JP7694230B2 - Actuator Device - Google Patents

Description

The present invention relates to an actuator device.

Electric actuators that convert the rotational force of a motor into linear thrust to operate the actuator have become widespread in recent years.

In an electric actuator, the control amount is determined based on the input, but depending on the operating state, different control amounts must be used to output the same thrust. In other words, even with the same control amount, different thrusts can be output depending on the operating state of the electric actuator. One of the factors behind this is the change in internal pressure of the sealed space provided within the electric actuator. Conventionally, electric actuators have a sealed space configured around the drive unit to ensure airtightness for the purposes of waterproofing, dustproofing, etc. As the electric actuator operates, the internal pressure of the sealed space within the electric actuator changes, affecting the output depending on the degree of this change.

For example, Patent Document 1 discloses a configuration in which an actuator is provided with a vent that opens in response to changes in internal pressure to suppress changes in internal pressure. Patent Document 2 discloses a configuration in which the actuator's airtightness is improved and grease leakage is prevented while releasing the internal pressure of the casing.

Patent No. 6841415 JP 2013-154843 A

As in Patent Documents 1 and 2, configurations have been considered for actuator devices to improve stability when outputting thrust while ensuring internal airtightness, but there is room for further improvement.

In view of the above problems, the present invention aims to improve the stability of the output by suppressing the effects of internal pressure changes that accompany the operation of the actuator device while ensuring internal airtightness.

In order to solve the above problems, the present invention has the following configuration. That is, an actuator device composed of a plurality of parts,
a plurality of sealed spaces, the internal pressure of which changes in response to the operation of the actuator device, are formed by at least some of the plurality of portions;
At least some of the plurality of portions are provided with ventilation sections for communicating at least two of the plurality of sealed spaces.

The present invention makes it possible to improve the stability of the output by suppressing the effects of internal pressure changes that accompany the operation of the actuator device while ensuring internal airtightness.

1 is a schematic diagram showing a configuration example of an electric actuator according to a first embodiment; FIG. 11 is a schematic diagram showing an example of the configuration of an electric actuator according to a second embodiment. FIG. 13 is a schematic diagram showing an example of the configuration of an electric actuator according to a third embodiment. FIG. 13 is a schematic diagram showing an example of the configuration of an electric actuator according to a fourth embodiment. FIG. 13 is a schematic diagram showing an example of the configuration of an electric actuator according to a fifth embodiment. FIG. 13 is a schematic diagram showing an example of the configuration of an electric actuator according to a fifth embodiment. FIG. 13 is a schematic diagram showing an example of the configuration of an electric actuator according to a sixth embodiment. FIG. 13 is a schematic diagram showing an example of the configuration of an electric actuator according to a sixth embodiment. FIG. 13 is a schematic diagram showing an example of the configuration of an electric actuator according to a seventh embodiment. FIG. 13 is a schematic diagram showing an example of the configuration of an electric actuator according to a seventh embodiment. 13A and 13B are diagrams for explaining changes in internal pressure of an electric actuator in a conventional configuration.

The following describes the embodiment of the present invention with reference to the drawings. Note that the embodiment described below is one embodiment for explaining the present invention, and is not intended to be interpreted as limiting the present invention, and not all of the configurations described in each embodiment are necessarily essential configurations for solving the problems of the present invention. In addition, in each drawing, the same components are given the same reference numbers to indicate their correspondence.

First Embodiment
A first embodiment of the present invention will be described below.

[Changes in internal pressure in a closed space]
First, a change in the internal pressure of the sealed space provided in the actuator device in a conventional configuration will be described with reference to Fig. 11. In order to compare with the configuration according to the present embodiment described later, a conventional example is shown in which parts other than the characteristic parts of the present embodiment are common. In addition, in order to simplify the explanation, only parts required for comparison with the configuration according to the present embodiment are shown as examples.

Figure 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 component 1103, a linear 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 the housing of the electric actuator 1100, and the above-mentioned components are installed inside. The output shaft 1102 is connected to the linear component 1103 via the linear 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 relative to the housing 1101.

The linear motion part 1103 is configured as a screw shaft with a helical groove (not shown) formed on its outer circumferential surface. A helical groove (not shown) is also formed on the inner circumferential surface of the linear motion part nut 1104. The groove of the linear motion part 1103 and the groove of the linear motion part nut 1104 are used as rolling surfaces, and a spherical rolling body (not shown) is installed between them so that it can roll. A lubricant (lubricating oil, grease, etc.) may be supplied around the rolling body and the groove by any lubrication method, so that the friction between them is reduced. When the linear motion part 1103 rotates, the rotation is converted into a linear movement (piston movement) via the linear motion part nut 1104, and a thrust force is output by the output shaft 1102. The movement direction (extension direction or contraction direction) of the output shaft 1102 is determined according to the rotation direction of the motor 1106.

The motor 1106 rotates 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 portion 1107. The gears 1108, 1109, and 1110 each have a plurality of teeth, and the rotation of the motor 1106 is converted into a predetermined rotation and transmitted to the linear motion part 1103 by the teeth of the gears meshing and rotating. 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 the linear motion part 1103 can rotate based on the rotational force transmitted through the gear 1110. 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.

In addition, multiple sealed spaces are formed inside the housing 1101. Here, four sealed spaces will be described as an example. Sealed spaces 1114, 1115, and 1116 are spaces whose internal pressure changes with the operation of the electric actuator 1100. On the other hand, sealed space 1117 is a space whose internal pressure does not change with the operation of the electric actuator 1100.

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.

As described above, the rotational force of the motor 1106 is transmitted to the output shaft 1102, and is converted into linear motion in the left and right directions in FIG. 11. In FIG. 11, the right direction is the extension direction of the output shaft 1102, and the left direction is the contraction direction of the output shaft 1102. In the conventional configuration shown in FIG. 11, the inner diameter of the part where the output shaft 1102 is installed in the housing 1101 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. In addition, if each sealed space is assumed to be completely sealed and there is no heat exchange with the outside (insulation), the internal pressure may change as shown in Table 1 below. Here, a certain position of the output shaft 1102 is set as a reference position (extension 0 mm, internal pressure 0 MPa), and the extension and contraction of the output shaft 1102 from that position is shown.

The calculation of the internal pressure change in Table 1 is based on the assumption that each sealed space is a completely sealed adiabatic change, and can be expressed as PV = constant (P: pressure, V: volume) according to Boyle's law. Resistance to the output shaft 1102 and the linear motion component nut 1104 is generated according to the cross-sectional area of the surface to which the pressure in Table 1 is applied. In reality, there are some gaps at the joints of each component, and they are not completely sealed, so the above values are only examples. When taking gaps into account, it is also necessary to consider that the resistance of the air passing through the gaps changes depending on the speed of the output shaft.

Due to the above-mentioned changes in internal pressure, it is conceivable that the operation of the electric actuator 1100 may become unstable. More specifically, even if the rotation by the motor 1106, i.e., the control amount (control signal) for the motor 1106, is constant, the output thrust may differ due to changes in internal pressure.

Therefore, in this embodiment, a configuration is provided that minimizes the above-mentioned changes in internal pressure, stabilizing the output of the electric actuator. Specifically, by connecting the individual sealed spaces via a ventilation section, the volume of the sealed spaces is expanded, and the bias in the changes in internal pressure within the sealed spaces is suppressed, stabilizing the operation of the electric actuator.

[composition]
FIG. 1 is a schematic cross-sectional view showing an example of the configuration 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 component 103, a linear motion component nut 104, an output shaft support member 105, a motor 106, a connecting portion 107, gears 108, 109, and 110, a gear fixing nut 111, a bearing 112, and a bearing fixing housing 113. The housing 101 is a housing of the electric actuator 100, and the above-mentioned components are installed inside. The output shaft 102 is connected to the linear motion component 103 via the linear motion component nut 104 that operates as a connecting mechanism, and outputs a thrust force by linear motion in a predetermined direction. The output shaft 102 is supported relative to the housing 101 by the output shaft support member 105.

The linear motion part 103 is configured as a screw shaft with a helical groove (not shown) formed on its outer circumferential surface. A helical groove (not shown) is also formed on the inner circumferential surface of the linear motion part nut 104. The groove of the linear motion part 103 and the groove of the linear motion part nut 104 are used as rolling surfaces, and a spherical rolling body (not shown) is installed between them so that it can roll. A lubricant (lubricating oil, grease, etc.) may be supplied around the rolling body and the groove by any lubrication method, so that friction between them can be reduced. When the linear motion part 103 rotates, it is converted into a linear movement (piston movement) via the linear motion part nut 104, and a thrust force is output by the output shaft 102. The movement direction (extension direction or contraction direction) of the output shaft 102 is determined according to the rotation direction of the motor 106.

The motor 106 rotates based on instructions from a control device (not shown). The motor 106 is equipped 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 rotation control is performed based on the detection result. The control device (not shown) may be composed of, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Single Processor), or a dedicated circuit. Although not shown in FIG. 1, the control device (not shown) may further include volatile and non-volatile storage media such as a hard disk drive (HDD), a read only memory (ROM) and a random access memory (RAM), a power supply that supplies power to the motor 106, an inverter, etc.

The rotation of the motor 106 is transmitted to the gear 108 via the connecting portion 107. Each of the gears 108, 109, and 110 has multiple teeth, and as the teeth of each gear mesh and rotate, the rotation of the motor 106 is converted into a predetermined rotation and transmitted 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 the linear motion component 103 can rotate based on the rotational force transmitted via the gear 110. The bearing 112 is also fixed to the housing 101 by a bearing fixing housing 113. Here, an angular ball bearing is shown as an example of the bearing 112, but other types of bearings may be used.

In addition, multiple sealed spaces are formed inside the housing 101. The sealed spaces prevent, for example, the inflow of liquids and the like into the electric actuator 100, thereby realizing waterproofing and dustproofing. Here, four sealed spaces 114, 115, 116, and 117 will be described as an example. The specifications (volume and arrangement) of each sealed space are not particularly limited. Note that, 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.

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.

The electric actuator 100 according to this embodiment is provided with multiple air vents that connect the respective sealed spaces in order to suppress changes in the internal pressure of the sealed spaces that accompany its operation. An air vent 120 is provided in the axial center of the linear motion component 103. The air vent 120 connects the sealed space 114 and the sealed space 117, allowing the gas therein to move between the sealed space 114 and the sealed space 117. Note that the diameter of the air vent 120 is preferably less than half the diameter of the linear motion component 103 in order to prevent a decrease in the strength and rigidity of the linear motion component 103 and the electric actuator 100 as a whole.

Furthermore, one or more vent holes 121 are provided on the output shaft 102 and the linear motion component nut 104 to connect the sealed space 115 and the sealed space 116. The one or more vent holes 121 connect the sealed space 115 and the sealed space 116, allowing gas therein to move between the sealed space 115 and the sealed space 116.

Furthermore, the bearing fixing housing 113 is provided with one or more air vents 122 for connecting the sealed space 116 and the sealed space 117. The one or more air vents 122 connect the sealed space 116 and the sealed space 117, allowing the gas therein 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 this embodiment, the corresponding sealed space 117 is connected to another sealed space, thereby expanding the sealed space. Therefore, the internal pressure of the sealed space 117 changes with the operation of the electric actuator 100.

As described above, in this embodiment, multiple sealed spaces are connected. This configuration makes it 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 is operated. In other words, by connecting the sealed spaces, the degree of freedom of movement of gas within the sealed spaces can be improved. In particular, in this embodiment, sealed spaces whose internal pressure does not change with the operation of the electric actuator in the conventional configuration are further connected. This makes it possible to expand the volume of the entire sealed space, suppress changes in the internal pressure of the entire sealed space, and stabilize the operation of the actuator device. In addition, since ventilation sections are provided in advance in each part of the actuator device, no new additional parts are required, and the structure can be easily configured.

Second Embodiment
A second embodiment of the present invention will be described below. Note that a description of configurations that overlap with the configurations described in the first embodiment will be omitted, and the description will focus on the differences.

[composition]
2 is a schematic cross-sectional view showing an example of the configuration of an electric actuator 200 according to this 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 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, respectively.

In addition, multiple sealed spaces are formed inside the housing 201. The sealed spaces prevent, for example, liquids and the like from flowing 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 in accordance with the operation of the electric actuator 200, similar to the sealed spaces 114 to 117 shown in FIG. 1 of the first embodiment.

The electric actuator 200 according to this embodiment is provided with multiple vents that connect each sealed space to suppress changes in internal pressure. The vent 220 is provided in the axial center of the linear motion component 203. Furthermore, the linear motion component 203 is provided with a vent 222 that connects to the vent 220 in a direction perpendicular to the axial direction. The vent 220 and the vent 222 connect the sealed spaces 214, 216, and 217, allowing gas therein to move between the sealed spaces 214, 216, and 217. Note that the diameter of the vent 220 is preferably less than half the diameter of the linear motion component 203 to prevent a decrease in the strength and rigidity of the linear motion component 203 and the electric actuator 200 as a whole.

Furthermore, one or more vent holes 221 are provided on the output shaft 202 and the linear motion component nut 204 to connect the sealed space 215 and the sealed space 216. The one or more vent holes 221 connect the sealed space 215 and the sealed space 216, allowing gas therein to move between the sealed space 215 and the sealed space 216.

As described above, in this embodiment, multiple air vents are used to connect multiple sealed spaces. With this configuration, it is possible to obtain the same effect as in the first embodiment even if the bearing fixing housing 113 does not have enough space to provide a sufficiently large air vent.

Third Embodiment
A third embodiment of the present invention will be described below. Note that a description of configurations that overlap with the configurations described in the first embodiment will be omitted, and the description will focus on the differences.

[composition]
3 is a schematic cross-sectional view showing an example of the configuration of an 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, a bearing 312, and a bearing fixing housing 313. These 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, respectively.

In addition, multiple sealed spaces are formed inside the housing 301. The sealed spaces prevent, for example, liquids from flowing 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 in response to the operation of the electric actuator 300, similar to the sealed spaces 114 to 117 shown in FIG. 1 of the first embodiment.

The electric actuator 300 according to this embodiment is provided with multiple vents that connect the sealed spaces to suppress changes in internal pressure. One or more vents 320 are provided in the output shaft 302 and the linear motion component nut 304 to connect the sealed spaces 314 to 316. The one or more vents 320 connect the sealed spaces 314 to 316, allowing gas inside them to move between the sealed spaces 314 to 316.

Furthermore, one or more vent holes 321 are provided in the bearing fixing housing 313 to connect the sealed space 316 and the sealed space 317. The one or more vent holes 321 connect the sealed space 316 and the sealed space 317, allowing gas therein to move between the sealed space 316 and the sealed space 317.

As described above, in this embodiment, multiple air vents are used to connect multiple sealed spaces. This configuration makes it possible to obtain the same effect as the first embodiment.

Fourth Embodiment
A fourth embodiment of the present invention will be described below. Note that a description of configurations that overlap with the configurations described in the first embodiment will be omitted, and the description will focus on the differences.

[composition]
4 is a schematic cross-sectional view showing an example of the configuration of an electric actuator 400 according to this 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 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, respectively.

In addition, multiple sealed spaces are formed inside the housing 401. The sealed spaces prevent, for example, liquids from flowing into the electric actuator 400. Here, four sealed spaces 414, 415, 416, and 417 will be described as an example. The specifications (volume and arrangement) of each sealed space are not particularly limited. The sealed spaces 414 to 417 are spaces whose internal pressure changes in accordance with the operation of the electric actuator 400, similar to the sealed spaces 114 to 117 shown in FIG. 1 of the first embodiment.

The electric actuator 400 according to this embodiment is provided with multiple vents and vent grooves that connect the sealed spaces to suppress changes in internal pressure. An air vent 420 is provided in the axial center of the linear motion component 403. The air vent 420 connects the sealed space 414 and the sealed space 417, allowing gas therein to move between the sealed space 414 and the sealed space 417. It is preferable that the diameter of the air vent 420 be half or less of the diameter of the linear motion component 403 to prevent a decrease in the strength and rigidity of the linear motion component 403 and the electric actuator 400 as a whole.

Furthermore, one or more ventilation grooves 421 for connecting the sealed space 415 and the sealed space 416 are provided on the outer circumferential surface of the output shaft 402. The one or more ventilation grooves 421 connect the sealed space 415 and the sealed space 416, allowing the gas therein to move between the sealed space 414 and the sealed space 416. The shape and number of the ventilation grooves 421 are not particularly limited, but are provided taking into consideration the strength and rigidity of the output shaft 402 and the electric actuator 400.

Furthermore, one or more vent holes 422 are provided in the bearing fixing housing 413 to connect the sealed space 416 and the sealed space 417. The one or more vent holes 422 connect the sealed space 416 and the sealed space 417, allowing gas therein to move between the sealed space 416 and the sealed space 417.

As described above, in this embodiment, multiple air vents and air grooves are used to connect multiple sealed spaces. This configuration makes it possible to obtain the same effect as the first embodiment.

Fifth embodiment
Hereinafter, a fifth embodiment of the present invention will be described. Note that a description of configurations that overlap with the configurations shown in the first embodiment will be omitted, and the description will focus on the differences.

[composition]
5 is a schematic cross-sectional view showing an example of the configuration 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, a bearing 512, and a bearing fixing housing 513. These 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, respectively.

In addition, multiple sealed spaces are formed inside the housing 501. The sealed spaces prevent, for example, liquids from flowing 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 in accordance with the operation of the electric actuator 500, similar to the sealed spaces 114 to 117 shown in FIG. 1 of the first embodiment.

In the electric actuator 500 according to this embodiment, a plurality of vent holes and vent grooves are provided to connect the respective sealed spaces in order to suppress changes in internal pressure. A vent hole 520 is provided in the axial center of the linear motion component 503. Furthermore, a plurality of vent grooves 521 are provided along the axial direction on the outer peripheral surface of the linear motion component 503. The vent hole 520 connects the sealed space 514 and the sealed space 517, allowing the gas therein to move between the sealed space 514 and the sealed space 517. The vent groove 521 also connects the sealed space 514 and the sealed space 516, allowing the gas therein to move between the sealed space 514 and the sealed space 516. Note that the diameter of the vent hole 520 is preferably less than half the diameter of the linear motion component 503 in order to prevent a decrease in the strength and rigidity of the linear motion component 503 and the electric actuator 500 as a whole. Additionally, the shape and number of the ventilation grooves 521 are not particularly limited, but they are formed so as not to affect the spiral grooves that form the rolling surfaces of the rolling elements provided on the outer circumferential surface of the linear motion component 503.

Furthermore, one or more vent holes 522 are provided on the output shaft 502 and the linear motion component nut 504 to connect the sealed space 515 and the sealed space 516. The one or more vent holes 522 connect the sealed space 515 and the sealed space 516, allowing gas therein to move between the sealed space 515 and the sealed space 516.

Figure 6 is a diagram for explaining a detailed configuration example of the electric actuator 500 according to this embodiment. Figure 6(a) is an external perspective view of the output shaft 502 and the linear motion component 503. An air vent 520 is provided at the axial center of the linear motion component 503. Figure 6(b) is an external perspective view of the linear motion component 503. A spiral groove 601 is provided on the outer peripheral surface of the linear motion component 503, which serves as the rolling surface of the rolling body. In addition, one or more air vent grooves 521 are provided along the axial direction on the outer peripheral surface of the linear motion component 503.

Figure 6(c) is a view of the output shaft 502 and linear motion part 503 shown in Figure 6(a) viewed from a direction perpendicular to the axial direction. Figure 6(d) is a cross-sectional view taken along section line A in Figure 6(c). The linear motion part 503 and the linear motion part nut 504 each have a spiral groove, with a plurality of rolling elements 602 provided between them. Figure 6(e) is a cross-sectional view taken along section line B in Figure 6(c). Figure 6(f) is a cross-sectional view taken along section line C in Figure 6(c). As shown in Figures 6(d) to (f), ventilation holes 520, 522, and ventilation groove 521 are provided.

As described above, in this embodiment, multiple air vents and air grooves are used to connect multiple sealed spaces. This configuration makes it possible to obtain the same effect as the first embodiment.

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

[composition]
7 is a schematic cross-sectional view showing an example of the configuration of an electric actuator 700 according to this 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, and 710, a gear fixing nut 711, a bearing 712, and a bearing fixing housing 713. These 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, and 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, respectively.

In addition, multiple sealed spaces are formed inside the housing 701. The sealed spaces prevent, for example, liquids and the like from flowing into the electric actuator 700. Here, four sealed spaces 714, 715, 716, and 717 will be described as examples. 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 in response to the operation of the electric actuator 700, similar to the sealed spaces 114 to 117 shown in FIG. 1 of the first embodiment.

In the electric actuator 700 according to this embodiment, a plurality of vent holes and vent grooves are provided to connect the respective sealed spaces in order to suppress changes in internal pressure. A vent hole 720 is provided in the axial center of the linear motion component 703. Furthermore, the linear motion component 703 is provided with a vent hole 723 connected to the vent hole 720 in a direction perpendicular to the axial direction. Furthermore, a plurality of vent grooves 721 are provided along the axial direction on the outer peripheral surface of the linear motion component 703. The vent hole 720 and the vent hole 723 connect the sealed spaces 714, 716, and 717, and the gas therein can move between the sealed spaces 714, 716, and 717. Furthermore, the vent groove 721 connects the sealed spaces 714 and 716, and the gas therein can move between the sealed spaces 714 and 716. In addition, the diameter of the ventilation hole 720 is preferably less than half the diameter of the linear motion component 703 in order to prevent a decrease in the strength and rigidity of the linear motion component 703 and the electric actuator 700 as a whole. In addition, the shape and number of the ventilation grooves 721 are not particularly limited, but they are formed so as not to affect the spiral groove that forms the rolling surface of the rolling body provided on the outer circumferential surface of the linear motion component 703.

Furthermore, one or more ventilation parts 722 for connecting the sealed spaces 714-716 are provided on the output shaft 702 and the linear motion component nut 704. Each of the one or more ventilation parts 722 is composed of a ventilation groove 722a provided on the outer circumferential 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 714-716, allowing gas therein to move between the sealed spaces 714-716.

Furthermore, one or more vent holes 724 are provided in the bearing fixing housing 713 to connect the sealed space 716 and the sealed space 717. The one or more vent holes 724 connect the sealed space 716 and the sealed space 717, allowing gas therein to move between the sealed space 716 and the sealed space 717.

Figure 8 is a diagram for explaining a detailed configuration example of the electric actuator 700 according to this embodiment. Figure 8 (a) is an external perspective view of the output shaft 702 and the linear motion component 703. The outer peripheral surface of the output shaft 702 is provided with an air vent groove 722a that constitutes the air vent 722. Figure 8 (b) is an external perspective view of the linear motion component 703. The outer peripheral surface of the linear motion component 703 is provided with a spiral groove 801 that serves as the rolling surface of the rolling body. In addition, one or more air vent grooves 821 are provided along the axial direction on the outer peripheral surface of the linear motion component 703. In addition, an air vent 720 is provided at the axial center of the linear motion component 703, and an air vent 723 is further provided in a direction perpendicular to the axial direction.

Figure 8(c) is a view of the output shaft 702 and linear motion part 703 shown in Figure 8(a) viewed from a direction perpendicular to the axial direction. Figure 8(d) is a cross-sectional view taken along section line A in Figure 8(c). The linear motion part 703 and the linear motion part nut 704 each have a spiral groove, and a plurality of rolling elements 802 are provided between them. Figure 8(e) is a cross-sectional view taken along section line B in Figure 8(c). Figure 8(f) is a cross-sectional view taken along section line C in Figure 8(c). As shown in Figures 8(d) to (f), ventilation holes 720, ventilation grooves 721, ventilation sections 722 (ventilation grooves 722a and ventilation holes 722b), and ventilation holes 723 are provided.

As described above, in this embodiment, a plurality of air vents and air grooves are used to connect a plurality of sealed spaces together, and this configuration makes it possible to obtain the same effects as those of the first embodiment.
Seventh embodiment
The seventh embodiment of the present invention will be described below. Note that the description of the configuration overlapping with the configuration shown in the first embodiment will be omitted, and the description will focus on the differences. In this embodiment, a form in which a damping effect based on the amount of change in internal pressure is implemented by changing the shape and number of the configuration shown in the sixth embodiment will be described.

[composition]
9 is a schematic cross-sectional view showing an example of the configuration of an electric actuator 900 according to this 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, and 910, a gear fixing nut 911, a bearing 912, and a bearing fixing housing 913. These 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, and 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, respectively.

In addition, multiple 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 in response to the operation of the electric actuator 900, similar to the sealed spaces 114 to 117 shown in FIG. 1 of the first embodiment.

The electric actuator 900 according to this embodiment is provided with multiple air vents and air grooves that connect each sealed space in order to suppress changes in internal pressure and realize a damping effect that utilizes changes in internal pressure. The electric actuator 900 according to this embodiment is provided with air vent 920, air groove 921, ventilation section 922 (air groove 922a and air hole 922b), air hole 923, and air hole 924. These respectively correspond to the air vent 720, air groove 721, ventilation section 722 (air groove 722a and air hole 722b), air hole 723, and air hole 724 provided in the electric actuator 700 shown in FIG. 7 and FIG. 8 in the sixth embodiment.

Figure 10 is a diagram for explaining a detailed configuration example of the electric actuator 900 according to this embodiment. Figure 10 (a) is an external perspective view of the output shaft 902 and the linear motion component 903. A plurality of ventilation grooves 922a constituting the ventilation section 922 are provided on the outer peripheral surface of the output shaft 902. Figure 10 (b) is an external perspective view of the linear motion component 903. A spiral groove 1001 that serves as the rolling surface of the rolling body is provided on the outer peripheral surface of the linear motion component 903. In addition, one or more ventilation grooves 921 are provided along the axial direction on the outer peripheral surface of the linear motion component 903. In addition, 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 perpendicular to the axial direction.

Figure 10(c) is a view of the output shaft 902 and linear motion part 903 shown in Figure 10(a) viewed from a direction perpendicular to the axial direction. Figure 10(d) is a cross-sectional view shown at section line A in Figure 10(c). The linear motion part 903 and the linear motion part nut 904 each have a spiral groove, and a plurality of rolling elements 1002 are provided between them. Figure 10(e) is a cross-sectional view shown at section line B in Figure 10(c). Figure 10(f) is a cross-sectional view shown at section line C in Figure 10(c). As shown in Figures 10(d) to (f), an air vent 920, an air vent groove 921, an air vent 922 (air vent groove 922a and air vent 922b), and an air vent 923 are provided.

In this embodiment, in order to implement a damping effect due to changes in internal pressure, a configuration is shown in which the diameter of the ventilation hole 920, the diameter of the ventilation hole 922b constituting the ventilation section 922, and the diameter of the ventilation hole 924 are made smaller than the configurations of Figures 7 and 8 shown in the sixth embodiment. In addition, the damping effect may be realized by making the dimensions, shape, and number of each ventilation hole different from the configuration of the sixth embodiment. Also, the damping effect may be realized by reducing the dimensions, shape, and number of each ventilation groove, such as the depth and width, compared to the configuration of the sixth embodiment. Furthermore, the damping effect may be realized by combining any of the above, and may be designed according to the size and function of the electric actuator.

As described above, in this embodiment, multiple air vents and air grooves are used to connect multiple sealed spaces. This configuration provides the same effect as the first embodiment, and also makes it possible to implement a damping effect that takes into account changes in internal pressure caused by sealed spaces.

<Other embodiments>
In the above embodiment, a vent hole or a vent groove is provided to connect a plurality of sealed spaces. Furthermore, the vent hole or the vent groove may be provided with a breathable material so that only a predetermined substance (e.g., air) passes through. That is, a filter part is provided for filtering the air when passing through. This makes it possible to prevent the movement of lubricants such as grease and lubricating oil provided around linear motion parts, and to maintain a constant lubricating function. As the breathable material, for example, Gore-Tex (registered trademark) or Neozoic (registered trademark) having a waterproof function, or Strom (registered trademark) having a high breathability and water resistance function may be used.

The present invention can also be realized by providing a program or application for controlling an electric actuator to a system or device via a network or storage medium, and having one or more processors in the computer of the system or device read and execute the program.

It may also be realized by a circuit that realizes one or more functions (for example, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array)).

As such, the present invention is not limited to the above-described embodiment, and the invention also contemplates the mutual combination of the various components of the embodiment, as well as modifications and applications by those skilled in the art based on the description in the specification and well-known technology, and these are included in the scope of the protection sought.

As described above, the present specification discloses the following:
(1) An actuator device comprising a plurality of parts,
a plurality of sealed spaces, the internal pressure of which changes in response to the operation of the actuator device, are formed by at least some of the plurality of portions;
An actuator device, characterized in that at least some of the plurality of portions are provided with ventilation portions for communicating at least two of the plurality of sealed spaces.
According to this configuration, it is possible to suppress the influence of internal pressure changes accompanying the operation of the actuator device while ensuring internal airtightness, thereby improving the stability of the output.

(2) The plurality of portions include
Housing and
A motor;
A screw shaft to which a rotational force from the motor is input;
A connecting mechanism configured to move linearly along the screw shaft as the screw shaft rotates due to the rotational force;
an output shaft connected to the connecting mechanism and moving linearly together with the connecting mechanism to output a thrust force,
The actuator device according to (1), wherein the internal pressure of the plurality of sealed spaces changes when thrust is output by the output shaft.
According to this configuration, it is possible to suppress the influence of internal pressure changes accompanying the operation of the actuator device in accordance with the parts of the actuator device, thereby improving the stability of the output.

(3) The plurality of sealed spaces include
A first sealed space defined within the output shaft;
a second sealed space defined by the output shaft and a support member that supports the output shaft on the housing;
a third sealed space defined by the output shaft, the connecting mechanism, the screw shaft, and the housing;
The actuator device described in (2) is characterized in that it includes at least two sealed spaces: a first sealed space formed within the housing and a second sealed space formed in a space that connects the screw shaft and the motor.
According to this configuration, it is possible to suppress the effects of internal pressure changes accompanying the operation of the actuator device in accordance with the multiple sealed spaces formed within the actuator device, thereby improving the stability of the output.

(4) The actuator device according to (3), wherein the ventilation portion includes a first ventilation hole provided in the screw shaft along an axial direction of the screw shaft, the first ventilation hole allowing ventilation between the first sealed space and the fourth sealed space.
According to this configuration, a configuration in which a ventilation portion is provided for the screw shaft can be used.

(5) The actuator device according to (4), wherein the ventilation portion further includes a second ventilation hole provided in the screw shaft perpendicular to the first ventilation hole, which allows ventilation between the screw shaft and the third sealed space.
According to this configuration, a configuration in which a ventilation portion is provided for the screw shaft can be used.

(6) The actuator device according to any one of (3) to (5), wherein the ventilation portion includes a first ventilation groove provided along the axial direction on an outer peripheral surface of the screw shaft, the first ventilation groove allowing ventilation between the first sealed space and the third sealed space.
According to this configuration, a configuration in which a ventilation portion is provided for the screw shaft can be used.

(7) A fixing member is further provided between the third sealed space and the fourth sealed space to fix a bearing supporting the screw shaft,
The actuator device according to any one of (3) to (6), wherein the ventilation portion includes a third ventilation hole provided in the fixed member to allow ventilation between the third sealed space and the fourth sealed space.
According to this configuration, a configuration in which a ventilation portion is provided in the fixed member of the bearing can be used.

(8) The actuator device according to any one of (3) to (7), wherein the ventilation portion includes a fourth ventilation hole provided inside the output shaft and the connecting mechanism, the fourth ventilation hole allowing ventilation between the second sealed space and the third sealed space.
According to this configuration, a configuration in which ventilation portions are provided for the output shaft and the connecting mechanism (i.e., the linear motion part nut) can be used.

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

(10) The actuator device described in any one of (3) to (7), wherein the ventilation section includes a fifth ventilation hole provided inside the output shaft and the connecting mechanism, which allows ventilation between the first sealed space, the second sealed space, and the third sealed space.
According to this configuration, a configuration in which ventilation portions are provided for the output shaft and the connecting mechanism (i.e., the linear motion part nut) can be used.

(11) The actuator device according to any one of (1) to (10), characterized in that a damping function is provided by adjusting an amount of change in internal pressure of the plurality of sealed spaces using at least one of a shape, a dimension, and a number of the ventilation parts.
According to this configuration, it is possible to realize a damping function by utilizing the ventilation portion.

(12) The actuator device according to any one of (1) to (11), wherein the ventilation section is provided with a filter section made of a predetermined breathable material.
This configuration makes it possible to prevent the movement of lubricants such as grease and lubricating oil, and to maintain a constant lubricating function.

100... Electric actuator 101... Housing 102... Output shaft 103... Linear motion part 104... Linear motion part 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... Ventilation hole

Claims (8)

An actuator device comprising a plurality of parts,
a plurality of sealed spaces, the internal pressure of which changes in response to the operation of the actuator device, are formed by at least some of the plurality of portions;
At least some of the plurality of portions are provided with ventilation portions for communicating at least two of the plurality of sealed spaces ,
The plurality of sites include
Housing and
A motor;
A screw shaft to which a rotational force from the motor is input;
A connecting mechanism configured to move linearly along the screw shaft as the screw shaft rotates due to the rotational force;
an output shaft that is connected to the connecting mechanism and moves linearly together with the connecting mechanism to output a thrust;
Including,
The internal pressure of the plurality of sealed spaces changes when a thrust is output by the output shaft,
The plurality of sealed spaces include
A first sealed space defined within the output shaft;
a second sealed space defined by the output shaft and a support member that supports the output shaft on the housing;
a third sealed space defined by the output shaft, the connecting mechanism, the screw shaft, and the housing;
a fourth sealed space formed in the housing to connect the screw shaft and the motor;
At least two of the following are included:
The ventilation portion includes a first ventilation hole provided in the screw shaft along the axial direction of the screw shaft to allow ventilation between the first sealed space and the fourth sealed space,
The actuator device according to claim 1, wherein the ventilation section further includes a second ventilation hole provided in the screw shaft perpendicular to the first ventilation hole, which allows ventilation between the screw shaft and the third sealed space . 2. The actuator device according to claim 1, wherein the ventilation portion includes a first ventilation groove provided along the axial direction on an outer peripheral surface of the screw shaft, the first ventilation groove allowing ventilation between the first sealed space and the third sealed space. Further, a fixing member is provided between the third sealed space and the fourth sealed space to fix a bearing supporting the screw shaft,
3. The actuator device according to claim 1, wherein the ventilation portion includes a third ventilation hole provided in the fixing member, which allows ventilation between the third sealed space and the fourth sealed space. 4. The actuator device according to claim 1, wherein the ventilation section includes a fourth ventilation hole provided inside the output shaft and the connecting mechanism, the fourth ventilation hole allowing ventilation between the second sealed space and the third sealed space. 5. The actuator device according to claim 1, wherein the ventilation portion includes a second ventilation groove provided on an outer peripheral surface of the output shaft, the second ventilation groove allowing ventilation between the second sealed space and the third sealed space. 4. The actuator device according to claim 1, wherein the ventilation section includes a fifth ventilation hole provided inside the output shaft and the connecting mechanism, the fifth ventilation hole allowing ventilation between the first sealed space, the second sealed space, and the third sealed space. 7. The actuator device according to claim 1 , further comprising: a damping function that provides a damping function by adjusting an amount of change in internal pressure of the plurality of sealed spaces using at least one of a shape, a dimension, and a number of the ventilation parts. 8. The actuator device according to claim 1 , wherein the ventilation portion is provided with a filter portion made of a predetermined breathable material.

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