Driving device and positioning device

Abstract

To provide a driving device, etc. that can appropriately combine linear drive and rotational drive.SOLUTION: An actuator 1 includes: a driven member 2 that is linearly driven in an axial direction T and rotatably driven around the axial direction T and provided with a polygonal square shaft portion 21 in a cross-section viewed in the axial direction T; and a bearing member 3 that is rotatably driven while linearly supporting at least the square shaft portion 21 of the driven member 2 and having a polygonal-shaped square hole 31 in cross section in the axial direction T through which the square shaft portion 21 passes. A fluid bearing is formed between the outer circumference of the square shaft portion 21 and the inner circumference of a square hole 31, and a fluid bearing groove is formed on the inner circumference of the square hole 31 into which the fluid forming the fluid bearing is supplied.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a drive device and the like. [Background technology]

[0002] Patent Document 1 discloses a technology for mounting a semiconductor chip on a substrate. Specifically, a long tool or tool holder having a semiconductor chip attached to its lower end is lowered in the Z direction (vertical direction) to mount the semiconductor chip on a substrate supported by a stage below. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] WO 2002 / 49094 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the hydrostatic air bearing (18) supporting the axial tool holder (17) is provided so as to only allow the tool to move up and down in the Z direction (up and down movement) and prohibit rotation around the Z axis. For this reason, it is not possible to properly correct errors in the rotational position or rotational angle that may occur when mounting a semiconductor chip on the tool. It is also possible to provide a hydrostatic air bearing so as to allow rotation around the Z axis, but with a configuration that employs such a non-contact bearing, it is difficult to properly achieve both linear and rotational drive of the tool.

[0005] The present disclosure has been made in consideration of these circumstances, and has as its object to provide a drive device etc. that can appropriately achieve both linear drive and rotational drive. [Means for solving the problem]

[0006] In order to solve the above problems, a driving device according to an embodiment of the present disclosure includes: a driven member that is linearly driven in an axial direction and rotationally driven about the axial direction, the driven member having an angular shaft portion having a polygonal cross section as viewed in the axial direction; and a bearing member that is rotationally driven while supporting at least the angular shaft portion of the driven member so as to be linearly drivable, the bearing member having an angular hole portion having a polygonal cross section as viewed in the axial direction through which the angular shaft portion passes. A fluid bearing is formed between an outer peripheral surface of the angular shaft portion and an inner peripheral surface of the angular hole portion, and a fluid bearing groove is formed on the inner peripheral surface of the angular hole portion to which a fluid that forms the fluid bearing is supplied.

[0007] In this embodiment, the cross sections of the angular shaft portion of the driven member and the angular hole portion of the bearing member as viewed in the axial direction are both polygonal (e.g., substantially similar). When such a bearing member is rotationally driven, the angular shaft portion in the angular hole portion (i.e., the driven member) is also rotationally driven substantially integrally without spinning freely. The bearing member including the angular hole portion supports the driven member including the angular shaft portion so that it can be linearly driven. Here, a fluid bearing groove formed on the inner peripheral surface of the angular hole portion forms a fluid bearing between the outer peripheral surface of the angular shaft portion and the inner peripheral surface of the angular hole portion that appropriately supports linear and rotational drive.

[0008] Another aspect of the present disclosure is a positioning device. The positioning device positions an object in a rotational direction, and includes: a driven member to which the object is attached, which is linearly driven in an axial direction, and which is rotationally driven in a rotational direction about the axial direction, the driven member having an angular shaft portion having a polygonal cross section as viewed in the axial direction; and a bearing member which is rotationally driven while supporting at least the angular shaft portion of the driven member so as to be linearly drivable, the bearing member having an angular hole portion having a polygonal cross section as viewed in the axial direction through which the angular shaft portion passes. A fluid bearing is formed between an outer peripheral surface of the angular shaft portion and an inner peripheral surface of the angular hole portion, and a fluid bearing groove is formed on the inner peripheral surface of the angular hole portion to which a fluid forming the fluid bearing is supplied.

[0009] Any combination of the above components, or any conversion of these components into a method, device, system, recording medium, computer program, or the like, is also encompassed by the present disclosure. Effect of the Invention

[0010] According to the present disclosure, linear drive and rotational drive can be appropriately achieved at the same time. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a cross-sectional view illustrating a schematic configuration of an actuator. [Diagram 2] FIG. 4 is a perspective view showing only a square shaft portion and a piston portion of a driven member. [Diagram 3] 2 shows a simplified cross section taken along line AA in FIG. 1. [Figure 4] 4 shows a simplified cross section taken along line BB in FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In the following, a form for carrying out the present disclosure (hereinafter also referred to as an embodiment) will be described in detail with reference to the drawings. In the description and / or drawings, identical or equivalent components, members, processes, etc. will be given the same reference numerals, and duplicated descriptions will be omitted. The scale and shape of each part shown in the drawings are set for convenience in order to simplify the description, and are not to be interpreted as being limiting unless otherwise specified. The embodiment is an example, and does not limit the scope of the present disclosure in any way. All features and their combinations presented in the embodiment are not necessarily essential to the present disclosure. The embodiment is presented for convenience, decomposed into components for each function and / or each functional group that realizes it. However, one component in the embodiment may actually be realized by a combination of multiple components as separate entities, and multiple components in the embodiment may actually be realized by one component as an integrated entity.

[0013] FIG. 1 is a cross-sectional view showing a schematic configuration of an actuator 1 which is an embodiment of a driving device or a positioning device according to the present disclosure. The actuator 1 is a driving device which linearly drives a driven member 2 in a linear driving direction T (up and down direction in FIG. 1) shown in the figure and rotates the driven member 2 in a rotational driving direction R shown in the figure. The linear driving direction T is, for example, the direction of the central axis of the substantially columnar driven member 2, and is also referred to as the axial direction T below. The rotational driving direction R is the circumferential direction around the linear driving direction T or the axial direction T, and is also referred to as the rotational direction R below. In the following description, the terms "up" and "down" are used for convenience to represent the directions "up" and "down" in FIG. 1, which is also the axial direction T. These terms do not limit the installation direction or axial direction T of the actuator 1 to, for example, a vertical direction, and the installation direction or axial direction T of the actuator 1 is arbitrary depending on the driving purpose.

[0014] The actuator 1 may constitute a positioning device that positions an object (not shown), such as a semiconductor device (typically a semiconductor chip) attached to the lower end of the driven member 2, in the rotation direction R. For example, the actuator 1 or the positioning device may constitute a mounting device (semiconductor mounting device) that positions the semiconductor device at a desired rotation position or rotation angle in the rotation direction R, and then lowers the semiconductor device together with the driven member 2 along the axial direction T to mount it on a mounting board (not shown) or the like.

[0015] The actuator 1 mainly includes a driven member 2, a bearing member 3, and a cylinder member 4. As described later, the driven member 2 is linearly driven along the axial direction T by the pressure of a fluid such as pressurized air inside the cylinder member 4. Also, as described later, the driven member 2 is rotationally driven along the rotational direction R (i.e., around the axial direction T) via the bearing member 3 which is rotationally driven by a motor 9.

[0016] The driven member 2, which is generally columnar and long along the axial direction T, is provided with, in order from bottom to top in Fig. 1, a square shaft portion 21, a piston portion 22, and a sensor rod portion 23. Fig. 2 is a perspective view showing only the square shaft portion 21 and the piston portion 22.

[0017] As shown in FIG. 3 (only a part of the driven member 2 (angled shaft portion 21) and the bearing member 3 is shown), which is a simplified view of the AA cross section of FIG. 1, the angular shaft portion 21 is formed to have a polygonal cross section as viewed in the axial direction T. The polygonal shape of the angular shaft portion 21 is arbitrary, but is rectangular or square in the illustrated example. The bearing member 3 has an angular hole portion 31 having a polygonal cross section as viewed in the axial direction T through which the angular shaft portion 21 of the driven member 2 penetrates. The polygonal shape of the angular hole portion 31 is arbitrary, but is preferably approximately similar to the polygonal shape of the angular shaft portion 21, and is rectangular or square in the illustrated example. Here, the polygonal shape of the angular hole portion 31 is preferably formed slightly larger than the polygonal shape of the angular shaft portion 21 so that the angular shaft portion 21 can penetrate the inside of the angular hole portion 31 in the axial direction T.

[0018] A fluid such as pressurized air is supplied to a small gap (shown exaggerated in FIG. 3) between the outer circumferential surface of the rectangular shaft portion 21 and the inner circumferential surface of the rectangular hole portion 31 to form a fluid bearing 5. Furthermore, as described later, one or more fluid bearing grooves 32 to which a fluid such as pressurized air is supplied is formed on the inner circumferential surface of the rectangular hole portion 31.

[0019] In FIG. 1, one or more piston portions 22 provided above the angular shaft portion 21 are housed inside a cylindrical cylinder body 41 in the cylinder member 4. The cross sections of the cylinder body 41 and the piston portion 22 (FIG. 2) as viewed in the axial direction T are both circular. As shown in FIG. 2, the diameter or size of the piston portion 22 in the circular cross section is significantly larger than the diameter or size of the angular shaft portion 21 in the polygonal cross section. Alternatively, in the cross section (as viewed in the axial direction T), the polygonal cross section of the angular shaft portion 21 is included in the circular cross section of the piston portion 22. In the illustrated example, the polygonal cross section of the angular shaft portion 21 is inscribed in the circular cross section of the piston portion 22.

[0020] In FIG. 1, a substantially columnar space inside a cylindrical cylinder body 41 is divided into upper and lower spaces by the piston portion 22. The space above the piston portion 22 inside the cylinder body 41 is a pressure control chamber 8 capable of controlling the pressure for linearly driving the piston portion 22 (driven member 2). For example, the pressure inside the pressure control chamber 8 can be controlled by controlling the amount of fluid in the pressure control chamber 8 with a fluid supply / discharge unit (not shown). In addition to or instead of the pressure control chamber 8, the space below the piston portion 22 inside the cylinder body 41 may be configured as a second pressure control chamber 81 capable of controlling the pressure for linearly driving the piston portion 22 (driven member 2). As with the pressure control chamber 8, the pressure inside the second pressure control chamber 81 can be controlled by controlling the amount of fluid in the second pressure control chamber 81 with a fluid supply / discharge unit (not shown).

[0021] The pressure control chamber 8, which is an upper space inside the cylinder body 41, is substantially closed from above by the upper cover portion 42 of the cylinder member 4. The lower end surface 421 of the upper cover portion 42 may determine the upper movement limit of the piston portion 22. In addition, the second pressure control chamber 81, which is a lower space inside the cylinder body 41, is substantially closed from below by the bearing member 3. This is because, as shown in FIG. 1, the diameter or size of the polygonal angular hole portion 31 in the bearing member 3 is significantly smaller than the diameter or size of the circular piston portion 22. The upper end surface 33 of the bearing member 3 may determine the downward movement limit of the piston portion 22.

[0022] 1, the sensor rod portion 23 provided above the piston portion 22 is formed in a cylindrical or rod-like shape, preferably from the center upward on the upper end surface of the piston portion 22. A long positioning hole 422 is formed in the upper cover portion 42 of the cylinder member 4 along the axial direction T, into which the sensor rod portion 23 as the portion to be positioned is inserted. A sensor coil 423 is provided on the inner circumferential surface of the positioning hole 422, preferably at the lower end, facing the sensor rod portion 23 and serving as a positioning portion for measuring its position in the axial direction T.

[0023] For example, a magnetic scale of a predetermined pitch that can be magnetically detected by the sensor coil 423 is provided on the outer circumferential surface of the sensor rod portion 23 along the axial direction T. The detected value or counted value by the sensor coil 423 represents the position or displacement of the sensor rod portion 23 (i.e., the entire driven member 2) in the axial direction T. In this way, the position of the entire driven member 2 including the angular shaft portion 21 and the piston portion 22 in the axial direction T can be grasped by the sensor rod portion 23 as the positioned portion and the sensor coil 423 as the positioning portion.

[0024] As described above, the driven member 2 is linearly driven along the axial direction T by the pressure of a fluid such as compressed air inside the cylinder member 4. Specifically, the piston portion 22 accommodated inside the cylinder body 41 of the cylinder member 4 is linearly driven along the axial direction T by the pressure of a fluid in the upper pressure control chamber 8 and / or the lower second pressure control chamber 81. The maximum movement distance (stroke) of the piston portion 22 (driven member 2) in the axial direction T is determined by the lower end surface 421 (upward movement limit) of the upper cover portion 42 provided at the upper end of the cylinder body 41 and the upper end surface 33 (downward movement limit) of the bearing member 3 provided at the lower end of the cylinder body 41. The position of the driven member 2 in the axial direction T is grasped by the sensor coil 423 that measures the position of the sensor rod portion 23.

[0025] When the driven member 2 is linearly driven along the axial direction T, the angular shaft portion 21 of the driven member 2 moves up and down along the axial direction T inside the angular hole portion 31 of the bearing member 3. Here, as shown in FIG. 3, a fluid such as pressurized air is supplied between the outer peripheral surface of the angular shaft portion 21 and the inner peripheral surface of the angular hole portion 31 to form a fluid bearing 5, so that the angular shaft portion 21 can smoothly move or slide along the axial direction T without substantially contacting the inner peripheral surface of the angular hole portion 31. Note that the fluid such as pressurized air for forming the fluid bearing 5 may be supplied through, for example, the second pressure control chamber 81 described above. In this way, the angular hole portion 31 of the bearing member 3 supports the angular shaft portion 21 of the driven member 2 so that it can be linearly driven.

[0026] As shown in FIG. 3, one or more fluid bearing grooves 32 to which a fluid such as pressurized air is supplied are formed on the inner peripheral surface of the square hole portion 31. Moreover, as shown in FIG. 4, which is a simplified view of the BB cross section of FIG. 3, it is preferable that one or more fluid bearing grooves 32 extend along the axial direction T (the vertical direction in FIG. 4) in order to effectively support the linear drive of the opposing square shaft portion 21. However, at least one fluid bearing groove 32 may extend in a direction intersecting the axial direction T (for example, the horizontal direction in FIG. 4). Moreover, the number of fluid bearing grooves 32 provided on each inner peripheral surface of the square hole portion 31 (for example, the square hole portion 31 according to this embodiment having a rectangular cross section has four inner peripheral surfaces) is arbitrary, and may be three as shown in FIG. 4, may be zero (a fluid bearing groove 32 is provided on at least one other inner peripheral surface), may be one, two, or may be four or more.

[0027] As shown in FIG. 4, a plurality of fluid bearing grooves 32 extending along the axial direction T between an upper end 321 as one end and a lower end 322 as the other end may be provided in parallel or in parallel on each inner peripheral surface of the square hole portion 31. Here, the upper end 321 of each fluid bearing groove 32 on the piston portion 22 (FIG. 1) side in the axial direction T is open to the inside of the cylinder body 41 (FIG. 1) of the cylinder member 4 (or the second pressure control chamber 81). Therefore, the pressurized air, etc. in the second pressure control chamber 81 is effectively supplied into each fluid bearing groove 32, and the fluid bearing 5 is reliably formed. On the other hand, the lower end 322 of each fluid bearing groove 32 in the axial direction T is closed, so that the pressurized air, etc. in each fluid bearing groove 32 does not leak to the outside of the cylinder member 4.

[0028] These fluid dynamic bearing grooves 32 may be formed on the outer peripheral surface of the angular shaft portion 21 of the driven member 2, instead of the inner peripheral surface of the angular hole portion 31 of the bearing member 3. However, in this case, as shown in FIG. 2, the fluid dynamic bearing grooves 32 must be formed on the outer peripheral surface of the long angular shaft portion 21 over at least the stroke length in the axial direction T of the driven member 2. In contrast, when the fluid dynamic bearing grooves 32 are formed on the inner peripheral surface of the angular hole portion 31 of the bearing member 3, the fluid dynamic bearing grooves 32 may be formed over substantially the entire length in the axial direction T of the angular hole portion 31 (bearing member 3) as shown in FIG. 4, regardless of the stroke length in the axial direction T of the driven member 2. In addition, when the fluid dynamic bearing grooves 32 are formed on the outer peripheral surface of the angular shaft portion 21 of the driven member 2, it is difficult to keep the pressurized air, etc., inside the fluid dynamic bearing grooves 32 and / or the cylinder member 4, as shown in the lower end portion 322 in FIG. 4. In consideration of these points, the fluid dynamic bearing grooves 32 are preferably provided on the inner peripheral surface of the angular hole portion 31 of the bearing member 3, as shown in FIG. 4.

[0029] As shown in FIG. 2, hydrodynamic bearing grooves 221 and 222 similar to the hydrodynamic bearing groove 32 described above may be provided on the outer circumferential surface of the piston portion 22.

[0030] Of the two piston portions 22 in the illustrated example, one or more first fluid bearing grooves 221, which are open at their upper ends and closed at their lower ends and extend along the axial direction T, are provided along the circumferential direction on the outer circumferential surface of the upper first piston portion 22. Here, the upper end of the first fluid bearing groove 221 is open to the pressure control chamber 8. For this reason, the pressurized air or the like in the pressure control chamber 8 is effectively supplied into the first fluid bearing groove 221, and a fluid bearing is reliably formed between the outer circumferential surface of the first piston portion 22 and the inner circumferential surface of the cylinder body 41.

[0031] Of the two piston portions 22 in the illustrated example, one or more second fluid bearing grooves 222, which are open at their lower ends and closed at their upper ends, are provided along the circumferential direction on the outer circumferential surface of the lower second piston portion 22. Here, the lower end of the second fluid bearing groove 222 is open to the second pressure control chamber 81. For this reason, the pressurized air or the like in the second pressure control chamber 81 is effectively supplied into the second fluid bearing groove 222, and a fluid bearing is reliably formed between the outer circumferential surface of the second piston portion 22 and the inner circumferential surface of the cylinder body 41.

[0032] As described above, each fluid bearing formed between the outer peripheral surface of each piston portion 22 and the inner peripheral surface of the cylinder body 41, together with the fluid bearing 5 formed between the outer peripheral surface of the square shaft portion 21 and the inner peripheral surface of the square hole portion 31, supports the driven member 2 so that it can be linearly driven.

[0033] Next, a mechanism for rotationally driving the driven member 2 in the rotation direction R will be described with reference to FIG.

[0034] The outer peripheral surface of the bearing member 3, which supports the angular shaft portion 21 of the driven member 2 so as to be linearly drivable by the angular hole portion 31 on the inner peripheral surface and / or the fluid bearing 5, is connected to the motor 9 via a belt 91. The belt 91 meshes with gears of the motor 9 at the left end in Fig. 1 and with gears of the bearing member 3 at the right end in Fig. 1, thereby transmitting the rotational power generated by the motor 9 to the bearing member 3. As a result, the bearing member 3 is rotationally driven by the motor 9 in the rotational direction R.

[0035] 3, the cross sections of the angular shaft portion 21 of the driven member 2 and the angular hole portion 31 of the bearing member 3 as viewed in the axial direction are both polygonal. When such a bearing member 3 is rotationally driven by a motor 9, the angular shaft portion 21 in the angular hole portion 31 (i.e., the driven member 2) is rotationally driven substantially integrally via the fluid bearing 5 without spinning freely.

[0036] 1, a rotary bearing 6 of any type, such as a rolling bearing, is provided between the outer circumferential surface of the bearing member 3 and the inner circumferential surface of a protruding portion 43 that protrudes downward in the cylinder member 4. The rotary bearing 6 allows the bearing member 3 and the driven member 2, which are rotationally driven together by a motor 9, to rotate smoothly in the rotation direction R relative to the cylinder member 4.

[0037] The present disclosure has been described above based on the embodiments. Various modifications are possible to the combinations of the components and processes in the exemplary embodiments, and it will be obvious to those skilled in the art that such modifications are included within the scope of the present disclosure.

[0038] The configuration, action, and function of each device and method described in the embodiments can be realized by hardware resources or software resources, or by the cooperation of hardware resources and software resources. For example, a processor, ROM, RAM, and various integrated circuits can be used as hardware resources. For example, programs such as an operating system and applications can be used as software resources. [Explanation of symbols]

[0039] 1 actuator, 2 driven member, 3 bearing member, 4 cylinder member, 5 fluid bearing, 9 motor, 21 square shaft portion, 22 piston portion, 31 square hole portion, 32 fluid bearing groove.

Claims

1. A driven member that is linearly driven in an axial direction and rotationally driven around the axial direction, the driven member having a polygonal cross section as viewed in the axial direction; a bearing member that is rotationally driven while supporting at least the angular shaft portion of the driven member so as to be linearly drivable, the bearing member having a polygonal cross section as viewed in the axial direction through which the angular shaft portion passes; Equipped with A fluid bearing is formed between an outer circumferential surface of the square shaft portion and an inner circumferential surface of the square hole portion, a fluid bearing groove to which a fluid forming the fluid bearing is supplied is formed on an inner circumferential surface of the rectangular hole portion; Drive unit.

2. A cylinder member is provided, The driven member includes a piston portion that is linearly driven by the pressure of a fluid inside the cylinder member. The drive device according to claim 1 .

3. The drive unit according to claim 2 , wherein the bearing member is rotatably provided around the axial direction relative to the cylinder member.

4. The drive device according to claim 3 , further comprising a motor that rotates and drives the bearing member.

5. 5. The drive unit according to claim 2, wherein one end of the hydrodynamic bearing groove on the piston portion side in the axial direction is open to the inside of the cylinder member, and the other end is closed.

6. The drive unit according to claim 5 , wherein a plurality of the hydrodynamic bearing grooves are provided in parallel and extend along the axial direction between the one end and the other end.

7. The drive unit according to claim 2 , wherein the cylinder member and the piston portion each have a circular cross section as viewed in the axial direction.

8. The drive unit according to claim 1 , wherein the polygonal shape of said angular shaft portion and the polygonal shape of said angular hole portion are both rectangular.

9. The drive unit according to claim 1 , wherein the hydrodynamic bearing groove extends along the axial direction.

10. A positioning device for positioning an object in a rotational direction, comprising: a driven member to which the object is attached, which is linearly driven in an axial direction, and which is rotationally driven in the rotational direction around the axial direction, the driven member having a polygonal cross section as viewed in the axial direction; a bearing member that is rotationally driven while supporting at least the angular shaft portion of the driven member so as to be linearly drivable, the bearing member having a polygonal cross section as viewed in the axial direction through which the angular shaft portion passes; Equipped with A fluid bearing is formed between an outer circumferential surface of the square shaft portion and an inner circumferential surface of the square hole portion, a fluid bearing groove to which a fluid forming the fluid bearing is supplied is formed on an inner circumferential surface of the rectangular hole portion; Positioning device.

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