Ultrasonic Motor Transmission System

Abstract

The invention covers a system for driving transmission members, particularly made from glass and of a relatively small diameter, at an ultrasonic rate in which the transmission member is coupled to a base member by means of an epoxy, swaging, or a combination thereof. In addition an ultrasonic motor system including an ultrasonic motor, and transmission assembly for use with a receptacle is also disclosed.

Description

BACKGROUND OF THE INVENTION

This invention relates to an ultrasonic motor system and a transmission assembly which may be used therewith for transmitting high frequency mechanical vibrations for performing certain processes.

The present invention solves the problems of introducing ultrasonic vibrations into a heated receptacle or flask which is under reflux or any other condition which requires sealing from the external atmosphere and/or might contain corrosive or highly reactive agents. This would also include gaseous reactions and reactions of two immiscible phases for which mechanical stirring or agitation is insufficient to cause interfacial contact for reaction. Attempts were made to insert the receptacle in an ultrasonic tank but it was found cumbersome and if a wide range of temperature was needed it would have an effect on the piezoelectric driving elements. Furthermore, the insertion of a metallic vibratory transmission member into the fluid medium often caused corrosion and contamination of the receptacle contents.

The present invention also deals with the solution of the problem of transmitting ultrasonic vibrations for use as a disperser in which mixtures of liquid or liquids and solids are dispersed to form suspensions, emulsions, and the like under the influence of ultrasonic vibrations and where it is desired to have an energy transmission member of minimum diameter. Various applications of ultrasonic energy require the tool or transmission member to be of a small diameter where it is not practical or feasible to use the method of a threaded portion for coupling to an ultrasonic motor. For example, when it is desired to use glass as the material for the transmission member then a threaded coupling is not always feasible due to the problems inherent in machining glass or forming it with a fine enough screw thread to properly transmit ultrasonic vibrations. The same holds true for relatively thin plastic and metallic tool members.

OBJECTS OF THE INVENTION

An object of the invention is to provide an ultrasonic transmission assembly for transmitting ultrasonic mechanical vibrations from an ultrasonic motor to a glass or relatively thin transmission member.

Another object is to provide an ultrasonic motor system for transmitting ultrasonic mechanical vibrations to a glass or relatively thin transmission member capable of being inserted in a receptacle and mounted in sealed relation to the opening therein.

Other objects and advantages of the present invention will be obvious as the disclosure proceeds.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention an ultrasonic transmission assembly consists of base member adapted to be connected to an ultrasonically vibrated driving member or ultrasonic motor, that may be hand held or mounted in a fixed position, and the base member is fixed to the driving member substantially in the region of high frequency vibration, for example, a loop of longitudinal, torsional, or radial vibration. In this manner the base member is vibrated at a frequency and amplitude which substantially corresponds to the frequency and amplitude of vibration of the driving member to which the base is secured. The means for coupling the base member to the energy transmission or tool member, as well as the length, diameter and composition of the tool member all play an interrelated role on the frequency of the overall system.

In the illustrated preferred embodiments of the invention, as will be hereafter more fully described, coupling means are provided to firmly secure the terminal end of the transmission member to the base member whereby vibratory motion is imparted to the transmission member. To receive the transmission member an aperture which extends substantially perpendicular to the face surface of the base member is provided for receiving an end of said transmission member. A bonding agent in the form of an epoxy cement couples the base member to the transmission member so that a proper transmission of the high frequency mechanical vibrations induced in the base member is transmitted to the tool member.

A feature of the invention resides in the arrangement of the bonding agent within the aperture and in surrounding relation to the terminal end of the tool member so that a maximum amount of energy is transmitted with a minimal of loss in the form of heat. The bonding agent in the form of epoxy provides a joining or coupling of the generally glass tool member to the base member. This coupling is generally in a transition area with the tubular sections in telescopic relation to each other and an epoxy layer between the transmission member and base member. The tubular sections may be designed so that the base member extends in surrounding relation to the transmission member.

Another feature of the invention resides in the provision of means for acoustically mounting and sealing the tool member relative to an opening in a receptacle with the tool member extending therein for introducing the high frequency mechanical vibrations within the medium contained in the receptacle. The sealing means may include a stopper or plug adapted to fit within the receptacle opening and having an axial bore through which the transmission member extends with an O-ring extending in a seat provided within the axial bore or on the transmission member, without acoustically loading the transmission member.

Still another feature of the present invention is the arrangement and interrelationship of the ultrasonic motor and transmission assembly to form an ultrasonic motor system to obtain the selective application of high frequency mechanical vibrations through a glass, plastic or metallic tool without fatigue fractures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Although the characteristic features of this invention will be particularly pointed out in the claims, the invention itself, and the manner in which it may be made and used, may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part hereof, wherein like reference numerals refer to like parts throughout the several views and in which:

FIG. 1, is a assembled view, in partial cross section of an ultrasonic motor system according to the present invention;

FIG. 2, is a section view of the ultrasonic transmission assembly;

FIG. 3, is an exploded view of the ultrasonic transmission assembly;

FIG. 4, is an enlarged section view of a stopper for positioning within a receptacle;

FIG. 5, is an enlarged sectional view illustrating the manner in which the coupling means in the form of the bonding agent may vary in configuration in accordance with this invention;

FIGS. 6--8, are views similar to FIG. 2, illustrating other forms of the coupling means;

FIG. 9, is a sectional view in which the base member is the substantial length of the transmission assembly;

FIG. 10, is a sectional view in which the driving member directly engages the tool member.

PREFERRED EMBODIMENTS OF THE INVENTION

Turning now to FIGS. 1--4, we have the ultrasonic transmission system generally referred to by numeral 10 and seen to include an ultrasonic motor 11 having a driving member 12 extending therefrom for transmitting the ultrasonic vibrations as indicated by arrow 14 to the transmission system or assembly 15.

The ultrasonic motor 11 may be powered by generator 16 and connected by electrical cable 17, the generator is an oscillator adapted to produce electrical energy having an ultrasonic frequency. The ultrasonic motor 11, may be in the form of a driving member adapted for being hand held as by an operator and generally comprising a tubular housing or casing from which the driving element 12 extends. The transducer in the ultrasonic motor 11 is longitudinally dimensioned so as to have lengths which are whole multiple of half-wavelengths of the compressional waves established therein at the frequency of the alternating current supplied so that longitudinal loops of motion occur at the end of the driving element 12. Thus, the optimum amplitude of longitudinal vibration and hyperaccelerations of driving element 12 is achieved, and such amplitude is determined by the relationship of the masses which may be made effective to either magnify or reduce the amplitude of the vibrations received from the transducer.

The ultrasonic motor 11 may be retained in a fixed position for extended periods of time by mounting means 20 which may be in the form of a stand on which the motor rests or as schematically illustrated it may be in the form of an arm 21 extending outwardly from a fixed support 22.

The transmission assembly 15 includes a base member which may be formed of any suitable material capable of supporting ultrasonic vibrations, generally metallic, and adapted to be set into vibration in a given direction at ultrasonic frequencies, and is rigidly affixed to the forward end of the driving member 12 by securing means 26 which may consist of a threaded fastener 27 extending from the rear end 28 of base member 25 and a complementary threaded recess 29 in the driving member 12 to properly couple the vibratory motion unimpeded to the base member 25 and consequently to the transmission or tool member 40 mounted therein. An aperture or recess 32 extends inwardly from the front end 33 of the base member 25 and is defined by a downwardly extending skirt or rim 34 terminating in a bottom edge or surface 35. The base member 25 has an axial length which is usually less than a quarter wavelength at the frequency of longitudinal vibration thereof.

Certain features of the invention can best be explained in terms of the diameter, D, of the transmission member 40 and depth, L, of recess 32, and diameter, S, of the recess so that a defined thickness, T, remains between the diameter, D, and recess diameter, S, and depth, L, and depth of insertion, X, to assure that the coupling means 45 properly transmits the vibrations induced in the base member 15. The tool member 40 has a terminal end 42 positioned within the recess 32 and an output or free end 43 in axial spaced relation thereto with an outer surface 44.

The transmission member is embedded or cast within the bonding agent 46 to guarantee a sufficient coupling of the vibratory energy. A depth of insertion, X, within the bonding agent of about 0.60 inch has been found satisfactory for a glass tool member 40 ranging in diameter from 0.10 to 1.0 inch. The range of insertion may be approximately from 0.06 to 2.0 inch, but as great as 20 inches for certain applications. Accordingly, for a diameter, D, in the range of 0.10 to 2.0 inch the recess diameter, S, may in each instance exceed the diameter, D, by at least 0.002 inch to leave a minimum thickness, T, of 0.001 inch. The range of thickness, T, may be generally from .0005 to 0.50 inch, but preferably from 0.002 to 0.1000 inch for a diameter, D, of less than one inch. For diameters of D, in say excess of one inch the dimensions are selected accordingly. The layer of bonding agent 46 is in the form of an epoxy which is capable of supporting ultrasonic vibrations and firmly securing the end of the transmission member 30 to the base member 25 so that the ultrasonic mechanical vibratory motion is imparted to the transmission member 40. A suitable bonding agent for this purpose is manufactured by the Shell Chemical Company and is designated as Epibond 123 used with a conventional hardener. When the transmission member 40 is made of glass, Pyrex has proven satisfactory since it is inert and strong, this is not to exclude using ceramic or other glass compositions. The transmission member 40 may also be made from a plastic or metallic material and coupled to the base member in the various forms described herein. In particular when a metallic or plastic tool member is used of a small cross section or diameter it is not always practical to form a thread thereon. For example, tools having a diameter in the range 0.060 to 0.20 inch are more suitably joined to a base member by the coupling means described herein. Obviously, larger diameter tools may also be coupled as described herein.

The transmission assembly 15 may be used for a number of applications in which it is desired to transmit the vibratory energy to perform useful work. When a glass tool member 40 is used an ideal application is for use in chemical processes in which it is desired to immerse the free end 43 of the transmission member within a receptacle or flask 48 having a fluid 50 contained therein with an opening 52 at one end thereof. The receptacle may be supported on a surface 49.

Sealing means 55 is provided between the opening 52 at the neck 54 and the transmission member 40 to provide the required seal. One form of sealing means may be that of a ring seal that is either in the side wall, top or bottom of the receptacle so that the transmission assembly is essentially permanently secured to the receptacle. As seen in FIGS. 3 and 4, a stopper or bushing 56 which may be made of rubber or a plastic such as Nylon or Teflon having an outer tapered surface to coincide with the taper at the neck 54 has a passageway or bore 60 extending therethrough with a radial O-ring seat or depression 61 contained therein. In like manner the transmission member 40 may have a mating O-ring seat 62 which is adapted to receive therein a gasket or O-ring 64. The O-ring 64 is preferably mounted a distance Y from the output end 43 such that it is situated at a nodal plane or section at the frequency of longitudinal vibration of the transmission member 40. The O-ring 64 snap fits into the seats 61 and 62 and the bushing 56 then slides into a standard tapered ground glass joint for chemical glassware. A simple straight bushing can be used without an O-ring if the seal in the flask is not crucial.

Accordingly, as illustrated in FIGS. 1--4, a complete motor system 10 is described that may be conveniently used to transmit ultrasonic mechanical vibrations through a transmission member which may have various cross-sectional configurations since a threaded joint is not relied upon. In addition glass, ceramic, sapphire and diamond, transmission members of various diameters may be induced to vibrate at ultrasonic frequencies for performing various experiments and processes. The transmission member may be designed to magnify the amplitude of vibration between its input and output surfaces in a well known manner. The transmission member may also be tubular in the form of a cylinder.

FIGS. 5--10, illustrate other forms of the transmission assembly that may be used in the overall transmission system. Referring to FIG. 5, we have a transmission assembly 15a in which the vibratory energy as indicated by the mechanical vibration arrow 14a extends in a plane perpendicular to the direction of motion. The base member 25a has a recess 32a extending from the front end 33a and which accommodates the transmission member 40a which has a projection or finger 65a extending from the rear end 42a and terminating in face 66a. The securing means may be in the form of a threaded fastener 27a. In this manner the outside diameter of the base member 25a and tool member 40a may be the same, with the coupling means in the form of the bonding agent 46a extending therebetween. The vertically extending portions or layers of bonding agent 46a are not at the outer surface of the joint but contained between horizontal portions where the vibrations are transmitted by compressional waves through the radially extending bonding agent 46a.

FIG. 6, illustrates a transmission assembly 10b in which the base member 25b has a threaded opening 68b at its rear end 28b with a downwardly extending skirt 34b having an inwardly flared portion 70b and terminating in a front end 33b. The transmission member 40b has a front tapered or conical section extending inwardly between the ledge 71b and free end 43b to obtain an increase of the amplitude of longitudinal vibrations in accordance with known methods of amplitude magnification. The rear section of the tool member 40b has a tapered body or conical section 72b extending inwardly and a straight shank portion 73b terminating in a rounded or beveled edge 74b which merges with face 66b. The body portion 70b is initially straight until it is assembled with the tool member 40b so that the rear section extends coaxially within the recess 32b and the section 70b is swaged into intimate contact with the tool member 40b. The intimate contact between base member 25b which may be metallic, and tool member 40b which may be glass, permits the mechanical vibrations to be transmitted through the interface of the contacting areas.

FIG. 7, is similar to FIG. 6, with the transmission assembly 10c having a threaded fastener 27c extending from the rear face 28c with a downwardly extending skirt 34c having an inwardly flared portion 70c and terminating in a front end 33c. The transmission member 40c, in the form of an acoustical impedance transformer, has an amplitude magnification gain built into it by having an upper cylindrical section of greater diameter than the lower cylindrical section, as in accordance with U.S. Pat. Re 25,033. In this manner the amplitude of vibration is greater at the output end 43c than at the rear ledge 71c. The rear section of the tool member 40c has a tapered body 72c and a straight shank portion 73c terminating in a rounded or beveled edge 74c. The coupling means is in the form of a layer of bonding agent 46c interposed between the mating surfaces as seen in FIG. 7. In this manner the bonding agent 46c firmly retains the overlapping portions of the base member 25c and tool member 40c in energy transferring relation to each other transmitting the ultrasonic mechanical vibration, defined herein as vibrations in the range of 1,000 cycles per second to 1,000,000 cycles per second.

FIG. 8, illustrates a transmission assembly 10d having retaining means 75d in the recess 32d of base member 25d, in the form of annular rings having crests 76d and depressions 77d starting from the terminal end 42d and extending to the front end 33d. The transmission member 40d may be similarly provided with complimentary retaining means in the form of corrugations formed by crests 78d and depressions 79d that may be blended together by curved portions. The retaining means increases the area of contact for the bonding agent 46d which forms the coupling means to obtain the proper transmission of the vibratory energy. The respective configurations of the retaining means may take various forms and shapes.

FIG. 9, illustrates a transmission assembly 10e in which the base member 25e may be of extended longitudinal length and substantially equal to a half wavelength of the frequency of vibration and having the base member 40e secured thereto by the bonding agent 46e. For certain applications only the tip need be of say, glass and therefore the remaining extent of the transmission assembly 10e may be of some other material, such as metal. The base member 40e may include a finger 65e extending from the terminal end 42e in spaced relation to the front end 33e of the base member 25e. The finger 65e extends within recess 32e with the energy transmitted to the free end 43e. The size and shape of the finger 65e may vary as desired.

FIG. 10, illustrates a transmission assembly 10f in which the recess 32f extends through the base member 25f between its front end 33f and rear end 28f. The transmission member 40f is contained within the recess 32f and coupled to the base member by means of the bonding agent 46f. The securing means of the driving element has an exterior threaded portion 80f engaging an internal threaded portion 81f, with a projection or tip 82f extending therefrom in engagement with the terminal end 42f of the tool member 40f. In this manner the vibratory energy is transmitted to the base member 25f through the threaded engaging portions and in turn through the bonding agent 46f to the tool member 40f. In addition, the mechanical vibrations are also transmitted via the pressure contact coupling between the tip 82f and its engagement with the rear end 42f of the transmission member 40f. To permit rotation of the transmission assembly 10f relative to the driving member 12f gripping means may be provided, as for example, in the form of spaced apart flats 83f on the circular outer surface.

Although illustrative embodiments of the invention have been described in detail herein with reference to the accompanying drawings it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein without departing from the scope or spirit of the invention.

Claims

I claim:

1. An ultrasonic transmission assembly for use with an ultrasonic driving member, comprising:

A. an energy transmission member, having a longitudinal length substantially greater than the largest diameter defined by its cross-sectional, area for transmitting vibrations along its longitudinal length,

B. a base member capable of supporting ultrasonic vibrations and adapted to be set into vibration in a given direction at ultrasonic frequencies, said base member being provided with an aperture for receiving an end of said transmission member, and having an axial length less than a quarter wavelength at the frequency of longitudinal vibration thereof, with said transmission member extending axially within said aperture a distance in the range of 0.06 to 2.0 inch,

C. means for connecting said base member to said driving member, said means including a threaded portion for mating with a similarly threaded portion on the driving member, and

D. means for coupling the vibrations induced in said base member to said transmission member, said coupling means includes a layer of bonding agent in said aperture between said transmission member and said base member capable of supporting ultrasonic vibrations for firmly securing the end of said transmission member to the base member, said layer of bonding agent having a thickness in the range of 0.0005 to 0.50 inch, whereby ultrasonic vibratory motion is imparted to said transmission member.

2. An ultrasonic transmission assembly as defined in claim 1, and further including retaining means contained within said aperture or on said transmission member.

3. An ultrasonic transmission assembly as defined in claim 2, wherein said transmission member positioned within said aperture includes a plurality of spaced apart annular crests and depressions blended together, wherein the area of contact for said bonding agent is increased.

4. An ultrasonic transmission assembly as defined in claim 1, wherein said transmission member is of a glass material.

5. An ultrasonic transmission assembly as defined in claim 1, wherein said transmission member is of a plastic material.

6. An ultrasonic transmission assembly as defined in claim 1, wherein said transmission member is of a metallic material.

7. An ultrasonic transmission assembly as defined in claim 1, wherein said transmission member is of a ceramic material

8. An ultrasonic transmission assembly as defined in claim 1, wherein

a. said aperture extends axially through said base member between opposite ends thereof, and

b. means for connecting said base member to said driving member so the latter is adapted to extend within said aperture in contacting pressural relationship to said transmission member, wherein the mechanical vibrations of said driving member are transmitted to said transmission member through said coupling means and said contacting pressural relationship.

9. An ultrasonic transmission assembly as defined in claim 1, and further including gripping means provided on said base member.

10. An ultrasonic transmission assembly as defined in claim 1, wherein said transmission member has a projection extending within said aperture and a rear surface in spaced relation to the front end of said base member so that said bonding agent also extends radially between said spaced apart rear surface and said front end.

11. An ultrasonic transmission assembly as defined in claim 1, wherein

a. said transmission member is provided with a tapered section extending inwardly at the end thereof, and

b. said base member has an inwardly flared portion extending coaxially in spaced relation to said tapered section, and said layer of bonding agent extends therebetween.

12. An ultrasonic motor system, comprising:

A. an ultrasonic motor having a driving member,

B. a glass energy transmission member, having a longitudinal length substantially greater than the largest diameter defined by its cross-sectional area for transmitting vibrations along its longitudinal length,

C. a base member capable of supporting ultrasonic vibrations and adapted to be set into vibration in a given direction at ultrasonic frequencies, said base member being provided with an aperture for receiving an end of said transmission member, with said transmission member extending axially within said aperture a distance in the range of 0.06 to 2.0 inch,

D. means connecting said base member to said driving member of the ultrasonic motor, and

E. means for coupling the vibrations induced in said base member to said transmission member, said coupling means includes a layer of bonding agent in said aperture between said transmission member and said base member for firmly securing the end of said transmission member to the base member within said aperture, said layer of bonding agent having a thickness in the range of 0.0005 to 0.50 inch, whereby ultrasonic vibratory motion is imparted to said transmission member.

13. An ultrasonic motor system as defined in claim 12, and further including:

a. a receptacle having an opening therein,

b. means for mounting said ultrasonic motor wherein said transmission member extends through said opening and into said receptacle, and

c. means for sealing said transmission member at said opening, said sealing means including a stopper adapted to fit within said opening and having an axial bore through which said transmission member extends with an O-ring extending therebetween.

14. An ultrasonic motor system as defined in claim 13, wherein said transmission member is provided with an O-ring seat for receiving said O-ring.

15. An ultrasonic motor system as defined in claim 14, wherein said stopper is provided with a mating O-ring seat in said axial bore.

16. An ultrasonic transmission assembly as defined in claim 12, and further including retaining means contained on said transmission member, in the form of a plurality of spaced apart annular crests and depressions blended together to increase the area of contact for said bonding agent.

17. An ultrasonic transmission assembly as defined in claim 12, wherein

a. said aperture extends axially through said base member between opposite ends thereof, and

b. means for connecting said base member to said driving member so that the latter is adapted to extend within said aperture in contacting pressural relationship to said transmission member, wherein the mechanical vibrations of said driving member are transmitted to said transmission member through said coupling means and said contacting pressural relationship.

18. An ultrasonic transmission assembly as defined in claim 12, and further including gripping means provided on said base member.

19. An ultrasonic motor system adapted to be positioned within a receptacle having an opening therein, comprising:

A. an ultrasonic motor having a driving member,

B. a glass energy transmission member,

C. a base member capable of supporting ultrasonic vibrations and adapted to be set into vibration in a given direction at ultrasonic frequencies, said base member being provided with an aperture for receiving an end of said transmission member, and having an axial length less than a quarter wavelength at the frequency of longitudinal vibration thereof, with said transmission member extending axially within said aperture a distance in the range of 0.06 to 2.0 inch,

D. means connecting said base member to said driving member of the ultrasonic motor,

E. means for coupling the vibrations induced in said base member to said transmission member, said coupling means includes a layer of bonding agent capable of supporting ultrasonic vibrations for firmly securing the end of said transmission member to the base member, said layer of bonding agent having a thickness in the range of 0.0005 to 0.50 inch, whereby ultrasonic vibratory motion is imparted to said transmission member,

F. means for mounting said ultrasonic motor wherein said transmission member extends through said opening and into said receptacle, and

G. means for sealing said transmission member at said opening, said sealing means including a stopper adapted to fit within said opening and having an axial bore through which said transmission member extends with an O-ring extending therebetween.

20. An ultrasonic motor system as defined in claim 19, wherein

a. said transmission member is provided with a tapered section extending inwardly at the end thereof, and

b. said member has an inwardly flared portion extending coaxially in spaced relation to said tapered section, and said layer of bonding agent extends therebetween.

21. An ultrasonic motor system as defined in claim 19, wherein said transmission member has a projection extending within said aperture and a rear surface in spaced relation to the front end of said base member, so that said bonding agent also extends radially between said spaced apart rear surface and said front end.