Actuator

Abstract

To provide an actuator that can properly prevent belt deflection and operate smoothly with a simple configuration. [Solution] The device comprises a base, a drive pulley rotatably mounted on the base end, a driven pulley rotatably mounted on the tip of the base, a belt wound between the drive pulley and the driven pulley, a slider having a belt fixing part to which the belt is fixed and which moves linearly along a rail installed on the base in accordance with the movement of the belt and to which a workpiece can be attached, and an idler pulley installed on the base so as to face the bottom surface of the slider, wherein the belt is supported by the idler pulley and is fixed to the belt fixing part on the surface side of the slider, passing through the slider from the bottom side.

Description

Technical Field

[0001] The present invention relates to an actuator driven by a belt, and particularly to an actuator devised so as to appropriately prevent belt deflection and enable smooth operation with a simple configuration.

Background Art

[0002] As an example of disclosing an actuator driven by a belt that prevents belt deflection, there is Patent Document 1. The actuator described in Patent Document 1 is provided with a belt idler body that supports a toothed belt for reciprocating a moving table. The belt idler body has a frame that is movably installed on a guide rail, and two free pulleys as belt supports are rotatably installed on the frame. A meshing pulley as a lifting and lowering engaging body is installed between the two free pulleys.

[0003] The meshing pulley is provided with teeth that mesh with the toothed belt, but not all circumferences are provided with the teeth, and there are portions where no teeth are provided. As a result, the rotation range of the meshing pulley is restricted. The meshing pulley is supported by a roller holder, and a wheel is rotatably installed on the roller holder. The wheel is rolled on the guide rail and moved up and down by the slope of the guide rail. Normally, the meshing pulley is located below the free pulley and does not mesh with the toothed belt, but when it is moved upward, it meshes with the toothed belt.

[0004] When the moving table moves in one direction and contacts the belt idler body, the belt idler body is pressed by the moving table and moved. Then, after advancing a certain distance, the meshing pulley meshes with the toothed belt.

[0005] When the above-mentioned movable table moves to the end and then moves in the reverse direction, the belt idler body, which has been pressed against the above-mentioned movable table, is moved by the toothed belt because it is engaged with the meshing pulley and the toothed belt. After that, the meshing pulley moves downward, the meshing between the meshing pulley and the toothed belt is released, and only the belt idler body stops. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Utility Model Publication No. 04-041143 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The above conventional configuration had the following problems: In the actuator described in Patent Document 1, the meshing pulley of the belt idler body is configured to be able to move up and down, and at a predetermined position, the meshing pulley rises and meshes with the toothed belt, so that it is moved by the toothed belt even when it is not pressed against the moving table, which makes the configuration complex.

[0008] The present invention is based on these points, and its objective is to provide an actuator that can properly prevent belt deflection and operate smoothly with a simple configuration. [Means for solving the problem]

[0009] To achieve the above objective, the actuator according to claim 1 of the present invention comprises a base, a drive pulley rotatably mounted on the base end, a driven pulley rotatably mounted on the tip of the base, a belt wound between the drive pulley and the driven pulley, a slider having a belt fixing portion to which the belt is fixed and which moves linearly along a rail installed on the base in accordance with the movement of the belt and to which a workpiece can be attached, and an idler pulley installed on the base so as to face the bottom surface of the slider, wherein the belt is supported by the idler pulley and is fixed to the belt fixing portion on the surface side of the slider by passing through the slider from the bottom side. Furthermore, the actuator according to claim 2 is characterized in that, in the actuator according to claim 1, one end and the other end of the belt are fixed to the belt fixing portion. Furthermore, the actuator according to claim 3 is characterized in that, in the actuator according to claim 1, the belt is a timing belt having teeth, and the drive pulley, the driven pulley, and the idler pulley are timing pulleys having teeth that mesh with the teeth of the belt. Furthermore, the actuator according to claim 4 is characterized in that, in the actuator according to claim 3, the bottom surface of the slider is provided with a slider-side gearing portion that engages with the idler pulley between a portion through which one end of the belt passes and a portion through which the other end of the belt passes. Furthermore, the actuator according to claim 5 is characterized in that, in the actuator according to claim 4, at least a portion of the portion of the slider-side gear joint that is located on both ends in the direction of movement of the slider and the portion of the belt that is located on the bottom surface side of the slider are superimposed in the direction of movement of the slider. Furthermore, the actuator according to claim 6 is characterized in that, in the actuator according to claim 4, the slider-side gear portion is a separate member installed on the slider. Furthermore, the actuator according to claim 7 is characterized in that, in the actuator according to claim 3, the belt fixing portion is provided with a belt fixing engagement portion into which the teeth of the belt engage. Furthermore, the actuator according to claim 8 is characterized in that, in the actuator according to claim 1, a belt holding member is installed in the belt fixing portion, and the belt is interposed between the slider and the belt holding member. [Effects of the Invention]

[0010] As described above, the actuator according to claim 1 of the present invention comprises a base, a drive pulley rotatably mounted on the base end, a driven pulley rotatably mounted on the tip of the base, a belt wound between the drive pulley and the driven pulley, a slider having a belt fixing part to which the belt is fixed and which moves linearly along a rail installed on the base in accordance with the movement of the belt and to which a workpiece can be attached, and an idler pulley installed on the base so as to face the bottom surface of the slider. The belt is supported by the idler pulley and passes through the slider from the bottom side and is fixed to the belt fixing part on the surface side of the slider, so that the belt deflection is properly prevented and smooth operation is possible with a simple configuration. Furthermore, according to the actuator of claim 2, in the actuator described in claim 1, one end and the other end of the belt are fixed to the belt fixing part, making it easy to replace the belt and eliminating the need for other members to hold the belt in a loop shape, thus simplifying the configuration. Furthermore, according to the actuator of claim 3, in the actuator described in claim 1, the belt is a timing belt with teeth, and the drive pulley, driven pulley, and idler pulley are timing pulleys with teeth that mesh with the teeth of the belt, so that they can be operated more reliably. Furthermore, according to the actuator of claim 4, in the actuator described in claim 3, the bottom surface of the slider is provided with a slider-side gearing portion that engages with the idler pulley between at least one end of the belt and the other end of the belt. Therefore, even in areas where the belt is not positioned on the bottom surface of the slider, the idler pulley can be engaged to prevent slippage and thus prevent vibration and noise. Furthermore, according to the actuator of claim 5, in the actuator described in claim 4, at least a portion of the portion of the slider-side gearing portion located on both ends in the direction of movement of the slider and the portion of the belt located on the bottom surface side of the slider are superimposed in the direction of movement of the slider, so that there is no portion between the belt and the slider-side gearing portion where the idler pulley is not geared, and it can operate smoothly. Furthermore, according to the actuator of claim 6, in the actuator described in claim 4, the slider-side gear portion is a separate component installed on the slider, so there is no need to perform additional processing on the slider, and it is easy to replace only the slider-side gear portion. Furthermore, according to the actuator of claim 7, in the actuator described in claim 3, the belt fixing portion is provided with a belt fixing engagement portion into which the teeth of the belt engage, so that the belt can be securely fixed. Furthermore, according to the actuator of claim 8, in the actuator described in claim 1, a belt holding member is installed in the belt fixing portion, and the belt is interposed between the slider and the belt holding member, so that the belt can be securely fixed. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows one embodiment of the present invention, and is a perspective view of the actuator. [Figure 2] This figure shows one embodiment of the present invention and is a plan view of the actuator. [Figure 3]A diagram showing an embodiment of the present invention. Fig. 3(a) is a cross-sectional view taken along line IIIa-IIIa of Fig. 2, and Fig. 3(b) is an enlarged view of a portion IIIb of Fig. 3(a). [Figure 4] A diagram showing an embodiment of the present invention. It is a cross-sectional view taken along line IV-IV of Fig. 2. [Figure 5] A diagram showing an embodiment of the present invention. It is a cross-sectional view taken along line V-V of Fig. 2. [Figure 6] A diagram showing an embodiment of the present invention. It is a view taken in the direction of arrow VI-VI of Fig. 3(a), with a part of the base removed. [Figure 7] A diagram showing an embodiment of the present invention. It is an enlarged view of a portion VII of Fig. 3(b). [Figure 8] A diagram showing an embodiment of the present invention. Fig. 8(a) is an exploded perspective view of the slider seen from the upper surface side with the belt holding member removed, and Fig. 8(b) is an exploded perspective view of the slider seen from the bottom surface side with the slider-side meshing portion removed.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 8. As shown in Figs. 1 to 3, the actuator 1 according to this embodiment has a base 3. As shown in Figs. 4 and 5, the base 3 is open at the upper side in Fig. 4, and base-side rails 5 are installed on both sides in the inner width direction (left and right direction in Fig. 4). A belt penetration portion 7 is formed at the bottom of the base 3.

[0013] As shown in FIGS. 1 to 3, a drive unit 11 is installed on the proximal end side (the left side in FIG. 3) of the base 3. A motor 13 and a drive pulley 15 are installed in the drive unit 11. A shaft 17 is rotatably installed in the drive unit 11. The drive pulley 15 is fixed to the shaft 17 and is rotatably installed in the drive unit 11. A motor-side pulley 21 is fixed to the output shaft 19 of the motor 13, and a pulley 23 is fixed to the distal end side of the shaft 17. A power transmission belt 25 is wound around the motor-side pulley 21 and the pulley 23, and the drive pulley 15 is rotated by the motor 13.

[0014] A pulley housing 31 is installed on the distal end side (the right side in FIG. 3) of the base 3. A driven pulley 33 is rotatably installed in the pulley housing 31.

[0015] A slider 41 is movably installed on the base 3 along the base-side rail 5. As shown in FIGS. 4 and 5, no-load circulation paths 43 are provided on both sides in the width direction (the left-right direction in FIG. 4) inside the slider 41. Slider-side rails 45 are installed on both side surfaces (the surfaces on both sides in the left-right direction in FIG. 4) of the slider 41.

[0016] Also, as shown in FIG. 2, end caps 47 are installed on both sides in the width direction (the up-down direction in FIG. 2) at one end side in the moving direction (the left side in FIG. 2) of the slider 41, and end caps 49 are installed on both sides in the width direction (the up-down direction in FIG. 2) at the other end side in the moving direction (the right side in FIG. 2) of the slider 41. A plurality of steel balls 51 are circulated inside the no-load circulation path 43, in the space between the base-side rail 5 and the slider-side rail 45, and inside a return path (not shown) inside the end caps 47 and 49. Also, the end caps 47 and 49 are covered by an end cap cover 48.

[0017] Furthermore, as shown in Figures 3 and 6, a belt through-hole 53 is formed at one end of the slider 41 in the direction of movement (right side in Figure 3), connecting the surface side (upper side in Figure 3) and the bottom side (lower side in Figure 3) of the slider 41, and a belt through-hole 55 is also formed at the other end of the slider 41 in the direction of movement (left side in Figure 3), connecting the surface side (upper side in Figure 3) and the bottom side (lower side in Figure 3) of the slider 41.

[0018] Furthermore, on the surface side (upper side in Figure 3) of the slider 41, a belt fixing engagement recess 57 is provided between the belt through hole 53 and the belt through hole 55. Furthermore, as shown in Figure 1, the surface of the slider 41 is provided with a female screw portion 59 used to fix an object (not shown) to the slider 41.

[0019] The actuator 1 has a belt 61 that moves the slider 41. As shown in Figure 3, the belt 61 is wound around the drive pulley 15 and the driven pulley 33. As shown in Figure 7, one end of the belt 61 passes through the belt through hole 55 from the bottom side of the slider 41 and is fixed to the surface side of the slider 41, and the other end of the belt 61 also passes through the belt through hole 53 from the bottom side of the slider 41 and is fixed to the surface side of the slider 41. Furthermore, a roller 63 and a pulley 65 are rotatably mounted on the drive unit 11, and the belt 61 is wound around the drive pulley 15, the roller 63, the pulley 65, and the driven pulley 33. The pulley housing 31 is connected to the base 3 via a pulley housing fixing bracket 35 and is slidable relative to the pulley housing fixing bracket 35. A position adjustment bolt 37 is installed, which is screwed into the pulley housing 31 and abuts against the front end side (left end side in Figure 2) of the base 3. By rotating the position adjustment bolt 37, the position of the pulley housing 31 and, consequently, the position of the driven pulley 33 can be adjusted, thereby adjusting the tension of the belt 61. When the tension of the belt 61 is adjusted to a predetermined value, the pulley housing 31 is secured by fixing bolts 39 that are screwed through the pulley housing 31 from both sides in the width direction (up and down direction in Figure 2) and contact the pulley housing fixing bracket 35.

[0020] Furthermore, all of the aforementioned pulleys are timing pulleys with teeth, and all of the aforementioned belts are timing belts with teeth, and the corresponding belts and pulleys are meshed together. As shown in Figure 8(a), one end and the other end of the belt 61 are engaged with the belt fixing engagement recess 57 of the slider 41, and are interposed and fixed between the belt holding members 71, 71 installed on the surface side of the slider 41 and the slider 41. The belt retaining member 71 is fixed by passing fixing bolts 73 through the belt retaining member 71 and screwing them into both sides of the slider 41 in the width direction.

[0021] Furthermore, multiple (for example, two) idler pulleys 81 are rotatably mounted on the base 3. The idler pulleys 81 are located on the bottom side of the slider 41 and inside the belt 61. The idler pulleys 81 are also timing pulleys with teeth formed on them, and are meshed with the belt 61. Furthermore, the idler pulley 81 supports the upper portion of the belt 61 in Figure 3 at two points where the deflection is greater in the direction of movement of the slider 41 of the base 3 (left-right direction in Figure 3), for example, near the positions that divide the range of movement of the slider 41 into three equal parts. Furthermore, as shown in Figure 3, multiple (for example, two) belt back-side rollers 83 are rotatably installed on the bottom side (lower side in Figure 3) of the belt penetration portion 7 of the base 3. The belt back-side rollers 83 are pulleys without teeth and support the toothless side (back side) of the belt 61. The belt back-side rollers 83 also support the lower portion of the belt 61 in Figure 3 at two locations where the deflection is greater in the direction of movement of the slider 41 of the base 3 (left-right direction in Figure 3), for example, near the positions that divide the range of movement of the slider 41 into three equal parts.

[0022] Furthermore, a slider-side gearing portion 91 is provided on the bottom surface of the slider 41. The slider-side gearing portion 91 is a plate-shaped member on which teeth that engage with the idler pulley 81 are formed. Due to the slider-side gearing portion 91, the teeth that engage with the idler pulley 81 are positioned between the belt through holes 53 and 55 where the belt 61 is located on the surface side of the slider 41.

[0023] Furthermore, as shown in Figure 6, notches 93 and 95 are provided at the center of the width direction at both ends of the slider 41 in the direction of movement of the slider-side gear portion 91. The belt through hole 53 is located inside the notch 93, and the belt through hole 55 is located inside the notch 95.

[0024] With this configuration, the ends of the slider-side gear portion 91 in the direction of movement of the slider 41 and a portion of the belt 61 located on the bottom side of the slider 41 overlap in the direction of movement of the slider 41. As shown in Figures 6 and 7, a gap is created at the openings of the belt through holes 53 and 55 because the belt 61 enters the belt through holes 53 and 55. However, since the ends of the slider-side gear portion 91 in the direction of movement of the slider 41 and a portion of the belt 61 located on the bottom side of the slider 41 overlap in the direction of movement of the slider 41 (left-right direction in Figure 6), the idler pulley 81 is geared with the slider-side gear portion 91 even in the gap, and the idler pulley 81 is continuously geared with the belt 61 and the slider-side gear portion 91 on the bottom side of the slider 41.

[0025] As shown in Figure 8(b), the slider-side gear portion 91 is fixed by passing a fixing screw 99 through the slider-side gear portion 91 and screwing it into the bottom of the slider 41.

[0026] Next, the operation according to this first embodiment will be described. When the output shaft 19 of the motor 13 rotates, the drive pulley 15 rotates via the power transmission belt 25. When the drive pulley 15 rotates, the slider 41 moves via the belt 61.

[0027] The belt 61 is supported by idler pulleys 81, 81 to prevent deflection. The idler pulleys 81, 81 are positioned below the track of the slider 41, so that the slider 41 and the idler pulleys 81, 81 do not interfere with each other.

[0028] A slider-side gear engagement portion 91 is provided on the bottom surface of the slider 41. Therefore, even in areas on the bottom surface of the slider 41 where the belt 61 is not positioned, the idler pulleys 81, 81 are engaged with the slider-side gear engagement portion 91, preventing the idler pulleys 81, 81 from free-rotating and preventing them from re-engaging with the belt 61 and colliding with the teeth of the belt 61.

[0029] Furthermore, since the parts of the slider-side gearing portion 91 located on both sides in the direction of movement of the slider 41 and the parts of the belt 61 located on the bottom side of the slider 41 overlap in the direction of movement of the slider 41, when the slider 41 passes the idler pulleys 81, 81, the idler pulleys 81, 81 continuously engage with the slider-side gearing portion 91 from the belt 61. As a result, even at the boundary between the belt 61 and the slider-side gearing portion 91, the idler pulleys 81, 81 do not slip, and the teeth of the idler pulleys 81, 81 do not collide with the teeth of the belt 61 or the slider-side gearing portion 91, and damage to the belt 61 or the slider-side gearing portion 91 is prevented, and noise and vibration are reduced.

[0030] Next, the effects of this embodiment will be described. First, since the idler pulleys 81, 81 are installed on the bottom side of the slider 41, a simple configuration can be used to support the belt 61 while preventing interference with the slider 41, thereby preventing the belt 61 from bending.

[0031] The slider 41 is provided with belt through-holes 53 and 55 on both ends in the direction of travel (left-right direction in Figure 3), connecting the surface side (upper side in Figure 3) and the bottom side (lower side in Figure 3). One end of the belt 61 passes through the belt through-hole 55 from the bottom side (lower side in Figure 3) of the slider 41 and is fixed to the surface side (upper side in Figure 3) of the slider 41. The other end of the belt 61 also passes through the belt through-hole 53 from the bottom side (lower side in Figure 3) of the slider 41 and is fixed to the surface side (upper side in Figure 3) of the slider 41. Therefore, the belt 61 can be fixed to the slider 41 from the surface side of the actuator 1.

[0032] Furthermore, one end and the other end of the belt 61 are engaged with the belt-fixing engagement recess 57 of the slider 41, and are interposed and fixed between the belt-holding members 71, 71 installed on the surface side of the slider 41 and the slider 41, so that the belt 61 and the slider 41 can be securely fixed.

[0033] Furthermore, a slider-side gear portion 91 is provided on the bottom surface of the slider 41, so that even between the belt through holes 53 and 55 where the belt 61 is positioned on the surface side of the slider 41, the idler pulley 81 does not slip and can operate smoothly.

[0034] Furthermore, notches 93 and 95 are provided at the center of the width direction at both ends of the slider 41 in the direction of movement of the slider-side gear portion 91, the belt through hole 53 is located inside the notch 93, and the belt through hole 55 is located inside the notch 95. As a result, the ends of the slider-side gear portion 91 in the direction of movement of the slider 41 and a portion of the belt 61 located on the bottom side of the slider 41 overlap in the direction of movement of the slider 41, allowing the idler pulley 81 to continuously mesh with the belt 61 and the slider-side gear portion 91 on the bottom side of the slider 41. This reduces noise and vibration and allows for smoother operation.

[0035] However, the present invention is not limited to the above-described embodiment. The number of idler pulleys can vary depending on the length of the belt and how easily the belt flexes. It is also conceivable that the slider-side tooth contact portion be integrated with the slider. Furthermore, although the belt-fixing engagement recess is provided integrally with the slider, it is also conceivable that it be provided on a separate component from the slider. Furthermore, the illustrated configuration is just one example, and various other configurations are possible. [Industrial applicability]

[0036] The present invention relates to a belt-driven actuator, and more particularly to one that is designed to properly prevent belt deflection and enable smooth operation with a simple configuration, and is suitable, for example, for actuators used in industrial robots. [Explanation of Symbols]

[0037] 1 Actuator 3 base 5 Base rail 15 Drive pulley 33 Driven pulley 53 Belt through-hole (the part where the belt passes through the slider) 55 Belt through-hole (the part where the belt passes through the slider) 41 Slider 57 Belt fixing engagement recess (belt fixing engagement part, part of belt fixing part) 61 belt 71 Belt holding member (part of the belt fixing part) 73 Fixing bolts (part of the belt fixing section) 81 Idler Pulley 91 Slider side tooth contact area 93 Notch (the portion where the belt and the slider-side teeth meet in the direction of the slider's movement) 95 Notch (the portion where the belt and the slider-side teeth meet in the direction of the slider's movement) 99 Fixing screw (a component that secures the slider-side gear joint to the slider)

Claims

1. Bass and, A drive pulley is rotatably mounted on the base end of the above-mentioned base, A driven pulley is rotatably mounted at the tip of the above base, A belt wound between the above-mentioned drive pulley and the above-mentioned driven pulley, A belt fixing section is provided to secure the belt, and a slider is provided that moves linearly along a rail installed on the base in accordance with the movement of the belt and to which a workpiece can be attached. An idler pulley is installed on the base so as to face the bottom surface of the slider mentioned above, It is equipped with, The actuator is characterized in that the above-mentioned belt is supported by the above-mentioned idler pulley and is fixed to the belt fixing part on the surface side of the slider by passing through the slider from the bottom side of the slider.

2. In the actuator according to claim 1, An actuator characterized in that one end and the other end of the belt are fixed to the belt fixing portion described above.

3. In the actuator according to claim 1, The above belt is a timing belt with teeth, The actuator is characterized in that the above-mentioned drive pulley, driven pulley, and idler pulley are timing pulleys provided with teeth that mesh with the teeth of the belt.

4. In the actuator according to claim 3, The actuator is characterized in that the bottom surface of the slider is provided with a slider-side meshing portion that meshes with the idler pulley between at least one end of the belt through and the other end of the belt through.

5. In the actuator according to claim 4, An actuator characterized in that at least a portion of the parts of the slider-side gear joint that are located on both ends in the direction of movement of the slider and the portion of the belt located on the bottom surface side of the slider are superimposed in the direction of movement of the slider.

6. In the actuator according to claim 4, The actuator is characterized in that the slider-side gear portion is a separate component installed on the slider.

7. In the actuator according to claim 3, The actuator is characterized in that the belt fixing portion is provided with a belt fixing engagement portion into which the teeth of the belt engage.

8. In the actuator according to claim 1, A belt retaining member is installed in the belt fixing section mentioned above. The actuator is characterized in that the belt is interposed between the slider and the belt holding member.

Images