JP2020085232A - Brake employing functional fluid - Google Patents

Abstract

To simplify a structure of a rotary shaft type brake using a non-shear flow of a functional fluid such as an ER (electrorheological) fluid or an MR (magnetorheological) fluid, and to attain downsizing and increase of brake power.SOLUTION: A partition plate (18) is attached to a rotary disc (15) of a brake, and a fixing plate (16) is attached to an inner wall of a container. A clearance (17) is provided between the rotary disc (15) and the fixing plate (16), and a functional fluid which is pushed by the partition plate (18) when the rotary disc (15) is rotated flows in the clearance (17). An electric field or a magnetic field is applied to the clearance (17), such that flowing resistance is changed by changing viscosity of the fluid in the clearance (17) and rotation resistance of the rotary disc (15), namely, brake power is controlled. Otherwise, the fixing plate (16) may be attached to the rotary disc (15) and the partition plate (18) may be attached to the inner wall of the container. An electric field or a magnetic field is applied to a fluid in the clearance (17) between the inner wall of the container and the rotary disc (15) and fluid leakage from the clearance (17) is eliminated, thereby suppressing reduction in brake power.SELECTED DRAWING: Figure 7

Description

We aim to provide brakes that use functional fluids such as ER (electrorheological) fluid and MR (magnetorheological) fluid and have a simple structure with a small number of parts and are suitable for mass production. Expected to be used for transmission and control.

ER fluids and MR fluids are fluids whose viscosity can be controlled with good response by the strength of electric and magnetic fields. For a long time, torque transmission/control of brakes and clutches, vibration/shock absorption of dampers and shock absorbers, cylinders, etc. It is used in the field of mechatronics such as control of force, position and speed of valves, etc., and not only for applications in automobiles and industrial machines, but due to the excellent responsiveness of these fluids and the characteristics that no noise is generated in operation, recently It is also beginning to be used in applications such as robots and medical/health equipment.

By the way, the use of fluid in mechatronics is basically classified into three flow modes as shown in FIG. 1, namely (A) shear flow mode, (B) pressure flow mode, and (C) squeeze flow mode. It There is also a composite mode that combines them.

Rotational brakes using fluid are classified into two types, (A) disk type and (B) cylinder type, as shown in FIG. 2, both of which utilize the shear flow mode of the fluid, that is, the shear force. To do. Since the shear force of fluid is smaller than that of solid friction, a brake that uses this shear flow mode is compact and requires multiple discs and cylinders to increase the friction area in order to obtain large stopping and transmitting forces. A general example of the multiple disk type is shown in (C).

With the recent widespread use of human coexistence type robots, in applications such as joint movement control and tactile presentation, there is a demand for a rotating shaft type brake that is used at a limited rotation angle of one rotation or less instead of multiple rotations. Has also increased.

Although there are very few published documents regarding brakes that are used at a limited angle of one rotation or less using a functional fluid, JP 2006-087559A discloses a brake using MR fluid as shown in FIG. Brake as shown in (B) has been published for prosthetic devices.

Japanese Unexamined Patent Publication No. 2006-087559

The brake using the MR fluid of JP-A-2006-087559 does not use the shear mode so far, but uses the pressure flow mode and the squeeze flow mode. ) Is obtained. The brake shown in FIG. 3A has MR fluid in the left and right fluid chambers (cylinder chambers) 11 partitioned into two chambers by a dam plate 8 attached to a rotary shaft (hereinafter referred to as the rotary shaft 7). 12 are filled. The rotation of the rotary shaft 7 causes the fluid 12 in the fluid chamber on the side pushed by the dam plate 8 to flow into the other fluid chamber 11 through the communication hole 9 provided in the dam plate 8. A coil 10 is attached to the communication hole 9 so that a magnetic field can be applied. By changing the strength of the magnetic field, the flow resistance of the MR fluid 12 in the communication hole 9 is changed, and the magnetic field of the rotating shaft 7 is changed. It controls the rotation resistance, that is, the braking force.

On the other hand, in FIG. 3B, instead of providing the communication hole 9 in the dam plate 8 as in FIG. 3A, a bypass passage 13 is provided outside the cylinder chamber 11 and the permanent magnet 14 is provided in that portion. The flow resistance of the fluid is changed depending on the strength of the magnetic field in the approaching communication hole.

13A and 13B, it is possible to control the rotational resistance of the shaft, that is, the braking force by changing the strength of the magnetic field, but the method of FIG. Since the stop plate 8 must be provided with the coil 10 (electromagnet), it is difficult to widen the opening area of the communication hole 9, and the flow resistance of the fluid increases even when no magnetic field is applied, and the rotation axis in the base state is increased. There is a problem that the rotation resistance of No. 7 becomes large. Further, when the rotating shaft 7 is rotated in a state where a magnetic field is applied, it becomes difficult for the fluid in the communication hole 9 to flow, but the MR fluid 12 passes through the gap between the dam plate 8 and the inner wall of the cylinder chamber 11 (hereinafter referred to as a container). Leaks and the rotation restraint is reduced. In order to avoid this, there is a method of closing the dam plate 8 with a sealing material such as soft rubber, but with a fluid containing iron powder such as MR fluid, the sealing material is easily worn and the sealing performance deteriorates.

On the other hand, in the method of FIG. 3(B), it is necessary to provide the bypass passage 14 outside the container 4, so that the compactness is lost, and, as in FIG. 3(A), the dam plate 8 and the inner wall of the container 4 are formed. The MR fluid 12 leaks from the gap, and the force for suppressing rotation is reduced.

Reduction of rotation resistance of the rotating shaft in the ground state without applying such a magnetic field (similar to the electric field), and reduction of stopping force due to fluid leakage from the gap between the dam plate and the inner wall of the cylinder when a magnetic field is applied. As a method of preventing the above, instead of increasing the opening area of the flow holes of the dam plate, the following method was conceived. That is, a cylindrical disk provided with a partition plate is provided with a rotary disk that rotates together with a rotary shaft, and a predetermined gap is provided on the opposing surface between the fan-shaped fixing plate attached to the rotary disk and the inner wall surface of the container. By allowing the fluid pushed by to pass through this gap and at the same time applying an electric field or magnetic field to this gap, the flow resistance when rotating the rotating shaft, that is, the braking force is adjusted.

This method may be a method in which a gap is similarly provided between the rotary disk provided with the partition plate and the fixed plate attached to the inner wall of the container. Further, the fixing plate is not limited to the fan type and may be a partial cylindrical type.

In order to make this easy to understand, a conceptual diagram thereof is shown in FIG. 4A shows a method in which a fixed plate is provided on the rotating disk and a partition plate is provided on the wall surface of the container (hereinafter referred to as A type), and FIG. 4B shows a fixed plate on the inner wall surface of the container and a partition plate on the rotating disk. The concept of the method (hereinafter referred to as type B) provided with is shown.

In such a method, it is possible to obtain a desired braking force by optimizing the width and length of the gap, the length of the flow path, etc., and also to the fluid in the gap between the inner wall of the container and the rotating disk. An electric field or magnetic field can be applied, and it is possible to suppress fluid leakage from this gap.

That is, the present invention relates to a cylindrical rotary shaft type brake filled with a functional fluid whose viscosity changes in response to the strength of an electric field or a magnetic field. In the same direction, a partition plate is attached to the inner wall surface of the cylinder container (called type A) or a rotating disk (hereinafter referred to as type B), and a fan-shaped or partially cylindrical fixed plate is a rotating disk. (Type A) or the inner wall surface of the cylinder container (Type B). A gap is provided on the surface where the inner wall surface of the cylinder container faces the fixed plate (type A) or the surface where the fixed plate faces the rotating disk (type B). The two fluid chambers separated by the partition plate and the fixed plate are filled with a functional fluid, and when the rotating shaft of the rotating disk is rotated, this fluid is fixed plate (in the case of type A) or partition plate (type B). In the case of) and flows into the other fluid chamber through this gap. An electric field or a magnetic field is applied to this gap. By changing the strength of the electric field or magnetic field, the flow resistance of the fluid flowing through this gap is changed, and the rotation resistance of the rotating shaft is controlled. The functional fluid brake has the above structure.

Further, according to the present invention, a plurality of fan-shaped or partially-cylindrical fixed plates attached to the inner wall surface (in the case of type A) or the rotary disk (in the case of type B) of the cylinder container are provided. Or in the case of type B), a plurality of discs or cylinders sandwiching the plurality of fixing plates are attached to the functional fluid brake.

The fan-shaped fixing plate referred to in the present invention is a plate having a shape as shown in FIG. 5(A) and the partially cylindrical fixing plate is as shown in FIG. 5(B). The angle and width of may be selected arbitrarily. For these fixing plates, a metal such as aluminum or stainless steel or a resin whose surface is metal-plated is used when an ER fluid is used, and a magnetic metal such as iron, permalloy or silicon steel is generally used when an MR fluid is used. Can be used. These fan-shaped or partially-cylindrical fixed plates are fixed to the rotating disk (in the case of type A) or the inner wall of the container (in the case of type B).

The partition plate referred to in the present invention is a partition plate for dividing the functional fluid in the cylinder container into two fluid chambers and is fixed to the inner wall of the container (in the case of type A) or the rotating cylinder (in the case of type B). To be done. The same material as the fan-shaped or partially cylindrical fixing plate can be used, but resin can also be used. It is preferable that the gap between the partition plate and the rotary disk (in the case of type A), or the space between the partition plate and the inner wall of the container is as narrow as possible in terms of fluid leakage prevention. If the partition plate is made of a conductive metal or a magnetic metal, the viscosity of the fluid in the gap increases when an electric field or a magnetic field is applied, which has the effect of preventing fluid leakage.

The rotating disk referred to in the present invention is a disk directly connected to the rotating shaft, and is usually one, but may be one on each of the left and right or upper and lower inner wall surfaces. Generally, it is made of metal, but when ER fluid is used, it may be made of resin whose surface is metal-plated to have conductivity. When using an MR fluid, a magnetic metal is used. A partition plate and a fixed plate are attached to the rotating disk.

The gap between the fan-shaped fixed plate and the disk or the gap between the partially cylindrical fixed plate and the cylinder referred to in the present invention is usually about 1 to 5 mm, and if it is too narrow, the fluid flow deteriorates and the basal resistance (electric field or magnetic field Rotational resistance when not applied) increases. On the other hand, if it is too wide, the basal resistance decreases, but the braking force when an electric field or magnetic field is applied decreases. Further, if the length of the gap is increased, the braking force is increased, but the idling resistance is also increased, and the rotatable angle of the rotary shaft is narrowed.

As a method of applying an electric field to the gap according to the present invention, a voltage is applied between the fixed plate and the inner wall surface of the container, or between the rotating disk and the inner wall surface of the container, and the rotating disk and the fixed plate (type A) or a rotating disk (type B) with high voltage, and a low voltage (ground) with the inner wall of the container (type A) or the inner wall of the container and the fixed plate attached (with type B). Is desirable for safety. Of course, it is necessary to prevent fluid leakage by a seal such as an O-ring and to insulate the rotary shaft to which the rotary disk is attached from the inner wall of the container by using a bearing made of resin or the like.

On the other hand, as a method of applying a magnetic field to the gap, there is a method of applying with an electromagnet or a permanent magnet from the outside as in Example 7, but a method of applying a coil from the inside by winding a coil around the shaft core as in Example 8. There is also.

In particular, the electromagnet built-in type in which the coil is wound around the rotation axis as shown in Example 8 is excellent in compactness.

Note that the brake of the present invention may be a disc type with a part thereof removed as shown in FIG. 6, in addition to the cylinder type (disc type). In this case, the left and right inner wall surfaces of the defective portion may be regarded as partition plates.

The functional fluid that changes its viscosity in response to an electric field or a magnetic field as referred to in the present invention is a fluid generally called an ER (electrorheology) fluid or an MR (magnetorheology) fluid.

It is also possible to adapt to a fluid called magnetic fluid.

An ER fluid is a fluid whose viscosity changes momentarily and greatly when a voltage is applied, and the change is reversible. The ER fluid is roughly classified into a dispersion system in which micron-sized dielectric particles are dispersed in insulating oil and a uniform system in which particles are not used. As the particles used in the former, water capable of ionic polarization, containing acid, alkali or organic electrolyte, inorganic particles such as silica and zeolite, or organic particles such as ion exchange resin and cellulose, water-free ions Examples thereof include semiconductive particles such as carbon, polyaniline, and metal phthalocyanine that easily generate electronic polarization rather than polarization, and metal particles and conductive polymer particles having an insulating thin film layer formed on the surface. As the insulating oil, mineral oil, silicon oil, fluorine oil or the like is used. As the latter homogeneous system, liquid crystals, particularly polymer liquid crystals, are mentioned as preferable ones. The former dispersion system exhibits so-called Bingham flow, in which the shear stress is almost constant regardless of the shear rate when an electric field is applied. On the other hand, the latter homogeneous system generally exhibits so-called Newtonian flow in which the shear stress is proportional to the shear rate. Any fluid can be used in the present invention.

On the other hand, the MR fluid is a fluid in which magnetic particles are dispersed in a medium, and its viscosity can be greatly changed by applying an external magnetic field. Examples of the material of the magnetic particles include iron, carbonyl iron, iron nitride, iron carbide, low carbon steel, nickel and cobalt. Further, an iron alloy containing an element such as aluminum, silicon, cobalt or nickel may be used. In addition, particles of paramagnetic, superparamagnetic or ferromagnetic compound particles of gadolinium or an organic derivative of gadolinium and particles of a mixture thereof may be used. Of these, carbonyl iron is the most suitable material. The average particle diameter of the magnetic particles is preferably several μm to several tens μm, and for example, particles of sub μm or nano μm may be included. As the dispersion medium, mineral oil, silicon oil, fluorine oil, paraffin or the like is used. The magnetic particles are used by being dispersed in a medium at a volume ratio of 15 to 45%, generally 20 to 40%.

In an ER fluid or MR fluid brake that uses a shear flow, the ultimate shear stress when an electric field or magnetic field is applied is low, but in the method of using the compressive flow or squeeze flow of the present invention, even an ER fluid can be created by designing a gap. Since a large braking force can be obtained and a strong electric field can be applied to the gap between the inner wall surface of the container and the rotating disk to prevent fluid leakage, it can be said that the brake has a structure particularly suitable for ER fluid.

The brake having the structure of the present invention can be used as a clutch, although the rotation angle is limited by connecting the container side or the rotating shaft side to the rotation input means.

A brake using a functional fluid such as an ER (electrorheological) fluid or an MR (magnetorheological MR) fluid of the present invention has good responsiveness, does not cause seizure, has a low noise, and is like a solid friction plate. No friction powder is generated. The brake of the present invention uses a compression flow resistance or a squeeze flow resistance of fluid, and is compact and can obtain a large braking force, and has a small number of parts, as compared with a conventional brake fluid flow shear resistance. It has a simple structure, can be downsized, and is suitable for mass production. In addition, an electric field or magnetic field can be applied to the gap between the inner wall surface of the container and the rotating disk, or the gap between the inner wall surface of the container and the fixed plate or partition plate, and leakage from these gaps can be suppressed even without a special seal. Therefore, the braking force can be improved.

3 illustrates three flow modes of a fluid. The basic structure of a rotary brake using the shear flow mode is shown. 1 illustrates a prior art MR fluid brake utilizing pressure and squeeze flow modes. It is a figure of the basic structure shown in order to make it easy to understand the difference in structure of two types of brakes, Type A and Type B, of the present invention. It is the conceptual diagram drawn in order to make it easy to understand the fixing plate of a fan type and a partial cylinder type said to this invention. An example of a partially defective cylinder-shaped container which is one of the shapes other than the cylinder-shaped container of the present invention is shown. 1 is a sectional view of a type A ER fluid brake according to the present invention of Example 1 in which a partition plate is attached to the inner wall surface of a cylindrical container and a fan-shaped fixed plate is attached to a rotating disk. The sectional view of the type B ER fluid brake of the second embodiment of the present invention in which a fan-shaped fixed plate is attached to the inner wall surface of a cylindrical container and a partition plate is attached to the rotating disk is shown. The cross-sectional structure of the type A ER fluid brake according to the present invention of Example 3 in which a fan-shaped fixed plate is attached to the inner wall of the container and two rotating disks are sandwiched so that the fixed plates face each other is shown. Sectional structure of the type A ER fluid brake according to the present invention of Example 4 in which two fan-shaped fixing plates are attached to the inner wall of the container, and three rotating disks are provided so as to sandwich the fixing plates facing each other. Indicates. A partial cylindrical fixing plate is attached to the inner wall of the container, and the rotary disk is provided with a cylindrical groove so as to be sandwiched on both sides of the partial cylindrical fixing plate with a certain gap therebetween. 1 shows a sectional structure of a type A ER fluid brake according to the invention. The present invention according to the sixth embodiment of the present invention having a structure in which the partial cylindrical fixing plates are doubly attached to the inner wall of the container and the cylindrical grooves are provided in two rows on the rotating disk so as to sandwich the partial cylindrical fixing plates. 2 shows a cross-sectional structure of the type A ER fluid brake. The sectional view of the type A MR fluid brake according to the present invention of Example 7 in which a fan-shaped fixed plate is attached to the inner wall surface of the cylinder container 4 and a partition plate is attached to the rotating disk is shown. In Example 7, a method of applying a magnetic field from the outside of the container using a permanent magnet will be described. A fan-shaped fixed plate is attached to the inner wall of the container, two rotating discs are provided so as to sandwich the fixed plates facing each other, and an electromagnet coil is incorporated in the MR fluid brake of the type A referred to in the present invention of Example 8. A cross-sectional structure is shown.

Hereinafter, the contents of the present invention will be supplemented with examples.

FIG. 7A shows a sectional view of a type A ER fluid brake according to the present invention in which a partition plate 18 is attached to the inner wall surface of the cylinder container 4 and a fan-shaped fixed plate 16 is attached to the rotating disk 15. FIG. 7B shows a view of the AA plane. All of these members are made of aluminum except for the rotating shaft 7 made of stainless steel, and have electrical conductivity. The inside of the container 4 is completely filled with ER fluid (not shown), and when the rotating shaft 7 is rotated, the fluid pushed by the fixed plate 16 causes a gap (flow passage) 17 between the fixed plate 16 and the inner wall of the container 4. Through the opposite direction. A resin bearing (not shown) is attached to the rotary shaft 7 together with an O-ring seal (not shown) for preventing liquid leakage, so that when the liquid leaks, electrical contact between the container 4, the rotary shaft 7, and the fixed plate 16 is made. Good insulation is maintained. The inner diameter of the container 4 is 30 mm, the internal length (height) is 15 mm, the diameter of the rotating shaft 4 is 5 mm, the angle of the fan-shaped fixing plate 16 is 45 degrees, and the gap 17 between the fixing plate 16 and the container 4 is 3 mm. The gap between the rotary disk 15 and the container 4 and the gap between the partition plate 18 and the container 4 are 1 mm. A low voltage (ground) wiring 22 is connected to the container 4, and a high voltage wiring 22 is connected to the fan-shaped fixing plate 16 through the rotating shaft 4, so that a maximum DC 3 kV can be applied.

FIG. 8A shows a sectional view of a type B ER fluid brake according to the present invention in which a fan-shaped fixed plate 16 is attached to the inner wall surface of the cylinder container 4 and a partition plate 18 is attached to the rotary disk 15. .. FIG. 8B shows a cross section taken along the line AA, and FIG. 8C shows a cross section taken along the line BB. The members, basic structure, and dimensions are the same as in the first embodiment. The ER fluid is completely filled in the container, but is not shown in the figure along with wiring and the like.

FIG. 9A shows a type A ER fluid brake according to the present invention in which a fan-shaped fixed plate 16 is attached to the inner wall of the container 4 and two rotary disks 15 are provided so as to sandwich the fixed plate 16 so as to face each other. The cross-sectional structure of is shown. 9A shows a cross section taken along the line AA, and FIG. 9B shows a cross section taken along the line BB. The members and the basic structure are the same as in Example 1, but the gap between the rotary disk 15 and the fixed plate 16 is 2 mm.

FIG. 10A shows a type A according to the invention in which two fan-shaped fixing plates 16 are attached to the inner wall of the container 4 and three rotating disks 15 are provided so as to sandwich the fixing plates 16 facing each other. 2 shows a sectional structure of the ER fluid brake of FIG. 10A shows a cross section taken along the line AA, and FIG. 10B shows a cross section taken along the line BB. The members and the basic structure are the same as in Example 1, but the gap between the rotating disk and the fixed plate is 2 mm.

In FIG. 11(A), a partial cylindrical fixed plate 21 is attached to the inner wall of the container 4, and the rotary disk 15 is formed into a cylindrical type so as to be sandwiched on both sides of the partial cylindrical fixed plate 21 while leaving a constant gap 17. 2 shows a sectional structure of an ER fluid brake of type A according to the present invention, which has a structure in which the groove of FIG. FIG. 11B shows a cross section taken along the line AA. The members and the basic structure are the same as in Example 1, but the gap between the partially cylindrical fixed plate 21 and the groove of the rotary disk 15 is 2 mm, and the gap between the inner surface of the container 4 and the cylinder is 1 mm.

In FIG. 12(A), the partial cylindrical fixing plates 19 are doubly attached to the inner wall of the container 4, and the rotary disk 15 has two rows of cylindrical grooves so as to sandwich the partial cylindrical fixing plates 19. 1 shows a sectional structure of a type A ER fluid brake according to the present invention having the structure provided. FIG. 12B shows a cross section taken along the line AA. The members and the basic structure are the same as in Example 1, but the gap between the partially cylindrical fixed plate 19 and the groove of the rotary disk 15 is 2 mm, and the gap between the inner surface of the container 4 and the outermost surface of the cylinder 20 is 1 mm. is there.

FIG. 13A shows a sectional view of a type A MR fluid brake according to the present invention in which a fan-shaped fixed plate 16 is attached to the inner wall surface of the cylinder container 4 and a partition plate 18 is attached to the rotary disk 15. 13B shows a cross section taken along the line AA, and FIG. 13C shows a cross section taken along the line BB. All of these members are magnetic silicon steels. The MR fluid (not shown) is completely filled in the container 4, and when the rotating shaft 7 made of stainless steel is rotated, the fluid pressed by the fan-shaped fixing plate 16 is removed from the fixing plate 16 and the inner wall of the container 4. Flow in the opposite direction through the gap. An O-ring seal (not shown) for preventing liquid leakage is attached to the rotary shaft 7. The inner diameter of the container is 30 mm, the inner length (height) is 15 mm, the diameter of the rotating shaft 7 is 5 mm, the angle between the fan-shaped fixing plate 16 and the container is 45 degrees, and the gap between the fixing plate 16 and the container 4 is 2 mm. The gap between the rotary disk 15 and the container 4 and the gap between the partition plate 18 and the container 4 are 0.2 mm. A permanent magnet 23 is attached to the outside of the container 4 as shown in FIG. 14, and the strength of the magnetic field can be adjusted by moving the distance from and away from the container 4 with a lever (not shown). There is.

FIG. 15(A) shows a type A MR fluid according to the present invention in which a fan-shaped fixed plate 16 is attached to the inner wall of the container 4 and two rotary disks 15 are provided so as to sandwich the fixed plate 16 so as to face each other. The cross-sectional structure of a brake is shown. The coil 24 is wound around the rotary shaft 7 of the rotating disk 15, and a resin-made isolation cylinder 25 is attached to the outer surface of the coil 24 with a thin O-ring seal (not shown) interposed therebetween. 15A shows a cross section taken along the line AA, and FIG. 15B shows a cross section taken along the line BB. The members and the basic structure are the same as in the seventh embodiment. The gap 17 between the rotating disk 15 and the fixed plate 16 is 2 mm. When an electric current is applied to the coil 24, a magnetic field is generated in the direction of the red arrow, changing the fluidity of the MR fluid (not shown) passing through the gap 17 between the fixed plate 16 and the rotating disk 15, and the braking force is increased. Controlled. In addition, the viscosity of the MR fluid in the gap between the inner wall of the container 4 and the rotating disk 16 is changed by flowing a current to generate a magnetic field, and fluid leakage at this portion is prevented.

It is expected to be used for transmission and stopping of rotational force in the field of mechatronics that does not require multiple rotations. In particular, with the recent development of human coexistence type robots, in applications such as joint movement control and tactile presentation, use as a rotating axis type brake that is used at a rotation angle of one rotation or less instead of multiple rotations. Can be expected to.

1: Fluid 2: Substrate 3: Piston 4: Housing (container)
5: Cylinder 6: Disc 7: Rotating shaft (rotating shaft)
8: Dam plate 9: Communication hole 10: Coil 11: Fluid chamber 12: MR fluid 13: Bypass flow path 14: Permanent magnet 15: Rotating disk 16: Fan type fixed plate 17: Gap 18: Partition plate 19: Cylindrical type Partial cylinder 20: Cylinder 21: Wiring (high voltage side)
22: Wiring (low voltage side)
23: Permanent magnet 24: Coil 25: Isolation cylinder

Claims (5)

In a cylinder type rotary shaft type brake filled with a functional fluid whose viscosity changes in response to the strength of an electric field or magnetic field, a partition plate is installed in the same direction as the axis from the inner wall surface of the cylinder container toward the central axis. , Mounted on the inner wall surface of the cylinder container (this type of installation is hereinafter referred to as type A), or mounted on a rotating disk (this type of installation is hereinafter referred to as type B), and fixed in the shape of a fan or a partial cylinder. The plate is attached to the rotating disk (for type A) or the inner wall surface of the cylinder container (for type B),
A gap is provided on the surface where the inner wall surface of the cylinder container faces the fixed plate (in the case of type A) or the surface where the fixed plate and the rotating disk face (in the case of type B).
The two fluid chambers, which are divided by the partition plate and the fixed plate, are filled with functional fluid, and when the rotating shaft of the rotating disk is rotated, this fluid is fixed plate (in the case of type A) or partition plate (type B). In the case of), flow into the other fluid chamber through this gap,
An electric field or magnetic field can be applied to this gap. By changing the strength of the electric field or magnetic field, the flow resistance of the fluid flowing through this gap is changed, and the rotation resistance of the rotating shaft is controlled.
A functional fluid brake having the above structure. There are a plurality of fan-shaped or partially cylindrical fixed plates attached to the inner wall surface (in the case of type A) or the rotating disk (in the case of type B) of the cylinder container. 2. The functional fluid brake according to claim 1, wherein a plurality of rotating disks or cylinders sandwiching the plurality of fixed plates are attached to the inner wall surface (in the case of type B). The functional fluid is an ER (electrorheological) fluid, and a high voltage is applied to the rotating disk attached to the rotating shaft and the fixed plate (for type A) or rotating disk (for type B) attached to it. 3. A low voltage (ground) is applied to the inner wall of the container (in the case of type A) or the inner wall of the container and the fixing plate attached thereto (in the case of type B). Functional fluid brake. The functional fluid brake according to claim 1 or 2, wherein the functional fluid is an MR (Magnetic Viscosity) fluid, and a coil for generating a magnetic field is wound around a central portion of the shaft. The functional fluid brake according to claim 1 or 2, wherein the functional fluid is an MR (magnetorheological) fluid, and the magnetic field is applied from the outside of the cylinder container.