MXPA98006820A - Magneto-reolog torsion vibration shock absorber - Google Patents

Abstract

The present invention relates to a torsional vibration damping device for a rotating object, the device comprises: a housing having an annular chamber, said housing being arranged to be connected to the rotating object to be torsionally damped, an annular ring located inside the With an annular chamber free to rotate with respect thereto, the annular ring is dimensioned so that a space is provided between the annular ring and an inner surface of the annular chamber, the annular ring has two annular pieces and an annular cavity placed between the two parts, a magneto-rheological fluid placed within said space, an electric winding to induce a select magnetic field within the annular chamber to alter the shear strength of the magneto-rheological fluid, the electric winding is positioned to rotate with the annular ring , wherein the winding is wound around a portion of the ring to nular and has a collinear winding shaft with an annular chamber axis, a stationary source of electrical power, and sliding ring means for conducting electrical power from the stationary source to the winding, the slip ring means include ring conductors placed on the annular ring and electrical contacts that slide said conductors, mounted to said annular chamber

Description

MAGNETO-RHEOLOGICAL TORSION VIBRATING SHOCK ABSORBER DESCRIPTION OF THE INVENTION The present invention relates to the viscous torsional damping of rotating arrows, and in particular to controlling the viscous damping of rotating arrows using a magneto-reo-logic fluid inside the housing of the shock absorber that also contains a ring of inertia. Torsion fluid dampers using an inertia ring located within an annular housing and having a viscous shear stress fluid deployed between the inertial ring and the housing are known as described in U.S. Patent 2,514,136, 3,462,136, 3,603,172, 3,552,230 and 2,724,983. It is also known to adjust the viscous shear forces between a relatively rotating inertia ring and a housing by changing the space through which a viscous shear fluid flows. This is described, for example, in U.S. Patent No. 5,542,507. Agneto-rheological fluids are fluids that can have their shear stress or their viscosity influenced by exerting an electromagnetic field through the fluid. Such fluids are described, for example, in U.S. Patents 5,452,957; 5,398,917; and 5,277,281. The term "fluid" is defined as any fluid that exhibits a significant change in its ability to flow, or shear, to the application of an appropriate energy field, such as electric or magnetic fields. A magneto-rheological fluid responds < ? The presence of a magnetic field to change its ability to undergo shear or flow. Ge knows that magneto-reol gas fluids ("MR" fluids) are composed of magnetizable particles such as iron carbonyl contained in a fluid such as silicone oil, which is aligned under a magnetic field and reduces the fluid's ability magneto-rheological to undergo shearing or to flow. The reduction in the ability to flow is proportional, on a scale, to the resistance of the magnetic field. An electro-rheological fluid responds to electric fields. It is an object of the present invention to provide a viscous damping device wherein the resistance to internal torsion and viscous damping can be maintained in an adjustable manner. It is an object of the present invention to provide a viscous damping device that can be adjusted to control the frequency of damping selection during operation. It is an object of the present invention to provide a viscous damping device which when mounted on a rotating shaft, can be adjusted during the operation to increase or decrease the damping effect of the device. It is an object of the present invention to provide a damping device that can be controlled in an adjustable manner to provide an effective vibration damping device for any operating speed of a rotating engine shaft of an internal combustion engine mounted thereon. It is an object of the present invention to provide a viscous damping device that conserves energy. The objects are achieved in an inventive manner with a viscous magneto-rheological fluid absorber having an annular chamber containing an inertia ring, and between the inertial ring and the inner wall of the annular chamber the rheological fluid is placed such as a magneto-rheological fluid, and surrounding the annular chamber that retains the magneto-rheological fluid is an annular chamber that retains a plurality of windings effectively wound around the annular chamber. A mechanism for charging said windings with an adjustable current is provided to vary a magnetic field with said housing. Alternatively, an electro-rheological fluid can be used and the electric field within the housing can be controlled.

The object is furthermore achieved with at least two detaching rings externally applied to the outer housing and which are electrically connected to opposite electrical ends of the winding, and at least two sliding contacts, each sliding contact which conducts electrical current through the sliding rings. and inside the winding. The sliding contacts are electrically connected to a power source. The object is further achieved in that a controller communicates to the power source to adjust the current applied to the winding. The object is further achieved in that a vibration sensor can be applied to the arrow being damped, or to the other structure related thereto that needs to be controlled in vibration, the sensor feeds a signal back to the controller to control the damping of the absorber, or control the selection frequency of the absorber, to keep the vibration in target limits. The electric current from a DC power supply is continuously fed during motor operation and continuously adjusted to vary the electric current and therefore the magnetic field during the operation of the motor to minimize the torsional vibration. The torsional vibration is therefore reduced to a minimum by manipulating the torsional strength and / or dampening the vibration damper by varying the shear strength of the magneto-rheological fluid. The controller manipulates the input current to the windings using an appropriate control algorithm. This can also be achieved by continuously monitoring the amplitude of the torsional vibration at the location of the engine flywheel or some other suitable location along the crankshaft of the engine, or in a stationary adjacent structure such as a bearing housing, and adjusting the current input to the windings accordingly. As an alternate embodiment, a two-part inertia ring having a cavity formed between the two parts for supporting a winding can be provided. The slip rings within the annular chamber transfer electrical energy from the annular chamber to the inertial ring winding. An external pair of slip rings transfers the energy from a DC source to the annular chamber. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic sectional view through a diameter of a damper arrangement according to the present invention; Figure 2 is a schematic sectional view through a diameter of an alternate damper arrangement according to the present invention; and Figure 3 is an enlarged partial schematic view of a portion of Figure 2. Figure 1 illustrates a torsional vibration damper 10 which includes a support disc shaped body 12 having a plurality of bolt holes 14. in a bolt-fastening pattern towards a flywheel or flange 18 connected to a crankshaft 20. The crankshaft 20 may be associated with an internal combustion engine for example. The damper 10 further includes a housing portion 24 in the form of an annular C closed by an annular cover plate 26 to form a rectangular chamber 30. Within the annular chamber 30 the inertial ring 32 is trapped. Located between the ring of inertia . 32 and the inner surface 34 of the annular chamber 30 is the space 36 which is filled with a magneto-rheological fluid such as RHEOACTIVE MR fluid # 137A or equivalent or similar to fluids based on magnetic particles with variable viscosities as required for the application. A threaded plug 40 covers an opening 42 used to fill the chamber 30 with the magneto-rheological fluid 41. In addition to the space 36 a container 46 is provided to retain the additional fluid. Circling the C-shaped channel 24 is an additional C-shaped channel 48 which is also closed by the cover 26, defining a second rectangular annular chamber 50. Within this second annular chamber 50 are plural windings of a winding 54 having an electrical end connected by a connection 56 to a sliding ring 58, and another respective electrical end of the winding 54 connected through a connection 60 to a second sliding ring 62. The connections are shown and, entering the shell 26, penetratingly, there will be provided suitable seal openings for penetration. The winding 54 may be a winding of wound wire wrapped circumferentially around a wall 59 that divides the chamber 30, 50. The slip rings 58, 62 are ring-shaped and may be mounted for example on the cover plate 26, or on an external side of an inner annular wall 63 of the annular chamber 30 (as shown in for example in Fig. 2), or elsewhere. The sliding ring 58, 62 has a central shaft 70 which is collinear with the shaft of the arrow 20 and collinear with a shaft of the shock absorber 10. A first sliding contact 72 is connected to the first sliding ring 58 and a second sliding contact 74 is connected to the second sliding ring 62. The sliding contact 72, 74 is connected by wiring to a DC power source 76 which in turn is the signal connected to a controller 80, the operation of which will be described below.

A vibration envelope 86 is connected to the structure for which vibration is required to be controlled or monitored. For example, a vibration sensor 86 may be mechanically coupled to the flywheel 18 or arrow 20 which is being controlled for vibration.

Alternatively, the sensor 86 may be connected to the stationary structure such as a bearing housing 87 (not shown). The sensor 86 communicates via a connection 88 to the controller 80. The controller 80, by the appropriate electronic algorithm increases or reduces the DC current from the source 76 to the winding 54 to change the viscosity or shear force of the magneto-rheological fluid within the buffer 10 depending on the amplitude of the vibration detected by the sensor 86. Therefore the vibration control of the arrow 20 can be achieved in an efficient and effective manner using the feedback from the vibration sensor 86 and controlling the damper damping to change the selection frequency of the shock absorber 10. If an electro-rheological fluid ("ER fluid") is being used, the plate electrodes contain the fluid and a high-voltage source creates a controllable electric field between the plate electrodes.

Figures 2 and 3 illustrate an alternate embodiment of the torsion damper 100 which includes an annular chamber in shape of C 110 connected to its center for (or formed with) an annular disc 112, and closed by an annular cover plate 114. The cover plate provides a filling opening 116 for filling the chamber 110 with magneto-rheological fluid 118. Inside the chamber 110 is a two-part inertia ring 122 having a left piece 124 and a right piece 126 as shown in FIG. see in Figure 2. Pieces 124 and 126 have correspondingly staggered outer and inner circumferential areas 125, 127 that engage. The parts 124, 126 can be fixed together by welding or fasteners or they can be held together functionally by the housing 110 and the cover plate by means of plastic bearings 180, 182, 184. The two pieces 124, 126 have formed within their respective mating surfaces 124a, 126a an annular cavity 128 supporting an induction winding 130. Winding 130 in this embodiment rotates with inertial ring 122. Two connections 134, 136 penetrate through a hole in the inertial ring 122 , through a hole 137 in the left piece 124 for example, to connect to the mounted sliding rings 140, 142 exposed in an internal circumference of the left piece 124 for example.

As shown in elongated forms in Fig. 3, the electrical contacts 146, 148 are spring-loaded in contact with the slip rings 140, 142 respectively, by means of one or more springs 150 supported by at least one threaded electrical accessory 152 to through a wall 160 of the chamber 110. The external connections 16? 164 connect the electrical contacts 146, 148 to the slip rings 166, 168 mounted on the crank shaft 20 having controlled vibration. The sliding contacts 170, 172 connect the slip rings 166, 168 by means of a cable 174 to the power source CD 76. The controller 80 and the vibration sensor 86 can operate identically as described in Figure 1. Figure 2 presents a more compact design that eliminates the external chamber 50 of Figure 1. Although the present invention has been described with reference to a specific embodiment, those skilled in the art will recognize that changes can be made thereto without departing from the scope and spirit of the invention as set forth in the appended claims.

Claims (11)

1. CLAIMS 1.
2. A torsional vibration dampening device for a rotating object, the device is characterized in that it comprises: a housing having an annular chamber, the housing adapted to connect the rotating object to be torsionally damped; an annular ring located inside the annular chamber and free to rotate with respect thereto, the annular ring dimensioned so as to provide a space between the annular ring and an inner surface of the annular chamber, the annular ring having two annular parts and an annular cavity placed between the two pieces; a magneto-rheological fluid placed within said space; an electric winding for inducing a select magnetic field within the annular chamber to alter the shear strength of the magneto-rheological fluid, the electric winding positioned to rotate with the annular ring wherein the winding is wound around a portion of the annular ring and has a collinear winding shaft with the axis of the annular chamber; a stationary source of electrical energy; and sliding ring means for conducting electrical power from the stationary source to the winding, sliding ring means including annular conductors placed on the annular ring and electric contacts sliding said conductors, mounted to said chamber.
3. The device according to claim 1, characterized in that the electric winding is controllable and further comprises a controller for controlling the magnetic field.
4. The device according to claim 2, further characterized in that it comprises a sensor adapted to be applied in vibration communication to the object being damped and having a signal line connected thereto and connected to said controller, said winding electrical includes a winding of electrical conductors forming a winding mass around said annular chamber and having at least two of said sliding ring means for driving a voltage within said winding to generate said magnetic field, said controller varying said voltage to said winding mass in response to a signal from said signal line.
5. The device according to claim 1, characterized in that the electric winding comprises a winding of electric conductors forming a winding mass around the annular chamber and having at least two of said sliding ring means for driving a voltage inside the winding to generate said magnetic field.
6. The device according to claim 4, characterized in that the winding of electrical conductors are slid in a circumferential direction around an outer circumference of said housing.
7. The device according to claim 1, characterized in that the housing comprises a disk member placed in an internal area of the annular chamber connected thereto, and wherein the disk member is attached to a flywheel of a combustion engine internal The device according to claim 1, characterized in that the winding includes two connections that penetrate from said cavity towards an internal diameter of the annular ring, and said annular conductors placed in said internal diameter connected to said connections, and said electrical contacts that they are spring loaded towards said annular conductors and said electric winding further comprises additional connections from the electrical contacts towards additional annular conductors rotating with the annular chamber, and additional sliding contacts for transmitting electrical energy.
8. 8. A method of controlling the torsional vibration of a rotary member characterized in that it comprises the steps of: providing a shock absorber fixed to said rotating member, the shock absorber having two separate elements for relative rotation between them, and a space between the filled rotating elements with a rheological fluid, said fluid responds to the influence of the selected energy field to alter the shear strength of the same; apply the selected energy field to the rheological fluid to adjust the shear resistance thereof to alter the damping frequency of the damper.
9. 9. The method of compliance with the claim 8, characterized in that the step of applying the selected energy field is further defined in that said selected energy field is a magnetic field and a winding surrounding the rheological fluid is provided, the winding is energized with a controllable DC voltage to change a magnetic field through said fluid.
10. 10. The method of compliance with the claim 9, characterized in that it comprises the additional step of detecting a vibration amplitude of said rotating member and controlling the DC voltage towards said * winding proportionally to the vibration amplitude detected. The method according to claim 10, characterized in that the rotating member comprises a flywheel for a crankshaft of an internal combustion engine. I ?. A torsion fluid absorber mounted to a rotating shaft characterized in that it comprises: an annular chamber having surrounding walls mounted for rotation with the rotating shaft to be damped for torsional vibration; an annular ring at least partially supported within said chamber and free to rotate with respect thereto, the annular ring dimensioned so as to provide a space between the annular ring and an inner surface of the annular chamber, the annular ring having two annular pieces and an annular cavity placed between the two pieces; a magneto-rheological fluid maintained within said space between the surrounding walls and the annular ring, the fluid having a chemical composition that is susceptible to changing its resistance to shear stress under the influence of a selected magnetic field applied through the fluid; an electric winding for inducing the selected magnetic field through the fluid, the electric winding surrounding said chamber, the electric winding positioned to rotate with the annular ring wherein the winding is wound around a portion of the annular ring and has an axis of coiled colinear with an axis of the annular chamber; and at least one sliding ring and at least one corresponding sliding contact connected to the electric winding and a source of electrical energy. The damper according to claim 12, further comprising a controller for adjusting the magnitude of the selected magnetic field, the controller operatively connected to the electric winding.