Drive device, robot system, and printing system

Abstract

To provide a drive device capable of controlling the relative movement between a table portion and a base portion with high precision.SOLUTION: A drive device includes piezoelectric motors 5a, 5b each having a piezoelectric element that outputs a drive force by vibrating upon receiving a drive signal, a drive circuit 4 that generates the drive signal, a base portion 22 on which the piezoelectric motors 5a, 5b and the drive circuit 4 are arranged, and a table portion 21 that receives the drive force and moves relative to the base portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a drive device, a robot system, and a printing system. [Background technology]

[0002] Conventionally, there is known a moving device that controls the movement of a table by a drive signal. For example, Patent Document 1 discloses a fine movement mechanism in which an ultrasonic actuator receives a drive signal output from a control device and moves a moving body and a fixed base relative to each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-27865 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the micromotion mechanism described in Patent Document 1, the drive signal may be attenuated when it is output from the control device and passes through the electrical wiring, which poses a problem that the relative movement between the moving body and the fixed base cannot be controlled with high precision. [Means for solving the problem]

[0005] A driving device according to an application example of the present invention is characterized by comprising a piezoelectric motor having a piezoelectric element that outputs a driving force by vibrating upon receiving a driving signal from the piezoelectric element, a driving circuit that generates the driving signal, a base portion on which the piezoelectric motor and the driving circuit are arranged, and a table portion that receives the driving force and moves relative to the base portion.

[0006] A robot system according to an application example of the present invention includes a robot having an arm and the drive device described above, and is characterized in that the base unit and the table unit are arranged at the tip of the arm.

[0007] A printing system according to an application example of the present invention comprises a robot having an arm, the drive device described above, and a print head that can be moved by the drive device, and is characterized in that the base portion and the table portion are arranged between the print head and the tip of the arm. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an overall view showing the overall configuration of a drive device according to a first embodiment. [Figure 2] FIG. 2 is a plan view showing the internal configuration of the moving stage of FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the line A1-A1 in FIG. 2. [Figure 4] FIG. 2 is a plan view showing the configuration of a piezoelectric motor. [Figure 5] FIG. 2 is a plan view showing the configuration of a vibrator. [Figure 6] FIG. 2 is a functional block diagram of the drive device of FIG. [Figure 7] FIG. 10 is an overall view of a robot system according to a second embodiment. [Figure 8] FIG. 10 is an overall view showing the overall configuration of a drive device according to a third embodiment. [Figure 9] FIG. 10 is an overall view of a robot system according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1. First embodiment A drive device 1 according to a first embodiment will be described with reference to FIGS.

[0010] For ease of explanation, each figure illustrates three mutually orthogonal axes: the X-axis, the Y-axis, and the Z-axis. The direction along the X-axis is referred to as the "X-axis direction," the direction along the Y-axis as the "Y-axis direction," and the direction along the Z-axis as the "Z-axis direction." The arrowed side of each axis is also referred to as the "plus side," and the opposite side as the "minus side." The positive side of the Z-axis is also referred to as the "upper side," and the negative side of the Z-axis is also referred to as the "lower side." A plane parallel to the plane containing the X-axis and Y-axis is referred to as the "XY plane."

[0011] FIG. 1 is an overall view showing the overall configuration of a drive device 1. The drive device 1 of this embodiment includes a moving stage 2 and a control device 3. The moving stage 2 includes a base 22 and a table 21 that moves relative to the base 22. Piezoelectric motors 5a and 5b and a drive circuit 4 are disposed on the base 22. The drive device 1 also includes wiring 91 that electrically connects the drive circuit 4 and the control device 3. In this drive device 1, the piezoelectric motors 5a and 5b generate driving force, and the table 21 that receives this driving force moves in the direction of arrow L. In this embodiment, the direction of arrow L is parallel to the Y-axis. When there is no need to distinguish between the piezoelectric motors 5a and 5b, they are also simply referred to as piezoelectric motors 5.

[0012] FIG. 2 is a plan view showing the internal configuration of the moving stage 2 of FIG. 1. FIG. 3 is a cross-sectional view taken along line A1-A1 in FIG. 2. Note that part of the table portion 21 is not shown in FIG. 2. The table portion 21 is disposed above the base portion 22. The table portion 21 has rail portions 23a and 23b on its surface facing the base portion 22. The rail portions 23a and 23b extend in the Y-axis direction and are arranged side by side in the X-axis direction. The base portion 22 has block portions 24a and 24b. The block portions 24a and 24b extend in the Y-axis direction and are arranged adjacent to the rail portions 23a and 23b in the X-axis direction. The rail portions 23a and 23b move relative to the block portions 24a and 24b while in contact with them, thereby guiding the movement of the table portion 21 in the Y-axis direction.

[0013] The base portion 22 includes a housing portion 22u and a bottom portion 22v. The housing portion 22u is concave with an opening at the bottom. The bottom portion 22v is disposed in the opening of the housing portion 22u and closes the opening. This defines a space S inside the base portion 22.

[0014] The driving device 1 includes wiring 92 for transmitting a driving signal, and the wiring 92 connects the driving circuit 4 and the piezoelectric motors 5a and 5b.

[0015] The drive circuit 4 includes electronic components 41 and 42. The electronic components 41 and 42 are disposed on a drive substrate 43 disposed in the space S.

[0016] The electronic components 41 and 42 are provided with heat dissipation members 71 and 72. The heat dissipation members 71 and 72 are disposed between the electronic component 41 and the housing part 22u and between the electronic component 42 and the bottom part 22v. The heat dissipation member 71 is in contact with the electronic component 41 and the housing part 22u. The heat dissipation member 72 is in contact with the electronic component 42 and the bottom part 22v.

[0017] A light-emitting unit (not shown) that emits light and a light-receiving unit 62 that receives light are arranged on the base unit 22. The light-emitting unit and the light-receiving unit 62 form part of an encoder 6, which will be described later. The light-emitting unit and the light-receiving unit 62 are arranged on an encoder substrate 63 that is fixed inside the space S.

[0018] On the table portion 21, driven portions 25a and 25b to which driving forces are transmitted from the piezoelectric motors 5a and 5b, and a scale 61 that constitutes a part of the encoder 6 are arranged.

[0019] The driven parts 25a, 25b are fixed to the rail parts 23a, 23b and are disposed between the rail parts 23a, 23b and the piezoelectric motors 5a, 5b. When the piezoelectric motors 5a, 5b receive a drive signal output from the drive circuit 4, they generate a drive force and transmit it to the driven parts 25a, 25b. When the driven parts 25a, 25b receive the drive force, they move relative to the piezoelectric motors 5a, 5b. This causes the table part 21 to move relative to the base part 22. Note that the number of piezoelectric motors 5 is not limited to two and may be, for example, one, three or more. When the driven parts 25a, 25b are not to be distinguished from each other, they are also referred to simply as the driven parts 25.

[0020] The moving stage 2 is equipped with an encoder 6 that detects the amount of movement of the table 21 relative to the base 22. As described above, the encoder 6 is configured to include a light-emitting unit, a scale 61, and a light-receiving unit 62. The scale 61 has reflective and non-reflective units (not shown), which are arranged in a predetermined pattern. The light-emitting unit emits light toward the scale 61, and the light-receiving unit 62 receives the light reflected by the reflective units, thereby detecting the position of the table 21 relative to the base 22. In other words, the light-receiving unit 62 receives light from the scale 61. In this embodiment, the scale 61 is disposed on the table 21, and the light-receiving unit 62 is disposed on the base 22, but this is not limited thereto, and the scale 61 may be disposed on the base 22, and the light-receiving unit 62 may be disposed on the table 21. Furthermore, the detection method of the encoder 6 is a so-called reflective type in which light from the light-emitting unit is reflected by the scale 61 and received by the light-receiving unit 62, but is not limited to this and may be a so-called transmissive type in which light from the light-emitting unit passes through the scale 61 and is received by the light-receiving unit 62. In the case of a transmissive type, the transmissive portion of the scale 61 that transmits light corresponds to the reflective portion in this embodiment. In other words, even when the encoder 6 is a transmissive type, it can be said that the light-receiving unit 62 receives light from the scale 61.

[0021] FIG. 4 is a plan view showing the configuration of the piezoelectric motor 5. FIG. 5 is a plan view showing the configuration of the vibrator 500. The piezoelectric motor 5 includes the vibrator 500, a biasing unit 53 that biases the vibrator 500 toward the driven unit 25, and a fixing unit 52 that fixes the piezoelectric motor 5 to the base unit 22. The biasing unit 53 is plate-shaped and has multiple beams that extend approximately in the Y-axis direction, and is disposed on both sides of the vibrator 500 in the Z-axis direction. The biasing unit 53 generates a biasing force when the multiple beams are deformed in the X-axis direction. The biasing unit 53 and a portion of the fixing unit 52 are integrally configured.

[0022] The vibrator 500 includes a vibrating body 512, a protrusion 51 disposed at the tip of the vibrating body 512 in the X-axis direction, and a support portion 511 that supports the vibrating body 512 via connection portions 521 and 522. The vibrating body 512 has a rectangular shape that is long in the X-axis direction, and piezoelectric elements 531, 532, 533, 534, and 535 are disposed on the surface of the vibrating body 512, i.e., the XY plane. The piezoelectric elements 531, 532, 533, 534, and 535 each have a rectangular shape that extends in the X-axis direction, with the piezoelectric elements 531 and 532 disposed along one long side of the vibrating body 512 and the piezoelectric elements 534 and 535 disposed along the other long side of the vibrating body 512. The piezoelectric element 533 is disposed between the piezoelectric elements 531 and 534 and between the piezoelectric elements 532 and 535.

[0023] When receiving an AC drive signal, the piezoelectric elements 531, 532, 533, 534, and 535 generate vibrations that expand and contract in the X-axis direction. By adjusting the phase of the drive signal supplied to each of the piezoelectric elements 531, 532, 533, 534, and 535, the vibrating body 512 undergoes both expansion and contraction in the X-axis direction and bending in the XY plane. The combination of this expansion and contraction and bending motions causes the convex portion 51 to move along an elliptical orbit in the XY plane. This motion causes the convex portion 51 to repeatedly come into contact with and separate from the driven portion 25, and at the moment of contact, transmits a driving force to the driven portion 25 in the Y-axis direction. As a result, the driven portion 25 moves, causing the table portion 21 to move relative to the base portion 22. The direction and speed at which the driven portion 25 moves can be controlled by changing the shape and size of the elliptical orbit of the convex portion 51. In this way, the piezoelectric motor 5 outputs a driving force when the piezoelectric elements 531, 532, 533, 534, and 535 receive a driving signal and vibrate.

[0024] As such, the piezoelectric motor 5 does not require the use of magnets as its components. Therefore, the piezoelectric motor 5 is smaller and lighter than an electromagnetic motor. Furthermore, when no voltage is supplied, the piezoelectric elements 531, 532, 533, 534, and 535 do not vibrate, and the convex portion 51 remains in contact with the driven portion 25. At this time, the biasing force from the biasing portion 53 generates a frictional force between the convex portion 51 and the driven portion 25, and this frictional force limits the movement of the driven portion 25. In other words, the moving stage 2 does not require a brake mechanism separate from the piezoelectric motor 5, which results in an even smaller and lighter device.

[0025] Each of the piezoelectric elements 531, 532, 533, 534, and 535 includes a piezoelectric body, electrodes for supplying a drive signal to the piezoelectric body, and wiring (not shown). The material of the piezoelectric body is not particularly limited, and examples of piezoelectric ceramics that can be used include lead zirconate titanate (PZT), barium titanate, lead titanate, potassium niobate, lithium niobate, lithium tantalate, sodium tungstate, zinc oxide, barium strontium titanate (BST), strontium bismuth tantalate (SBT), lead metaniobate, and lead scandium niobate. In addition to the above-mentioned piezoelectric ceramics, polyvinylidene fluoride, quartz, and the like may also be used as the piezoelectric body. In this embodiment, lead zirconate titanate (PZT) is used as the material of the piezoelectric body. This results in a piezoelectric body with excellent piezoelectric effect.

[0026] In this embodiment, the piezoelectric body is formed using a sol-gel method. This allows for the formation of a thin-film piezoelectric body, compared to when it is formed from a bulk material. The sol-gel method is a film-forming method in which a sol liquid of an organometallic compound is applied to a silicon substrate by spin coating or the like, dried to obtain a gel film, and then baked to obtain a metal oxide film on the silicon substrate. In other words, the vibrating body 512 has a silicon substrate as its base material, and piezoelectric elements 531, 532, 533, 534, and 535 on this silicon substrate.

[0027] Furthermore, the sol-gel method can form a piezoelectric body with smaller contour dimensions (the dimension perpendicular to the thickness direction) than when formed from bulk material. Similarly to when formed by the sol-gel method, sputtering can also form a thin piezoelectric body with small contour dimensions. Because the piezoelectric body can be made small and thin, the piezoelectric motor 5 can be made small and lightweight. Consequently, the moving stage 2 can also be made small and lightweight.

[0028] In this embodiment, the piezoelectric element is formed to have a small volume, resulting in a high resonance frequency. Therefore, the drive signal supplied to the piezoelectric element is a high frequency. In this embodiment, the frequency of the drive signal is high, at approximately 500 kHz, which is several tens of times higher than the drive frequency of a piezoelectric motor that uses a piezoelectric element formed from a bulk material.

[0029] 6 is a functional block diagram of the drive device 1. The control device 3 has a power supply unit 31, a PWM signal generation unit 32, a movement amount detection unit 33, and a movement direction detection unit .

[0030] The power supply unit 31 supplies power to the moving stage 2 including the drive circuit 4 through a wiring 91. The encoder 6 detects the position of the table unit 21 relative to the base unit 22 and transmits the position information to the movement amount detection unit 33 and the movement direction detection unit 34 through the wiring 91. The movement amount detection unit 33 detects the amount of movement of the table unit 21 relative to the base unit 22 based on the received position information and transmits the detected movement amount information to the PWM signal generation unit 32. The movement direction detection unit 34 detects the direction of movement based on the received position information and transmits the detected direction information to the PWM signal generation unit 32. The PWM signal generation unit 32 outputs a PWM (Pulse Width Modulation) signal based on the received movement amount information and direction information. The PWM signal is transmitted to the drive circuit 4 through the wiring 91. Here, the wiring 91 corresponds to the first wiring in the drive device 1.

[0031] Based on the received PWM signal, the drive circuit 4 generates a drive signal from the power supplied from the power supply unit 31. The generated drive signal is a signal for driving the piezoelectric motor 5, and is transmitted to the piezoelectric motor 5 through a wiring 92. The drive signal received by the piezoelectric motor 5 is an AC voltage signal, and as the amplitude of the signal increases, the driving force of the piezoelectric motor 5 also increases. Here, the wiring 92 corresponds to the second wiring in the drive device 1.

[0032] While an example has been described above in which the control device 3 controls the movement of the table unit 21 relative to the base unit 22, the control is not limited to this. For example, information about the position of the table unit 21 relative to the base unit 22 may be information received from a sensor that is provided outside the moving stage 2 and detects the position. Furthermore, in this embodiment, the control device 3 has the PWM signal generation unit 32, the movement amount detection unit 33, and the movement direction detection unit 34, but this is not limiting, and for example, the moving stage 2 may have some of these functions.

[0033] In this embodiment, the control device 3 may be provided in one housing or may be configured with multiple housings. An example of a configuration with multiple housings is when the power supply unit 31 is provided in a first housing, and the PWM signal generation unit 32, the movement amount detection unit 33, and the movement direction detection unit 34 are provided in a second housing.

[0034] As shown in FIGS. 1 to 3, the piezoelectric motors 5a and 5b and the drive circuit 4 are disposed on the base 22. This shortens the length of the wiring 92 connecting the piezoelectric motors 5a and 5b to the drive circuit 4 compared to conventional drive devices. Therefore, the drive signal is less susceptible to the inductance of the wiring 92. This reduces the attenuation of the drive signal between its transmission from the drive circuit 4 and its reception by the piezoelectric motors 5a and 5b. This reduced attenuation eliminates the need to excessively increase the output of the drive signal transmitted from the drive circuit 4, thereby suppressing amplification of noise components in the drive signal. As a result, the piezoelectric motors 5a and 5b can receive drive signals with reduced noise, enabling accurate control of the relative movement between the table 21 and the base 22. Because the drive circuit 4 is disposed on the base 22, the length of the wiring 92 is significantly shorter than the length of the wiring 91. Therefore, the second wiring is shorter than the first wiring.

[0035] As shown in FIG. 3, the heat dissipation members 71, 72 are in contact with the electronic components 41, 42. This allows the heat dissipation members 71, 72 to absorb heat from the electronic components 41, 42. This prevents the electronic components 41, 42 from overheating. As a result, the components that make up the moving stage 2 are less susceptible to heat damage. Specifically, this prevents deterioration in position detection accuracy, such as deviations in the width or position of the reflecting parts in the arrangement direction due to thermal expansion of the scale 61, or deterioration in the light receiving performance or shortened lifespan of the light receiving parts 62 due to heat. This allows for accurate control of the movement of the table 21 relative to the base 22.

[0036] Furthermore, the heat dissipation members 71, 72 are also in contact with the housing 22u and the bottom 22v. This allows the heat absorbed from the electronic components 41, 42 to be conducted to the housing 22u and the bottom 22v. This allows for efficient heat dissipation from the moving stage 2. This allows for more accurate control of the movement of the table 21 relative to the base 22.

[0037] The properties of the heat dissipation members 71, 72 are not particularly limited, but for example, it is possible to use materials with higher thermal conductivity than the surfaces of the electronic components 41, 42. This allows the heat dissipation members 71, 72 to efficiently dissipate the heat absorbed from the electronic components 41, 42. Note that the thermal conductivity can be measured according to JIS A1412-1 (2016), for example.

[0038] In this embodiment, the heat dissipation members 71, 72 are sheet-shaped and may also be called "heat dissipation sheets" or "thermal conduction sheets." However, the form of the heat dissipation members 71, 72 is not particularly limited, and may be softer than the electronic components 41, 42, i.e., more flexible. Specifically, the heat dissipation members 71, 72 may be gel-like. This increases the area of ​​contact with the electronic components 41, 42, allowing the heat dissipation members 71, 72 to efficiently absorb heat from the electronic components 41, 42 and achieve a high heat dissipation effect.

[0039] The material of the heat dissipation members 71 and 72 is not particularly limited, but may be, for example, primarily made of acrylic or silicone resin. This allows the aforementioned flexibility to be achieved. Such heat dissipation members 71 and 72 are sometimes called "heat dissipation silicone" or "heat dissipation acrylic." The heat dissipation members may also contain additives to adjust thermal conductivity.

[0040] The material of the housing part 22u and the bottom part 22v is not particularly limited, but may be, for example, a metal such as aluminum, stainless steel, iron, etc. In particular, when aluminum is used as the material of the housing part 22u and the bottom part 22v, excellent heat dissipation properties can be obtained.

[0041] 3, the encoder board 63 and the drive board 43 are arranged apart from each other in the space S of the base part 22. By arranging them in this manner, heat generated in the drive circuit 4 is less likely to be transmitted to the light receiving part 62. This makes it possible to reduce the deterioration in the accuracy with which the light receiving part 62 receives light from the scale 61, which is caused by the influence of heat. Therefore, it is possible to prevent a decrease in the accuracy with which the position of the table part 21 relative to the base part 22 is detected.

[0042] The electronic component 41 included in the drive circuit 4 includes, for example, a coil 41a. The dashed-dotted line in FIG. 3 indicates the center line CL of the base 22 in the direction of arrow L along which the table 21 moves relative to the base 22. The coil 41a is disposed on the opposite side of the center of the base 22 from the light-receiving unit 62 in the direction of arrow L. This arrangement increases the distance from the coil 41a to the light-receiving unit 62. Furthermore, heat generated by the coil 41a, which generates a relatively large amount of heat among the electronic components 41 and 42, is less likely to be transmitted to the light-receiving unit 62. This reduces the degradation of the accuracy of the light-receiving unit 62 receiving light from the scale 61 due to the influence of heat. This configuration is more effective because the greater the range of the relative movement of the table 21, the greater the distance can be.

[0043] 3, the base unit 22 may include a blower 45, and the drive circuit 4 and the blower 45 may be disposed in the space S. Specific examples of the blower 45 include, but are not shown, a fan or a nozzle that blows air from outside the base unit 22. This prevents the temperature in the space S of the base unit 22 from rising excessively, and reduces the deterioration of the accuracy with which the light receiving unit 62 receives light from the scale 61 due to the influence of heat. The shape and configuration of the blower 45 are not particularly limited as long as it can generate a gas flow in the space S. For example, a hole may be drilled in the base unit 22 and the blower 45 may be attached to the outside of the base unit so that the air in the space S can be forced to circulate by the blower 45.

[0044] The above has described the drive device 1 according to the first embodiment. As described above, the drive device 1 includes piezoelectric motors 5a and 5b each having piezoelectric elements 531, 532, 533, 534, and 535, which output a drive force when the piezoelectric elements 531, 532, 533, 534, and 535 vibrate upon receiving a drive signal, a drive circuit 4 that generates the drive signal, a base 22 on which the piezoelectric motors 5a and 5b and the drive circuit 4 are disposed, and a table 21 that receives the drive force and moves relative to the base 22. This allows the piezoelectric motors 5a and 5b to receive drive signals with little noise, enabling accurate control of the relative movement between the table 21 and the base 22.

[0045] Furthermore, as described above, since the piezoelectric body is formed by the sol-gel method, the piezoelectric motors 5a and 5b are driven by high-frequency drive signals. In such cases, conventional drive devices are susceptible to the so-called high-frequency attenuation. However, in this embodiment, the attenuation of the drive signal can be suppressed, thereby realizing a drive device 1 that takes advantage of the characteristics of the piezoelectric motors 5a and 5b described above.

[0046] This configuration also has the effect of reducing heat generation in the wiring 92 connecting the drive circuit 4 and the piezoelectric motors 5a and 5b, thereby preventing the wiring 92 from melting and breaking.

[0047] 2. Second embodiment A robot system 900 according to the second embodiment will be described with reference to Fig. 7. In the drawings of this embodiment, the same components as those in the previously described embodiment are denoted by the same reference numerals.

[0048] 7 is an overall view of a robot system 900 according to the second embodiment. The robot system 900 includes a robot 200, a driving device 1 including a moving stage 2 attached to the robot 200, a tool T attached to the moving stage 2, and a control device 3 located at a distance from the robot 200. This configuration enables operations such as supplying, removing, transporting, assembling, and printing precision equipment and components constituting the equipment. However, the use of the robot 200 is not particularly limited.

[0049] The robot 200 is a six-axis robot with six joints, and includes a base 210 fixed to the floor or ceiling, and a robot arm 220 connected to the base 210. The robot arm 220 includes a first arm 221 rotatably connected to the base 210, a second arm 222 rotatably connected to the first arm 221, a third arm 223 rotatably connected to the second arm 222, a fourth arm 224 rotatably connected to the third arm 223, a fifth arm 225 rotatably connected to the fourth arm 224, and a sixth arm 226 rotatably connected to the fifth arm 225.

[0050] The movable stage 2, i.e., the table unit 21 and the base unit 22, are disposed at the tip of the robot arm 220, i.e., the sixth arm 226. A tool T is attached to the side of the movable stage 2 opposite to the side attached to the sixth arm 226. This makes it possible to change the position of the tool T by operating the movable stage 2. This makes it possible to precisely control the operation of the tool T at the tip of the robot arm 220. This makes it possible to improve the precision of work using the robot 200.

[0051] The portion of the moving stage 2 that is fixed to the robot arm 220 may be either the table 21 side or the base 22 side, but in this embodiment, the base 22 side is fixed to the robot arm 220. That is, the base 22 is disposed between the table 21 and the tip of the robot arm 220. Specifically, a bottom 22v of the base 22 is connected to the tip surface of the sixth arm 226. This allows heat from the electronic components 41 and 42 of the base 22 to be conducted from the bottom 22v to the sixth arm 226, thereby enabling efficient heat dissipation. Note that the bottom 22v does not necessarily have to be directly connected to the sixth arm 226, and may be fixed via, for example, an attachment or a jig.

[0052] The control device 3 of the drive device 1 is installed away from the robot arm 220, and is electrically connected to the moving stage 2 by a wire 91. The wire 91 is arranged along the robot arm 220 so as not to interfere with the operation of the robot arm 220. The length of the wire 91 is the total length of the robot arm 220, as well as a length that includes allowances at the joints of the robot arm 220.

[0053] As described above, the piezoelectric motors 5a and 5b included in the driving device 1 can receive driving signals with little noise, enabling accurate control of the relative movement between the table unit 21 and the base unit 22. Therefore, the robot system 900 including the moving stage 2 and the tool T can perform work with high reliability.

[0054] Furthermore, in the robot system 900, the tool T may be a print head 300. In this case, the base unit 22 and the table unit 21 are disposed between the print head 300 and the tip of the sixth arm 226. The print head 300 can be moved by the operation of the movable stage 2. In this way, the robot system 900 functions as a printing system 900a that performs printing while changing the position of the print head 300 relative to the target object by the operation of the robot 200. This enables highly accurate printing to be performed on a three-dimensional target object. An example of such printing is DTS (Direct to Shape) printing.

[0055] In the present embodiment, the control device 3 has been described as being installed at a position away from the robot 200, but this is not limiting and the control device 3 may be installed, for example, on the base 210. Alternatively, the control device 3 may be installed in a robot controller (not shown) that controls the operation of the robot 200.

[0056] In addition, in this embodiment, a six-axis robot (vertical articulated robot) has been described as an example of the robot 200, but this is not limited to this, and various robots may be used, such as a horizontal articulated robot (SCARA robot), a parallel link robot, or a human collaborative robot.

[0057] 3. Third embodiment A driving device 1a and a robot system 910 according to a third embodiment will be described with reference to FIGS.

[0058] In this embodiment, the drive unit 1a is equipped with a moving stage 2a that is different from the moving stage 2. The moving stage 2a does not include a drive circuit 4, and the drive circuit 4 is disposed between the control unit 3 and the moving stage 2a. This embodiment is similar to the previously described embodiment, except that the drive circuit 4 is disposed between the control unit 3 and the moving stage 2a. In the following description, differences between this embodiment and the previously described embodiment will be mainly described, and similar points will not be described again. In addition, in the drawings of this embodiment, the same reference numerals are used to designate the same components as those in the previously described embodiment.

[0059] FIG. 8 is an overall diagram showing the overall configuration of a drive unit 1a according to the third embodiment. The control unit 3, drive circuit 4, and moving stage 2a are electrically connected in series in this order. The control unit 3 and drive circuit 4 are electrically connected by wiring 91a, and the drive circuit 4 and moving stage 2a are electrically connected by wiring 92a. The drive circuit 4 and piezoelectric motors 5a and 5b are electrically connected by wiring 92c. Note that wiring 92c includes wiring 92a and wiring 92b inside the moving stage 2a.

[0060] FIG. 9 is an overall view of a robot system 910 according to the third embodiment. The robot system 910 includes a driving device 1a. A moving stage 2a is disposed on the sixth arm 226, while a driving circuit 4 is fixed to the housing of the fourth arm 224. A control device 3 is disposed at a position away from the robot 200, and a wiring 91a is disposed along the first arm 221, the second arm 222, the third arm 223, and the fourth arm 224. A wiring 92a is disposed along the fourth arm 224, the fifth arm 225, and the sixth arm 226. In the driving device 1a, the wiring 91a corresponds to the first wiring, and the wiring 92c corresponds to the second wiring.

[0061] Because the drive circuit 4 is connected between the control device 3 and the moving stage 2a, the length of the wiring 92c is shorter than the length of the wiring from the drive circuit 4 to the piezoelectric motors 5a and 5b when a conventional drive device is used in the robot system 910. Therefore, with the configuration of this embodiment, the piezoelectric motors 5a and 5b can receive drive signals with less noise, enabling accurate control of the relative movement between the table portion 21a and the base portion 22a. Furthermore, by positioning the drive circuit 4 away from the control device 3 and the moving stage 2a, the distance from the drive circuit 4 to the tool T can be adjusted. This reduces the impact of heat generated by the drive circuit 4 on the print head 300, an example of the tool T, and enables the printing system 910a to perform work with high precision. Therefore, the robot system 910 equipped with the drive device 1a and the tool T can perform work with high reliability.

[0062] Furthermore, if the length of the wiring 92c is shorter than the length of the wiring 91a, the work can be performed with higher reliability.

[0063] The portion of fourth arm 224 where drive circuit 4 is arranged may be the outer or inner surface of the housing of fourth arm 224. Furthermore, drive circuit 4 may be attached directly to fourth arm 224, or may be attached indirectly via an attachment, jig, or the like.

[0064] The arm on which the drive circuit 4 is arranged is not limited to the fourth arm 224, but may be any of the first arm 221 to the third arm 223, the fifth arm 225, or the sixth arm 226.

[0065] The robot system 910 and the drive device 1a according to the third embodiment have been described above. As described above, the drive device 1a includes piezoelectric motors 5a and 5b, each of which includes piezoelectric elements 531, 532, 533, 534, and 535. The piezoelectric elements 531, 532, 533, 534, and 535 receive a drive signal, vibrating to output a drive force. The base 22a includes the piezoelectric motors 5a and 5b. The table 21a receives the drive force and moves relative to the base 22a. The control device 3 includes a drive circuit 4 that generates the drive signal, a power supply 31 that supplies power to the drive circuit 4, and controls the movement. A first wiring line connects the control device 3 and the drive circuit 4. A second wiring line connects the drive circuit 4 and the piezoelectric motors 5a and 5b, the second wiring line being shorter than the first wiring line. This allows the piezoelectric motors 5a and 5b to receive a drive signal with less noise, enabling the drive device 1a to accurately control the relative movement between the table 21a and the base 22a. In addition, in such a robot system 910, the table portion 21a and the base portion 22a are disposed at the tip of the robot arm 220. This allows the robot system 910 to perform work with high reliability.

[0066] The drive device, robot system, and printing system have been described above based on the illustrated embodiments, but the present embodiments are not limited to these, and the configuration of each part can be replaced with any configuration having a similar function. Furthermore, any other components may be added to the present embodiments. Furthermore, the respective embodiments may be combined as appropriate. [Explanation of symbols]

[0067] DESCRIPTION OF SYMBOLS 1,1a...drive device, 2,2a...moving stage, 3...control device, 4...drive circuit, 5,5a,5b...piezoelectric motor, 6...encoder, 21,21a...table portion, 22,22a...base portion, 22u...casing portion, 22v...bottom portion, 23a,23b...rail portion, 24a,24b...block portion, 25,25a,25b...driven portion, 31...power supply portion, 32...PWM signal generating portion, 33...movement amount detecting portion, 34...movement direction detecting portion, 41,42...electronic components, 41a...coil, 43...drive board, 45...blower, 51...protrusion portion, 52...fixed portion, 53...energizing portion, 61...scale, 62...light receiving portion , 63...encoder board, 71, 72...heat dissipation member, 91, 91a, 92, 92a, 92b, 92c...wiring, 200...robot, 210...base, 220...robot arm, 221...first arm, 222...second arm, 223...third arm, 224...fourth arm, 225...fifth arm, 226...sixth arm, 300...print head, 500...vibrator, 511...support part, 512...vibrating body, 521, 522...connection part, 531 to 535...piezoelectric element, 900, 910...robot system, 900a, 910a...printing system, CL...center line, L...arrow, S...space, T...tool.

Claims

1. a piezoelectric motor including a piezoelectric element, the piezoelectric element vibrating in response to a drive signal to output a drive force; a drive circuit for generating the drive signal; a base portion on which the piezoelectric motor and the drive circuit are disposed; a table portion that receives the driving force and moves relative to the base portion; A drive device comprising:

2. 2. The driving device according to claim 1, wherein the piezoelectric element has a piezoelectric body formed by a sol-gel method.

3. A heat dissipation member is provided, The drive device according to claim 1 , wherein the heat dissipation member is in contact with an electronic component included in the drive circuit.

4. an encoder having a scale and a light receiving unit disposed on an encoder substrate and receiving light from the scale, the encoder detecting a position of the table portion relative to the base portion; a drive substrate on which electronic components included in the drive circuit are arranged, The base portion has a space defined therein, The drive device according to claim 1 , wherein the encoder board and the drive board are spaced apart from each other in the space.

5. the electronic component includes a coil; The drive device according to claim 4 , wherein the coil is disposed on an opposite side to the light receiving portion with respect to a center of the base portion in a direction in which the table portion moves relative to the base portion.

6. Equipped with a blower, The base portion has a space defined therein, The drive device according to claim 1 , wherein the drive circuit and the blower are disposed in the space.

7. a robot having an arm; The drive device according to claim 1 or 2, The robot system is characterized in that the base unit and the table unit are disposed at the tip of the arm.

8. The base portion is disposed between the table portion and the tip of the arm. The robot system according to claim 7 .

9. a robot having an arm; The drive device according to claim 1 or 2; a print head that is movable by the drive device, A printing system, characterized in that the base portion and the table portion are disposed between the print head and the tip of the arm.

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