Rotary tool

Abstract

To realize a rotary tool which enables reduction of a vibration risk of the rotary tool when a motor shaft rotates.SOLUTION: In a rotary tool, when seen through from a rotation axis direction of a motor shaft, a first circle defined by an outer edge of a first adjustment portion and a second circuit defined by an outer edge of a second adjustment portion are inscribed in a virtual circle centered on a rotation axis of the motor shaft.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to rotary tools. [Background technology]

[0002] Patent document 1 discloses a hand sander in which the balance weight has two equal adjustable compensation members, the centers of gravity of which are located symmetrically with respect to an axis of symmetry connecting the axis of the shaft driven by the motor and the axis of eccentric rotation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 1-135460 Summary of the Invention [Problem to be solved by the invention]

[0004] In the hand sander disclosed in Patent Document 1, there are no restrictions on the relationship between the motor-driven shaft and the balance weight, making it difficult to adjust the weight of the balance weight, etc. As a result, it is difficult to reduce the vibration of the hand sander when the motor-driven shaft rotates. [Means for solving the problem]

[0005] A rotary tool according to one aspect of the present disclosure includes a housing that houses a motor shaft extending in an up-down direction and a motor that enables the motor shaft to rotate, a pad located below the housing, and an eccentric member located between the motor and the pad, which is eccentric with respect to the rotation axis of the motor shaft and can move in a circular locus as the motor shaft rotates.

[0006] Furthermore, the rotary tool according to one aspect of the present disclosure includes an adjustment member that is located in a path that can transmit rotation of the motor shaft to the eccentric member and that can reduce vibrations that occur when the motor shaft rotates.

[0007] Furthermore, in a rotary tool according to one embodiment of the present disclosure, the adjustment member has a first adjustment portion having an arc-shaped outer edge and a second adjustment portion located above the first adjustment portion and having an arc-shaped outer edge, and when viewed from the direction of the rotational axis of the motor shaft, a first circle defined by the outer edge of the first adjustment portion and a second circle defined by the outer edge of the second adjustment portion are inscribed in a virtual circle centered on the rotational axis of the motor shaft. [Effects of the Invention]

[0008] According to one aspect of the present disclosure, a rotary tool capable of reducing the risk of vibration of the rotary tool when the motor shaft rotates can be realized. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a rotary tool according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view of the motor shaft as seen from above. [Figure 3] 1 is a perspective view of a rotary tool according to an embodiment of the present disclosure, viewed from the direction of a rotation axis of a motor shaft. [Figure 4] 1A and 1B are diagrams illustrating the principle of achieving both static balance and even balance in a rotary tool when a motor shaft rotates. [Figure 5] 4 is a perspective view of the adjustment members of a first adjustment portion and a second adjustment portion different from those in FIG. 3, as viewed from below. FIG. [Figure 6] 6A and 6B are diagrams of the first adjustment portion and the second adjustment portion shown in FIG. 5. [Figure 7] 1 is a perspective view showing a schematic configuration of a rotary tool according to an embodiment of the present disclosure. [Figure 8] 8 is a perspective view showing a state in which a housing cover is removed from the rotary tool shown in FIG. 7.

[0023] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes an embodiment of the present disclosure. For convenience of explanation, the same reference numerals are used to designate components having the same functions as those previously described, and the description thereof may not be repeated.

[0011] Fig. 1 is a cross-sectional view showing a schematic configuration of a rotary tool 101 according to an embodiment of the present disclosure. Fig. 1 is a cross-sectional view passing through and parallel to a central axis 7 of a motor shaft 1. The rotary tool 101 may include a motor shaft 1, a motor 2, a housing 3, a pad 4, an eccentric member 5, and an adjustment member 6.

[0012] The motor shaft 1 extends in the vertical direction. The vertical direction may refer to the vertical direction of the rotary tool 101. The upper and lower sides of the rotary tool 101 may refer to the upper and lower sides, respectively, of the rotary tool 101 in an upright position, as shown in FIG. 7 described later. The motor 2 may be capable of rotating the motor shaft 1. The motor shaft 1 and the motor 2 may be housed in a housing 3.

[0013] The pad 4 may be located below the housing 3. The pad 4 may be located so as to protrude from the lower side of the housing 3. The eccentric member 5 may be located between the motor 2 and the pad 4, for example, in the vertical direction. The eccentric member 5 may be eccentric with respect to the rotation axis 7 of the motor shaft 1.

[0014] In the embodiment of the present disclosure, when viewed from the direction of the rotating shaft 7 of the motor shaft 1, the eccentric member 5 is eccentric with respect to the rotating shaft 7 of the motor shaft 1. More specifically, when viewed from the direction of the rotating shaft 7 of the motor shaft 1, the center of the eccentric member 5 (axis center 17 of the eccentric member 5) is offset from the rotating shaft 7 of the motor shaft 1. Note that in the embodiment of the present disclosure, the rotating shaft 7 of the motor shaft 1 and the axis center 17 of the eccentric member 5 both extend in the vertical direction.

[0015] The eccentric member 5 may be capable of circular locus motion due to the rotation of the motor shaft 1. More specifically, the axis 17 of the eccentric member 5 may be capable of circular motion around the rotation axis 7 of the motor shaft 1. The circular motion of the axis 17 of the eccentric member 5 is not limited to a perfect circle, and may be, for example, an ellipse. The circular locus motion of the eccentric member 5 causes the pad 4 to move circularly. The rotary tool 101 can polish and / or remove rust from an object that comes into contact with the pad 4 by the circular locus motion of the pad 4.

[0016] The adjustment member 6 may be located on a path that can transmit the rotation of the motor shaft 1 to the eccentric member 5. The adjustment member 6 may be capable of reducing vibrations that occur when the motor shaft 1 rotates. Specifically, being able to reduce vibrations that occur when the motor shaft 1 rotates means being able to reduce wobbling of the motor shaft 1 and reduce large vibrations of the rotary tool 101 itself when the motor shaft 1 rotates.

[0017] The adjustment member 6 may be, for example, a weight positioned at a desired position with a desired weight distribution for the purpose of adjusting the static balance and couple balance of the rotating tool 101 when the motor shaft 1 rotates. Because the eccentric member 5 is eccentric with respect to the rotation axis 7 of the motor shaft 1, the static balance and couple balance of the rotating tool 101 when the motor shaft 1 rotates must take into account the amount of eccentricity. The adjustment member 6 is a member that functions to adjust the imbalance in the static balance and couple balance caused by the eccentricity of the eccentric member 5.

[0018] As long as the member has such a function, it is not limited to a specific configuration, and may be, for example, a weight positioned at a desired position with a desired weight distribution, as described above. For example, the weight positioned with a desired weight distribution may be configured such that the axis of adjustment member 6 is located on the opposite side of axis 17 of eccentric member 5 with respect to rotation axis 7 of motor shaft 1.

[0019] Specifically, when the adjustment member 6 is a homogeneous member, the volume of the portion of the adjustment member 6 located on the side of the axis 17 of the eccentric member 5 relative to the rotating shaft 7 of the motor shaft 1 may be smaller than the volume of the portion located on the opposite side of the axis 17 of the eccentric member 5 relative to the rotating shaft 7 of the motor shaft 1.

[0020] As another specific example, the specific gravity of the components constituting the portion of the adjustment member 6 located on the side of the axis 17 of the eccentric member 5 relative to the rotating shaft 7 of the motor shaft 1 is smaller than the specific gravity of the components constituting the portion located on the opposite side of the axis 17 of the eccentric member 5 relative to the rotating shaft 7 of the motor shaft 1.

[0021] Static balance may refer to the balance that corresponds to the equilibrium when rotational motion is stopped. Even balance (dynamic balance) may refer to the balance that corresponds to the equilibrium during rotational motion, assuming that static balance is achieved.

[0022] The adjustment member 6 may connect the motor shaft 1 and the eccentric member 5. In other words, the adjustment member 6 may be separate from the motor shaft 1. This makes it easier to adjust the weight of the adjustment member 6, thereby realizing the rotary tool 101 that can reduce the risk of vibration of the rotary tool 101 when the motor shaft 1 rotates. In the embodiment of the present disclosure, the adjustment member 6 is connected at its upper end to the lower end of the motor shaft 1.

[0023] The eccentric member 5 may be connected to the adjustment member 6 on its upper side and to the pad 4 on its lower side. In other words, the adjustment member 6 may be located above the eccentric member 5 and connected to the eccentric member 5, and the pad 4 may be located below the eccentric member 5 and connected to the eccentric member 5.

[0024] As a result, the adjustment member 6, eccentric member 5, and pad 4 are connected in this order from top to bottom, making it easy to transmit the rotational driving force of the motor shaft 1 to the pad 4 in the order of the adjustment member 6, eccentric member 5, and pad 4.

[0025] The motor shaft 1 may be connected to the adjustment member 6 at its lower side. In other words, the adjustment member 6 may be located below the motor shaft 1 and connected to it. This allows the motor shaft 1 and adjustment member 6 to be connected in this order from top to bottom, making it easy to transmit the rotational driving force of the motor shaft 1 to the adjustment member 6. In the embodiment of the present disclosure, the lower end of the motor shaft 1 has a recess 62. The upper end of the adjustment member 6 has a protrusion 63.

[0026] 1, the protrusion 63 may be fitted into the recess 62. Furthermore, a cross section perpendicular to the rotation axis 7 of the motor shaft 1 may include the bearing (ball bearing 57), the recess 62, and the protrusion 63. In other words, the bearing (ball bearing 57), the recess 62, and the protrusion 63 are located at the same height in the vertical direction.

[0027] 2 is a perspective view of motor shaft 1 as seen from above. Motor shaft 1 may have a groove 8 on its upper side that can engage with fastener 51. This allows fastener 51 to be inserted into groove 8 through hole 52 formed to expose the upper side of motor shaft 1, and motor shaft 1 can be rotated by fastener 51. As a result, fastener 51 can easily be used to fix motor shaft 1 to a member (adjustment member 6) connected to motor shaft 1.

[0028] In the embodiment of the present disclosure, a groove 8 is provided at the upper end of the motor shaft 1. Furthermore, the groove 8 may overlap with the rotation shaft 7 of the motor shaft 1 when viewed from the direction of the rotation shaft 7 of the motor shaft 1.

[0029] 2 further illustrates fastener 51. An example of fastener 51 is a screwdriver. If fastener 51 is a Phillips head screwdriver, groove 8 may have a Phillips head shape, and if fastener 51 is a flat head screwdriver, groove 8 may have a flat head shape.

[0030] The rotary tool 101 may include a bearing 9. The bearing 9 may be located above the motor 2. The bearing 9 may be in contact with the motor shaft 1. In the vertical direction, the upper end 10 of the bearing 9 may be at the same position as the upper end 11 of the motor shaft 1, or may be located above the upper end 11 of the motor shaft 1. This prevents the motor shaft 1 from protruding above the bearing 9, making it possible to reduce the width of the rotary tool 101 in the vertical direction.

[0031] The adjustment member 6 may have a first adjustment portion 12 having an arc-shaped outer edge and a second adjustment portion 13 having an arc-shaped outer edge. The second adjustment portion 13 may be located above the first adjustment portion 12.

[0032] 3 is a perspective view of the rotary tool 101 from the direction of the rotation axis 7 of the motor shaft 1. When viewed from the direction of the rotation axis 7 of the motor shaft 1, a first circle 15 defined by the outer edge of the first adjustment portion 12 and a second circle 16 defined by the outer edge of the second adjustment portion 13 may be inscribed in an imaginary circle 14 centered on the rotation axis 7 of the motor shaft 1.

[0033] The first circle 15 may define the outer edge of the first adjustment region 12. The second circle 16 may define the outer edge of the second adjustment region 13. Both the first circle 15 and the second circle 16 may be inscribed in the imaginary circle 14.

[0034] In the embodiment of the present disclosure, the outer edges of first adjustment portion 12 and second adjustment portion 13 are arc-shaped of a perfect circle except for the portions where notches 22 are provided. Therefore, imaginary circle 14 in the embodiment of the present disclosure is defined by the arc-shaped outer edges of the above-mentioned perfect circle.

[0035] In an embodiment of the present disclosure, since the radius of the virtual circle 14 is fixed and the first circle 15 and the second circle 16 are inscribed in the virtual circle 14, both static balance and even balance can be achieved in the rotating tool 101 when the motor shaft 1 rotates by setting a minimum of three variables, thereby realizing a rotating tool 101 that can reduce the risk of vibration of the rotating tool 101 when the motor shaft 1 rotates.

[0036] FIG. 4 is a diagram illustrating the principle of achieving both static balance and couple balance in rotary tool 101 when motor shaft 1 rotates. FIG. 4 includes explanatory images 1001 and 1002. Explainatory image 1001 is a perspective view of rotary tool 101, different from that of FIG. 3, viewed from the direction of rotation axis 7 of motor shaft 1. Explainatory image 1002 is a perspective front view of adjustment member 6 and eccentric member 5 connected to adjustment member 6, viewed from the direction perpendicular to rotation axis 7.

[0037] The three variables required to achieve both static balance and even balance in the rotary tool 101 when the motor shaft 1 rotates may be as follows (a) to (c).

[0038] (a) Outer diameter P1 of the first adjustment portion 12 (b) Outer diameter P2 of the second adjustment portion 13 (c) Thickness P3 of the second adjustment portion 13 C1 is the distance between the rotation axis 7 of the motor shaft 1 and the center 18 of the first circle 15. C2 is the distance between the rotation axis 7 of the motor shaft 1 and the center 19 of the second circle 16. C3 is the sum of the thickness of the first adjustment portion 12 and the thickness of the second adjustment portion 13.

[0039] Since the first circle 15 is inscribed in the imaginary circle 14, if the radius of the imaginary circle 14 is fixed, C1 is a function of P1 above. Also, since the second circle 16 is inscribed in the imaginary circle 14, if the radius of the imaginary circle 14 is fixed, C2 is a function of P2 above.

[0040] When the rotary tool 101 is viewed from the direction of the rotary shaft 7 of the motor shaft 1, the following conditions (1) and (2) may be satisfied.

[0041] (1) The outer shape of the first adjustment portion 12 and the outer shape of the second adjustment portion 13 are shown.

[0042] (2) The rotation axis 7 of the motor shaft 1 is indicated by an imaginary point 53 .

[0043] In the embodiment of the present disclosure, as shown in FIG. 4, when viewed from the direction of the rotation axis 7 of the motor shaft 1, the axis 17 of the eccentric member 5 is indicated by an imaginary point 54.

[0044] Since both the first circle 15 and the second circle 16 are inscribed in the imaginary circle 14, once the values ​​of the variables P1 and P2 are determined, the amount of eccentricity of the axis 17 of the eccentric member 5 relative to the rotating shaft 7 of the motor shaft 1 can be determined. Based on the amount of eccentricity and the value of the variable P3, both static balance and even balance can be achieved in the rotating tool 101 when the motor shaft 1 rotates.

[0045] In addition, in the embodiment of the present disclosure, the virtual circle 14 is a single circle. That is, regardless of whether C1 or C2 is defined, the radius of the virtual circle 14 is the same, and therefore, by adjusting P1 and P2, the sizes of the first adjustment part 12 and the second adjustment part 13 can be controlled. As a result, it becomes easier to control the weight distribution of the adjustment member 6, and the risk of the rotary tool 101 vibrating significantly when the motor shaft 1 rotates can be reduced.

[0046] The first adjustment member 12 may adjust the static balance, and the second adjustment member 13 may adjust the even balance. When viewed from the direction of the rotation axis 7 of the motor shaft 1, the center 18 of the first circle 15 may be located on the opposite side of the axis 17 of the eccentric member 5 with respect to the rotation axis 7 of the motor shaft 1. This makes it easy to balance the entire rotary tool 101 by adjusting the weight distribution of the eccentric member 5 and the first adjustment member 12, and therefore makes it easy to adjust the static balance.

[0047] In addition, being located on the opposite side of the axis 17 of the eccentric member 5 with respect to the rotation axis 7 of the motor shaft 1 is not limited to being 180° rotationally symmetric with respect to the rotation axis 7 of the motor shaft 1, but may be within a range that allows for manufacturing errors.

[0048] Fig. 5 is a perspective view of the adjustment member 6 of the first adjustment portion 12 and the second adjustment portion 13, different from those in Fig. 3, as viewed from below. Fig. 6 is a view of the first adjustment portion 12 and the second adjustment portion 13 shown in Fig. 5. Although Fig. 6 shows the first adjustment portion 12 and the second adjustment portion 13 individually, the viewpoint in Fig. 6 is the same as the viewpoint in a view seen from the direction of the rotation shaft 7 of the motor shaft 1. In other words, Fig. 6 is a view of the first adjustment portion 12 and the second adjustment portion 13 shown in Fig. 5 as seen from the direction of the rotation shaft 7 of the motor shaft 1.

[0049] When viewed from the direction of the rotating shaft 7 of the motor shaft 1, at least one of the first adjustment part 12 and the second adjustment part 13 may have a semicircular outer edge. The semicircular arc defining the semicircular outer edge is indicated by semicircular arc 20.

[0050] When viewed from the direction of rotating shaft 7 of motor shaft 1, at least one of first adjustment portion 12 and second adjustment portion 13 may have a notch 22 formed on a straight line 21 that passes through rotating shaft 7 of motor shaft 1 and axis 17 of eccentric member 5. By forming notch 22, it is possible to easily align adjustment portion 6 with rotating shaft 7 of motor shaft 1 and axis 17 of eccentric member 5 using notch 22 as a landmark.

[0051] In the above, the entire outer edge excluding the portion where the notch 22 is formed may be arc-shaped. The arc defining the arc-shaped outer edge is indicated by arc 23. In such a case, machining on a lathe is easy, and machining efficiency is likely to be improved. From the viewpoint of facilitating machining on a lathe, it is desirable that the arc shape be a perfect circle.

[0052] When viewed from the direction of the rotating shaft 7 of the motor shaft 1, at least one of the first adjustment part 12 and the second adjustment part 13 may be circular. Here, the circular shape refers to the case where the first adjustment part 12 or the second adjustment part 13 differs from the first adjustment part 12 and the second adjustment part 13 in this embodiment in that it does not have the notch 22, and the overall shape of either the first adjustment part 12 or the second adjustment part 13 is a perfect circle. The circumference of the circle that defines this circular shape is indicated by circumference 24.

[0053] First circle 15 and second circle 16 are not limited to being perfect circles and may be, for example, ellipses. In other words, the outer shape of first adjustment portion 12 and the outer shape of second adjustment portion 13 may be any shape defined by a circle, i.e., they are not limited to being shapes defined by perfect circles and may be, for example, shapes defined by ellipses.

[0054] The rotary tool 101 may include a housing cover 55, a stator assembly 56, a ball bearing 57, a fan 58, a needle bearing 59, and a ball bearing 60. The housing cover 55 may cover an opening of the housing 3. The stator assembly 56 may secure the motor 2. The ball bearing 57 may support the rotating motor shaft 1. The fan 58 may cool the components housed in the housing 3. The needle bearing 59 and the ball bearing 60 may each support the rotating eccentric member 5.

[0055] The pad 4 and the eccentric member 5 may be fixed to each other by screws. The motor shaft 1 and the adjustment member 6 may be fixed to each other by screws. More specifically, the recess 62 of the motor shaft 1 and the protrusion 63 of the adjustment member 6 may each be provided with a screw groove.

[0056] Fig. 7 is a perspective view showing a schematic configuration of the rotary tool 101. Fig. 8 is a perspective view showing a state in which the housing cover 55 is removed from the rotary tool 101. In a state in which the housing cover 55 is removed from the rotary tool 101, the upper side of the motor shaft 1, specifically the groove 8, may be exposed from the hole 52.

[0057] As shown in explanatory image 1001 in Figure 4, when viewed from the direction of the rotating shaft 7 of the motor shaft 1, the distance C1 between the center 18 of the first circle 15 and the rotating shaft 7 of the motor shaft 1, and the distance C2 between the center 19 of the second circle 16 and the rotating shaft 7 of the motor shaft 1 may be larger than the distance CA between the axis 17 of the eccentric member 5 and the rotating shaft 7 of the motor shaft 1.

[0058] The rotary tool 101 can also be interpreted as having the following configuration.

[0059] The adjustment member 6 may have a third portion 61 located above the second adjustment portion 13 and having an arc-shaped outer edge. The motor shaft 1 and the adjustment member 6 may be connected at the third portion 61.

[0060] The adjustment member 6 may be arranged in the order of the protrusion 63, the third portion 61, the second portion 13, and the first portion 12 from top to bottom. The outer diameter of the protrusion 63 may be smaller than the outer diameter of the third portion 61. The outer diameter of the third portion 61 may be smaller than the outer diameter of the first portion 12 or the second portion 13. In addition, a cross section of the motor shaft 1 perpendicular to the rotation axis 7 and including the third portion 61 may include the eccentric member 5.

[0061] In other words, the third portion 61 is located at the same height as the eccentric member 5 in the vertical direction. The third portion 61 may be in contact with a bearing (ball bearing 57). More specifically, the upper end of the third portion 61 may be in contact with a lower end of the bearing (ball bearing 57).

[0062] The first adjustment portion 12, the second adjustment portion 13, and the third portion 61 may be integrally formed. The specific gravity of the first adjustment portion 12, the specific gravity of the second adjustment portion 13, and the specific gravity of the third portion 61 may be the same.

[0063] In an embodiment of the present disclosure, the rotary tool 101 may include a housing 3 that houses a motor shaft 1 extending in the vertical direction and a motor 2 that rotates the motor shaft 1. The rotary tool 101 may include a pad 4 located below the housing 3. The rotary tool 101 may include an eccentric member 5 located between the motor 2 and the pad 4 and having an axis 17 that is eccentric with respect to the rotation axis 7 of the motor shaft 1. The rotary tool 101 may include an adjustment member (coupling member) 6 that connects the motor shaft 1 and the eccentric member 5. The adjustment member 6 may include a first adjustment portion (first part) 12 that has an arc-shaped outer edge, and a second adjustment portion (second part) 13 that is located above the first adjustment portion 12 and has an arc-shaped outer edge.

[0064] In an embodiment of the present disclosure, the rotary tool 101 may include a housing 3 that houses a motor shaft 1 extending in the vertical direction and a motor 2 that rotates the motor shaft 1. The rotary tool 101 may include a pad 4 located below the housing 3. The rotary tool 101 may include an eccentric member 5 located between the motor 2 and the pad 4 and eccentric with respect to a rotation axis 7 of the motor shaft 1. The rotary tool 101 may include an adjustment member (intermediate member) 6 located between the motor shaft 1 and the eccentric member 5. The adjustment member 6 may include a first adjustment portion (first part) 12 having an arc-shaped outer edge, and a second adjustment portion (second part) 13 located above the first adjustment portion 12 and also having an arc-shaped outer edge. When viewed from the direction of the rotation axis 7 of the motor shaft 1, a first circle 15 defining the outer edge of the first adjustment portion 12 and a second circle 16 defining the outer edge of the second adjustment portion 13 may be inscribed in a virtual circle 14 centered on the rotation axis 7 of the motor shaft 1.

[0065] (summary) A rotary tool according to a first aspect of the present disclosure comprises a housing that houses a motor shaft extending in an up-down direction and a motor that rotates the motor shaft; a pad located below the housing; an eccentric member located between the motor and the pad, eccentric with respect to the rotational axis of the motor shaft, and capable of moving in a circular locus as the motor shaft rotates; and an adjustment member located on a path that can transmit the rotation of the motor shaft to the eccentric member and that can reduce vibration when the motor shaft rotates. The adjustment member has a first adjustment portion having an arc-shaped outer edge, and a second adjustment portion located above the first adjustment portion and also having an arc-shaped outer edge. When viewed from the direction of the rotational axis of the motor shaft, a first circle defined by the outer edge of the first adjustment portion and a second circle defined by the outer edge of the second adjustment portion are inscribed in a virtual circle centered on the rotational axis of the motor shaft.

[0066] A rotary tool according to aspect 2 of the present disclosure is the same as that of aspect 1, wherein the first adjustment portion adjusts static balance and the second adjustment portion adjusts even balance, and when viewed from the direction of the rotational axis of the motor shaft, the center of the first circle is located on the opposite side of the axis of the eccentric member from the rotational axis of the motor shaft.

[0067] In a rotary tool according to aspect 3 of the present disclosure, in aspect 1 or 2, when viewed from the direction of the rotational axis of the motor shaft, at least one of the first adjustment portion and the second adjustment portion has a semicircular arc-shaped outer edge.

[0068] In the rotary tool according to aspect 4 of the present disclosure, in any of aspects 1 to 3, when viewed from the direction of the rotational axis of the motor shaft, at least one of the first adjustment portion and the second adjustment portion has a notch formed on a straight line passing through the rotational axis of the motor shaft and the axis of the eccentric member.

[0069] A rotary tool according to a fifth aspect of the present disclosure is the rotary tool of the fourth aspect, wherein the entire outer edge except for the portion where the notch is formed is arc-shaped.

[0070] A rotary tool according to aspect 6 of the present disclosure is one of aspects 1 to 3, in which at least one of the first adjustment portion and the second adjustment portion is circular when viewed from the direction of the rotational axis of the motor shaft.

[0071] In the rotary tool according to aspect 7 of the present disclosure, in aspect 1, when viewed from the direction of the rotational axis of the motor shaft, the distance between the center of the first circle and the rotational axis of the motor shaft, and the distance between the center of the second circle and the rotational axis of the motor shaft are greater than the distance between the axis of the eccentric member and the rotational axis of the motor shaft.

[0072] A rotary tool according to an eighth aspect of the present disclosure is the rotary tool of any one of the first to seventh aspects, wherein the adjustment member connects the motor shaft and the eccentric member.

[0073] A ninth aspect of the present disclosure relates to the rotary tool of the eighth aspect, wherein the eccentric member is connected to the adjustment member at an upper side and to the pad at a lower side.

[0074] A rotary tool according to a tenth aspect of the present disclosure is the rotary tool of the eighth or ninth aspect, wherein the motor shaft is connected to the adjustment member at a lower side thereof.

[0075] A rotary tool according to an eleventh aspect of the present disclosure is the rotary tool of any one of the eighth to tenth aspects, wherein the motor shaft has a groove on the upper side that can engage with a fastener.

[0076] A rotary tool according to aspect 12 of the present disclosure is, in any of aspects 8 to 11, provided with a bearing located above the motor and in contact with the motor shaft, and in the vertical direction, the upper end of the bearing is at the same position as the upper end of the motor shaft or is located above the upper end of the motor shaft.

[0077] A rotary tool according to aspect 13 of the present disclosure comprises a housing that houses a motor shaft extending in an up-down direction and a motor that enables the motor shaft to rotate, a pad located below the housing, an eccentric member located between the motor and the pad and eccentric with respect to the rotation axis of the motor shaft, and an intermediate member located between the motor shaft and the eccentric member, wherein the intermediate member has a first portion having an arc-shaped outer edge and a second portion located above the first portion and also having an arc-shaped outer edge, and when viewed from the direction of the rotation axis of the motor shaft, a first circle defined by the outer edge of the first portion and a second circle defined by the outer edge of the second portion are inscribed in a virtual circle centered on the rotation axis of the motor shaft.

[0078] The invention according to the present disclosure has been described above based on the drawings and examples. However, the invention according to the present disclosure is not limited to the above-described embodiments. In other words, the invention according to the present disclosure can be modified in various ways within the scope of the present disclosure, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the invention according to the present disclosure. In other words, it should be noted that a person skilled in the art can easily make various modifications or corrections based on the present disclosure. It should also be noted that these modifications or corrections are included in the scope of the present disclosure. [Explanation of symbols]

[0079] 1 Motor shaft 2 motors 3. Housing 4 pads 5 Eccentric member 6 Adjustment member 7 Motor shaft rotation axis 8 grooves 9 Bearings 10 Upper end of bearing 11 Upper end of motor shaft 12 1st adjustment part (1st part) 13 Second adjustment part (second part) 14 Virtual Circle 15 1st Yen 16 Second Circle 17 Axis of eccentric member 18 Center of the First Circle 19 Center of the Second Circle 20 semicircular arcs 21 straight line 22 Cutout 23 Arc 24 circumference 101 Rotary Tools

Claims

1. a housing that houses a motor shaft extending in the vertical direction and a motor that rotates the motor shaft; a pad located below the housing; an eccentric member located between the motor and the pad, eccentric with respect to a rotation axis of the motor shaft, and capable of circular locus movement due to rotation of the motor shaft; an adjustment member that is located on a path that can transmit the rotation of the motor shaft to the eccentric member and that can reduce vibrations that occur when the motor shaft rotates; The adjustment member is a first adjustment portion having an arc-shaped outer edge; a second adjustment portion located above the first adjustment portion and having an arc-shaped outer edge, A rotary tool, wherein when viewed from the direction of the rotational axis of the motor shaft, a first circle defined by the outer edge of the first adjustment portion and a second circle defined by the outer edge of the second adjustment portion are inscribed in a virtual circle centered on the rotational axis of the motor shaft.

2. The first adjustment portion adjusts static balance, The second adjustment portion adjusts the couple balance, The rotary tool according to claim 1 , wherein when viewed from the direction of the rotation axis of the motor shaft, the center of the first circle is located on an opposite side of the axis of the eccentric member with respect to the rotation axis of the motor shaft.

3. The rotary tool according to claim 1 , wherein at least one of the first adjustment portion and the second adjustment portion has a semicircular arc-shaped outer edge when viewed from the rotation axis direction of the motor shaft.

4. 2. The rotary tool according to claim 1, wherein, when viewed from the direction of the rotational axis of the motor shaft, at least one of the first adjustment portion and the second adjustment portion has a notch formed on a straight line passing through the rotational axis of the motor shaft and the axis of the eccentric member.

5. The rotary tool according to claim 4 , wherein the entire outer edge except for the portion where the notch is formed is arc-shaped.

6. The rotary tool according to claim 1 , wherein at least one of the first adjustment portion and the second adjustment portion has a circular shape when viewed from the direction of the rotation axis of the motor shaft.

7. 2. The rotary tool according to claim 1, wherein, when viewed from the direction of the rotational axis of the motor shaft, a distance between the center of the first circle and the rotational axis of the motor shaft and a distance between the center of the second circle and the rotational axis of the motor shaft are larger than a distance between the axis of the eccentric member and the rotational axis of the motor shaft.

8. The rotary tool according to claim 1 , wherein the adjustment member connects the motor shaft and the eccentric member.

9. The rotary tool according to claim 8 , wherein the eccentric member is connected to the adjustment member at an upper side and to the pad at a lower side.

10. The rotary tool according to claim 8 , wherein the motor shaft is connected to the adjustment member at a lower side thereof.

11. The rotary tool of claim 8 , wherein the motor shaft has a groove on an upper side thereof that is engageable with a fastener.

12. a bearing located above the motor and in contact with the motor shaft; The rotary tool according to claim 8 , wherein an upper end of the bearing is located at the same position as an upper end of the motor shaft or is located higher than an upper end of the motor shaft in the vertical direction.

13. a housing that houses a motor shaft extending in the vertical direction and a motor that rotates the motor shaft; a pad located below the housing; an eccentric member located between the motor and the pad and eccentric to a rotation axis of the motor shaft; an intermediate member located between the motor shaft and the eccentric member, The intermediate member is a first portion having an arcuate outer edge; a second portion located above the first portion and having an arcuate outer edge, When viewed from the direction of the rotation axis of the motor shaft, a first circle defined by the outer edge of the first part and a second circle defined by the outer edge of the second part are inscribed in a virtual circle centered on the rotation axis of the motor shaft.

Images