CA1299228C - Ultrasonic driving device - Google Patents
Ultrasonic driving deviceInfo
- Publication number
- CA1299228C CA1299228C CA000576354A CA576354A CA1299228C CA 1299228 C CA1299228 C CA 1299228C CA 000576354 A CA000576354 A CA 000576354A CA 576354 A CA576354 A CA 576354A CA 1299228 C CA1299228 C CA 1299228C
- Authority
- CA
- Canada
- Prior art keywords
- stator
- rotary
- driving device
- rolling
- ultrasonic driving
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000000750 progressive effect Effects 0.000 claims abstract description 15
- 229910052751 metal Inorganic materials 0.000 claims description 15
- 239000002184 metal Substances 0.000 claims description 15
- 239000000919 ceramic Substances 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 7
- 230000010363 phase shift Effects 0.000 claims description 3
- 238000005096 rolling process Methods 0.000 claims 13
- 239000010687 lubricating oil Substances 0.000 claims 1
- 230000003247 decreasing effect Effects 0.000 abstract description 7
- 239000000203 mixture Substances 0.000 description 3
- 241000901720 Stator Species 0.000 description 2
- 208000036366 Sensation of pressure Diseases 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
Abstract
Abstract of the Disclosure A rotary member rotatably supports a plurality of balls, disks or rolls which are pressed on a stator by a pressure member. When the stator generates progressive wave, the balls, disks or rolls are rolled on the stator and the pressure member by the progressive waves. Since the balls, disks or rolls are rolled on the stator and the pressure member, the wear of the stator, the pressure member and the balls, disks or rolls is decreased. Lubricative oil may be applied to the circumference of the balls, disks or rolls of the rotary member.
Description
z~
BACKGROUND OF TH~ INVENTION
_ _ _ _ _ . _ The present invention relates to an ultrasonic driving device having a structure for decreasing wear between a stator and a rotary member.
In a known ultrasonic motor using a ring type piezoelectric vibrator, two groups of electrodes are attached to one end of a ring type piezoelectric ceramic, the two groups of electrodes are so positioned that standing waves respectively genera-ted by the two groups of electrodes are shif-ted every ~/2 in each position.
The parts of the ring type piezoelectric vibrator corresponding to the electrode are alternately polarized in reverse. Also, the two groups of the electrodes are respectively connected to two oscillators for respectively generating alternating current vol-~ages having ~/2 phase shift from each other. When the alternat-ing current voltages from the lwo oscillators are respectively applied to the two groups of electrodes, the two standing waves having ~/2 phase shift from each other are generated on the sur-faces of the ring type piezoelectric vibrator and then progressive waves owing to an compound of -the two standing waves generate on the surfaces of the ring type piezoelectric vibrator. Therefore, when a slider attaching a rotary member is put on the ring type piezoelectric vibrator and is s-trongly pressed to the ring type piezoelectric vibrator, the rotary member is rotated by the pro-gressive waves.
In the prior ultrasonic motor, however, the slider is easily worn out because the slider of the rotary member is directly pres-sed on the piezoelectric vibrator.
There is known an ul-trasonic motor comprising a Langevin type vibrator having two ring type piezoelectric vibrators which are put between two metal blocks. In this ultrasonic motor, a twist-ing joint body is connected to the end of the one metal block by a bol-t for fixing the metal blocks and the piezoelectric vibrator and a rotary member is pressed on the twisting joint body by a spring.
In this ultrasonic motor, however, the rotary member is easi-ly worn out because the rotary member is pressed on the twisting joint body.
1'~9~32Z~3 SUMMARY _F THE INVENTIO_ It is, therefore, -the primary object of the present inven-tion to provide an ultrasonic driving device having a structure for decreasing wear of a rotary member or a stator.
It is another object of -the present invention to provide an ultrasonic driving device having a rotary membèr in which balls, disks or rolls are rotatably attached for decreasing wear of the rotary member.
It is another object of the present invention to provide an ultrasonic driving device in which lubricate oil is supplied to the circumference of balls, disks or rolls of a rotary member for decreasing wear of the rotary member.
In order to accomplish the above and other object, the pre-sent invention comprises a sta-tor for generating a progressive wave by driving a piezoelectric vibrator or vibrators, a rotary member rotatably attaching a plurality balls, disks or rolls, and pressure means for making the balls, disks or rolls contac-t with the stator.
BRIEF DESCRIPT-[_N OF THE DRAWINGS
Fig. 1 shows a sectional v:iew of an ultrasonic motor in the prior art.
Fig. 2 shows a plane view of a form of a piezoelectric vibra-~or and a composition of electrodes of the piezoelectric vibrator in the ultrasonic motor in Fig. 1.
Fig. 3 shows a separated perspective view of the stator of an ultrasonic motor in the prior art.
Fig. 4 shows a side view having a partial sectional view of an ultrasonic motor in the prior art.
Fig. 5 shows a side view of an ultrasonic driving device pro-vided by the present applicant.
Fig. 6 shows a side view of one part of an ultrasonic driving device of an embodiment in the presen-t invention.
Fig. 7 shows a plane view of a rotary member of the ultra-sonic driving device in Fig. 6.
Fig. 8 shows a view for explaining a principle of an ultra-sonic driving device in Fig. 6.
Fig. 9 shows a side view of an ultrasonic driving device of ., ,~, 1,!`
lZ9~
rhe other embodiment according to -the present invention.
Fig. 10. shows a plane view of a rotary member of ultrasonic driving device in Fig. 9.
Fig. 11 shows a plane view of an ultrasonic driving device of another embodiment according to the present invention.
Fig. 12 shows a side sectional view of an ultrasonic driving device another embodiment according to the present invention.
Fig. 13 shows a side sectional view of an ultrasonic driving device another embodiment according to the present invention.
Fig. 1~ shows a side view of a concrete composition of the ultrasonic driving device in Fig. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the prior art in Fig. 1, a ring type piezo-electric vibrator B is attached -to a ring type resilient member A
a n d t h e p i e z o e l e c t r i c v i b r a t o r B vibrates with the resilient member. The pieæoelectric vibrator B is divided in 17 parts by the ration of e.g. 22.5 or 11.25.
The respective neighbouring portions in the 17 parts of the piezo-electric vibrator B are polarized by a reverse polarity to each other as shown in Fig. 2. The two portions C and D in the one side of the piezoelectric vibrator B are respectively attached as an electrode by conductive paint as shown in Fig. 2. The portion G in Fig. 2 shows an earth electrode. The member F to be driven to which slider E is attached is mounted on the resilient member A.
In the ultrasonic motor in the pri.or art, the alternating current voltage of Vosinwt is applied to the one electrode C and the alternating current voltage Vocoswt is applied to the other electrode D, where Vo is an instantaneous value, w is radian frequency and t is time. The phases of these voltages shift by rl/2 from each other. Thereby, the divided portions of the piezo-electric vibrator B alternately produce expansion and contraction and thus, the resilient member A produces bending vibration.
Therefore, a standing wave is generated in the resilien-t member A
and a progressive wave is generated on the resilient member A.
Thus, the driven member F having the slider E is rotated on the resilient member A.
However, in the prior ultrasonic motor, because the slider E
~z~z~
lS strongly contacted with the resilient member A, the slider E or the resilient member ~ is worn out and the life of the ul-trasonic motor is short.
Referring to the prior art in Fig. 3, a piezoelectric vibra-tor 3, a terminal plate 4, a piezoelectric vibrator 5, a terminal ~la~_e 6 and an aluminum disk 7 aLe put on a washer 1 and a bolt 2 is inserted through the center holes of these members. The screw ~a of the bolt 2 is engaged with the screw hole 8a of a twisting joint body 8. A drain 8b is formed on the under surface of the twisting joint body 8, arcuate projections 8c are formed in both sides of drain 8b, and a beam 8d is so formed in the upper portion of the twisting joint body 8 that an angle between the beam 8d and drain 8b becomes a predetermined value.
In this prior ultrasonic driving device, when alternating current voltage is applied through the terminal plates 4 and 6 to the piezoelectric vibrators 3 and 5 and the piezoelectric vibra-tors 3 and 5 are vibrated in the direction of their thickness, the arcuate projections 8c of the twisting joint body 8 are pushed and twisted by the vibration of the piezoelectric vibrators 3 and 5.
Therefore, the twisting joint body 8 is vibrated to be twisted.
When the excitation fre~uency of the alternating current voltage approaches a resonance fre~uency, elliptic vibration arises on the beam 8d of the twisting joint body 8.
Therefore, as shown in Fig. 4, a rotary member 9 is put on of the beam 8d of the twisting joint body 8, a center bolt 10 passed through a bearing 11 of the rotary member 9 fixes the twisting body 8, and a spring 12 is attached between the upper end of the bolt 10 and the bearing 11, whereby the rotary member 9 is strong-ly touched on the beam 8d of the twisting joint body 8 and is ro-tated by the elliptic vibration on the beam 8d.
However, in the prior ultrasonic motor, because the rotary member 9 is strongly contacted with the beam 8d of the twisting joint body 8, the beam 8d or the rotary member 9 is worn out and t-he life of the ultrasonic motor is short.
Referring to Fig. 5, in the ultrasonic driving device provid-ed b~ the present applicant, ring type piezoelectric vibrators 13 of piezoelectric ceramics are put between a short metal block 1~
and a long metal block 15, male screw threads 16a and 16b at both 2~3 ends of a bolt 16 are engaged with female screw threads of the metal blocks 14 and 15, whereby a stator 17 is constituted. A
rotary member 18 is strongly contacted with one end of the stator 17 by a spring.
In the above ultrasonic driving device, when alternating cur-~ent voltage is supplied to the piezoelectric vibrators 13, the vibration toward the thickness arises in the piezoelectric vibra-~ors 13 and then presses -the rnetal blocks 14 and 15. The pressure of the metal blocks 14 and 15 is influenced by the screw threads 16a and 16b of the bolt 1~, whereby twist vibration arises in the metal blocks 14 and 15. When the resonance frequency of the twist vibration is coincident with that of the vibration toward the thickness of the piezoelectric vibrators 13, a progressive wave (ellipse vibration) arises on the ends and side portion of the stator 17. Therefore, when the rotary member 18 is contacted with the end of the stator 17, the rotary member 18 is smoothly rotat-ed.
In the ultrasonic driving device, however, the rotary member 18 is strongly pressed to the stator 17 by a spring for transmit-ting the ellipse vibration generated on the end of -the stator 17 ~o the rotary member 1~. Therefore, the contact faces between the end of the stator 17 and the rotary member 18 are worn on each other. Thus, a lining material is put between the end of the sta-tor 17 and the rotary member 18 for decreasing the wear between the stator 17 and the rotary member 18. However, even if the lin-ing material is put between the end of the stator 17 and rotary rnember 18, the lining material is worn out, noise generates in the contact face between the stator 17 and the rotary member 18 and the life of the ultrasonic driving device is short.
Referring to Figs. 6 and 7, a plurality of balls 19 are ro-tatably supported in the rotary member 20 and these balls are contacted with the end of the stator 17 as shown in Fig. 5. One end of a bolt 22 is engaged with screw -threads at the end of the stator 17 and the other end of the bolt 22 is passed through the center holes of the rotary member 20, a pressure member 21 and a s p r i n g w a s h e r 2 3 a n d t h e n , a n u t 2 4 a r e engaged with the screw threads at the other end of the bolt 22.
Therefore, the balls 19 are pressed on the end of the stator 17 by "''`"~:
22~
the pressure member 21.
Explaining the motion of -the ultrasonic driving device ac-cording to the present invention, in fig. 8, when the progressive wave is generated on the end of the stator 17 as shown by the ar-rows B, the balls 19 are rotated in the direction of arrows A.
When the balls 19 are rotated in the direction of arrows A, fric-tion arises on the contact por-tion between the balls 19 and the surface 21a of the pressure member 21 and thus the balls 19 roll on che surface 21a of the pressure rnember 21. The rotary member 20 is rotated toward the arrow C according to the rotation of the balls 19.
Therefore, when teeth of a gear are formed on the side of the rotary member 20 and are engaged with another gear, the rotary force of the rotary member 20 is transmitted through the other gear to the other machine and the ultrasonic driving device ac-cording to the present invention is used instead of a known elec-tric motor.
When lubricative oil is supplied to the circumference of the balls 19, the lubricative oil influences the rotation of the balls 19 for good, because the balls are respectively contacted with the surface 21a of the pressure member 21 by each point and are glided on the end of the stator 17. The wear of the balls 19, the end of the stator 17 and the pressure member 21 is decreased. Therefore, the life of the ultrasonic driving device according to the present invention becomes long.
Referring to Fig. 9, 17 designates a stator, 20; a rotary member, 21; a pressure member, 22; a bolt, 23; a washer, 24; a nut. These compositions are the same as those in Fig. 6 and a plurality of disks or rolls are rotatably supported with the rotary member 20 in a circle instead of the balls 19.
The ultrasonic driving device of this embodiment is driven the same as the above embodiment and has the same effect.
Referring to Figs. 11 and 12, electrodes 26a and 26b are formed on both ends of a ring type ceramic piezoelectric vibrator 26, and a member 27 for transmitting vibration and a member 28 for not transmitting vibration are closely attached with the same t-hickness on the electrode 26a of the piezoelectric vibrator 26.
A bolt 29 is passed through the holes of the close portion between '2;~
che members 27 and 28, the piezoelectric vibrator 26 and the electrodes 26a and 26b and holes of a rotary member 20 supporting balls 19 and a pressure member 21. The screw threads at both ends of the bolt are engaged with nuts 30a and 30b and these elements are fixed.
The ultrasonic driving device having this ring type piezo-electric vibrator 26 is provided by the applican-t. When al-ternat-ing current voltage is app~ied ~o the electrodes 26a and 26b in the ultrasonic driving device, a progressive wave is generated from its circumferential edge to its center edge on both sides of the piezoelectric vibrator 26. Therefore, the balls transmitted through the member 27 and thus the rotary member 20 is rotated with the balls 19.
In this embodiment, rolls and disks are used instead of the balls as shown in Figs. 9 and 10.
Referring to Fig. 13, in an ultrasonic driving device of another embodiment accordi.ng to the present invention, a resilient member 27 and a pie~oelectric vibrator 26 are the sarne as the re-silient member A and the piezoelectric vibrator B in Fig. 1. A
plurality of balls 19 supported ~ith a rotary member 27. A rotary shaft 28 of the rotary member 20 protrudes beyond a bearing 30 of a case 29. A screw 31 is engaged with the screw of the resilient mernber 27 through the holes of a bottorn plate 29a and a washer 31a, and the bottom plate 29a is fixed with the case 29 by screws 29b. Therefore, the balls 19 are strongly contacted with the in-side of the case 29 and the surface of the resilient member 27 by the rotation of the screw 31.
In the ultrasonic driving device of another embodiment ac-cording to the present invention, the balls 19 are rotated with the progressive wave, whereby the rotary member 20 is rotated.
Therefore, the rotary force is obtained from the rotary shaft 28.
In this embodiment, rolls and disks are used instead of the balls as shown in Figs. 9 and 10.
Referring to Fig. 14, in an ultrasonic driving device of another embodiment according to the present invention, a stator 17 comprises a short metal block 14, a long metal block 15 ancl a bolt 16 and is the same as the stator 17 in Fig. 5. A hole 32 is ormed through the metal blocks 14 and 15 and bolt 16 and a bolt ~S, 2~
33 is passed through the hole 32. The one end of bolt 33 is en-gaged with a nut 34b through a spring washer 34c and the other end of the bolt 33 is passed through a bearing 20a supported with a rotary member 20 and a hole of a pressure member and is engaged with a nut 34a. Balls 19 rota-tably supported with the rotary mem-ber 20 are pressed between the end of the stator 17 and the pres-sure member 21. Both ends of an arm 37 having a rotary shaft 36 are fixed with both sides of the rotary member 20.
In this ultrasonic driving device, when the balls 19 are ro-tated owing to the progressive wave generated on the end of the stator 17, the rotary member 20 is rotated and the rotary shaft 36 is rotated. Therefore, this ultrasonic driving device can be used instead of the known electric motor.
~.
~.
BACKGROUND OF TH~ INVENTION
_ _ _ _ _ . _ The present invention relates to an ultrasonic driving device having a structure for decreasing wear between a stator and a rotary member.
In a known ultrasonic motor using a ring type piezoelectric vibrator, two groups of electrodes are attached to one end of a ring type piezoelectric ceramic, the two groups of electrodes are so positioned that standing waves respectively genera-ted by the two groups of electrodes are shif-ted every ~/2 in each position.
The parts of the ring type piezoelectric vibrator corresponding to the electrode are alternately polarized in reverse. Also, the two groups of the electrodes are respectively connected to two oscillators for respectively generating alternating current vol-~ages having ~/2 phase shift from each other. When the alternat-ing current voltages from the lwo oscillators are respectively applied to the two groups of electrodes, the two standing waves having ~/2 phase shift from each other are generated on the sur-faces of the ring type piezoelectric vibrator and then progressive waves owing to an compound of -the two standing waves generate on the surfaces of the ring type piezoelectric vibrator. Therefore, when a slider attaching a rotary member is put on the ring type piezoelectric vibrator and is s-trongly pressed to the ring type piezoelectric vibrator, the rotary member is rotated by the pro-gressive waves.
In the prior ultrasonic motor, however, the slider is easily worn out because the slider of the rotary member is directly pres-sed on the piezoelectric vibrator.
There is known an ul-trasonic motor comprising a Langevin type vibrator having two ring type piezoelectric vibrators which are put between two metal blocks. In this ultrasonic motor, a twist-ing joint body is connected to the end of the one metal block by a bol-t for fixing the metal blocks and the piezoelectric vibrator and a rotary member is pressed on the twisting joint body by a spring.
In this ultrasonic motor, however, the rotary member is easi-ly worn out because the rotary member is pressed on the twisting joint body.
1'~9~32Z~3 SUMMARY _F THE INVENTIO_ It is, therefore, -the primary object of the present inven-tion to provide an ultrasonic driving device having a structure for decreasing wear of a rotary member or a stator.
It is another object of -the present invention to provide an ultrasonic driving device having a rotary membèr in which balls, disks or rolls are rotatably attached for decreasing wear of the rotary member.
It is another object of the present invention to provide an ultrasonic driving device in which lubricate oil is supplied to the circumference of balls, disks or rolls of a rotary member for decreasing wear of the rotary member.
In order to accomplish the above and other object, the pre-sent invention comprises a sta-tor for generating a progressive wave by driving a piezoelectric vibrator or vibrators, a rotary member rotatably attaching a plurality balls, disks or rolls, and pressure means for making the balls, disks or rolls contac-t with the stator.
BRIEF DESCRIPT-[_N OF THE DRAWINGS
Fig. 1 shows a sectional v:iew of an ultrasonic motor in the prior art.
Fig. 2 shows a plane view of a form of a piezoelectric vibra-~or and a composition of electrodes of the piezoelectric vibrator in the ultrasonic motor in Fig. 1.
Fig. 3 shows a separated perspective view of the stator of an ultrasonic motor in the prior art.
Fig. 4 shows a side view having a partial sectional view of an ultrasonic motor in the prior art.
Fig. 5 shows a side view of an ultrasonic driving device pro-vided by the present applicant.
Fig. 6 shows a side view of one part of an ultrasonic driving device of an embodiment in the presen-t invention.
Fig. 7 shows a plane view of a rotary member of the ultra-sonic driving device in Fig. 6.
Fig. 8 shows a view for explaining a principle of an ultra-sonic driving device in Fig. 6.
Fig. 9 shows a side view of an ultrasonic driving device of ., ,~, 1,!`
lZ9~
rhe other embodiment according to -the present invention.
Fig. 10. shows a plane view of a rotary member of ultrasonic driving device in Fig. 9.
Fig. 11 shows a plane view of an ultrasonic driving device of another embodiment according to the present invention.
Fig. 12 shows a side sectional view of an ultrasonic driving device another embodiment according to the present invention.
Fig. 13 shows a side sectional view of an ultrasonic driving device another embodiment according to the present invention.
Fig. 1~ shows a side view of a concrete composition of the ultrasonic driving device in Fig. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the prior art in Fig. 1, a ring type piezo-electric vibrator B is attached -to a ring type resilient member A
a n d t h e p i e z o e l e c t r i c v i b r a t o r B vibrates with the resilient member. The pieæoelectric vibrator B is divided in 17 parts by the ration of e.g. 22.5 or 11.25.
The respective neighbouring portions in the 17 parts of the piezo-electric vibrator B are polarized by a reverse polarity to each other as shown in Fig. 2. The two portions C and D in the one side of the piezoelectric vibrator B are respectively attached as an electrode by conductive paint as shown in Fig. 2. The portion G in Fig. 2 shows an earth electrode. The member F to be driven to which slider E is attached is mounted on the resilient member A.
In the ultrasonic motor in the pri.or art, the alternating current voltage of Vosinwt is applied to the one electrode C and the alternating current voltage Vocoswt is applied to the other electrode D, where Vo is an instantaneous value, w is radian frequency and t is time. The phases of these voltages shift by rl/2 from each other. Thereby, the divided portions of the piezo-electric vibrator B alternately produce expansion and contraction and thus, the resilient member A produces bending vibration.
Therefore, a standing wave is generated in the resilien-t member A
and a progressive wave is generated on the resilient member A.
Thus, the driven member F having the slider E is rotated on the resilient member A.
However, in the prior ultrasonic motor, because the slider E
~z~z~
lS strongly contacted with the resilient member A, the slider E or the resilient member ~ is worn out and the life of the ul-trasonic motor is short.
Referring to the prior art in Fig. 3, a piezoelectric vibra-tor 3, a terminal plate 4, a piezoelectric vibrator 5, a terminal ~la~_e 6 and an aluminum disk 7 aLe put on a washer 1 and a bolt 2 is inserted through the center holes of these members. The screw ~a of the bolt 2 is engaged with the screw hole 8a of a twisting joint body 8. A drain 8b is formed on the under surface of the twisting joint body 8, arcuate projections 8c are formed in both sides of drain 8b, and a beam 8d is so formed in the upper portion of the twisting joint body 8 that an angle between the beam 8d and drain 8b becomes a predetermined value.
In this prior ultrasonic driving device, when alternating current voltage is applied through the terminal plates 4 and 6 to the piezoelectric vibrators 3 and 5 and the piezoelectric vibra-tors 3 and 5 are vibrated in the direction of their thickness, the arcuate projections 8c of the twisting joint body 8 are pushed and twisted by the vibration of the piezoelectric vibrators 3 and 5.
Therefore, the twisting joint body 8 is vibrated to be twisted.
When the excitation fre~uency of the alternating current voltage approaches a resonance fre~uency, elliptic vibration arises on the beam 8d of the twisting joint body 8.
Therefore, as shown in Fig. 4, a rotary member 9 is put on of the beam 8d of the twisting joint body 8, a center bolt 10 passed through a bearing 11 of the rotary member 9 fixes the twisting body 8, and a spring 12 is attached between the upper end of the bolt 10 and the bearing 11, whereby the rotary member 9 is strong-ly touched on the beam 8d of the twisting joint body 8 and is ro-tated by the elliptic vibration on the beam 8d.
However, in the prior ultrasonic motor, because the rotary member 9 is strongly contacted with the beam 8d of the twisting joint body 8, the beam 8d or the rotary member 9 is worn out and t-he life of the ultrasonic motor is short.
Referring to Fig. 5, in the ultrasonic driving device provid-ed b~ the present applicant, ring type piezoelectric vibrators 13 of piezoelectric ceramics are put between a short metal block 1~
and a long metal block 15, male screw threads 16a and 16b at both 2~3 ends of a bolt 16 are engaged with female screw threads of the metal blocks 14 and 15, whereby a stator 17 is constituted. A
rotary member 18 is strongly contacted with one end of the stator 17 by a spring.
In the above ultrasonic driving device, when alternating cur-~ent voltage is supplied to the piezoelectric vibrators 13, the vibration toward the thickness arises in the piezoelectric vibra-~ors 13 and then presses -the rnetal blocks 14 and 15. The pressure of the metal blocks 14 and 15 is influenced by the screw threads 16a and 16b of the bolt 1~, whereby twist vibration arises in the metal blocks 14 and 15. When the resonance frequency of the twist vibration is coincident with that of the vibration toward the thickness of the piezoelectric vibrators 13, a progressive wave (ellipse vibration) arises on the ends and side portion of the stator 17. Therefore, when the rotary member 18 is contacted with the end of the stator 17, the rotary member 18 is smoothly rotat-ed.
In the ultrasonic driving device, however, the rotary member 18 is strongly pressed to the stator 17 by a spring for transmit-ting the ellipse vibration generated on the end of -the stator 17 ~o the rotary member 1~. Therefore, the contact faces between the end of the stator 17 and the rotary member 18 are worn on each other. Thus, a lining material is put between the end of the sta-tor 17 and the rotary member 18 for decreasing the wear between the stator 17 and the rotary member 18. However, even if the lin-ing material is put between the end of the stator 17 and rotary rnember 18, the lining material is worn out, noise generates in the contact face between the stator 17 and the rotary member 18 and the life of the ultrasonic driving device is short.
Referring to Figs. 6 and 7, a plurality of balls 19 are ro-tatably supported in the rotary member 20 and these balls are contacted with the end of the stator 17 as shown in Fig. 5. One end of a bolt 22 is engaged with screw -threads at the end of the stator 17 and the other end of the bolt 22 is passed through the center holes of the rotary member 20, a pressure member 21 and a s p r i n g w a s h e r 2 3 a n d t h e n , a n u t 2 4 a r e engaged with the screw threads at the other end of the bolt 22.
Therefore, the balls 19 are pressed on the end of the stator 17 by "''`"~:
22~
the pressure member 21.
Explaining the motion of -the ultrasonic driving device ac-cording to the present invention, in fig. 8, when the progressive wave is generated on the end of the stator 17 as shown by the ar-rows B, the balls 19 are rotated in the direction of arrows A.
When the balls 19 are rotated in the direction of arrows A, fric-tion arises on the contact por-tion between the balls 19 and the surface 21a of the pressure member 21 and thus the balls 19 roll on che surface 21a of the pressure rnember 21. The rotary member 20 is rotated toward the arrow C according to the rotation of the balls 19.
Therefore, when teeth of a gear are formed on the side of the rotary member 20 and are engaged with another gear, the rotary force of the rotary member 20 is transmitted through the other gear to the other machine and the ultrasonic driving device ac-cording to the present invention is used instead of a known elec-tric motor.
When lubricative oil is supplied to the circumference of the balls 19, the lubricative oil influences the rotation of the balls 19 for good, because the balls are respectively contacted with the surface 21a of the pressure member 21 by each point and are glided on the end of the stator 17. The wear of the balls 19, the end of the stator 17 and the pressure member 21 is decreased. Therefore, the life of the ultrasonic driving device according to the present invention becomes long.
Referring to Fig. 9, 17 designates a stator, 20; a rotary member, 21; a pressure member, 22; a bolt, 23; a washer, 24; a nut. These compositions are the same as those in Fig. 6 and a plurality of disks or rolls are rotatably supported with the rotary member 20 in a circle instead of the balls 19.
The ultrasonic driving device of this embodiment is driven the same as the above embodiment and has the same effect.
Referring to Figs. 11 and 12, electrodes 26a and 26b are formed on both ends of a ring type ceramic piezoelectric vibrator 26, and a member 27 for transmitting vibration and a member 28 for not transmitting vibration are closely attached with the same t-hickness on the electrode 26a of the piezoelectric vibrator 26.
A bolt 29 is passed through the holes of the close portion between '2;~
che members 27 and 28, the piezoelectric vibrator 26 and the electrodes 26a and 26b and holes of a rotary member 20 supporting balls 19 and a pressure member 21. The screw threads at both ends of the bolt are engaged with nuts 30a and 30b and these elements are fixed.
The ultrasonic driving device having this ring type piezo-electric vibrator 26 is provided by the applican-t. When al-ternat-ing current voltage is app~ied ~o the electrodes 26a and 26b in the ultrasonic driving device, a progressive wave is generated from its circumferential edge to its center edge on both sides of the piezoelectric vibrator 26. Therefore, the balls transmitted through the member 27 and thus the rotary member 20 is rotated with the balls 19.
In this embodiment, rolls and disks are used instead of the balls as shown in Figs. 9 and 10.
Referring to Fig. 13, in an ultrasonic driving device of another embodiment accordi.ng to the present invention, a resilient member 27 and a pie~oelectric vibrator 26 are the sarne as the re-silient member A and the piezoelectric vibrator B in Fig. 1. A
plurality of balls 19 supported ~ith a rotary member 27. A rotary shaft 28 of the rotary member 20 protrudes beyond a bearing 30 of a case 29. A screw 31 is engaged with the screw of the resilient mernber 27 through the holes of a bottorn plate 29a and a washer 31a, and the bottom plate 29a is fixed with the case 29 by screws 29b. Therefore, the balls 19 are strongly contacted with the in-side of the case 29 and the surface of the resilient member 27 by the rotation of the screw 31.
In the ultrasonic driving device of another embodiment ac-cording to the present invention, the balls 19 are rotated with the progressive wave, whereby the rotary member 20 is rotated.
Therefore, the rotary force is obtained from the rotary shaft 28.
In this embodiment, rolls and disks are used instead of the balls as shown in Figs. 9 and 10.
Referring to Fig. 14, in an ultrasonic driving device of another embodiment according to the present invention, a stator 17 comprises a short metal block 14, a long metal block 15 ancl a bolt 16 and is the same as the stator 17 in Fig. 5. A hole 32 is ormed through the metal blocks 14 and 15 and bolt 16 and a bolt ~S, 2~
33 is passed through the hole 32. The one end of bolt 33 is en-gaged with a nut 34b through a spring washer 34c and the other end of the bolt 33 is passed through a bearing 20a supported with a rotary member 20 and a hole of a pressure member and is engaged with a nut 34a. Balls 19 rota-tably supported with the rotary mem-ber 20 are pressed between the end of the stator 17 and the pres-sure member 21. Both ends of an arm 37 having a rotary shaft 36 are fixed with both sides of the rotary member 20.
In this ultrasonic driving device, when the balls 19 are ro-tated owing to the progressive wave generated on the end of the stator 17, the rotary member 20 is rotated and the rotary shaft 36 is rotated. Therefore, this ultrasonic driving device can be used instead of the known electric motor.
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~.
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An ultrasonic driving device comprising (a) disk-type rotary means for rotating a rotary machine element, said rotary means including means for rotatably holding a plurality of rolling means with the rolling means being exposed at opposite surfaces of the rotary means;
(b) a stator means for producing a progressive wave, said stator means being in contact with the rolling means extending from one surface of the rotary means;
(c) pressure means for pressing the rolling means of the rotary means to the stator means, said pressure means being in contact with the rolling means extending from the opposite surface of the rotary means; and (d) fixing means for fixing the rolling means of the rotary means between the pressure means and the stator means;
whereby movement of the rolling means with the progressive wave on the stator means causes rotation of the rotary means.
(b) a stator means for producing a progressive wave, said stator means being in contact with the rolling means extending from one surface of the rotary means;
(c) pressure means for pressing the rolling means of the rotary means to the stator means, said pressure means being in contact with the rolling means extending from the opposite surface of the rotary means; and (d) fixing means for fixing the rolling means of the rotary means between the pressure means and the stator means;
whereby movement of the rolling means with the progressive wave on the stator means causes rotation of the rotary means.
2. An ultrasonic driving device according to claim 1, wherein said rolling means includes a rolling circumference, and further comprising lubricating oil applied to the rolling circumference of the rolling means.
3. An ultrasonic driving device according to claim 1, wherein said stator means includes at least one ceramic piezoelectric vi-brator, two metal blocks and bolt means for securing said at least one piezoelectric vibrator with said two metal blocks.
4. An ultrasonic driving device according to claim 1, wherein said stator means includes a ring type ceramic piezoelectric vi-brator having electrodes at opposite sides thereof.
5. An ultrasonic driving device according to claim 1, wherein said stator means includes a ring type ceramic piezoelectric vi-brator which is divided into a plurality of sections, adjacent sections of the piezoelectric vibrator being alternately polariz-ed, said sections being divided into two groups, and two elec-trodes respectively attached to the two groups, and further com-prising means for supplying alternating current voltages having a phase shift 90° displaced with respect to each other to the two electrodes.
6. An ultrasonic driving device according to claim 1, wherein said stator means includes at least one piezoelectric vibrator that is driven to produce said progressive wave, and a bolt having one end threadedly connected with the stator and an opposite end threadedly engaged with a nut.
7. An ultrasonic driving device according to claim 1, wherein said stator means includes a ring type ceramic piezoelectric vi-brator having electrodes on opposite sides thereof, a vibration-transmitting material and a vibration-isolating material closely attached on the electrode at one side of the piezoelectric vibra-tor; said pressure means presses the rolling means into contact with the vibration-transmitting material and the vibration-isolating material, and further comprising a bolt passing through holes of the stator means, the rotary means and the pressure means, said bolt having threads at opposite ends thereof which are threadedly engaged by respective nuts.
8. An ultrasonic driving device according to claim 1 further comprising a case having a bearing and a rotary shaft protruding beyond the bearing of the case; said stator means includes a ring type ceramic piezoelectric vibrator and a resilient member such that the rolling means is in contact with the resilient member;
and further comprising screw means engaged with a bottom plate of the case for pressing the resilient member.
and further comprising screw means engaged with a bottom plate of the case for pressing the resilient member.
9. An ultrasonic driving device according to claim 1, wherein said stator means includes at least one ceramic piezoelectric vibrator, two metal blocks and bolt means for securing together said at least one piezoelectric vibrator and said two metal blocks and for generating the progressive wave by driving the at least one piezoelectric vibrator, said rotary means includes a rotary shaft fixed by an arm and further including a bolt passing through holes of the bolt means of the stator, the rotary means and the pressure means, screw threads at opposite ends of the bolt being engaged by respective nuts.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000576354A CA1299228C (en) | 1988-09-01 | 1988-09-01 | Ultrasonic driving device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000576354A CA1299228C (en) | 1988-09-01 | 1988-09-01 | Ultrasonic driving device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1299228C true CA1299228C (en) | 1992-04-21 |
Family
ID=4138662
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000576354A Expired - Lifetime CA1299228C (en) | 1988-09-01 | 1988-09-01 | Ultrasonic driving device |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1299228C (en) |
-
1988
- 1988-09-01 CA CA000576354A patent/CA1299228C/en not_active Expired - Lifetime
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed | ||
| MKLA | Lapsed |
Effective date: 20030422 |