Actuator device

Abstract

To improve stability of output in consideration of internal pressure change in accordance with operation of an actuator device while securing internal airtightness.SOLUTION: An actuator device is constituted by a plurality of sections, and a plurality of sealed spaces where internal pressure is changed in accordance with the operation of the actuator device is constituted by at least a part of the plurality of sections. At least a part of the plurality of sections includes a ventilation portion for communicating at least two of the plurality of sealed spaces.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an actuator device.

Background Art

[0002] Recently, electric actuators having a configuration that converts the rotational force of a motor into a linear thrust force and operates have become widespread.

[0003] In an electric actuator, a control amount is determined based on an input. However, depending on the operating state thereof, it is necessary to use different control amounts in order to output the same thrust force. In other words, even with the same control amount, different thrust forces may be output depending on the operating situation of the electric actuator. One of the factors for this is the change in the internal pressure of the sealed space provided in the electric actuator. Conventionally, in an electric actuator, a sealed space is formed around the drive unit in order to ensure airtightness for the purpose of waterproofing, dustproofing, etc. As the electric actuator operates, the internal pressure of the sealed space within the electric actuator changes, and the output is affected according to the degree thereof.

[0004] For example, Patent Document 1 discloses a configuration in which a ventilation portion is provided in an actuator and the ventilation portion is opened according to a change in the internal pressure to suppress the change in the internal pressure. Further, Patent Document 2 discloses a configuration for improving the airtightness of an actuator and preventing grease leakage while discharging the internal pressure of the casing.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In actuator devices, as in Patent Document 1 and Patent Document 2, configurations for improving the stability during thrust output while ensuring internal airtightness have been studied, but there is still room for further improvement.

[0007] In view of the above problems, an object of the present invention is to suppress the influence of internal pressure changes associated with the operation of an actuator device while ensuring internal airtightness, and to improve the stability of the output.

Means for Solving the Problems

[0008] To solve the above problems, the present invention has the following configuration. That is, an actuator device composed of a plurality of parts, At least a part of the plurality of parts forms a plurality of sealed spaces in which the internal pressure changes in response to the operation of the actuator device, At least a part of the plurality of parts is provided with a ventilation part for communicating at least two of the plurality of sealed spaces.

Effects of the Invention

[0009] According to the present invention, it is possible to suppress the influence of internal pressure changes associated with the operation of the actuator device while ensuring internal airtightness, and to improve the stability of the output.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings and the like. Note that the embodiments described below are one embodiment for explaining the present invention and are not intended to limit the interpretation of the present invention, and not all the configurations described in each embodiment are essential configurations for solving the problems of the present invention. Also, in each drawing, the same reference numerals are assigned to the same components to indicate the correspondence.

[0012] <First Embodiment> Hereinafter, the first embodiment of the present invention will be described.

[0013] [Internal Pressure Change in a Sealed Space] First, with reference to FIG. 11, the change in the internal pressure of the sealed space provided in the actuator device in the conventional configuration will be described. Note that, for comparison with the configuration according to the present embodiment described later, a conventional example in which parts other than the characteristic parts of the present embodiment are made common is shown. Also, for simplicity of explanation, only the parts required for comparison with the configuration according to the present embodiment are illustrated.

[0014] FIG. 11 is a schematic cross-sectional view of an electric actuator 1100 as a conventional example. The electric actuator 1100 includes a housing 1101, an output shaft 1102, a linear motion component 1103, a linear motion component nut 1104, an output shaft support member 1105, a motor 1106, a connecting portion 1107, gears 1108, 1109, 1110, a gear fixing nut 1111, a bearing 1112, and a bearing fixing housing 1113. The housing 1101 is a casing of the electric actuator 1100, and each of the above-described parts is installed inside. The output shaft 1102 is connected to the linear motion component 1103 via the linear motion component nut 1104 that operates as a connecting mechanism, and outputs a thrust force by linear motion in a predetermined direction. The output shaft 1102 is supported by the output shaft support member 1105 with respect to the housing 1101.

[0015] The linear motion component 1103 is configured as a screw shaft having a spiral groove (not shown) formed on its outer peripheral surface. Also, a spiral groove (not shown) is formed on the inner peripheral surface of the linear motion component nut 1104. Using the groove of the linear motion component 1103 and the groove of the linear motion component nut 1104 as rolling surfaces, a spherical rolling element (not shown) is installed between them so as to be rollable. A lubricant (such as lubricating oil or grease) may be supplied around the rolling element and the groove by an arbitrary lubrication method so that these frictions are reduced. When the linear motion component 1103 rotates, the rotation is converted into a linear motion (piston motion) via the linear motion component nut 1104, and a thrust force by the output shaft 1102 is output. The moving direction (extension direction or contraction direction) of the output shaft 1102 is defined according to the rotation direction of the motor 1106.

[0016] The motor 1106 performs a rotational operation based on an instruction from an external device (not shown). The rotation of the motor 1106 is transmitted to the gear 1108 via the connecting part 1107. The gears 1108, 1109, and 1110 each have a plurality of teeth, and the teeth of each gear mesh and rotate, thereby converting the rotation of the motor 1106 into a predetermined rotation and transmitting it to the linear motion part 1103. The gear 1110 is fixed to the linear motion part 1103 by a gear fixing nut 1111. The bearing 1112 supports the linear motion part 1103 so that it can rotate based on the rotational force transmitted through the gear 1110. Also, the bearing 1112 is fixed to the housing 1101 by a bearing fixing housing 1113 which is a fixing member. Here, an example of an angular ball bearing is shown as the bearing 1112, but other types of bearings may be used.

[0017] Also, a plurality of sealed spaces are formed inside the housing 1101. Here, four sealed spaces will be described as an example. The sealed spaces 1114, 1115, and 1116 are spaces whose internal pressure changes as the electric actuator 1100 operates. On the other hand, the sealed space 1117 is a space whose internal pressure does not change as the electric actuator 1100 operates.

[0018] The sealed space 1114 is formed inside the output shaft 1102 by the output shaft 1102, the linear motion part 1103, and the linear motion part nut 1104. The sealed space 1115 is formed by the housing 1101, the output shaft 1102, and the output shaft support member 1105. The sealed space 1116 is formed by the housing 1101, the output shaft 1102, the linear motion part 1103, the linear motion part nut 1104, the output shaft support member 1105, the bearing 1112, and the bearing fixing housing 1113.

[0019] As described above, the rotational force of the motor 1106 is transmitted to the output shaft 1102 and converted into linear motion in the left and right directions in FIG. 11. In FIG. 11, the right direction is described as the extending direction of the output shaft 1102, and the left direction is described as the contracting direction of the output shaft 1102. In the conventional configuration shown in FIG. 11, the inner diameter of the portion where the output shaft 1102 of the housing 1101 is installed is 85 mm, the outer diameter of the output shaft 1102 is 80 mm, and the outer diameter of the linear motion part 1103 is 16 mm. Also, assuming that each sealed space is in a completely sealed state and there is no heat exchange with the outside (heat insulation), the following changes in internal pressure can occur as shown in Table 1 below. Here, a certain position of the output shaft 1102 is taken as the reference position (expansion / contraction 0 mm, internal pressure 0 MPa), and the expansion / contraction of the output shaft 1102 from that position is shown.

[0020]

Table 1

[0021] Note that the calculation of the internal pressure change in Table 1 is based on the premise that each sealed space is a completely sealed adiabatic change, so it can be expressed by the relationship of PV = constant (P: pressure, V: volume) according to Boyle - Charles' law. And according to the cross - sectional area of the surface where the pressure in Table 1 is applied, a resistance force against the output shaft 1102 and the linear motion part nut 1104 is generated. In reality, there is a certain gap at the joint of each component and it is not a complete seal, so the above values are just an example. When considering the gap, it is necessary to further consider that the resistance of the air passing through the gap changes with the speed of the output shaft.

[0022] Due to the change in internal pressure as described above, a situation where the operation of the electric actuator 1100 is unstable is assumed. More specifically, even if the rotation by the motor 1106, that is, the control amount (control signal) for the motor 1106 is constant, the thrust output will be different due to the change in internal pressure.

[0023] Therefore, in this embodiment, a configuration is provided to suppress the change in the internal pressure as much as possible to stabilize the output of the electric actuator. Specifically, the individual sealed spaces are communicated through the ventilation part to expand the volume of the sealed space, and the deviation of the internal pressure change in the sealed space is suppressed to stabilize the operation of the electric actuator.

[0024] [Configuration] FIG. 1 is a schematic cross-sectional view showing a configuration example of an electric actuator 100 which is an actuator device according to this embodiment. The electric actuator 100 includes a housing 101, an output shaft 102, a linear motion part 103, a linear motion part nut 104, an output shaft support member 105, a motor 106, a connecting part 107, gears 108, 109, 110, a gear fixing nut 111, a bearing 112, and a bearing fixing housing 113. The housing 101 is a casing of the electric actuator 100, and the above-described respective parts are installed inside. The output shaft 102 is connected to the linear motion part 103 via the linear motion part nut 104 that operates as a connecting mechanism, and outputs a thrust by linear motion in a predetermined direction. The output shaft 102 is supported by the housing 101 by the output shaft support member 105.

[0025] The linear motion part 103 is configured as a screw shaft having a spiral groove (not shown) formed on its outer peripheral surface. Also, a spiral groove (not shown) is formed on the inner peripheral surface of the linear motion part nut 104. Using the grooves of the linear motion part 103 and the linear motion part nut 104 as rolling surfaces, a spherical rolling element (not shown) is installed between them so as to be rollable. A lubricant (such as lubricating oil or grease) may be supplied around the rolling element and the groove by an arbitrary lubrication method so that these frictions are reduced. When the linear motion part 103 rotates, it is converted into a linear motion (piston motion) via the linear motion part nut 104, and the thrust by the output shaft 102 is output. The moving direction (extension direction or contraction direction) of the output shaft 102 is defined according to the rotation direction of the motor 106.

[0026] The motor 106 performs a rotational operation based on an instruction or the like from a control device (not shown). The motor 106 is provided with a rotational position sensor (not shown) that detects the rotational position associated with the rotational operation of the motor 106 using an encoder or the like, and rotational control is performed based on the detection result. The control device (not shown) may be composed of, for example, a CPU (Central Processing Unit), MPU (Micro Processing Unit), DSP (Digital Single Processor), or a dedicated circuit. Although not shown in FIG. 1, the control device (not shown) may further include a volatile and non-volatile storage medium such as an HDD (Hard Disk Drive), ROM (Read Only Memory), and RAM (Random Access Memory), a power supply that supplies power to the motor 106, an inverter, and the like.

[0027] The rotation by the motor 106 is transmitted to the gear 108 via the connecting portion 107. The gears 108, 109, and 110 each have a plurality of teeth, and the teeth of each gear mesh and rotate, thereby converting the rotation of the motor 106 into a predetermined rotation and transmitting it to the linear motion component 103. The gear 110 is fixed to the linear motion component 103 by a gear fixing nut 111. The bearing 112 supports the linear motion component 103 so that it can rotate based on the rotational force transmitted through the gear 110. Further, the bearing 112 is fixed to the housing 101 by a bearing fixing housing 113. Here, an example of an angular ball bearing is shown as the bearing 112, but other types of bearings may be used.

[0028] In addition, a plurality of sealed spaces are formed inside the housing 101. The sealed spaces prevent, for example, the inflow of liquid or the like into the electric actuator 100, thereby achieving waterproofing and dustproofing. Here, four sealed spaces 114, 115, 116, and 117 will be described as examples. The specifications (volume and arrangement) of each sealed space are not particularly limited. In this embodiment, unlike the conventional configuration shown in FIG. 11, the sealed spaces 114 to 117 are spaces whose internal pressure changes as the electric actuator 100 operates. Details will be described later.

[0029] The sealed space 114 is formed inside the output shaft 102 by the output shaft 102, the linear motion part 103, and the linear motion part nut 104. The sealed space 115 is formed by the housing 101, the output shaft 102, and the output shaft support member 105. The sealed space 116 is formed by the housing 101, the output shaft 102, the linear motion part 103, the linear motion part nut 104, the output shaft support member 105, the bearing 112, and the bearing fixing housing 113.

[0030] In the electric actuator 100 according to this embodiment, in order to suppress the change in the internal pressure of the sealed space accompanying its operation, a plurality of ventilation holes for connecting the sealed spaces are provided. A ventilation hole 120 is provided at the axial center of the linear motion part 103. Through the ventilation hole 120, the sealed space 114 and the sealed space 117 are connected, and the gas inside can move between the sealed space 114 and the sealed space 117. Note that the diameter of the ventilation hole 120 is preferably not more than half of the diameter of the linear motion part 103 in order to prevent reduction in the strength and rigidity of the linear motion part 103 and the entire electric actuator 100.

[0031] Furthermore, one or more ventilation holes 121 for connecting the sealed space 115 and the sealed space 116 are provided in the output shaft 102 and the linear motion part nut 104. Through the one or more ventilation holes 121, the sealed space 115 and the sealed space 116 are connected, and the gas inside can move between the sealed space 115 and the sealed space 116.

[0032] Furthermore, provide one or more ventilation holes 122 for connecting the sealed space 116 and the sealed space 117 to the bearing fixing housing 113. The one or more ventilation holes 122 connect the sealed space 116 and the sealed space 117, enabling the gas inside to move between the sealed space 116 and the sealed space 117. In the conventional example shown in FIG. 11, the internal pressure of the sealed space 1117 does not change even when the electric actuator 1100 operates. On the other hand, in the configuration according to the present embodiment, by connecting the corresponding sealed space 117 to other sealed spaces, the sealed space is expanded. Therefore, the internal pressure of the sealed space 117 changes with the operation of the electric actuator 100.

[0033] As described above, in the present embodiment, a plurality of sealed spaces are connected. With this configuration, it is possible to suppress changes in the internal pressure of each sealed space caused by the piston movement of the output shaft 102 when the electric actuator 100 operates. That is, by connecting the sealed spaces, the degree of freedom of movement of the gas inside the sealed space can be improved. In particular, in the present embodiment, a sealed space whose internal pressure does not change with the operation of the electric actuator in the conventional configuration is further connected. As a result, the volume of the entire sealed space can be expanded, changes in the internal pressure of the entire sealed space can be suppressed, and the operation of the actuator device can be stabilized. Also, since ventilation parts are provided in advance at each part of the actuator device, no new additional parts are required, and the structure can be configured simply.

[0034] <Second Embodiment> Hereinafter, a second embodiment of the present invention will be described. Note that descriptions of configurations overlapping with those shown in the first embodiment will be omitted, and the description will focus on the differences.

[0035] [Configuration] FIG. 2 is a schematic cross-sectional view showing a configuration example of the electric actuator 200 according to the present embodiment. The electric actuator 200 includes a housing 201, an output shaft 202, a linear motion component 203, a linear motion component nut 204, an output shaft support member 205, a motor 206, a connecting portion 207, gears 208, 209, 210, a gear fixing nut 211, a bearing 212, and a bearing fixing housing 213. These respectively correspond to the housing 101, the output shaft 102, the linear motion component 103, the linear motion component nut 104, the output shaft support member 105, the motor 106, the connecting portion 107, the gears 108, 109, 110, the gear fixing nut 111, the bearing 112, and the bearing fixing housing 113 included in the electric actuator 100 shown in FIG. 1 of the first embodiment.

[0036] Further, a plurality of sealed spaces are formed inside the housing 201. The sealed spaces prevent, for example, the inflow of liquid or the like into the electric actuator 200. Here, four sealed spaces 214, 215, 216, and 217 will be described as an example. The specifications (volume and arrangement) of each sealed space are not particularly limited. The sealed spaces 214 to 217 are spaces whose internal pressure changes as the electric actuator 200 operates, similar to the sealed spaces 114 to 117 shown in FIG. 1 of the first embodiment.

[0037] The electric actuator 200 according to the present embodiment is provided with a plurality of ventilation holes that connect the sealed spaces in order to suppress changes in internal pressure. A ventilation hole 220 is provided at the axial center of the linear motion component 203. Further, the linear motion component 203 is provided with a ventilation hole 222 that is connected to the ventilation hole 220 in a direction orthogonal to the axial direction. The ventilation holes 220 and 222 connect the sealed spaces 214, 216, and 217, and the gas inside them can move between the sealed spaces 214, 216, and 217. Note that the diameter of the ventilation hole 220 is preferably half or less of the diameter of the linear motion component 203 in order to prevent a reduction in the strength and rigidity of the linear motion component 203 and the entire electric actuator 200.

[0038] Furthermore, one or more ventilation holes 221 are provided for connecting the sealed space 215 and the sealed space 216 with respect to the output shaft 202 and the linear motion component nut 204. The one or more ventilation holes 221 connect the sealed space 215 and the sealed space 216, enabling the gas inside to move between the sealed space 215 and the sealed space 216.

[0039] As described above, in this embodiment, a plurality of sealed spaces are connected using a plurality of ventilation holes. With this configuration, even when there is no area for providing a ventilation hole of sufficient size in the bearing fixing housing 113, it is possible to obtain the same effect as in the first embodiment.

[0040] <Third Embodiment> Hereinafter, a third embodiment of the present invention will be described. Note that descriptions of configurations overlapping with those shown in the first embodiment will be omitted, and the description will focus on the differences.

[0041] [Configuration] FIG. 3 is a schematic cross-sectional view showing a configuration example of the electric actuator 300 according to this embodiment. The electric actuator 300 includes a housing 301, an output shaft 302, a linear motion component 303, a linear motion component nut 304, an output shaft support member 305, a motor 306, a connecting portion 307, gears 308, 309, 310, a gear fixing nut 311, bearings 312, and a bearing fixing housing 313. These respectively correspond to the housing 101, output shaft 102, linear motion component 103, linear motion component nut 104, output shaft support member 105, motor 106, connecting portion 107, gears 108, 109, 110, gear fixing nut 111, bearings 112, and bearing fixing housing 113 provided in the electric actuator 100 shown in FIG. 1 of the first embodiment.

[0042] Also, a plurality of sealed spaces are formed inside the housing 301. The sealed spaces prevent, for example, the inflow of liquid or the like into the electric actuator 300. Here, four sealed spaces 314, 315, 316, and 317 will be described as an example. The specifications (volume and arrangement) of each sealed space are not particularly limited. The sealed spaces 314 to 317 are spaces whose internal pressure changes as the electric actuator 300 operates, similar to the sealed spaces 114 to 117 shown in FIG. 1 of the first embodiment.

[0043] The electric actuator 300 according to the present embodiment is provided with a plurality of ventilation holes for connecting the sealed spaces in order to suppress changes in internal pressure. One or more ventilation holes 320 for connecting the sealed spaces 314 to 316 are provided for the output shaft 302 and the linear motion part nut 304. The one or more ventilation holes 320 connect the sealed spaces 314 to 316, and the gas inside them can move between the sealed spaces 314 to 316.

[0044] Furthermore, one or more ventilation holes 321 for connecting the sealed space 316 and the sealed space 317 are provided for the bearing fixing housing 313. The one or more ventilation holes 321 connect the sealed space 316 and the sealed space 317, and the gas inside them can move between the sealed space 316 and the sealed space 317.

[0045] As described above, in the present embodiment, a plurality of sealed spaces are connected using a plurality of ventilation holes. With this configuration, it is possible to obtain the same effect as in the first embodiment.

[0046] <Fourth Embodiment> Hereinafter, a fourth embodiment of the present invention will be described. Note that descriptions of configurations overlapping with those shown in the first embodiment will be omitted, and the description will focus on the differences.

[0047] [Configuration] FIG. 4 is a schematic cross-sectional view showing a configuration example of the electric actuator 400 according to the present embodiment. The electric actuator 400 includes a housing 401, an output shaft 402, a linear motion component 403, a linear motion component nut 404, an output shaft support member 405, a motor 406, a connecting portion 407, gears 408, 409, 410, a gear fixing nut 411, a bearing 412, and a bearing fixing housing 413. These respectively correspond to the housing 101, the output shaft 102, the linear motion component 103, the linear motion component nut 104, the output shaft support member 105, the motor 106, the connecting portion 107, the gears 108, 109, 110, the gear fixing nut 111, the bearing 112, and the bearing fixing housing 113 provided in the electric actuator 100 shown in FIG. 1 of the first embodiment.

[0048] Further, a plurality of sealed spaces are formed inside the housing 401. The sealed spaces prevent, for example, the inflow of liquid or the like into the electric actuator 400. Here, four sealed spaces 414, 415, 416, and 417 will be described as an example. The specifications (volume, arrangement, etc.) of each sealed space are not particularly limited. The sealed spaces 414 to 417 are spaces whose internal pressure changes as the electric actuator 400 operates, similar to the sealed spaces 114 to 117 shown in FIG. 1 of the first embodiment.

[0049] The electric actuator 400 according to the present embodiment is provided with a plurality of ventilation holes and ventilation grooves for connecting the sealed spaces in order to suppress changes in the internal pressure. A ventilation hole 420 is provided at the axial center of the linear motion component 403. The ventilation hole 420 connects the sealed space 414 and the sealed space 417, and the gas inside can move between the sealed space 414 and the sealed space 417. Note that the diameter of the ventilation hole 420 is preferably equal to or less than half of the diameter of the linear motion component 403 in order to prevent a reduction in the strength and rigidity of the linear motion component 403 and the entire electric actuator 400.

[0050] Furthermore, one or a plurality of ventilation grooves 421 for connecting the sealed space 415 and the sealed space 416 are provided on the outer peripheral surface of the output shaft 402. The one or a plurality of ventilation grooves 421 connect the sealed space 415 and the sealed space 416, enabling the gas inside to move between the sealed space 414 and the sealed space 416. Note that the shape, number, etc. of the ventilation grooves 421 are not particularly limited, but are provided in consideration of the strength and rigidity of the output shaft 402 and the electric actuator 400.

[0051] Furthermore, one or a plurality of ventilation holes 422 for connecting the sealed space 416 and the sealed space 417 are provided in the bearing fixing housing 413. The one or a plurality of ventilation holes 422 connect the sealed space 416 and the sealed space 417, enabling the gas inside to move between the sealed space 416 and the sealed space 417.

[0052] As described above, in this embodiment, a plurality of sealed spaces are connected using a plurality of ventilation holes and ventilation grooves. With this configuration, it is possible to obtain the same effect as in the first embodiment.

[0053] <The Fifth Embodiment> Hereinafter, the fifth embodiment of the present invention will be described. Note that descriptions of configurations overlapping with those shown in the first embodiment will be omitted, and the description will focus on the differences.

[0054] [Configuration] FIG. 5 is a schematic cross-sectional view showing a configuration example of an electric actuator 500 according to this embodiment. The electric actuator 500 includes a housing 501, an output shaft 502, a linear motion component 503, a linear motion component nut 504, an output shaft support member 505, a motor 506, a connecting portion 507, gears 508, 509, 510, a gear fixing nut 511, bearings 512, and a bearing fixing housing 513. These respectively correspond to the housing 101, output shaft 102, linear motion component 103, linear motion component nut 104, output shaft support member 105, motor 106, connecting portion 107, gears 108, 109, 110, gear fixing nut 111, bearings 112, and bearing fixing housing 113 provided in the electric actuator 100 shown in FIG. 1 of the first embodiment.

[0055] Further, inside the housing 501, a plurality of sealed spaces are formed. The sealed spaces prevent, for example, the inflow of liquid or the like into the electric actuator 500. Here, four sealed spaces 514, 515, 516, and 517 will be described as an example. The specifications (volume and arrangement) of each sealed space are not particularly limited. The sealed spaces 514 to 517 are spaces whose internal pressure changes as the electric actuator 500 operates, similar to the sealed spaces 114 to 117 shown in FIG. 1 of the first embodiment.

[0056] The electric actuator 500 according to the present embodiment is provided with a plurality of ventilation holes and ventilation grooves for connecting the sealed spaces in order to suppress changes in the internal pressure. A ventilation hole 520 is provided at the axial center of the linear motion component 503. Further, a plurality of ventilation grooves 521 are provided along the axial direction on the outer peripheral surface of the linear motion component 503. The ventilation hole 520 connects the sealed space 514 and the sealed space 517, and the gas inside can move between the sealed space 514 and the sealed space 517. Also, the ventilation groove 521 connects the sealed space 514 and the sealed space 516, and the gas inside can move between the sealed space 514 and the sealed space 516. Note that the diameter of the ventilation hole 520 is preferably not more than half the diameter of the linear motion component 503 in order to prevent a reduction in the strength and rigidity of the linear motion component 503 and the entire electric actuator 500. Also, the shape and number of the ventilation grooves 521 are not particularly limited, but they are formed so as not to affect the rolling surface of the rolling elements provided on the outer peripheral surface of the linear motion component 503, which is a spiral groove.

[0057] Furthermore, one or more ventilation holes 522 for connecting the sealed space 515 and the sealed space 516 are provided in the output shaft 502 and the linear motion component nut 504. The one or more ventilation holes 522 connect the sealed space 515 and the sealed space 516, and the gas inside can move between the sealed space 515 and the sealed space 516.

[0058] FIG. 6 is a diagram for explaining a detailed configuration example of the electric actuator 500 according to the present embodiment. FIG. 6(a) is an external perspective view of the output shaft 502 and the linear motion component 503. A vent hole 520 is provided at the axial center of the linear motion component 503. FIG. 6(b) is an external perspective view of the linear motion component 503. A spiral groove 601 serving as a rolling surface for rolling elements is provided on the outer peripheral surface of the linear motion component 503. Further, one or a plurality of vent grooves 521 are provided on the outer peripheral surface of the linear motion component 503 along the axial direction.

[0059] FIG. 6(c) is a view of the output shaft 502 and the linear motion component 503 shown in FIG. 6(a) as viewed from a direction orthogonal to the axial direction. FIG. 6(d) is a cross-sectional view taken along the cross-section line A in FIG. 6(c). Spiral grooves are provided on the linear motion component 503 and the linear motion component nut 504, respectively, and a plurality of rolling elements 602 are provided therebetween. FIG. 6(e) is a cross-sectional view taken along the cross-section line B in FIG. 6(c). FIG. 6(f) is a cross-sectional view taken along the cross-section line C in FIG. 6(c). As shown in FIGS. 6(d) to (f), vent holes 520, 522, and vent grooves 521 are provided.

[0060] As described above, in the present embodiment, a plurality of sealed spaces are connected using a plurality of vent holes and vent grooves. With this configuration, it is possible to obtain the same effects as in the first embodiment.

[0061] <Sixth Embodiment> Hereinafter, a sixth embodiment of the present invention will be described. Note that the description of configurations overlapping with those shown in the first embodiment will be omitted, and the description will focus on the differences. In the present embodiment, a form in which all the configurations shown in the above-described embodiments are combined will be described.

[0062] [Configuration] FIG. 7 is a schematic cross-sectional view showing a configuration example of an electric actuator 700 according to the present embodiment. The electric actuator 700 includes a housing 701, an output shaft 702, a linear motion component 703, a linear motion component nut 704, an output shaft support member 705, a motor 706, a connecting portion 707, gears 708, 709, 710, a gear fixing nut 711, a bearing 712, and a bearing fixing housing 713. These respectively correspond to the housing 101, the output shaft 102, the linear motion component 103, the linear motion component nut 104, the output shaft support member 105, the motor 106, the connecting portion 107, the gears 108, 109, 110, the gear fixing nut 111, the bearing 112, and the bearing fixing housing 113 included in the electric actuator 100 shown in FIG. 1 of the first embodiment.

[0063] Further, a plurality of sealed spaces are formed inside the housing 701. The sealed spaces prevent, for example, the inflow of liquid or the like into the electric actuator 700. Here, four sealed spaces 714, 715, 716, and 717 will be described as an example. The specifications (volume and arrangement) of each sealed space are not particularly limited. The sealed spaces 714 to 717 are spaces whose internal pressure changes as the electric actuator 700 operates, similar to the sealed spaces 114 to 117 shown in FIG. 1 of the first embodiment.

[0064] The electric actuator 700 according to this embodiment is provided with a plurality of ventilation holes and ventilation grooves for connecting the respective sealed spaces in order to suppress changes in internal pressure. A ventilation hole 720 is provided at the axial center of the linear motion component 703. Further, the linear motion component 703 is provided with a ventilation hole 723 connected to the ventilation hole 720 in a direction orthogonal to the axial direction. Further, a plurality of ventilation grooves 721 are provided on the outer peripheral surface of the linear motion component 703 along the axial direction. The ventilation holes 720 and 723 connect the sealed spaces 714, 716, and 717, and the gas inside them can move between the sealed spaces 714, 716, and 717. Also, the ventilation groove 721 connects the sealed space 714 and the sealed space 716, and the gas inside them can move between the sealed space 714 and the sealed space 716. Note that the diameter of the ventilation hole 720 is preferably equal to or less than half the diameter of the linear motion component 703 in order to prevent reduction in the strength and rigidity of the entire linear motion component 703 and the electric actuator 700. Also, the shape and number of the ventilation grooves 721 are not particularly limited, but they are formed so as not to affect the rolling surface of the rolling elements provided on the outer peripheral surface of the linear motion component 703, which is a spiral groove.

[0065] Furthermore, one or a plurality of ventilation parts 722 for connecting the sealed spaces 714 to 716 are provided for the output shaft 702 and the linear motion component nut 704. Each of the one or a plurality of ventilation parts 722 is composed of a ventilation groove 722a provided on the outer peripheral surface of the output shaft 702 and a ventilation hole 722b provided inside the output shaft 702 and the linear motion component nut 704. The ventilation part 722 connects the sealed spaces 714 to 716, and the gas inside them can move between the sealed spaces 714 to 716.

[0066] Furthermore, one or a plurality of ventilation holes 724 for connecting the sealed space 716 and the sealed space 717 are provided for the bearing fixing housing 713. The one or a plurality of ventilation holes 724 connect the sealed space 716 and the sealed space 717, and the gas inside them can move between the sealed space 716 and the sealed space 717.

[0067] FIG. 8 is a diagram for explaining a detailed configuration example of the electric actuator 700 according to the present embodiment. FIG. 8(a) is an external perspective view of the output shaft 702 and the linear motion component 703. A ventilation groove 722a that constitutes a ventilation portion 722 is provided on the outer peripheral surface of the output shaft 702. FIG. 8(b) is an external perspective view of the linear motion component 703. A spiral groove 801 that serves as a rolling surface for rolling elements is provided on the outer peripheral surface of the linear motion component 703. Further, one or a plurality of ventilation grooves 821 are provided on the outer peripheral surface of the linear motion component 703 along the axial direction. A ventilation hole 720 is provided at the axial center of the linear motion component 703, and a ventilation hole 723 is further provided in a direction orthogonal to the axial direction.

[0068] FIG. 8(c) is a view of the output shaft 702 and the linear motion component 703 shown in FIG. 8(a) viewed from a direction orthogonal to the axial direction. FIG. 8(d) is a cross-sectional view taken along the cross-section line A in FIG. 8(c). Spiral grooves are provided in the linear motion component 703 and the linear motion component nut 704, and a plurality of rolling elements 802 are provided therebetween. FIG. 8(e) is a cross-sectional view taken along the cross-section line B in FIG. 8(c). FIG. 8(f) is a cross-sectional view taken along the cross-section line C in FIG. 8(c). As shown in FIGS. 8(d) to (f), a ventilation hole 720, a ventilation groove 721, a ventilation portion 722 (ventilation groove 722a and ventilation hole 722b), and a ventilation hole 723 are provided.

[0069] As described above, in the present embodiment, a plurality of sealed spaces are connected using a plurality of ventilation holes and ventilation grooves. With this configuration, it is possible to obtain the same effects as in the first embodiment. <The Seventh Embodiment> Hereinafter, the seventh embodiment of the present invention will be described. Note that the description of the configurations overlapping with those shown in the first embodiment will be omitted, and the description will focus on the differences. In the present embodiment, a form in which a damper effect based on the amount of change in internal pressure is implemented by changing the shape and number of the configurations shown in the sixth embodiment will be described.

[0070] [Configuration] FIG. 9 is a schematic cross-sectional view showing a configuration example of an electric actuator 900 according to the present embodiment. The electric actuator 900 includes a housing 901, an output shaft 902, a linear motion component 903, a linear motion component nut 904, an output shaft support member 905, a motor 906, a connecting portion 907, gears 908, 909, 910, a gear fixing nut 911, a bearing 912, and a bearing fixing housing 913. These respectively correspond to the housing 101, output shaft 102, linear motion component 103, linear motion component nut 104, output shaft support member 105, motor 106, connecting portion 107, gears 108, 109, 110, gear fixing nut 111, bearing 112, and bearing fixing housing 113 provided in the electric actuator 100 shown in FIG. 1 of the first embodiment.

[0071] Further, a plurality of sealed spaces are formed inside the housing 901. Here, four sealed spaces 914, 915, 916, and 917 will be described as an example. The specifications (volume and arrangement) of each sealed space are not particularly limited. The sealed spaces 914 to 917 are spaces whose internal pressure changes as the electric actuator 900 operates, similar to the sealed spaces 114 to 117 shown in FIG. 1 of the first embodiment.

[0072] The electric actuator 900 according to the present embodiment is provided with a plurality of ventilation holes and ventilation grooves for connecting the respective sealed spaces in order to suppress changes in internal pressure and realize a damping effect using the change in internal pressure. The electric actuator 900 of the present embodiment includes a ventilation hole 920, a ventilation groove 921, a ventilation portion 922 (ventilation groove 922a and ventilation hole 922b), a ventilation hole 923, and a ventilation hole 924. These respectively correspond to the ventilation hole 720, ventilation groove 721, ventilation portion 722 (ventilation groove 722a and ventilation hole 722b), ventilation hole 723, and ventilation hole 724 provided in the electric actuator 700 shown in FIGS. 7 and 8 in the sixth embodiment.

[0073] FIG. 10 is a diagram for explaining a detailed configuration example of the electric actuator 900 according to the present embodiment. FIG. 10(a) is an external perspective view of the output shaft 902 and the linear motion component 903. A plurality of ventilation grooves 922a forming a ventilation portion 922 are provided on the outer peripheral surface of the output shaft 902. FIG. 10(b) is an external perspective view of the linear motion component 903. A spiral groove 1001 serving as a rolling surface for rolling elements is provided on the outer peripheral surface of the linear motion component 903. In addition, one or a plurality of ventilation grooves 921 are provided on the outer peripheral surface of the linear motion component 903 along the axial direction. A ventilation hole 920 is provided at the axial center of the linear motion component 903, and a ventilation hole 923 is further provided in a direction orthogonal to the axial direction.

[0074] FIG. 10(c) is a view of the output shaft 902 and the linear motion component 903 shown in FIG. 10(a) as viewed from a direction orthogonal to the axial direction. FIG. 10(d) is a cross-sectional view taken along the section line A in FIG. 10(c). Spiral grooves are provided in the linear motion component 903 and the linear motion component nut 904, respectively, and a plurality of rolling elements 1002 are provided therebetween. FIG. 10(e) is a cross-sectional view taken along the section line B in FIG. 10(c). FIG. 10(f) is a cross-sectional view taken along the section line C in FIG. 10(c). As shown in FIGS. 10(d) to (f), the ventilation hole 920, the ventilation groove 921, the ventilation portion 922 (ventilation groove 922a and ventilation hole 922b), and the ventilation hole 923 are provided.

[0075] In the present embodiment, in order to implement the damper effect due to the change in internal pressure, compared with the configurations of FIGS. 7 and 8 shown in the sixth embodiment, a configuration is shown in which the diameter of the ventilation hole 920, the diameter of the ventilation hole 922b forming the ventilation portion 922, and the diameter of the ventilation hole 924 are reduced. In addition to this, the damper effect may be realized by making the dimensions, shapes, and numbers of the respective ventilation holes different from those of the configuration of the sixth embodiment. Further, the damper effect may be realized by reducing the dimensions, shapes, and numbers such as the depth and width of each ventilation groove compared to the configuration of the sixth embodiment. Furthermore, the damper effect may be realized by combining any of the above, and it may be designed according to the size and function of the electric actuator.

[0076] As described above, in the present embodiment, a plurality of sealed spaces are connected using a plurality of ventilation holes and ventilation grooves. With this configuration, in addition to the same effects as those of the first embodiment, it is possible to implement a damper effect in consideration of changes in internal pressure due to the sealed spaces.

[0077] <Other Embodiments> In the above embodiment, ventilation holes and ventilation grooves for connecting a plurality of sealed spaces are provided. Further, a ventilation material may be provided so as not to allow substances other than a predetermined substance (for example, air) to pass through the ventilation holes and ventilation grooves. That is, a filter unit for performing filtering during ventilation is provided. Thereby, for example, it is possible to prevent the movement of lubricants such as grease and lubricating oil provided around the linear motion parts and keep the lubricating function constant. As the ventilation material, for example, GORE-TEX (registered trademark) having a waterproof function, Neo-Zoic (registered trademark), Strom (registered trademark) having functions of high air permeability and water resistance, etc. may be used.

[0078] Also, in the present invention, a program or application for controlling an electric actuator can be supplied to a system or device using a network or a storage medium, etc., and a process in which one or more processors in the computer of the system or device reads and executes the program can also be realized.

[0079] Also, it may be realized by a circuit (for example, ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array)) that realizes one or more functions.

[0080] Thus, the present invention is not limited to the above embodiments, and it is also contemplated by the present invention that those skilled in the art can change and apply the present invention by combining each configuration of the embodiments, based on the description in the specification and well-known techniques, and such changes and applications are included in the scope for which protection is sought.

[0081] As described above, the following matters are disclosed in this specification. (1) An actuator device composed of a plurality of parts, wherein a plurality of sealed spaces are formed by at least a part of the plurality of parts, and the internal pressure changes as the actuator device operates; at least a part of the plurality of parts is provided with a ventilation part for communicating at least two of the plurality of sealed spaces. An actuator device characterized by the above. According to this configuration, while ensuring the internal airtightness, it is possible to suppress the influence of the internal pressure change accompanying the operation of the actuator device and improve the output stability.

[0082] (2) The plurality of parts include a housing, a motor, a screw shaft to which the rotational force of the motor is input, a connection mechanism configured to linearly move along the screw shaft as the screw shaft rotates by the rotational force, an output shaft connected to the connection mechanism and linearly moving together with the connection mechanism to output a thrust force. Including The plurality of sealed spaces are characterized in that the internal pressure changes when the output shaft outputs a thrust force, according to (1). According to this configuration, corresponding to the parts included in the actuator device, it is possible to suppress the influence of the internal pressure change accompanying the operation of the actuator device and improve the output stability.

[0083] (3) The plurality of sealed spaces include a first sealed space formed inside the output shaft, a second sealed space formed by a support member that supports the output shaft on the housing and the output shaft, a third sealed space formed by the output shaft, the connection mechanism, the screw shaft, and the housing, a fourth sealed space formed in the housing in a space connecting the screw shaft and the motor. The actuator device according to (2), characterized by including at least two of them. According to this configuration, corresponding to a plurality of sealed spaces formed in the actuator device, it is possible to suppress the influence of internal pressure changes accompanying the operation of the actuator device and improve the stability of the output.

[0084] (4) The ventilation part includes a first ventilation hole provided on the screw shaft along the axial direction of the screw shaft, enabling ventilation between the first sealed space and the fourth sealed space. The actuator device according to (3). According to this configuration, a configuration in which a ventilation part is provided with respect to the screw shaft can be used.

[0085] (5) The ventilation part further includes a second ventilation hole provided on the screw shaft perpendicular to the first ventilation hole, enabling ventilation between the third sealed space. The actuator device according to (4). According to this configuration, a configuration in which a ventilation part is provided with respect to the screw shaft can be used.

[0086] (6) The ventilation part includes a first ventilation groove provided along the outer peripheral surface of the screw shaft in the axial direction, enabling ventilation between the first sealed space and the third sealed space. The actuator device according to any one of (3) to (5). According to this configuration, a configuration in which a ventilation part is provided with respect to the screw shaft can be used.

[0087] (7) Between the third sealed space and the fourth sealed space, a fixing member is further provided for fixing a bearing that supports the screw shaft. The ventilation part includes a third ventilation hole provided in the fixing member, enabling ventilation between the third sealed space and the fourth sealed space. The actuator device according to any one of (3) to (6). According to this configuration, a configuration in which a ventilation part is provided with respect to the fixing member of the bearing can be used.

[0088] (8) The ventilation part includes a fourth ventilation hole provided inside the output shaft and the connection mechanism, and is capable of ventilation between the second sealed space and the third sealed space. The actuator device according to any one of (3) to (7). According to this configuration, a configuration in which a ventilation part is provided for the output shaft and the connection mechanism (that is, the linear motion part nut) can be used.

[0089] (9) The ventilation part includes a second ventilation groove provided on the outer peripheral surface of the output shaft, and is capable of ventilation between the second sealed space and the third sealed space. The actuator device according to any one of (3) to (8). According to this configuration, a configuration in which a ventilation part is provided for the output shaft can be used.

[0090] (10) The ventilation part includes a fifth ventilation hole provided inside the output shaft and the connection mechanism, and is capable of ventilation among the first sealed space, the second sealed space, and the third sealed space. The actuator device according to any one of (3) to (7). According to this configuration, a configuration in which a ventilation part is provided for the output shaft and the connection mechanism (that is, the linear motion part nut) can be used.

[0091] (11) By adjusting the change amount of the internal pressure of the plurality of sealed spaces using at least any one of the shape, dimensions, and number of the ventilation parts, a damper function is provided. The actuator device according to any one of (1) to (10). According to this configuration, it becomes possible to realize a damper function by using the ventilation part.

[0092] (12) A filter part composed of a predetermined ventilation material is provided in the ventilation part. The actuator device according to any one of (1) to (11). According to this configuration, it is possible to prevent the movement of lubricants such as grease and lubricating oil and keep the lubrication function constant.

Explanation of Signs

[0093] 100…Electric actuator 101…Housing 102…Output shaft 103…Linear component 104…Linear component nut 105…Output shaft support member 106…Motor 107…Connection part 108, 109, 110…Gear 111…Gear fixing nut 112…Bearing 113…Bearing fixing housing 114, 115, 116, 117…Sealed space 120, 121, 122…Vent hole

Claims

1. An actuator device composed of a plurality of parts, A plurality of sealed spaces are formed by at least a part of the plurality of parts, and the internal pressure changes according to the operation of the actuator device. At least a part of the plurality of parts is provided with a ventilation part for communicating at least two of the plurality of sealed spaces. The plurality of parts include A housing, A motor, A screw shaft to which the rotational force of the motor is input, A connecting mechanism configured to linearly move along the screw shaft as the screw shaft rotates by the rotational force, An output shaft connected to the connecting mechanism and linearly moving together with the connecting mechanism to output a thrust force and include, When the output shaft outputs a thrust force, the internal pressure of the plurality of sealed spaces changes. The plurality of sealed spaces include A first sealed space formed inside the output shaft, A second sealed space formed by a support member that supports the output shaft in the housing and the output shaft, A third sealed space formed by the output shaft, the connecting mechanism, the screw shaft, and the housing, And a fourth sealed space formed in a space inside the housing that connects the screw shaft and the motor and include at least two of them. The ventilation part includes a first ventilation hole provided along the axial direction of the screw shaft to enable ventilation between the first sealed space and the fourth sealed space. The ventilation part further includes a second ventilation hole provided on the screw shaft orthogonal to the first ventilation hole to enable ventilation between the second ventilation hole and the third sealed space. The actuator device is characterized by this.

2. The ventilation part includes a first ventilation groove provided along the axial direction on the outer peripheral surface of the screw shaft, enabling ventilation between the first sealed space and the third sealed space. The actuator device according to claim 1 is characterized by this.

3. Between the third sealed space and the fourth sealed space, a fixing member is further provided for fixing a bearing that supports the screw shaft. The ventilation part includes a third ventilation hole provided in the fixing member, enabling ventilation between the third sealed space and the fourth sealed space. The actuator device according to claim 1 or 2 is characterized by this.

4. The ventilation part includes a fourth ventilation hole provided inside the output shaft and the connecting mechanism, enabling ventilation between the second sealed space and the third sealed space. The actuator device according to any one of claims 1 to 3 is characterized by this.

5. The ventilation part includes a second ventilation groove provided on the outer peripheral surface of the output shaft, enabling ventilation between the second sealed space and the third sealed space. The actuator device according to any one of claims 1 to 4 is characterized by this.

6. The ventilation part includes a fifth ventilation hole provided inside the output shaft and the connecting mechanism, enabling ventilation between the first sealed space, the second sealed space, and the third sealed space. The actuator device according to any one of claims 1 to 3 is characterized by this.

7. By adjusting at least any one of the shape, dimensions, and number of the ventilation part based on the change amount of the internal pressure of the plurality of sealed spaces, a damper function is provided. The actuator device according to any one of claims 1 to 6 is characterized by this.

8. The ventilation part is provided with a filter part composed of a predetermined ventilation material. The actuator device according to any one of claims 1 to 7 is characterized by this.

Images