JP5643076B2 - Geared motor, valve body driving device, and geared motor adjusting method - Google Patents

Description

  The present invention relates to a geared motor, a valve body drive device, and a geared motor adjustment method. More specifically, the present invention relates to an output shaft to which power of a motor is transmitted via a tooth wheel train, and a rotational direction position of the output shaft. The present invention relates to a geared motor adjustment method and a geared motor provided with position detecting means for detection.

  The geared motor has a configuration in which the driving force of the motor is decelerated at a predetermined reduction ratio by a gear train and transmitted to an output shaft. Patent Document 1 describes such a geared motor having a position detecting means for detecting the rotational position of the output shaft (or other rotating shaft).

  In the geared motor (motor with a rotation detection sensor for an opening / closing device) described in Patent Document 1, the driving force of the motor is transmitted to the output shaft through a gear wheel train (deceleration mechanism). The rotation direction position (rotation amount) of the output shaft is determined by detecting the rotation direction position (rotation amount) of the rotating body connected to the output shaft via the toothed wheel train by a position detection means (sensor). That is, the rotational direction position of the output shaft is detected from the rotational direction position of the rotating body in consideration of the reduction (acceleration) ratio of the toothed wheel train.

JP 2001-69722 A

  Such a geared motor for calculating the rotational direction position of the output shaft from the rotational direction position of the rotating body must be assembled in consideration of the rotational direction position of the rotating body with respect to the output shaft. That is, in all products, the rotational direction position of the rotating body with respect to the output shaft (the phase difference between them) must be the same. Therefore, if the geared motor is assembled with the rotational direction position of the rotating body relative to the output shaft deviating from the correct position, it is necessary to disassemble the geared motor once and reassemble so that the positional relationship between the two is correct. The conventional geared motor has a problem that the manufacturing cost increases due to the occurrence of such reassembly work.

  In view of the above problems, the problem to be solved by the present invention is to easily and accurately correct the rotational direction position of the rotating body with respect to the output shaft in a geared motor having a rotating body for detecting the rotational position of the output shaft. An object of the present invention is to provide a geared motor that can be used, and a valve body driving device including the same. Another object of the present invention is to provide a geared motor adjustment method capable of easily and accurately correcting the rotational direction position of a rotating body with respect to an output shaft.

In order to solve the above problems, a geared motor according to the present invention includes a motor as a driving source, power transmission means for transmitting the driving force of the motor to an output shaft, and the driving force of the motor is generated by the power transmission means. A rotating body that is transmitted through a path different from the power transmission path from the motor to the output shaft, and position detecting means that detects a rotational position of the rotating body, and the entire circumference of the rotating body includes: While the detection-side gear portion is formed, the output-side gear portion is formed on the entire circumference of the output shaft or the member that rotates integrally with the output shaft, and between the detection-side gear portion and the output-side gear portion. Includes a speed adjusting means having a compound gear satisfying the following relational expression, and the power transmission path from the detection side gear part to the output side gear part via the speed adjusting means has an output side gear part. Acceleration train and deceleration train are included when viewed from the side Is a = 1, the governor means, one composite having a first transmission gear portion meshed with the detection-side gear unit, a second transmission gear portion meshed with said output-side gear unit, the The first transmission gear part and the second transmission gear part are both set to have one tooth number or one tooth number less than the gear part of the mating counterpart. In addition, the gist of the invention is that the first transmission gear portion and the second transmission gear portion are set to have a different number of teeth .
| Cr-a | <| Cs-b |
Cr: Actual transmission ratio between the rotating body and the output shaft with speed control means (not a natural number)
a: Natural number closest to Cr, excluding 0 Cs: Gear ratio of the rotating body and the output shaft when it is assumed that the detection-side gear portion and the output-side gear portion are directly meshed (but not a natural number)
b: natural number excluding 0, which is closest to Cs

  In the present invention, the “speed ratio” is always greater than 1. In other words, the “transmission ratio” in the present invention means that the ratio of the angular speeds of the detection side gear part and the output side gear part is always larger than 1 (the angular speed of the faster gear part / the angular speed of the slow gear part). (The same applies hereinafter).

  The geared motor according to the present invention rotates the rotating body (detection side gear portion) and the output shaft (output side gear portion) whose position detection means detects the position in the rotation direction. The speed ratio of the both of which the speed adjusting means is interposed is not a natural number, that is, not an integer multiple, so that each time one of the gear portions rotates one or more, the meshing position (relative to the rotational direction position of one gear portion). The position of the other gear portion in the rotational direction (hereinafter sometimes simply referred to as a relative position) changes. That is, the position of the rotating body in the rotational direction relative to the output shaft can be adjusted to the correct position simply by driving the motor and rotating both. Therefore, even after the geared motor is assembled, both can be corrected to the correct positional relationship without once removing and reassembling the output shaft and the rotating body.

  Further, the degree of change in relative position (| Cr-a |) that changes every time one of the gears rotates one or more is assumed to be in direct meshing between the gears without using the speed control means. The degree of change in the relative position (| Cs−b |) is smaller than the above. That is, the detection-side gear portion and the output-side gear portion are smaller than the case where the detection-side gear portion and the output-side gear portion are directly meshed by the speed adjusting means interposed between the detection-side gear portion and the output-side gear portion. Therefore, the rotational direction position of the rotating body can be accurately matched to the rotational direction position of the output shaft. Thereby, the position of the output shaft in the rotational direction is more accurately detected by the position detection means.

Further , the gear ratio can be made closer to 1 than when the power transmission path from the detection side gear portion to the output side gear portion via the speed adjusting means is configured by only the speed increasing gear train or the speed reducing gear train. That is, since the relative position of the detection-side gear portion and the output-side gear portion can be changed in smaller increments, the rotational direction position of the rotating body can be more accurately matched to the rotational direction position of the output shaft.

Further , the actual gear ratio Cr of the detection side gear portion and the output side gear portion in which the speed adjusting means is interposed becomes a value closer to 1.

  An example of the position detecting means is a potentiometer.

  As described above, since it is possible to accurately match the rotational direction position of the rotating body with respect to the rotational direction position of the output shaft, when the position detecting means is a potentiometer, the potentiometer's detection range should be effectively used over a wide range. Can do. This is because it is not necessary to set the detection range of the potentiometer to be used in consideration of the deviation of the rotational direction position of the rotating body from the rotational direction position of the output shaft.

  The potentiometer may be mounted on a rigid board fixed to the apparatus main body.

  Thus, if the potentiometer is mounted on a rigid board that is fixed so as not to move, it is difficult to adjust the position of the potentiometer after the device is assembled. The above configuration that can accurately set the rotational direction position of the rotating body is particularly effective.

  In order to solve the above problems, a valve body drive device according to the present invention includes any one of the above geared motors, and the output shaft is connected to a valve body that changes the size of an opening through which a fluid passes. It is a summary.

  As described above, when the geared motor is used in the valve body drive device, the rotational direction position of the rotating body with respect to the rotational direction position of the output shaft can be set accurately, so that the fluid flow rate can be accurately controlled.

  In this case, the origin position of the output shaft may be a position where the fluid flow is blocked by the valve body.

  As described above, since the rotational direction position of the rotating body with respect to the rotational direction position of the output shaft can be set accurately, the origin position of the output shaft can also be accurately detected. Therefore, the fluid flow can be reliably blocked (fluid leakage in the closed state can be reliably prevented).

In order to solve the above problems, the geared motor adjustment method according to the present invention includes a motor as a drive source, power transmission means for transmitting the drive force of the motor to an output shaft, and the drive force of the motor. Adjustment of a geared motor comprising: a rotating body transmitted by a path different from a power transmission path from the motor to the output shaft by the power transmitting means; and a position detecting means for detecting a rotational position of the rotating body. In the method, a detection-side gear portion is formed on the entire circumference of the rotating body, and an output-side gear portion is formed on the entire circumference of the output shaft or a member that rotates integrally with the output shaft. Between the rotating body and the output shaft, a speed control unit having a composite gear satisfying the following relational expression is interposed, and a power transmission path from the detection side gear unit to the output side gear unit via the speed control unit From the output side gear section side A speed increasing gear train and a speed reducing gear train, and the speed adjusting means includes a first transmission gear portion meshed with the detection side gear portion, and a second transmission gear portion meshed with the output side gear portion. And the first transmission gear part and the second transmission gear part are both set to have one more tooth than the gear part of the mating counterpart, or the number of teeth is reduced by one. And setting the first transmission gear portion and the second transmission gear portion so that the number of teeth is different from each other, and driving the motor after the geared motor is assembled. The gist is that the output shaft is rotated, and the rotational direction position of the rotating body with respect to the rotational direction position of the output shaft is adjusted to a correct position.
| Cr-a | <| Cs-b |
Cr: Actual transmission ratio between the rotating body and the output shaft with speed control means (not a natural number)
a: Natural number closest to Cr, excluding 0 Cs: Gear ratio of the rotating body and the output shaft when it is assumed that the detection-side gear portion and the output-side gear portion are directly meshed (but not a natural number)
b: natural number excluding 0, which is closest to Cs

  According to the geared motor, the valve body driving device, and the geared motor according to the present invention, the direct detection side gear portion and the output side gear portion are directly controlled by the speed adjusting means interposed between the detection side gear portion and the output side gear portion. Since the relative position of the detection-side gear portion and the output-side gear portion can be changed in smaller increments than when the gears are engaged with each other, the rotational direction position of the rotating body with respect to the rotational direction position of the output shaft can be accurately matched.

It is a disassembled perspective view of the geared motor concerning 1st embodiment. It is an external view (state which removed the upper case) of the geared motor shown in FIG. FIG. 3 is an external view of the geared motor viewed from a direction different from that in FIG. 2 (with the upper case removed). The configuration (number of teeth) of the rotating body (detection side gear portion), the fourth gear (output side gear portion), and the composite gear (first transmission gear portion and second transmission gear portion) according to the first specific example. It is the schematic for demonstrating. The configuration (number of teeth) of the rotating body (detection side gear portion), the fourth gear (output side gear portion), and the composite gear (first transmission gear portion and second transmission gear portion) according to the second specific example. It is the schematic for demonstrating. The configuration (number of teeth) of the rotating body (detection side gear portion), the fourth gear (output side gear portion), and the composite gear (first transmission gear portion and second transmission gear portion) according to the third specific example. It is the schematic for demonstrating. It is a figure for demonstrating the valve body drive device concerning one Embodiment of this invention, and is a top view of the valve body with which a valve body drive device is provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an exploded perspective view of a geared motor 1 according to the present embodiment (first embodiment), and FIGS. 2 and 3 are external views of the geared motor 1 (with the lower case 71 and the upper case 72 removed). It is. In the following description, the vertical direction is the vertical direction in FIG.

  The geared motor 1 according to the present embodiment includes a motor 10 serving as a driving source, a tooth wheel train 20 (corresponding to power transmission means in the present invention) that transmits the driving force of the motor 10, a rotating body 30, A speed control means interposed between the gear (the fourth gear 24) and the rotating body 30, a (rotary) potentiometer 40 (corresponding to the position detecting means in the present invention) for detecting the position of the rotating body 30, and a potentiometer 40, a second substrate 60 for electrically connecting the motor 10 to a power source and the like, a case 70 for accommodating these members, a first substrate 50 and a second substrate And a connector portion 80 electrically connected to the substrate 60.

  A first gear 21 constituting a toothed wheel train 20 is integrally formed on the rotating shaft 11 of the motor 10. The motor 10 is attached in contact with the lower surface of the support plate 73 constituting the case 70. A through hole is formed in the approximate center of the support plate 73, and the first gear 21 fixed to the rotating shaft 11 protrudes on the support plate 73.

  The toothed wheel train 20 is composed of four gears in this embodiment. As described above, the first gear 21 formed integrally with the rotating shaft 11 of the motor 10 rotates together with the rotating shaft 11. The second gear 22 meshes with the first gear 21 while being rotatably supported by the support plate 73. Specifically, the large-diameter gear portion (lower gear portion) 221 in the second gear 22 meshes with the first gear 21. The third gear 23 meshes with the second gear 22 while being rotatably supported by the support plate 73. Specifically, the large-diameter gear portion (lower gear portion) 231 in the third gear 23 meshes with the small-diameter gear portion (upper gear portion) 222 in the second gear 22. The fourth gear 24 meshes with the third gear 23 while being rotatably supported by the support plate 73. Specifically, the large diameter gear portion 241 in the fourth gear 24 meshes with the small diameter gear portion (upper gear portion) 232 in the third gear 23. The driving force of the motor 10 is transmitted to the fourth gear 24 through the first gear 21, the second gear 22, and the third gear 23 at a predetermined reduction ratio.

  A connection hole 242 for fixing the output shaft 90 is formed at the upper end of the fourth gear 24. That is, the output shaft 90 rotates integrally with the fourth gear 24. On the other hand, an output side gear portion 243 (illustrated by a dotted line in FIG. 1) having a smaller diameter than the large diameter gear portion 241 is formed below the large diameter gear portion 241 in the fourth gear 24.

  The rotating body 30 is connected to the fourth gear 24 through speed control means. In the present embodiment, the speed control means is composed of one compound gear 35. The compound gear 35 has a first transmission gear portion 351 and a second transmission gear portion 352. The detection-side gear portion 31 formed at the upper end of the rotating body 30 meshes with the first transmission gear portion 351 of the compound gear 35. On the other hand, the large-diameter gear portion 241 of the fourth gear 24 meshes with the second transmission gear portion 352 of the compound gear 35. Therefore, the power of the motor 10 is transmitted from the fourth gear to the rotating body 30 via the compound gear 35. That is, the power of the motor 10 is transmitted to the rotating body 30 through a path different from the power transmission path from the motor 10 to the output shaft 90.

  A part of the rotating body 30 is supported by the potentiometer 40. That is, the potentiometer 40 functions as a position detection unit that detects the rotational position of the rotating body 30 (output shaft 90), and also functions as a bearing member that rotatably supports the rotating body 30.

  The potentiometer 40 is a ring-shaped position detection element that detects the rotational position (rotation amount) of the rotating body 30. The rotating body 30 is inserted inside the potentiometer 40 and is rotatably supported by the potentiometer 40. The potentiometer 40 preferably has a general configuration using a variable resistor. Specifically, an annular resistor (pattern) is formed inside the element, and when the rotating body 30 rotates, a conductor brush slides on the resistor, and the resistance value of the resistor changes. In general, the detection range is 0 degree to less than 360 degrees, but in this embodiment, the type in which the brush slides on the resistor is not the type in which the resistor and the terminal are mechanically connected. Therefore, there is no problem even if it is rotated 360 degrees or more in one direction (no problem occurs in the potentiometer 40). The potentiometer 40 having such a configuration is mounted on the first substrate 50.

  The first substrate 50 is fixed so as not to move on the support plate 73. That is, the first substrate is fixed to the case 70 (device main body). The potentiometer 40 is mounted on the upper surface of the first substrate 50. The first substrate 50 must be a substrate (rigid substrate) whose base material is made of a hard resin. This is because the first substrate 50 is a substrate on which the potentiometer 40 that supports the rotating body 30 is mounted. If the substrate is a so-called flexible substrate, the potentiometer 40 cannot function as a bearing.

  In addition, a predetermined number (three in this embodiment) of through holes 51 are formed at the end of the first substrate 50. A pin 82 for position detecting means constituting the connector portion 80 is inserted into the through hole 51. The position detecting means pin 82 inserted through the through hole 51 is electrically connected to the potentiometer 40 via the first substrate 50.

  The second substrate 60 is a substrate for electrically connecting power supply terminal pins of the motor 10 (not shown) and motor pins 81 constituting the connector unit 80. In this embodiment, the 2nd board | substrate 60 is what is called a flexible substrate comprised with the base material which has flexibility. However, the substrate is not necessarily a flexible substrate, and may be a rigid substrate, like the first substrate 50.

  These constituent members are accommodated in the case 70. The case 70 includes a lower case 71, an upper case 72, and a support plate 73. The lower case 71 is formed with a recessed portion that is recessed in a cylindrical shape, and the motor 10 is accommodated in the recessed portion. The support plate 73 is attached to the lower case 71 so as to cover the motor 10 accommodated in the lower case 71.

  The upper case 72 is attached to the lower case 71 so as to cover the toothed wheel train 20 and the rotating body 30 supported by the support plate 73. An output hole 721 is formed on the upper surface of the upper case 72. The upper surface of the fourth gear 24, that is, the connection hole 242 is exposed outside the output hole 721. That is, the output shaft 90 can be fixed from the outside of the case 70.

  The connector portion 80 is a portion into which a connector (not shown) that connects the geared motor 1 and an external device that controls the geared motor 1 is fitted. The connector 80 includes a motor pin 81 and a position detection means pin 82 that constitute input / output terminals. These terminal pins are fixed to a connector fitting portion 711 formed integrally with the lower case 71. Specifically, the connector fitting portion 711 is a substantially box-shaped portion provided in the lower case 71. The motor pin 81 and the position detection means pin 82 are fixed to the connector fitting portion 711.

  The position detecting means pin 82 is inserted into a through hole 51 formed in the first substrate 50 which is a rigid substrate, and is soldered to a land formed on the substrate. The motor pin 81 is inserted into a through hole 61 formed in the second substrate 60 which is a flexible substrate, and is soldered to a land formed on the substrate.

  As described above, in the present embodiment, the position detecting means pin 82 which is a part of the terminal pin constituting the connector unit 80 is connected to the first substrate 50 and electrically connected to the potentiometer 40, The other part of the motor pin 81 is connected to the second substrate and is electrically connected to the motor 10.

  The geared motor 1 having the above configuration operates as follows. When power is supplied to the motor 10 through the motor pin 81, the rotary shaft 11 rotates. When the rotating shaft 11 rotates, the first gear 21 formed integrally therewith rotates, and the power of the motor is transmitted in the order of the second gear 22, the third gear 23, and the fourth gear 24. Due to the rotation of the fourth gear 24, the output shaft 90 fixed to the tip thereof also rotates. Further, the rotation of the fourth gear 24 causes the compound gear 35 having the second transmission gear portion 352 that meshes with the output side gear portion 243 to rotate. When the compound gear 35 rotates, the rotating body 30 having the detection-side gear portion 31 that meshes with the first transmission gear portion 351 rotates. When the rotating body 30 rotates, the resistance value of the potentiometer 40 changes. From this change, the rotational direction position of the rotating body 30 is calculated, and the rotational position of the fourth gear 24 that meshes with the rotating body 30, that is, the output shaft 90 is calculated. The calculated rotational direction position of the output shaft 90 is output as a signal to an external control device or the like through the position detection means pin 82.

  Hereinafter, characteristics of the geared motor 1 according to the present embodiment will be described. When the geared motor 1 is assembled, the origin position of the fourth gear 24 (output shaft 90) and the origin position of the rotating body 30 are matched (the rotational direction position of the rotating body 30 with respect to the rotational direction position of the fourth gear 24). It is necessary to have a correct positional relationship). This is because the correct position in the rotation direction of the fourth gear 24 (that is, the output shaft 90) can be calculated from the position in the rotation direction of the rotating body 30 by this origin position alignment. The “origin” here does not need to be a so-called zero point. This is a point that serves as a guide for making the positional relationship between the two correct. Hereinafter, a configuration for accurately performing this correction (a geared motor adjusting method according to the present invention) will be described with reference to examples.

Example 1
In the first embodiment, the number of teeth of the first transmission gear portion 351 and the second transmission gear portion 352 of the compound gear 35 are both engaged with each other (the detection side gear portion 31 and the output side gear portion 243). One more than the number of teeth. Further, the number of teeth of the first transmission gear portion 351 and the number of teeth of the second transmission gear portion 352 are set to be different from each other. That is, the number of teeth of the first transmission gear portion 351 is A, the number of teeth of the second transmission gear portion 352 is B, the number of teeth of the detection-side gear portion 31 is C, and the number of teeth of the output-side gear portion 243 is D. Then
A = C + 1
B = D + 1
| A-B | = 1
The relationship is established. As an example satisfying this relationship, the number of teeth A of the first transmission gear portion 351 is 26, the number of teeth B of the second transmission gear portion 352 is 27, and the number of teeth C of the detection-side gear portion 31 is 25. A case where the number of teeth D of the output side gear portion 243 is 26 is mentioned (specific example 1 shown in FIG. 4). In this case, the first transmission gear portion 351 and the detection side gear portion 31 are viewed from the output side gear portion side, and the output side gear portion 243 and the second transmission gear portion 352 are on the output side gear portion side. A reduction gear train is formed as viewed from the side.

  This specific example 1 will be examined. In this case, the transmission gear ratio Cr between the rotating body 30 (detection side gear portion 31) with the compound gear 35 interposed and the output shaft 90 (output side gear portion 243) is (A / C) × (D / B) = (26/25) × (26/27) = 1.014148 (“speed ratio” in the present invention means that the ratio of the angular velocities of the detection side gear portion 31 and the output side gear portion 243 is always 1) Since (A / C) × (D / B) <1, it is calculated so as to increase (so that the angular speed of the faster gear part / the angular speed of the slow gear part). (C / A) × (B / D) becomes the gear ratio Cr). That is, when the output side gear portion 243 rotates “1”, the detection side gear portion 31 rotates “1.001481”. That is, every time the output side gear unit 243 makes one rotation, the rotational direction position (relative position) of the detection side gear unit 31 with respect to the rotational direction position of the output side gear unit 243 is shifted by 0.001481 × 360 = 0.53 degrees. It will follow. Thus, each time either one of the detection-side gear portion 31 and the output-side gear portion 243 makes one rotation, the relative position of both shifts, so that the relative position of both can finally be set correctly. . Furthermore, since the speed control means is composed of only one compound gear 35, it contributes to downsizing of the apparatus.

  In addition, the amount of change in the relative position for each rotation is as very small as 0.53 degrees. Therefore, the accuracy of adjusting the relative position is extremely high. This is because the compound gear 35 (speed control means) is interposed between the detection side gear portion 31 and the output side gear portion 243. For example, if the compound gear 35 does not exist in the condition of the specific example 1, and the detection side tooth portion 31 and the output side gear portion 243 are directly meshed with each other, the gear ratio Cs is (D / C) = ( 26/25) = 1.04 (Note that the gear ratio Cs is also calculated to be greater than 1. That is, the number of teeth of the detection-side gear unit 31 is greater than the number of teeth of the output-side gear unit 243. If there are many, the gear ratio Cs = (C / D)). Therefore, the amount of change in the relative position every time the output side gear portion 243 makes one rotation is 0.04 × 360 = 14.4 degrees. Thus, the amount of change in the relative position when the compound gear 35 is not present is larger than when the compound gear 35 is present. In order to achieve the same accuracy as described above without using the compound gear 35, the number of teeth of the detection side gear unit 31 must be 675, and the number of teeth of the output side gear unit 243 must be 676. This will lead to an increase in size.

  As described above, according to the present embodiment, the relative position of each of the detection side gear unit 31 and the output side gear unit 243 slightly changes every time one of the detection side gear unit 31 and the output side gear unit 243 makes one rotation. Can be adapted to That is, the rotation of the rotating body 30 relative to the rotational position of the fourth gear 24 and the output shaft 90 connected to the fourth gear 24 without removing and reassembling the fourth gear 24 and the rotating body 30 once incorporated in the case 70. The directional position can be corrected very accurately.

(Example 2)
In the first embodiment, the number of teeth of the first transmission gear portion 351 and the second transmission gear portion 352 of the compound gear 35 is the same as that of the mating gear portion (the detection side gear portion 31 and the output side gear portion 243). ), Which is one more than the number of teeth, but may be reduced by one as follows. That is, the number of teeth of the first transmission gear portion 351 is A, the number of teeth of the second transmission gear portion 352 is B, the number of teeth of the detection-side gear portion 31 is C, and the number of teeth of the output-side gear portion 243 is D. Then
A = C-1
B = D-1
| A-B | = 1
The number of teeth of each gear portion is set so that the relationship is established. As an example satisfying this relationship, the number of teeth A of the first transmission gear portion 351 is 24, the number of teeth B of the second transmission gear portion 352 is 24, and the number of teeth C of the detection-side gear portion 31 is 25. A case where the number D of teeth of the output side gear portion 243 is 26 is mentioned (specific example 2 shown in FIG. 5). In this case, the first transmission gear portion 351 and the detection side gear portion 31 are viewed from the output side gear portion side, and the output gear portion 243 and the second transmission gear portion 352 are viewed from the output side gear portion side. A speed increasing wheel train is formed as seen.

  This specific example 2 will be examined. In this case, since (A / C) × (D / B) = (24/25) × (26/25) = 0.9984, which is less than 1, the rotating body 30 with the compound gear 35 interposed (detection) The gear ratio between the side gear portion 31) and the output shaft 90 (output side gear portion 243) is (C / A) × (B / D) = (25/24) × (25/26) = 1.0001603. Become. That is, when the detection-side gear unit 31 rotates “1”, the output-side gear unit 243 rotates “1.0001603”. That is, every time the output side gear portion 243 makes one rotation, the relative position shifts by 0.001603 × 360 = 0.58 degrees. As described above, even if the number of teeth of the first transmission gear portion 351 and the second transmission gear portion 352 of the compound gear 35 is both one less than the number of teeth of the mating gear portion, the above-described implementation is performed. The same effect as in Example 1 can be expected. Furthermore, since the speed control means is composed of only one compound gear 35, it contributes to downsizing of the apparatus.

Example 3
In the first example (specific example 1) and the second example (specific example 2), when at least one of the detection-side gear unit 31 and the output-side gear unit 243 makes one rotation, the relative position between the two is minute. Although the configuration is changed, as described below, when either one makes one rotation and the other makes about two rotations, the relative position of both may be changed slightly. As an example satisfying this relationship, the number of teeth A of the first transmission gear unit 351 is 25, the number of teeth B of the second transmission gear unit 352 is 24, and the number of teeth C of the detection-side gear unit 31 is 26. A case where the number of teeth D of the output side gear portion 243 is 50 is mentioned (specific example 3 shown in FIG. 6).

  This specific example 3 will be examined. In this case, the gear ratio of the rotating body 30 (detection side gear portion 31) with the compound gear 35 interposed and the output shaft 90 (output side gear portion 243) is (25/26) × (50/24) = 2. It becomes 003205. That is, when the output side gear portion 243 rotates “1”, the detection side gear portion 31 rotates “2.003205”. That is, every time the output side gear portion 243 makes one rotation, the relative position shifts by 0.003205 × 360 = 1.15 degrees. As described above, even in the case where one of the detection-side gear unit 31 and the output-side gear unit 243 makes one rotation and the other makes about two rotations (except when the rotation is just two rotations), the above embodiment The same effect as in Example 1 and Example 2 can be expected. For example, if the compound gear 35 does not exist in the condition of the specific example 3 and the detection side gear unit 31 and the output side gear unit 243 are directly meshed with each other, the gear ratio is 50/26 = 1. 9231. Therefore, the amount of change in the relative position every time the output side gear portion 243 makes one rotation and the detection side gear portion 31 makes about two rotations is (2−1.0231) × 360 = 27.7 °.

  The third embodiment (specific example 3) is configured such that when one of the detection-side gear portion 31 and the output-side gear portion 243 rotates once, the other rotates approximately twice, but one rotates once. Then, the same effect can be expected even when the other makes about 3 rotations, about 4 rotations, about 5 rotations, and so on. That is, if one gear part makes one rotation and the other gear part rotates about an integral multiple, the relative position with respect to the other gear part is set so as to change slightly. The same effect can be expected.

  As can be seen from Examples 1 to 3 described above, according to the geared motor according to the present embodiment, the output of the composite gear 35 interposed between the detection-side gear portion 31 and the output-side gear portion 243 is caused. The rotational direction position of the rotating body 30 relative to the rotational direction position of the shaft 90 can be accurately corrected. That is, the compound gear 35 only needs to have a function of reducing the amount of change in the relative position as compared with the case where it is assumed that the detection side gear portion 31 and the output side gear portion 243 are directly meshed with each other. This point is expressed by the following relational expression.

| Cr-a | <| Cs-b |
Cr: Actual transmission ratio between the rotating body and the output shaft with speed control means (not a natural number)
a: Natural number closest to Cr, excluding 0 Cs: Gear ratio of the rotating body and the output shaft when it is assumed that the detection-side gear portion and the output-side gear portion are directly meshed (but not a natural number)
b: natural number excluding 0, which is closest to Cs

  The “| Cr−a |” is an index representing the relative position adjustment accuracy in an actual geared motor, and the smaller the value, the higher the accuracy. A value obtained by multiplying this value by 360 (degrees) is a change amount (angle) of the relative position (for example, | Cr−a | = 0.001481 in the above specific example 1). On the other hand, “| Cs−b |” is an index indicating the adjustment accuracy of the relative position when it is assumed that the detection-side gear unit 31 and the output-side gear unit 243 are directly meshed (for example, the specific example 1 described above). Then, | Cs−a | = 0.04). In other words, if “| Cr−a |” is smaller than “| Cs−b |”, both of them can be obtained by interposing the compound gear 35 between the detection side gear portion 31 and the output side gear portion 243. It can be said that the relative position adjustment accuracy has improved.

  Further, in the above embodiment, the number of teeth of the first transmission gear portion 351 and the second transmission gear portion 352 of the compound gear 35 is the same as that of the mating gear portion (the detection side gear portion 31 and the output side gear portion). One more or less than the number of teeth of 243). The number of teeth of the first transmission gear portion 351 and the number of teeth of the second transmission gear portion 352 are different from each other. With this setting, the actual gear ratio Cr between the detection-side gear unit 31 and the output-side gear unit 243 with the compound gear 35 interposed therebetween is a value closer to a natural number (integer multiple). That is, since the relative position can be changed in smaller increments, the relative position adjustment accuracy is further improved. Furthermore, since the speed control means is composed of only one compound gear 35, it contributes to downsizing of the apparatus.

  Moreover, in this embodiment, since the potentiometer 40 is used as a position detection means, the detection range of the potentiometer 40 can be used effectively over a wide range. This is because it is not necessary to set the detection range of the potentiometer 40 to be used in consideration of the deviation (assembly error, etc.) of the rotational body 30 relative to the rotational position of the output shaft 90 (fourth gear 24). .

  The potentiometer 40 is mounted on a first substrate 50 (rigid substrate) fixed to the apparatus main body, and it is difficult to adjust the position of the potentiometer 40 after the apparatus is assembled. Therefore, the above-described configuration that can accurately set the rotational direction position of the rotating body 30 with respect to the rotational direction position of the output shaft 90 (fourth gear 24) is particularly effective.

  Next, the valve body drive device to which the geared motor 1 is applied will be described. As an example of this valve element driving device (an example of a valve element), the configuration shown in FIG. In the valve body driving device, a valve body 92 is connected to the output shaft 90 via a power conversion mechanism 91, and the rotation of the output shaft 90 is output as a linear operation of the valve body 92. Specifically, the valve body 92 (valve body shaft 921) is prevented from rotating, and the male thread portion 9211 of the valve body shaft 921 is screwed into a female screw member 901 that rotates integrally with the output shaft 90. The valve body 92 that moves back and forth in the axial direction of the valve body shaft 921 changes the size of the flow path through which the fluid passes. In a state where the output shaft 90 is at the origin position, the valve body 92 completely covers the opening O (the valve body 92 is located at a location indicated by a dotted line in FIG. 7). That is, the flow of the fluid is interrupted, and the flow rate of the output fluid becomes zero. When the output shaft 90 is rotated so that the valve body 92 moves downward, the fluid flow path gradually increases. The flow rate of the fluid to be output changes according to the size of the portion. That is, the flow rate of the fluid changes according to the rotational direction position of the output shaft 90.

  As described above, when the geared motor 1 is applied to the valve body drive device, the geared motor 1 can accurately set the rotational direction position of the rotating body with respect to the rotational direction position of the output shaft 90 as described above. A valve body drive device that can be accurately controlled is obtained. Further, since the origin position of the output shaft 90 is also accurately detected, the origin position of the output shaft 90 is set to a position at which the fluid flow is completely blocked by the valve body 92 as in the above-described valve body driving device. Therefore, the flow of the fluid can be reliably blocked (the leakage of the fluid in the closed state can be reliably prevented).

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

  For example, in the above embodiment, the gear that meshes with the rotating body 30 is the fourth gear 24, but the gear that meshes with the rotating body 30 may be another gear. In other words, any one of the gears constituting the tooth wheel train 20 may be used.

  In the above-described embodiments (each example), it has been described that the speed adjusting means is composed of one compound gear 35, but this satisfies the relational expression "| Cr-a | <| Cs-b |". If so, the speed control means may have a plurality of compound gears.

DESCRIPTION OF SYMBOLS 1 Geared motor 10 Motor 11 Rotating shaft 20 Toothed wheel train 24 Fourth gear 243 Output side gear unit 30 Rotating body 31 Detection side gear unit 35 Compound gear (transmission gear train)
351 1st transmission gear part 352 2nd transmission gear part 40 Potentiometer (position detection means)
70 Case 90 Output shaft

Claims (6)

A motor as a drive source;
Power transmission means for transmitting the driving force of the motor to the output shaft;
A rotating body in which the driving force of the motor is transmitted by a path different from the power transmission path from the motor to the output shaft by the power transmission means;
Position detecting means for detecting the rotational position of the rotating body,
A detection side gear portion is formed on the entire circumference of the rotating body, while an output side gear portion is formed on the entire circumference of the output shaft or a member that rotates integrally with the output shaft,
Between the detection side gear portion and the output side gear portion, a speed control means having a compound gear that satisfies the following relational expression is interposed :
The power transmission path from the detection side gear part to the output side gear part via the speed control means includes a speed increasing wheel train and a speed reducing wheel train as seen from the output side gear part side, and a = 1.
The speed adjusting means is composed of one compound gear having a first transmission gear portion meshed with the detection side gear portion and a second transmission gear portion meshed with the output side gear portion, Both the one transmission gear part and the second transmission gear part have one tooth number more than the gear part of the mating counterpart, or the tooth number is set to one less,
The geared motor, wherein the first transmission gear part and the second transmission gear part are set so that the number of teeth is different by one .
| Cr-a | <| Cs-b |
Cr: Actual transmission ratio between the rotating body and the output shaft with speed control means (not a natural number)
a: Natural number closest to Cr, excluding 0 Cs: Gear ratio of the rotating body and the output shaft when it is assumed that the detection-side gear portion and the output-side gear portion are directly meshed (but not a natural number)
b: natural number excluding 0, which is closest to Cs It said position detecting means is a potentiometer geared motor according to claim 1. The geared motor according to claim 2 , wherein the potentiometer is mounted on a rigid board fixed to the apparatus main body. A valve body drive device comprising the geared motor according to any one of claims 1 to 3 ,
The said output shaft is a valve body drive device connected with the valve body which changes the magnitude | size of the opening part which a fluid passes. The valve body drive device according to claim 4 , wherein the origin position of the output shaft is a position where a flow of fluid is blocked by the valve body. A motor as a drive source;
Power transmission means for transmitting the driving force of the motor to the output shaft;
A rotating body in which the driving force of the motor is transmitted by a path different from the power transmission path from the motor to the output shaft by the power transmission means;
A position detecting means for detecting a rotational position of the rotating body, and a geared motor adjustment method comprising:
A detection-side gear portion is formed on the entire circumference of the rotating body, and an output-side gear portion is formed on the entire circumference of the output shaft or a member that rotates integrally with the output shaft. Between the output side gear portion, interposing a speed control means having a compound gear satisfying the following relational expression,
The power transmission path from the detection side gear part to the output side gear part via the speed adjusting means includes a speed increasing wheel train and a speed reducing wheel train as viewed from the output side gear part side,
The speed control means includes a first transmission gear portion that meshes with the detection-side gear portion, and a second transmission gear portion that meshes with the output-side gear portion, and the first transmission gear portion; The second transmission gear part is set to one tooth number more than the gear part of the mating counterpart, or the tooth number is set to one less,
The first transmission gear part and the second transmission gear part are set so that the number of teeth is different by one,
After assembling the geared motor, the rotating body and the output shaft are rotated by driving the motor, and the rotational direction position of the rotating body with respect to the rotational direction position of the output shaft is adjusted to a correct position. .
| Cr-a | <| Cs-b |
Cr: Actual transmission ratio between the rotating body and the output shaft with speed control means (not a natural number)
a: Natural number closest to Cr, excluding 0 Cs: Gear ratio of the rotating body and the output shaft when it is assumed that the detection-side gear portion and the output-side gear portion are directly meshed (but not a natural number)
b: natural number excluding 0, which is closest to Cs

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