JPH02150501A - Fluid actuator - Google Patents

Abstract

PURPOSE: To dispense with installation of an airtight seal by moving a ring type piston on the axial inside and outside of a closed circular ring type diaphragm and forming an inside rotational lobe and an outside rotational lobe on the inside and outside faces of the ring type piston individually. CONSTITUTION: A ring type piston 40 provided with a diameter D5 ranging between an inside diameter D4 and an outside diameter D3 of a diaphragm 12 moves in the axial inside and outside of the diaphragm 12, and inside rotational lobe 42 and an outside rotational lobe 43 moving upward and downward on the inside face 44 and the outside face 45 of the ring type piston 40 are formed. The inside wall 44 and the outside wall 45 of the ring type piston 40 are related to each other so that a variable effective area is formed on a stroke of a fluid actuator 10 when they make a certain angle with respect to a cylinder 24. In this way, load supporting ability of the actuator 10 on a stroke and a spring rate are changed. A fluid conduit 50 charges/discharges fluid into/from an internal working space 16 so as to vary an internal pressure of the diaphragm 12.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to fluid springs or actuators designed to use fluids, including incompressible and compressible fluids. The fluid actuator is in particular of the rotating lobe type, in which a flexible membrane rotates axially on the outer surface of the piston.

BACKGROUND OF THE INVENTION Conventional air springs use a flexible, airtight membrane that is secured by some means to a piston at one end and to an upper retainer at the opposite end.

The upper retainer forms an internal working space between the three elements for enclosing the intended fluid. However, attaching flexible rubber membranes to rigid components has long been a source of leakage and failure of air springs and air actuators. The flexible member may have a bead structure at its distal end and is attached to a suitably formed bead seating portion of the rigid member. In other common configurations, the axially extreme ends of the flexible member are banded, swaged, or compressively engaged to the outer surface of the rigid member, making the ends airtight. I keep it.

During use of conventional beaded, swaged air spring structures, failures and air leaks at the interface between the rigid member and the flexible membrane are very common.

In conventional tire technology, the toroidal elastomer composite structure shows superior ability to withstand high internal pressures due to the even distribution of force in the toroidal shape, and the reinforcement fabric placed on the bias creates smooth curves. It is known that forces can be uniformly distributed on the surface of a toroid depicting . While a tire is an open torus in which the rim or wheel of a vehicle closes the torus by utilizing the bead structure of the tire, the present invention provides a closed toroidal shape that withstands high internal pressure. membrane is used. This closed torus also presents the distinct advantage that no sheets or seals are required for air spring assembly and operation. moreover,
The fluid actuator of the present invention includes a central passageway along the entire axial length of the actuator, through which any shaft, damper, or other desired member passes. This shape is particularly useful for use as a clutch, where the drive shaft passes through the actuator. Since the central hub or axle conveniently passes through the central passage, it is also particularly suitable for use as a brake. A third aspect of Applicant's invention is the formation of dual concentric rotating lobes by an annular piston, which moves axially inward and outward of a closed toroidal diaphragm, An inner rotary lobe and an outer rotary lobe are formed on the inner and outer surfaces of the piston, respectively. This configuration has the advantage of a higher lateral spring rate and greater stability than a standard air spring, but results in a lower axial spring rate than a simple bellows air spring. It may also include a central shaft, axle, and shock absorbers, but no airtight sealing is required.

The fluid actuator of the present invention has the advantage that there is no need to install a hermetic seal on the rotating lobe spring assembly. Furthermore, the closed toroidal shape simplifies the structure of the flexible membrane. Also, since there is no obstruction in the center of the air spring or actuator, components of the device in which the air spring or actuator is used may pass through the central passage.

The above advantages are realized by using an actuator that moves along an axis with a predetermined stroke, the fluid actuator having a pair of concentric rotating lobes and an open passage passing through the actuator coaxially with the axis. a closed toroidal diaphragm,
including an annular piston, an annular cylinder and a fluid port;
A closed toroidal diaphragm is made of a strong, flexible elastomer and has an inner diameter and an outer diameter and surrounds the fluid working space. The annular piston has an inner wall and an outer wall, the average diameter of which is smaller than the outer diameter of the diaphragm and larger than the inner diameter. the piston is axially movable with the predetermined stroke, thereby causing diaphragm deformation on the inner and outer walls of the piston;
A pair of concentric rotating lobes are formed from the walls of the diaphragm rotating on the inner and outer walls. an annular cylinder having a diameter approximately the same as the inner diameter of the closed toroidal diaphragm and disposed within the passageway through the toroidal diaphragm, the radially most of the pair of concentrically rotating lobes; Limit the inside of the inner rotating lobe. A fluid port passes through the closed toroidal diaphragm and is connected to the fluid working space for fluid to enter and leave the fluid working space.

The actuator of the present invention is applied to various power transmission devices for brakes and clutches, and the power transmission device includes a housing, a driving member, a driven member, a device for frictionally engaging the driving member and the driven member, and a device for frictionally engaging the driving member and the driven member. A device for frictionally disengaging a member from the driven member includes a fluid actuator. A driving member is located within the housing and transmits rotational force into the housing.

a driven member is located adjacent to the driving member;
Transmitting rotational force to the outside of the housing. A device for frictionally engaging the driving member and the driven member is capable of transmitting rotational force from the driving member to the driven member and is located within the housing. A device for frictionally disengaging the driving member from the driven member is also located within the housing. A fluid actuator is located within the housing and has an open passage therethrough coaxial with the axis of actuation. The fluid actuator has a closed toroidal diaphragm, an annular piston, an annular cylinder, and a fluid port. A closed toroidal diaphragm is made of a strong, flexible elastomer and has an inner and outer diameter that surrounds the fluid working space. The annular piston has an inner wall and an outer wall, the average diameter of which is smaller than the outer diameter of the diaphragm and larger than the inner diameter. The piston is axially movable in the predetermined stroke, thereby causing a diaphragm to deform on the inner and outer walls of the piston, and a pair of concentric rotating lobes from the diaphragm wall rotating on the inner and outer walls of the piston. form. an annular cylinder having a diameter approximately the same as the inner diameter of the closed toroidal diaphragm, and disposed within the passageway through which the toroidal diaphragm passes, and which is arranged in a radial direction of the pair of concentrically rotating lobes; Limit the inside of the innermost rotating lobe. A fluid port passes through the closed toroidal diaphragm and is connected to the fluid working cavity to allow pressurized fluid to enter and exit the fluid working cavity. The actuator has a first position and a second position. Said first position is where pressurized fluid is injected into said working cavity through said fluid port and inflates said rubber to a diaphragm-inflated position, thereby causing said driving member and said driven member to be inflated. A device is actuated to frictionally engage the .

Said second position is a position where said pressurized fluid is evacuated from said working cavity by said fluid port to cause said diaphragm to be sized less than said expanded size, thereby A device is actuated to frictionally disengage the driving member from the driven member.

[Example] FIGS. 1 and 2 show a fluid actuator 1 of the present invention.
It is 0. The diaphragm 12 has a closed toroidal shape with a wall 14 surrounding the working space inside the diaphragm. Diaphragm 12 is primarily manufactured from a strong, flexible, resilient elastomeric matrix. The elastomer may be any conventionally used synthetic or natural rubber. Also, any number of known groups of thermoplastic elastomers may be utilized. The choice of elastomer type depends on flexibility life, internal working pressure, chemical resistance, environmental resistance including oxidation and ozone, heat supply conditions, and the individual application of the actuator or air spring used. is a function of a number of parameters including many other factors that dictate the Throughout the specification, the term actuator is used to characterize the structure 1o of the invention, but the term actuator is generally used for functionally similar but structurally different devices. synonymous with and interchangeable with the terms air spring, fluid spring, or air bellows. The wall 14 of the diaphragm 12 preferably consists of a plurality of reinforcing structures embedded within an elastomeric matrix 18. A pair of tissue layers 20 and 22 are shown in FIG. To maximize the applied pressure range, the tissue is preferably placed at a bias angle with respect to the actuator axis 23. This use of bias-laid reinforcement fabrics, such as plain weave and ridge weave fabrics, is known in air spring technology, and the selection of the bias angle of such fabrics and the uniqueness of the individual cord fabrics are well known in air spring technology. Specific details of gender are known in the art. The tissue layer resists the outward force F imposed by the action of the internal pressure P in the internal working cavity 16 of the diaphragm. The closed toroidal diaphragm has an inner diameter D4
and outer diameter D3, respectively indicating the inflated diaphragm diameter. The annular cylinder 24 has an internal passageway 26, and the outer diameter of the cylinder 24 is approximately equal to the inner diameter of the inner diameter D4 of the diaphragm 12. Cylinder 24 acts to restrict radial expansion within toroidal diaphragm 12 . The outer surface 28 of the cylinder 24 has an optional serrated notch 30 that compressively engages the inner diameter surface of the diaphragm 12 to cause the diaphragm to move relative to the cylinder 24 on a stroke 32 of the actuator 10. Prevents axial slippage.

The annular piston 40 has an intermediate diameter Da that is dimensionally located between the inner diameter D4 and the outer diameter p3 of the diaphragm 12. This annular piston and diaphragm relationship causes the annular piston 40 to move axially in and out of the diaphragm, thereby creating an internal rotating lobe 42 and an external rotating lobe 43 that move up and down on the inner surface 44 and outer surface 45 of the annular piston 40. Therefore, it is important. This unique pair of concentric rotating lobes makes the operation of this actuator 10 different from all other types of rotating lobe air springs. The diameter of the inner lobe is designated Dl and is measured from the axial length of the bottom of the inner lobe 42 while the actuator is moving on the stroke 32. Similarly, the diameter D2 of the outer lobe 43 is equal to the stroke 3
It is measured at the axial length of the lowest part of the diaphragm at a specific axial point in No. 2. Obviously, the effective range of the air spring on the axial stroke 32 of the actuator is uniform if the inner wall 44 and outer wall 45 of the annular piston 40 are parallel to the outer surface of the cylinder 24. Especially in this case. The entire length of the annular piston is annular and cylindrical, and the actuator applies force uniformly during the stroke.

Clearly, the relationship of the inner wall 44 and outer wall 45 of the annular piston 40 at an angle with respect to the cylinder 24 thereby creates a variable effective range on the stroke of the actuator. This changes the actuator's load carrying capacity and spring rate on the stroke.

The surfaces 44 and 45 may be tapered rearwardly or tapered forwardly with respect to cylinder 24 (as shown in FIG. 6). Further, by tapering the cylinder into an annular conical shape (as shown in FIG. 7), a range of variability can be created, and an effective range of variability also occurs on the stroke. Depending on the particular desired use characteristics, the radially outer surface forms an acute angle with the axis, and the surface can be manufactured in such a way as to produce a particularly constant load-deflection curve. The effective area of the diaphragm is that of a flat annular ring with an inner intermediate diameter and an outer intermediate diameter D2. The effective load due to the internal pressure P in the internal working cavity 16 is L = [P
It is expressed by the equation ((os os)-(o, DI))114. If it is desired that the load deflection characteristics be constant, Dl and D2 will remain constant over the axial stroke 32 of the actuator. If variable spring rate and load deflection characteristics are desired, DI and D2 are made to be varied by tapering the piston 40 and/or cylinder 24 in an appropriate manner. Such variable spring rate fluid springs and actuators are known;
Details of such shapes are not described herein.

A fluid conduit 50 is connected to the internal working cavity 16 to permit pressurization and depressurization of the diaphragm by the intake and withdrawal of suitable fluids. Fluid conduit 5
0 takes the form of any suitable stem or valve.

In its simplest form, an internal tube or valve manufactured by Schrader Bellows, a division of Scoviil Corporation, can be used, but other more complex two-way valves can be used if special actuators are used. device is more suitable. If the device is used as an air spring, simple components such as Schrader valves are used to introduce an internal pressure P that is maintained during the lifetime of the device. Although not shown, it is clear that a fluid conduit 50 passes through the top surface 50 of the annular piston, as shown in FIG. The outer surface portion of the diaphragm 12 that contacts the surface portion 52 of the piston is essentially fixed on the stroke 32 of the actuator, so that parts for this are located at that point on the wall 14 of the diaphragm 12. In particular, in this embodiment, the preferred fluid passageway is through which the piston 40 passes. Fluid conduit 50 connects to working cavity 16
is connected to a pressurized fluid source 53 capable of varying the internal pressure P of the spring, providing variable load-deflection curves and spring rates suitable for various usage conditions. Additionally, the pressurized fluid source is connected to a sensor mechanism or control device that continuously varies the internal pressure.

Depicted in brake assembly 60 of FIGS. 3 and 4 is an actuator similar in all respects to actuator 10 of FIGS. 1 and 2.

In FIG. 3, elements that are identical to elements of the actuator of FIGS. 1 and 2 are labeled with the same reference numerals. Cylinder 24 is conveniently mounted on bearings for axial movement along central shaft 62. An annular piston 40 is annularly adjacent to the diaphragm 12 and has an inner surface 44.
and create an inner lobe 42 and an outer lobe 43 on the outer surface 45, respectively. A fluid inlet 63 supplies pressurized, incompressible hydraulic fluid to a fluid conduit 50 extending into the wall 14 of the diaphragm 12 . A button plate assembly 64 surrounds the central shaft 62 and is moved axially during active movement of the actuator 10. The pusher plate assembly is slidably mounted to a frame 70 that prevents rotation of the pusher plate like a conventional self-propelled disc brake caliper device. Pisher plate 64 may be of any suitable shape and is simply an axially movable element of the braking device that engages friction element 66 and rotor assembly 68. When the friction elements engage the rotor, the energy of the inertia of the rotor and shaft is transferred to and absorbed by the bushing plate 64 into the frame 70 . The annular piston 40 is connected to the frame 70 of the device in which the brake assembly 60 is used.
It can be fixed and attached to. shaft and/or
The rotor is to be mounted on a suitable bearing arrangement in the frame 70, not shown.

The diaphragm 12 is shown in FIG. 3 in a compressed state with the pressure P at a predetermined low value, and the plate 64 in this position is axially retracted to a first axial position 72. Fluid inlet 63 to working cavity 16 of diaphragm 12
When hydraulic fluid is introduced into the diaphragm, the diaphragm expands pushing the plate axially into the second position 74 shown in FIG. The shape of the fully expanded and inflated diaphragm 12 and the arrangement of the various elements of the brake assembly 60 are also shown in FIG. 4, shown in the fully expanded and activated position.

Fluid inlet 63 is connected to a pressurized fluid source 76, which is connected to a device for controlling the flow rate of the fluid. The control device is a brake or clutch pedal 78 connected to a master hydraulic cylinder, which is supposed to correspond to a source of pressurized fluid 76.

A configuration similar to that shown in FIG. 3 is used in any of a number of activation applications, such as brake and clutch assemblies, but in some assemblies the piston is fixed. Some upper retaining plates move in the opposite direction to that shown in FIG. If the clutch assembly has a return spring, a fully expanded diaphragm serves to overcome the bias of the return spring.

In FIG. 5 a simplified diagram of the clutch is illustrated. Clutch 80 is actuated by an actuator 82 similar to the actuator shown in FIGS. 1 and 2. Although not shown, all elements of the clutch other than the engine, which is connected to the driving element, which is the flywheel 118, are within the bellhousing 116. Actuator 82 includes a toroidal diaphragm 84 having an annular piston 86 and a bushing plate 88 opposite annular piston 86 . The radially inward expansion of diaphragm 84 is limited by internal support cylinder 90 . Working cavity 92 communicates with a fluid flow path 94 through diaphragm 84 at port 96 . The pressurized fluid is
Work cavity 92 is entered through fluid flow path 94 from a suitable fluid source, such as a master hydraulic cylinder 98 . The master hydraulic cylinder is connected to an activation device, such as a clutch pedal 100. When the clutch mechanism is activated, the master cylinder 98 is activated by the clutch pedal 100 and hydraulic fluid enters the working cavity 92 through the port 96;
The butcher plate 88 is the throwout bearing 102
It is moved by pressing . When the throwout bearing activates the release lever 104, the release lever moves the butcher plate 106 axially out of contact with the friction pads 108 and 110, thereby causing the flywheel 118 to move toward the shaft 114 or driven plate 112. It can rotate freely even if it does not rotate. All such mechanical actions are conventional and within the range of standard automotive type clutches. When the clutch mechanism is in reverse engagement, the water pressure in the master cylinder 98 is reduced and a portion of the hydraulic fluid is discharged from the working cavity 92 of the actuator 82. The pressure spring 113 thereby returns the pressure plate and the throwout bearing to their original engaged position and moves the pressure plate 88 axially in the direction of the piston 86 fixedly attached to the housing 116; Hydraulic fluid is forced out of diaphragm 84. The flywheel 118 smoothly transfers rotational power from a rotational power source, such as an engine, and serves as the driving element of the illustrated rotational power transmission device. Many of the elements for rotation are mounted within the housing 116 in conventional spear shapes and using conventional bearing methods. It is contemplated that the clutch mechanism may take many other forms. The actuator 82 of the present invention can be used in any clutch mechanism requiring relatively little axial movement.

The advantage of not having to seal or worry about water leakage is achieved by this embodiment of the clutch.

Many other similar systems are possible.

Although some exemplary embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. Probably.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the simplest embodiment of the actuator of the invention. FIG. 2 is a cross-sectional view of the actuator of FIG. 1. FIG. 3 is a simplified block diagram of a clutch or brake assembly using an actuator shown in a disengaged position similar to FIGS. 1 and 2; FIG. 4 shows the assembly of FIG. 3 in an engaged position. FIG. 5 is a cross-sectional view of a clutch assembly using the actuator of the present invention. FIG. 6 is a cross-sectional view of an annular piston tapered at the front. FIG. 7 is a cross-sectional view of a conically tapered annular cylinder. DESCRIPTION OF SYMBOLS 10... Fluid actuator, 12... Toric diaphragm, 16.92... Fluid working space, 20, 22... Layer, 23... Axis line,
24... Annular ring, 26... Open passage, 28... Radial outer surface, 30... Serrated notch, 32... Stroke, 40... Piston, 42, 43... Concentric rotating lobe, 44... Inner wall, 45... Outer wall, 5
0... Fluid port, 62... Central shaft member, 80... Power transmission device, 82... Fluid actuator, 84... Diaphragm, 102... Throwout bearing, 106...
- Pressure plate, 112, 114... Driven member, 116... Housing, 118... Drive member. -＼FIG, 3

Claims (1)

Claims: 1. (a) a closed toroidal diaphragm (12); (b) a fluid port (50) passing through said diaphragm (12); and (c) said diaphragm (12). (d) an annular cylinder (24), wherein said actuator (10) moves during a predetermined stroke (32); a pair of concentric rotating lobes (4) moving along an axis (23) and having an open passageway (26) passing through the actuator coaxially with said axis (23);
The diaphragm (12) is made of a strong and flexible elastomer, and has an inner diameter (D_4) and an outer diameter (D_3).
), said outer diameter (D_3) being limited only by a reinforcing fabric embedded in said elastomer, said reinforcing fabric comprising at least two layers (20, 22) of plies of diagonal angled cord weave. , the diaphragm (
12) surrounds a fluid working space (16), said piston (40) having an inner wall (44) and an outer wall (45), the average diameter (D_5) of which is smaller than said diaphragm (1);
2) is smaller than the outer diameter (D_3) and larger than the inner diameter (D_4) of the piston (40) and the diaphragm (1).
2) are axially movable relative to each other during said predetermined stroke (32), said diaphragm (12)
are the inner wall (44) and outer wall (45) of the piston (40).
Deformed above to form a pair of concentric rotating lobes (42, 43)
and the annular cylinder (24) forms the diaphragm (12).
The passage (26) passing through the toroidal diaphragm (12) has an outer diameter approximately equal to the inner diameter (D_4) of
), said pair of concentric rotating lobes (42
, 43), the radially innermost rotating lobe (42
) and forming an inner restriction for said fluid port (50
) is connected to said fluid working space (16) such that fluid moves in and out of said fluid working space (16). 2. Said annular cylinder (24) further includes a plurality of circumferential serrations (30) on its radially outer surface.
, and the serrated notch is connected to the actuator (1).
contacting said diaphragm (12) for a predetermined stroke (32) of 0) to prevent said diaphragm (12) from slipping axially on said radially outer surface (28); The fluid actuator according to claim 1. 3. The annular piston (40) has a taper on at least one of the inner wall (44) and the outer wall (45) to provide variable spring rate over a predetermined stroke (32) of the actuator. The fluid actuator according to claim 1, characterized in that: 4. The fluid actuator of claim 1, wherein the fluid port (50) is a valve sealingly passing through the closed toroidal diaphragm (12). 5. A central shaft member (62) passing through said passageway (26).
The fluid actuator according to claim 1, characterized in that: 6. Fluid actuator according to claim 1, characterized in that said annular cylinder (24) has a radially outer surface forming an acute angle with said axis (23). 7. (a) a housing (116); (b) a drive member (118) disposed within the housing (116) and transmitting rotational power to the housing (116); (c) the drive member ( (d) a driven member (112, 114) disposed adjacent to the housing (118) and transmitting rotational power to the outside of the housing (116); (d) the driving member (118) and the driven member (11);
(e) a fluid actuator (2, 114) disposed within said housing (116), wherein an open passageway through said actuator is coaxial with an axis of motion of the actuator; 82), characterized in that the actuator is as defined in claim 1. 8. In a power transmission device used as a clutch,
The drive member (118) is a flywheel disposed within the housing (116), and the driven member is a shaft (114) extending through the housing (116) and rotatably mounted therein. ), and said shaft (
114) is fixedly connected to the driven plate (
112), the device for frictionally engaging and disengaging the driving member and the driven member includes a combination of a throwout bearing (102) and a pressure plate (106);
) is axially movable relative to said shaft (114) to a position in which a pressure plate (106) connected to a drive member (118) for rotation is disengaged from a driven plate (112). , a device rotatably mounted on the shaft (114) for frictionally engaging and disengaging the drive member and the driven member further includes a device for frictionally engaging and disengaging the drive member and the driven member; a biasing spring member (113) connected to said pressure plate (106) for biasing it into an engaged position, said pressure plate (106) being positioned next to said driven plate (112); from the driven plate (112) when the throwout bearing (102) and pressure plate (106) combination is in the disengaged position, the driven plate (112) and the drive member (118) the pressure plate (1
06) from the driven plate (112), and the biasing spring member (113) deflates the diaphragm (84). Power transmission device according to claim 7, characterized in that it is operative to move the actuator to a second position in which the pressurized liquid is excluded from the working space (92).