Piezoelectric motor with nanometer-level resolution

Abstract

The present invention relates to a piezoelectric motor that can move with extremely fine resolution at the nanometer level using a piezoelectric element (piezo actuator) that increases in length when a voltage is applied. The piezoelectric motor of the present invention includes: a body having an upper surface, a lower surface, and a side surface connecting the upper surface and the lower surface; a piezoelectric element disposed on the upper surface of the body and extending in the longitudinal direction; a rod disposed on the upper surface of the body, the rod having an upper surface and a lower surface, extending in the longitudinal direction, and one end connected to one end of the piezoelectric element; and a support member disposed across the rod and providing a predetermined frictional force to the rod, wherein the support member is driven by the rod, which is linked to the contraction or expansion of the piezoelectric element, and the lower surface of the support member is at least partially in contact with the upper surface of the body, so that the support member slides on the upper surface of the body.

Description

[Technical field]

[0001] The present invention relates to a piezoelectric motor that can move with extremely fine resolution at the nanometer level by using a piezoelectric element (piezo actuator) that increases in length when a voltage is applied. [Background technology]

[0002] A piezoelectric material is a material that generates voltage when pressure is applied and mechanically vibrates and deforms when voltage is applied. Based on these physical properties, piezoelectric materials are used in various technical fields, one of which is the piezoelectric motor, also known as a piezoelectric actuator.

[0003] Unlike electromagnetic motors, such piezoelectric motors do not require magnets or windings, nor do they require a complex gear structure to transmit power. Therefore, piezoelectric motors have the advantage of being less noisy and less disturbing than electromagnetic motors, and are suitable for miniaturization.

[0004] In particular, in scanning probe microscopes that measure physical quantities such as atomic force, tunneling current, and electromagnetic force acting between a sample and a probe, the above-mentioned piezoelectric motors are primarily used for the movement required to precisely adjust the distance between the sample and the probe from nanometers (nm) to micrometers (μm).

[0005] As a piezoelectric motor for achieving minute movements on the nanometer (nm) to micrometer (μm) scale, the following patent document discloses a piezoelectric motor that includes a base plate 1, a carriage 2 that moves on the base plate 1, a bearing 3 that enables the carriage 2 to slide on the base plate 1, a piezoelectric element 4, and a graphite rod 5 connected to the piezoelectric element 4, as shown in FIG. 10, and by controlling the normal force via a screw 9 including a spring 10 on both sides of the piezoelectric element 4, the position can be controlled with nanometer (nm) level resolution by deformation of the piezoelectric element 4.

[0006] The piezoelectric motor employs a structure in which a gap is provided or a bearing is inserted in order to reduce friction between the carriage 2, which is linked to the graphite rod 5, and the base plate 1. However, such a structure is not only complicated, but also has the problem that if the gap between the two parts is not parallel, the motor will move at an angle, ultimately failing to perform accurate linear motion.

[0007] In addition, in the case of the piezoelectric motor (piezoelectric motor for XY scanner) disclosed in the following patent document, the part supporting the graphite rod 5 is biased to one side compared to the whole part, and the rear part spreads as shown in Figure 11 due to the fixing force of the bolt and spring (especially when the graphite rod 5 moves in one direction, the contact area decreases, and this is even more so). When this happens, the movement of the graphite rod 5 changes, making it difficult to perform precise movements, and the distance the motor can move is shortened. It may even cause the motor to stop moving. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Patent Publication No. 5,912,527 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention is intended to solve the problems of the conventional technology described above, and one object of the present invention is to provide a piezoelectric motor that not only greatly expands the range in which extremely fine resolution at the nanometer level can be achieved to a range of several nm to several mm, but also does not use bearings, is structurally easy to manufacture, and is capable of precise linear movement.

[0010] Another object of the present invention is to provide a piezoelectric motor equipped with a position sensor that can obtain accurate information regarding the position of a workpiece without affecting the movement of the piezoelectric motor. [Means for solving the problem]

[0011] In order to achieve one of the above-mentioned objects, a first aspect of the present invention is to provide a piezoelectric motor comprising: a body having an upper surface, a lower surface, and a side connecting the upper surface and the lower surface; a piezoelectric body arranged on the upper surface of the body and extending in the longitudinal direction; a rod arranged on the upper surface of the body, the rod including an upper surface and a lower surface, extending in the longitudinal direction, one end of which is connected to one end of the piezoelectric body; and a support member arranged to interpose the rod and provide a predetermined frictional force to the rod, wherein the support member is driven by the rod which operates in conjunction with the contraction or expansion of the piezoelectric body, and the lower surface of the support member and the upper surface of the body are at least partially in contact with each other, so that the support member is driven by sliding along the upper surface of the body.

[0012] The abutting portions may be polished with abrasive paper of 600 grit or greater, or may be polished to have a surface roughness less than that obtainable with the abrasive paper.

[0013] The support member includes an upper support part arranged on the upper part of the rod and having at least a portion of its lower surface formed with a shape corresponding to the upper surface of the rod so as to contact the upper surface of the rod, a lower support part arranged on the lower part of the rod and having at least a portion of its upper surface formed with a shape corresponding to the lower surface of the rod so as to contact the lower surface of the rod, and a side support part having an insertion opening for inserting the rod and arranged on the sides of the upper support part and the lower support part to fix the upper support part and the lower support part so as to maintain the gap between them, and a friction force adjustment means for adjusting the friction force applied to the part in contact with the rod may be provided on the part of the upper support part formed to contact the upper surface of the rod and the part of the lower support part formed to contact the lower surface of the rod.

[0014] The side support portion may include a first side support portion arranged on one side of the upper support portion and the lower support portion in the direction in which the rod extends, a second side support portion arranged on a side opposite to the one side of the upper support portion and the lower support portion in the direction in which the rod extends, and a fastening member that fixes between the first side support portion and the second side support portion.

[0015] The frictional force adjustment means may include a bolt inserted into either a portion of the upper support part formed to contact a surface of the rod or a portion of the lower support part formed to contact a lower surface of the rod, and a spring inserted into an outer periphery of the bolt.

[0016] In order to achieve the above-mentioned other object, a second aspect of the present invention is to provide a piezoelectric motor comprising: a main body having an upper surface, a lower surface, and a side connecting the upper surface and the lower surface; a piezoelectric body arranged on the upper surface of the main body and extending in the longitudinal direction; a rod including an upper surface and a lower surface, extending in the longitudinal direction, one end of which is fixed to one end of the piezoelectric body and arranged on the upper surface of the main body; a support member arranged to interpose the rod and provide a predetermined frictional force to the rod; and a position sensor for detecting a position of the support member, wherein the support member is driven by a frictional force with the rod that is linked to the contraction or expansion of the piezoelectric body, and the position sensor comprises: a conductive band arranged on one side of the support member parallel to the driving direction, a first elastic body in contact with the conductive band, a resistive band arranged on the other side of the support member opposite the one side, and a second elastic body in contact with the resistive band, and the first elastic body and the second elastic body are arranged so that the elastic forces applied to the support member by the first elastic body and the second elastic body cancel each other out. Effect of the Invention

[0017] Compared with a mechanically operated step motor, the piezoelectric motor according to the present invention has high reliability in terms of position control since there is no reverse rotation that can occur due to mechanical meshing, and since the step size can be adjusted by changing the voltage, the desired movement can be obtained and precise adjustment is possible.

[0018] In addition, since the bottom surface of the support member, which is the workpiece, is driven by a sliding method while directly contacting the top surface of the main body, it has superior structural stability compared to conventional bearings or structures that operate at intervals, and it easily performs linear operation, solving the problem of the piezoelectric body and rod tilting under force.

[0019] In addition, the piezoelectric motor according to one embodiment of the present invention is formed with a side support part fixing means, which can prevent the upper and lower support parts constituting the support member from spreading, thereby solving the problem of slow movement of the piezoelectric motor caused by the spreading of the support member in the conventional piezoelectric motor.

[0020] As a result, the piezoelectric motor according to the present invention can greatly expand the range in which extremely fine resolution at the nanometer level can be achieved to a range of several nm to several mm.

[0021] In addition, a piezoelectric motor according to another embodiment of the present invention includes a contact-type position sensor that can obtain a position more accurately than an optical position sensor. The position sensor has a conductive band and a resistive band that are separated and installed on opposing sides of a support member, and two finger springs for measuring resistance are arranged facing each other, so that their elastic support forces cancel each other out, eliminating problems in which the piezoelectric motor is damaged or the operation of the piezoelectric motor is affected by the elastic support forces of the finger springs, reducing the precision of linear motion. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a cross-sectional plan view of a piezoelectric motor according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of a portion of a piezoelectric motor according to a first embodiment of the present invention, excluding a main body. [Diagram 3] FIG. 3 is a perspective view of FIG. 2. [Figure 4] FIG. 3 is an exploded perspective view of FIG. 2. [Diagram 5] 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 6] 4 is an illustration of a sawtooth voltage waveform used to drive a piezoelectric motor according to Example 1. [Figure 7] 1A is a graph showing the results of a drive test of a piezoelectric motor manufactured according to Example 1 of the present invention, and FIG. 1B is a graph showing the results of a drive test of a piezoelectric motor having a conventional structure without a side support portion. [Figure 8] FIG. 11 is a cross-sectional plan view of a piezoelectric motor according to a second embodiment of the present invention. [Figure 9] FIG. 11 is a schematic diagram of a position sensor constituting a piezoelectric motor according to a second embodiment of the present invention. [Figure 10] FIG. 1 is a perspective view of a piezoelectric motor according to the prior art. [Figure 11]1 is a schematic diagram showing a supporting state of a supporting member that supports a rod joined to a piezoelectric body in a piezoelectric motor structure according to the prior art; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the configuration and operation of the present invention will be described with reference to the accompanying drawings.

[0024] In the description of the present invention, if a detailed description of related known functions or configurations is deemed to unnecessarily obscure the gist of the present invention, the detailed description will be omitted. In addition, when a part is said to "include" a certain element, this does not mean that other elements are excluded, but that other elements may be further included, unless otherwise specified.

[0025] [Example 1] FIG. 1 is a plan cross-sectional view of a piezoelectric motor according to a first embodiment of the present invention, FIG. 2 is a perspective view of a portion excluding the main body constituting the piezoelectric motor according to the first embodiment of the present invention, FIG. 3 is a see-through view of FIG. 2, FIG. 4 is an exploded perspective view of FIG. 2, and FIG. 5 is a cross-sectional view along the line AA of FIG. 2.

[0026] Referring to FIG. 1, a piezoelectric motor 100 according to a first embodiment of the present invention generally includes a body 110, a piezoelectric body 120 disposed on the body 110, a rod 130 connected to the piezoelectric body 120, and a support member 140 formed to interpose the rod 130.

[0027] The body 110 is formed to have an upper surface, a lower surface, and a side surface connecting the upper surface and the lower surface, and is formed to be substantially rectangular when viewed from above in the first embodiment of the present invention. In the first embodiment of the present invention, the shape of the body 110 is formed to be rectangular when viewed from above, but is not particularly limited to a rectangular shape as long as each component arranged in the body 110 can be smoothly operated.

[0028] The body 110 is preferably made of titanium or a titanium alloy in order to reduce deformation at low temperatures and to avoid the influence of magnetic fields, but is not necessarily limited thereto and may be made of other materials such as aluminum, stainless steel, etc. depending on the application.

[0029] The piezoelectric body 120 is formed in a substantially rectangular prism shape extending in the length direction by laminating one or more piezoelectric elements that expand / contract when a voltage is applied. One end of the piezoelectric body 120 is fixed to the body 110.

[0030] The piezoelectric element may be a single element or a multi-layer structure, and the material of the piezoelectric element may be varied according to the size of the work (support member) and the performance such as the scanning range required for the piezoelectric motor.

[0031] As shown in Figures 1 to 4, the piezoelectric body 120 is formed into a rectangular prism shape to match the shape of the rod 130, but the shape of the piezoelectric body may be formed into a shape other than a rectangle, such as a circle, to match the shape of the rod 130, or may be formed into a shape different from the shape of the rod 130.

[0032] The rod 130 provides an inertia motion while operating in conjunction with the contraction / expansion of the piezoelectric body 120. The rod 130 is formed as a rectangular prism extending in the length direction, and one end is connected to an end of the piezoelectric body 120 that is not fixed to the body 110. Here, the rod 130 being connected to the piezoelectric body 120 includes a state in which it is physically bonded to the piezoelectric body 120 or a state in which it is simply in contact with the piezoelectric body 120.

[0033] The rod 130 is preferably made of graphite, but the material is not limited to graphite as long as it can function as the rod 130.

[0034] In addition, the graphite rod 130 is preferably polished using abrasive paper of 600 grit or more to reduce the coefficient of friction of the surface, and more preferably, SiC-based abrasive paper of 800 grit or more is used.

[0035] As shown in FIG. 4, the support member 140 is largely composed of an upper support portion 141, a lower support portion 142, a first side support portion 143, a second side support portion 144, a friction force control means 145, and a side support portion fixing means 146.

[0036] All of the lower surfaces of members 142, 143, and 144 constituting the lower surface of the support member 140, or at least a part of the lower surface of the lower support part 142, are disposed to directly contact the upper surface of the main body 110. Thus, the support member 140 is driven in a form of sliding on the upper surface of the main body 110.

[0037] For this reason, it is preferable that the upper surface of the body 110 on which the support member 140 slides and the lower surface of the support member 140 are polished using abrasive paper of 600 grit or more. That is, by lowering the surface roughness, the sliding movement of the support member 140 is possible. In the first embodiment of the present invention, polishing is performed using abrasive paper, but any polishing method that can maintain a lower surface roughness than that of the polishing using abrasive paper can be used without any restrictions.

[0038] In the first embodiment of the present invention, the surface roughness of the contact surface between the main body 110 and the support member 140 is reduced, and a method is used in which the support member 140 and the main body 110 directly contact and slide. This makes the structure more stable than the conventional method of placing a bearing or leaving a gap between the support member and the main body, and eliminates the problem of tilting due to the gap formed between the main body and the support member in the conventional piezoelectric motor, or tilting due to force applied to the piezoelectric body and rod.

[0039] The upper support part 141 is disposed on the upper part of the rod 130, and a V-shaped groove 141a is formed in a central part of the lower surface so as to correspond to the rectangular cross section of the rod 130, and a substantially semicircular groove 141b is formed extending from the V-shaped groove, and a substantially rectangular groove 141c is formed on both sides of the lower surface for inserting the side support part fixing means 146. Fastening holes 141d for fastening the frictional force control means 145 are formed on both sides of the V-shaped groove 141a.

[0040] The lower support part 142 is disposed under the rod 130 so as to interpose the rod 130 together with the upper support part 141, and a V-shaped groove 142a is formed in a central part of the upper surface so as to correspond to the rectangular cross section of the rod 130, and a substantially semicircular groove 142b is formed extending from the V-shaped groove 142a, and a substantially rectangular groove 142c is formed on both sides of the upper surface for inserting the side support part fixing means 146. Fastening holes 142d for fastening the frictional force control means 145 are formed on both sides of the V-shaped groove 142a. A spiral portion (not shown) is formed on at least a part of the inside of the fastening hole 142d.

[0041] The first side support part 143 is disposed on one side of the upper support part 141 and the lower support part 142 which are disposed above and below the rod 130, and as shown in FIG. 4, has a substantially semicircular groove 143a in the center and fastening holes 143b for inserting the side support part fixing means 146 are formed on both sides.

[0042] The second side support part 144 is disposed on the other side of the upper support part 141 and the lower support part 142 which are arranged above and below via the rod 130, and has an approximately semicircular groove 144a formed in the center facing in the opposite direction to the first side support part 143, and fastening holes 144b for inserting the side support part fixing means 146 are formed on both sides.

[0043] The frictional force control means 145 is a means for controlling the frictional force between the rod 130 and the support member 140 .

[0044] As shown in Figures 4 and 5, the frictional force control means 145 includes two bolts 145a and two springs 145b inserted into the two bolts 145a, respectively. With the springs 145b inserted, the bolts 145a are inserted into the fastening holes 141d of the upper support part 141 and spirally coupled to the spiral portion formed in the fastening holes 142d of the lower support part 142.

[0045] By adjusting the length of the bolt 145a and the spring 145b, the normal force between the rod 130 and the surfaces of the upper support part 141 and the lower support part 142 that contact the rod 130 can be adjusted, thereby adjusting the friction force applied to the rod 130.

[0046] The side support fixing means 146 includes two bolts. The bolt is inserted into a fastening hole 143b formed in the first side support 143, passes through rectangular grooves 141c and 142c formed in the upper support 141 and the lower support 142, and is inserted into a fastening hole 144b formed in the second side support 144, and is spirally coupled to a spiral portion formed in the fastening hole 144b. By using the side support fixing means 146, the upper support 141 and the lower support 142 can maintain a constant distance without widening or narrowing in the portion of the rod 130 other than the portion supported by the frictional force control means 145, and the rod 130 can perform a linear movement more precisely.

[0047] Next, an operation process of the piezoelectric motor 100 according to the first embodiment of the present invention will be described.

[0048] The piezoelectric motor 100 according to the first embodiment of the present invention can be driven in a stick-slip motion using a sawtooth waveform voltage.

[0049] In order to drive the support member 140 in the direction of the arrow in Fig. 2, a sawtooth waveform voltage as shown in Fig. 6 is applied. In the portion where the voltage gradually increases, the length of the piezoelectric body 120 gradually increases, and at this time, since one side of the piezoelectric body 120 is fixed to the body 110, it increases in the direction of the arrow where it is not fixed to the body 110. In conjunction with this, the rod 130 moves in the direction of the arrow, and the support member 140 supported by the rod 130 with a certain frictional force also moves in the direction of the arrow.

[0050] On the other hand, in the portion where the voltage suddenly decreases, the length of the piezoelectric body 120 instantly shortens and returns to its original position. In conjunction with this, when the rod 130 suddenly moves in the opposite direction of the arrow, the support member 140 slides due to inertia and maintains its position.

[0051] When a sawtooth waveform voltage is applied, the support member 140 is driven in the direction of the arrow by this stick / slip motion. If the opposite motion is required, a sawtooth waveform that causes a contraction motion can be applied.

[0052] At this time, the lower surface of the support member 140 slides while directly contacting the upper surface of the body 110, so the structure is stable and the problem of tilting due to the gap formed in the conventional piezoelectric motor or tilting due to the piezoelectric body and rod receiving force is solved.

[0053] Furthermore, in the first embodiment of the present invention, the side support fixing means 146 solves the problem of spreading on one side (see FIG. 11) like the support member 4 of the prior art, and solves the problem that as the rod moves in one direction, the area of ​​contact between the frictional force control means 145 and the rod 130 decreases, slowing down the movement of the piezoelectric motor and making linear motion difficult. This allows for more precise linear motion.

[0054] 7(a) is a graph showing the distance traveled by the piezoelectric motor when 4,000 sawtooth waves of 10V are applied to the piezoelectric motor according to Example 1 of the present invention. As can be seen from FIG. 7(a), the motor moves about 2 mm, and moves 500 nm for each sawtooth wave. In other words, it can be seen that the range in which extremely fine resolution at the nanometer level can be achieved by the piezoelectric motor according to Example 1 of the present invention is greatly expanded to a range of several nm to several mm.

[0055] In contrast, as shown in FIG. 7(b), in the case of a conventional piezoelectric motor without side support parts, partial bouncing values ​​are observed while reading the position, which shows that the stability of the piezoelectric motor according to the embodiment of the present invention is very excellent.

[0056] [Example 2] A piezoelectric motor 200 according to a second embodiment of the present invention is characterized in that, in addition to the piezoelectric motor 100 according to the first embodiment, it further includes a position sensor 210 for measuring the position of a workpiece (i.e., the support member 140) accompanying the movement. Since the other configurations are the same as those of the first embodiment, the description thereof will be omitted, and the configurations described in the first embodiment will be described using the same drawing numbers.

[0057] FIG. 8 is a cross-sectional plan view of a piezoelectric motor according to a second embodiment of the present invention, and FIG. 9 is a schematic view of a position sensor constituting the piezoelectric motor according to the second embodiment of the present invention.

[0058] 8 and 9, the position sensor 210 includes a conductive band 211, a first elastic body 212 in contact with the conductive band 211, a resistive band 213, a second elastic body 214 in electrical contact with the resistive band 213, and wiring (not shown) electrically connecting the first elastic body 212 and the second elastic body 214.

[0059] The conductive band 211 is formed on one side of the body 110 parallel to the moving direction of the support member 140 as shown in FIG. 8, and is formed in a dotted line shape as shown in FIG.

[0060] The conductive band 211 is in electrical contact with the support member 140 via a first elastic body 212 made of a finger spring disposed on one side of the support member 140 .

[0061] The resistance band 213 is formed on the other side surface of the main body 110 parallel to the moving direction of the support member 140 as shown in FIG. 8, and is formed in an oblique line shape as shown in FIG.

[0062] The resistance band 213 is in electrical contact with the support member 140 via a second elastic body 214 made of a finger spring disposed on the other side of the support member 140 .

[0063] On the other hand, if the resistance is read by directly connecting the wire to the finger spring, there is a risk that the wire will break due to the movement of the piezoelectric motor, and the wire may interfere with the movement of the finger spring. In the second embodiment of the present invention, such problems are solved by electrically connecting the finger spring in contact with the resistor and the finger spring in contact with the conductive band.

[0064] With this structure, the total resistance and the resistance between one end of the resistance and the finger spring can be obtained, and the magnitude of this resistance can be converted into a position, so that the position of the work (i.e., the support member 140) can be accurately known. Specifically, as shown in Fig. 9, the total resistance R and the resistance between one end of the resistance and the finger spring (R13 or R23) can be obtained, and the magnitude of the resistance can be converted into a position via R13 / R12 or R23 / R12.

[0065] On the other hand, when configuring a position sensor, position information can be obtained by arranging the finger springs on only one side of the support member 140. In this case, however, the elastic support force of the finger springs is applied to only one of the piezoelectric body 120, the rod 130, and the support member 140, and this force may separate the laminated piezoelectric layers or affect the movement of the piezoelectric motor itself.

[0066] In the piezoelectric motor 200 according to the second embodiment of the present invention, the position sensor 210 has a conductive band 211 and a resistive band 213 that are separated and provided on opposite sides of the support member 140, and two finger springs 212 and 214 are arranged to face each other, thereby canceling out each other's elastic support forces. This eliminates problems such as the piezoelectric motor being damaged by the elastic support forces of the finger springs or the operation of the piezoelectric motor being affected, thereby reducing the precision of linear motion.

[0067] Such a construction allows for precise linear movement of the support member 140 while at the same time allowing the position of the support member 140 to be precisely measured. [Explanation of symbols]

[0068] 100, 200: Piezoelectric motor 110: Main unit 120: Piezoelectric material 130: Rod 140: Support member 141: Upper support part 142: Lower support part 143: First side support 144: Second side support part 145: Friction force control means 146: Side support fixing means 210: Position sensor 211: Conductive band 212: First elastic body 213: Resistance band 214: Second elastic body

Claims

1. a body having an upper surface, a lower surface, and a side surface connecting the upper surface and the lower surface; a piezoelectric body disposed on an upper surface of the body and extending in a longitudinal direction; a rod including an upper surface and a lower surface, extending in a longitudinal direction, one end of the rod being connected to one end of the piezoelectric body, the rod being disposed on the upper surface of the body; a support member disposed between the rod and providing a predetermined frictional force to the rod; The support member is driven by the rod which is linked to the contraction or expansion of the piezoelectric body, a lower surface of the support member and an upper surface of the main body are at least partially in contact with each other, and the support member is driven by sliding on the upper surface of the main body; The support member is An upper support portion formed to contact an upper surface of the rod; A lower support portion formed to contact a lower surface of the rod; a first side support portion formed on a first side of the upper support portion and the lower support portion, the first side support portion having an insertion hole into which the rod is inserted; a second side support portion formed on a second side portion opposite the first side portion of the upper support portion and the lower support portion, the second side support portion having an insertion hole into which the rod is inserted.

2. 2. The piezoelectric motor of claim 1, wherein the abutting portion is polished with abrasive paper of 600 grit or more, or polished to have a surface roughness lower than that obtainable by the abrasive paper.

3. the upper support portion is disposed on the upper portion of the rod, and at least a portion of a lower surface of the upper support portion includes a shape corresponding to an upper surface of the rod; the lower support portion is disposed under the rod, and at least a portion of an upper surface of the lower support portion includes a shape corresponding to a lower surface of the rod; 2. The piezoelectric motor according to claim 1, wherein a portion of the upper support formed to contact an upper surface of the rod and a portion of the lower support formed to contact a lower surface of the rod are provided with a friction adjustment means for adjusting a friction force applied to the portion in contact with the rod.

4. A piezoelectric motor as described in claim 3, comprising a fastening member that fixes the first side support portion and the second side support portion.

5. The friction force adjusting means is 4. The piezoelectric motor of claim 3, further comprising: a bolt inserted into either a portion of the upper support formed to contact the surface of the rod or a portion of the lower support formed to contact the underside of the rod; a spring inserted into an outer periphery of the bolt; and a spiral portion formed near an end of the bolt to fix the end of the bolt.

6. Including a position sensor that detects the position of the support member, 2. The piezoelectric motor of claim 1, wherein the position sensor includes a conductive band arranged on one side of the support member parallel to the driving direction, a first elastic body in contact with the conductive band, a resistive band arranged on the other side of the support member opposite the one side, and a second elastic body in contact with the resistive band, and the first elastic body and the second elastic body are arranged so that elastic forces applied to the support member cancel each other out.

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