes 102. Furthermore, in some embodiments, each clutch member can be individually activated by applying a positive voltage to one clutch member electrode 102 and a negative voltage to the other clutch member electrode 102.

[0055] Several electrical configurations are possible for controlling the clutch unit 110 between engaged and disengaged states. In some embodiments, the inner clutch members receive power via a slip ring connection. In some embodiments, the inner clutch member electrodes 102 are electrically connected to each other in series to the rotary slip ring contacts. In other embodiments, each of the inner clutch member electrodes 102 is electrically connected to the rotary slip ring contacts in parallel. When multiple inner clutch members are connected in series, the electrical connection between them may be maintained by spring finger connections, conductive washers, pogo pins, permanent wiring connections, solder rods, vias, flex cables, or other electrical connections. When the inner clutch electrodes 102 are connected in parallel, the electrical connection may be made solely by mechanical contact via the adapter 125 or splined shaft. In other embodiments, the inner clutch members may receive voltage in a parallel configuration via slip rings or other methods.

[0056] In other embodiments, no systematic electrical connection to the movable clutch member is required. This is accomplished by electrically connecting two or more inner clutch members. A potential difference is then applied between two or more stationary clutch members such that the movable clutch member electrode 102 is located between them and is connected only through the dielectric member 103 separating the electrodes 102. The movable clutch electrode 102 will be at a potential intermediate the voltages applied to the upper and lower stationary electrodes 102.

[0057] The clutch 100, including one or more clutch units 110, may be connected to the host machine 120 by a variety of means, including clamping around a flat surface of the clutch 100 or the outer periphery of the clutch body 115, bolting to a flange or surface, press-fitting, keying, shaft mounting, or other methods of attachment. The clutch units 110 may be disposed within a housing, insulating enclosure, or sleeve 126. This enclosure may be for electrical insulation, structural, or aesthetic purposes. The stacked rotating clutch 100 may be surface-mounted, flange-mounted, shaft-mounted, clamped, keyed, or otherwise configured to connect to the mechanical inputs / outputs of the host machine system 120.

[0058] FIG. 9 shows another embodiment of a clutch unit 110, in which the outer clutch member includes a planar outer clutch member and an annular spacer, with the outer clutch member serving as a reinforcing structure 111. In this embodiment, the repeating clutch unit 110 includes only one outer electrode 102. In this embodiment shown in FIG. 9, the inner clutch member includes two flexible electrodes 102, and the outer clutch member may be flexible or rigid. The first of the inner clutch electrodes 102 is paired with the included outer clutch member. The other inner clutch electrode 102 is paired with the outer electrode 102 of an adjacent clutch unit 110 when multiple units 110 are stacked. The outer clutch member electrode 102 may be conductive on both planar surfaces, with or without an insulating carrier sandwiched therebetween. This is an example of an “open” clutch unit. Here, an “open” clutch unit 110 refers to a clutch unit 110 configured to be stacked with additional units 110, such that a clutch interface exists between adjacent units 110.

[0059] 10 shows one embodiment of an open clutch unit 110 having outer clutch members with an L-section reinforcing structure 111. In this configuration, the mechanical connection between the clutch units is established through the outer reinforcing structure 111. The outer structure 111 may be composed of multiple separate components that are combined before or during assembly of the clutch unit 110 stack. The components may be held together by adhesive or other bonding methods, press fits, bolts, rivets, or other mechanical connections, or surface friction caused by normal loading of the entire stack.

[0060] FIG. 11 shows a cross-sectional view of the embodiment shown in FIG. 10, where the reinforcing structure 111 is L-shaped and is incorporated into an open clutch unit 110. In this embodiment, the inner clutch member is flexible and is composed of a polymer carrier with an electrode 102 disposed on one side. A dielectric 103 is then placed on the electrode 102. The composite clutch member is adhered to the inner clutch structure 111 using a pressure-sensitive adhesive. One of the inner clutch members interfaces with an outer clutch member, which in this exemplary embodiment is rigid. The other inner clutch member must interface with a single clutch member disposed in another clutch unit 110 or an end cap.

[0061] Figure 12 shows two of the clutch units 110 shown in Figure 11 assembled together. As shown in Figure 12, one of the inner electrodes 102 of the lower clutch unit 110 forms a clutch interface with the outer electrode of the upper clutch unit 110. The thickness of the members is controlled to maintain a small gap that can be closed by the displacement of the flexible electrode 102 when a voltage is applied. In other embodiments, the thickness of the members is controlled so that the clutch members are in contact with each other even when no voltage is applied.

[0062] The outer clutch members shown in Figures 9-12 may be constructed from a single component fabricated to the desired shape, or from a permanent assembly of several components assembled before or during lamination, with or without the use of alignment tools, or from multiple components compressed together during or after lamination. For example, the outer clutch of Figure 9 may be constructed as a single component, or as two flat components stacked one on top of the other.

[0063] 13 shows another embodiment of a closed clutch unit 110 in which the outer clutch member comprises a T-section reinforcing structure 111 and two electrodes 102 surrounding the inner clutch member. In this configuration, the mechanical connection between the clutch units 110 is established via the outer portion of the reinforcing structure 111 of the outer clutch member. The electrodes 102 in this embodiment are flexible and are adhered to the outer reinforcing structure 111 using a pressure-sensitive adhesive.

[0064] FIG. 14 shows a closed clutch unit 110 in which an outer clutch member structure 111 has an L-shaped cross section, an inner clutch member is disposed in a central space, and two outer electrodes 102 surround the inner clutch member.

[0065] FIG. 15 illustrates a clutch unit 110 having a self-aligning reinforcing structure 111. In this configuration, the outer reinforcing structure 111 includes a recess on one side into which another identical unit can be placed. In some embodiments, the self-aligning feature can be a recess having a shape that can transfer torsional loads between the clutch units 110. The shape can include, but is not limited to, a spline, a keyed shape, a hexagon, a wave shape, other polygonal shapes, a star shape, or an abstract shape. In some embodiments, the self-aligning feature can include a corresponding recess and protrusion structure having a shape that can transfer torsional loads between the clutch units 110. The shape can include, but is not limited to, a spline, a keyed shape, a hexagon, other polygonal shapes, a star shape, or an abstract shape. These self-aligning configurations can also be achieved with an open clutch unit 110. In this embodiment, the outer clutch member electrodes 102 are each bonded to one surface of the inner clutch member. Other methods of alignment between clutch units 110 include holes with alignment pins or dowels, matching positive and negative features, or mechanical constraints on tubes or other features that remain or are removed after assembly.

[0066] 16 shows one embodiment of an open clutch unit 110 with an outer clutch member having a T-section reinforcing structure 111. The inner clutch member may include keyed or splined holes or recesses for connection to a shaft or other mechanical input or output, but these are not shown in the figure to maintain clarity of the cross-sectional view.

[0067] An intermediate component may be used to interface the inner reinforcing structure 111 and the mechanical input or output of the surrounding mechanical system 120. This component is referred to as an adapter 125. For example, FIG. 8 is an exploded view of a clutch assembly in which a splined adapter 125 interfaces with the splines of the inner clutch member. The adapter 125 may include a bore for a press fit onto a shaft. In other embodiments, the bore may include a key for interfacing with a keyed shaft. In other embodiments, the adapter 125 may include a shaped bore for interfacing with a similarly shaped input, such as a D-shaft or hex shaft. The inner clutch member may also be mechanically attached to the adapter 125 with epoxy, welding, a retaining ring, or other attachment. The adapter 125 may include an electrical isolation element to electrically isolate the inner clutch electrode 102 from the input shaft.

[0068] FIG. 17 illustrates an embodiment of a rotating clutch 100 configured so that the shape of the clutch body 115 is constrained by a matching negative shape in the higher-level mechanical system 120. This eliminates the need for an intermediate housing component with an internal shape that matches the shape of the outer clutch body 115 and an external mounting mechanism that connects to the larger mechanical structure 120. The shape may be square, rectangular, hexagonal, star-shaped, D-shaped, keyed, generally polygonal, oval, or abstract. Similarly, the periphery of the clutch unit 110 may be shaped to interact with an adapter or housing to enable the transfer of mechanical loads to the larger mechanical structure 120. The adapter may be electrically isolated.

[0069] FIG. 18 illustrates an embodiment in which a clutch unit 110 includes rollers, a roller cage, and inner and outer rolling surfaces. The rollers, roller cage, and inner and outer rolling surfaces are known in the art as ball bearings. The clutch-equipped ball bearing rotates freely when not in operation and is prevented from rotating, or even locked, when in operation. The clutch unit 110 includes a clutch member mechanically attached to the inner race of the bearing and a clutch member mechanically attached to the outer race of the ball bearing. The illustrated clutch member extends beyond the outer diameter of the inner race and overlaps a portion of the gap between the races. In other embodiments, the inner clutch member does not extend beyond the outer diameter of the inner race, or the inner clutch member itself is the inner race. The outer clutch member extends from the surface of the outer race and substantially overlaps the inner clutch member. Electrical connections may be made directly through the shaft and bearing cup. The stationary clutch member may also include electrical wires, a clamp tail, or other connectors for establishing electrical connections. The rotating clutch member may maintain electrical connection through an interface with the shaft or housing, or through a slip ring or other sliding electrical connection. This type of clutch unit 110 may be used alone, in multiples, or in combination with clutch units 110 that do not have roller elements. Additionally, other embodiments that place rolling elements between the inner and outer clutch members may not include a ball cage. Cylindrical rollers may be used instead of balls. This type of clutch unit 110 may be used alone, in multiples, or in combination with clutch units that do not have roller elements.

[0070] 19 shows a frameless clutch body 115. This embodiment does not have bolt holes or other engagement features for engaging fasteners such as screws, but instead is intended to be press-fit or clamped into a housing integrated into an upper structure 120.

[0071] FIG. 20 shows an embodiment in which the clutch body 115 is mounted on a shaft. The input and output are each mounted on a shaft. One shaft is connected to the end cap 130 and thus to the outer clutch member. The other shaft is mechanically attached to the inner clutch reinforcement structure 111. In other embodiments, the housing can serve as the input and be mounted via a face or flange mount, while the output may be a shaft that extends through the body of the clutch 100 and directly interacts with the inner clutch member. One or more bearings may be mounted to the end cap 130 or to other plate-like components at an intermediate location in the assembly.

[0072] Figure 21 shows one embodiment of a clutch 100 comprised of multiple clutch units 110. The mechanical input for this clutch is a threaded hole arrangement for surface mounting. The output is an adapter 125 mechanically connected to the inner clutch member, which includes a keyway for mounting to a keyed shaft. An overmolded electrical connector is attached to the end cap 130, and a thin sleeve 126 covers the clutch stack for environmental sealing. Because this sleeve 126 does not need to transmit mechanical loads, it is thinner than the housing of a conventional electrostatic clutch. The sleeve 126 for electrical insulation or environmental protection can be a rigid sleeve 126 made of metal, plastic, or composite material, or a flexible sleeve 126 formed from heat-shrink tubing. The sleeve 126 can also be a conformal coating that is applied in a liquid form and cured.

[0073] 22 shows one embodiment of a disassemblable closed clutch unit 110. The clutch unit 110 comprises two outer clutch members, each disposed on its own outer reinforcing structure 111. The outer clutch members are electrically connected to their respective outer reinforcing structures 111 via conductive adhesive. The outer reinforcing structures 111 are electrically connected to each other and to other identical clutch units 110 via mechanical contact of their conductive surface areas. The two outer clutch members surround an inner clutch member. Bolt holes allow the clutch units 110 to be fastened together as a single unit or as part of a larger clutch body 115.

[0074] Each of the disclosed embodiments may be used singly or in multiples. Each clutch must include at least two electrodes 102, but may include any number of electrodes 102.

[0075] In some embodiments, the clutch 100 may operate in response to sensor data from an accelerometer, a pressure-sensitive switch, an IMU accelerometer, a biosensor such as an EMG sensor, an optical sensor, an encoder, or the like. For example, some embodiments of the rotating clutch 100 may include a sensor internal or external to the clutch 100 to measure the rotation of the clutch 100 and / or its associated joint in the host device or mechanical system 120. The sensor may be an optical sensor, a magnetic sensor, an electric brush or spring finger contact interacting with a patterned conductive surface, or an inductive sensor. The signal from the sensor may be used to inform or control the behavior of the clutch. For example, a higher voltage may be commanded near the end of the host device's range of motion and a lower voltage may be applied near the center of the range of motion. The clutch 100 may also include sensors, such as a strain gauge, multiple strain gauges, or a fluid pressure sensor, to measure applied and / or transmitted torque. Additionally, the clutch 100 may include temperature, humidity, barometric, chemical, and other sensors to provide information to the clutch controller 140.

[0076] While the features disclosed in the foregoing description, the claims, or the accompanying drawings are, where appropriate, expressed in a specific form or in terms of means for performing a disclosed function or a method or process for achieving a disclosed result, these features can be utilized individually or in any combination of such features to realize the invention in various of its forms. In particular, one or more features of any of the embodiments described herein may be combined with one or more features of any of the other embodiments described herein.

[0077] Protection may also be sought for any feature disclosed in any one or more documents referenced in connection with and / or incorporated by reference in this disclosure.

Claims

1. The vehicle is provided with a plurality of clutch units, each of which is A reinforcing structure; a first electrode; a second electrode; and a dielectric member disposed between the first electrode and the second electrode; It is equipped with An electrostatic attraction clutch, wherein at least one of the first electrode and the second electrode is flexible.

2. 2. The electro-adhesive clutch of claim 1, wherein each clutch unit of said plurality of clutch units is a rotary clutch.

3. 10. The electro-adhesive clutch of claim 1, wherein each clutch unit of said plurality of clutch units is modular.

4. The electric adsorption clutch of claim 1 , wherein outer clutch units of the plurality of clutch units are physically and electrically connected.

5. The electrostatic attraction clutch according to claim 1 , wherein adjacent clutch units among the plurality of clutch units are physically and electrically connected to each other.

6. At least one clutch unit of the plurality of clutch units further includes a third electrode disposed adjacent to the second electrode opposite the first electrode; 2. The electrostatic attraction clutch of claim 1, wherein the first electrode and the third electrode surround the second electrode to form a closed clutch unit.

7. 2. The electrostatic attraction clutch according to claim 1, wherein at least one clutch unit of the plurality of clutch units has a second electrode that is open on one side, forming an open-type clutch unit.

8. 10. The electrostatic attraction clutch of claim 1, wherein the electrostatic attraction clutch is frameless and is attached to a surrounding mechanical system using a mounting mechanism.

9. The electrostatic attraction clutch of claim 8 , wherein the attachment mechanism includes a bolt, a rivet, or a fastener.

10. The electrostatic attraction clutch of claim 1 further comprising an adapter.

11. 11. The electrostatic attraction clutch of claim 10, wherein the adapter is electrically insulating.

12. 11. The electrostatic attraction clutch of claim 10, wherein an outer clutch member of each clutch unit of said plurality of clutch units is electrically isolated from mechanical input.

13. 11. The electrostatic attraction clutch of claim 10, wherein the inner clutch member of each clutch unit of the plurality of clutch units is electrically isolated from mechanical input.

14. 2. The electrostatic attraction clutch according to claim 1, wherein at least one clutch unit of the plurality of clutch units has a different configuration than another clutch unit of the plurality of clutch units.

15. The electrostatic attraction clutch of claim 1 , wherein at least one clutch unit of said plurality of clutch units further comprises an integrated ball bearing.

16. The electrostatic attraction clutch of claim 1 , wherein the plurality of clutch units are connected without an external housing.

17. The electrostatic attraction clutch of claim 1 , wherein the plurality of clutch units are connected to form an integrated housing.

18. The electrostatic attraction clutch according to claim 1 , wherein the plurality of clutch units are electrically connected in series.

19. 10. The electrostatic attraction clutch of claim 1, wherein said reinforcing structure is electrically conductive.

20. 10. The electrostatic attraction clutch of claim 1, wherein the reinforcing structure is partially conductive and partially non-conductive.

21. 21. The electrostatic attraction clutch of claim 20, further comprising an electrical connection through the reinforcement structure using vias.

22. 20. The electrostatic attraction clutch of claim 18, wherein at least one of the first electrode and the second electrode is connected as one continuous electrode.

23. 2. The electrostatic attraction clutch of claim 1, further comprising a sleeve surrounding an outer portion of said reinforcing structure.

Images