JP2000308303A - Driving equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain driving equipment in which noise is reduced. SOLUTION: A case for driving equipment is constituted of a lower case 21 and an upper case stuck on the lower case 21. A DC motor and a reduction gear, which decelerates and outputs the rotation of the DC motor at a prescribed speed reduction ratio are accommodated in the case. The DC motor is fixed to the lower case 21, and a rib 24, having a recessed part 24a into which the tip of an output shaft 2 of the DC motor is inserted, is protruded from the lower case 21. A slit groove 24b, stretching in the direction almost perpendicular to the axial direction of the output shaft 2, is formed in the rib 24. In both end portions of the bottom of the slit trench 24b, stepped parts 24c which is higher than the central part by one step are formed. Inside the slit groove 24b, a wire spring is arranged bridging both of the stepped parts 24c, and pressed and bent downward in figure by the output shaft 2. Through the spring restoring force of the wire spring 4, the output shaft 2 is pressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device.

[0002]

2. Description of the Related Art Conventionally, gas water heaters, oil water heaters, and the like have a valve in which the amount of hot water changes in accordance with the opening degree, and the hot water temperature is controlled to a predetermined temperature by adjusting the opening degree of the valve. To drive such a valve,
A driving device including a DC motor and a transmission mechanism that transmits the rotation of the DC motor to the outside while reducing the rotation of the DC motor at a predetermined reduction ratio has been used.

[0003]

As shown in FIG. 8, a brush-equipped DC motor 1 is used as the driving device.
And a reduction mechanism (not shown) for reducing the rotation of the DC motor 1 at a predetermined reduction ratio and transmitting the rotation to a valve (not shown) in a case. The DC motor 1 is fixed to a lower case 21, and a first gear 10 composed of a worm gear is attached to an output shaft 2 of the DC motor 1. Here, a rib 24 having a recess 24a into which the tip of the output shaft 2 is inserted protrudes from the lower case 21, and a portion of the output shaft 2 where the first gear 10 is mounted and the recess 24a are provided. A washer 30 for receiving the thrust of the first gear 10 is attached to a portion between the inserted front end portion.

By the way, the reason why the brushed DC motor 1 is used as the motor for the water heater is that the brushed DC motor 1 which can be obtained at a low cost in order to reduce the cost of the water heater is selected. If the valve of the water heater is left for a long time, the starting torque increases due to the sticking of the valve body and the like, and there is a reason that the DC motor 1 having a large starting torque is selected. However, the DC motor 1 generally has a winding portion formed of a rotor and can be obtained at low cost. However, since the rotor is not balanced, there is a disadvantage that vibration noise caused by imbalance of the rotor during rotation increases. . In addition, depending on the mounting state of the DC motor 1, there is a possibility that a resonance phenomenon may occur due to the vibration of the rotor.
It was necessary to reduce the vibration of the motor 1.

In recent years, the number of indoor water heaters has been increasing, and the demand for reducing the noise generated by the motor has become strict. In addition, there is a user who cares about the noise generated by the motor for the outdoor-installed water heater, and there is a demand for further reducing the noise generated by the motor. However, in the conventional driving device described above, the DC motor 1
Since a mechanism for reducing vibration caused by the rotation of the DC motor 1 is not provided, the DC motor 1 may be attached to the lower case 12 depending on the attachment state of the driving device or the like.
Since the noise generated greatly changes, the only countermeasure against noise is to select the DC motor 1 with low noise. Further, there is a type in which a pressing means for pressing the output shaft in one direction is provided inside the motor, but there is a problem that the cost is increased because a special motor is used (for example, see Japanese Patent Application Laid-Open No. 8-98452). .

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide a drive device in which generated noise is reduced.

[0007]

In order to achieve the above object, according to the present invention, a DC motor, a first gear provided on an output shaft of the DC motor, and the first gear mesh with each other. A transmission mechanism having at least a second gear and transmitting the rotation of the DC motor to the outside; and a case accommodating the DC motor and the transmission mechanism, and elastically contacting the output shaft of the DC motor;
The case is provided with a linear spring member for pressing the output shaft in a direction substantially orthogonal to the direction in which the first and second gears mesh with each other, and the output is achieved by pressing the output shaft with the spring member. The noise generated by the DC motor can be reduced by suppressing the vibration of the shaft, and since the spring member directly presses the output shaft of the DC motor, there is no necessary member other than the spring member. The mechanism for reducing vibration can be realized with a small number of components, and the number of components is small, so that it is inexpensive, has good assemblability, improves reliability, and can reduce assembly errors. Moreover, since the spring member is straight and can be formed only by cutting the wire material, processing is extremely easy, and since the shape is simple, processing can be performed with high precision. A mechanism for reducing the noise of the DC motor is extremely inexpensive. Can be realized. Further, the spring member for pressing the output shaft of the DC motor is a DC member.
Since it is provided outside the motor, it is not necessary to use a special motor provided with a mechanism for reducing vibration, and it is possible to use a DC motor that is inexpensive, highly reliable and highly available, and Since the spring member is provided outside the DC motor, the assembled state of the spring member can be visually confirmed from the outside, and the replacement operation of the spring member can be easily performed. Moreover, since the spring member presses the output shaft in a direction substantially perpendicular to the direction in which the first and second gears mesh, the meshing of the first and second gears varies due to variations in parts. However, the influence on the meshing of the first and second gears is small, and when the meshing of the first and second gears is jammed, the first and second gears are not affected.
If the spring member presses the output shaft in a direction substantially parallel to the direction in which the gears mesh with each other, a force generated by clogging of the mesh is applied to the spring member, and the spring member may be deformed. Although the life of the spring member may be shortened by the expansion and contraction of the spring member, since the spring member presses the output shaft in a direction substantially orthogonal to the direction in which the first and second gears mesh with each other, The spring member is not affected by the jamming of the first and second gears.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

The case 20 of this drive device is composed of a substantially box-shaped lower case 21 opened on one side, and a substantially box-shaped upper case 22 opened on one side and attached to the lower case 21. Includes a brushed DC motor 1 and a reduction mechanism 3 as a transmission mechanism for reducing the rotation of the DC motor 1 at a predetermined reduction ratio and transmitting the reduced rotation to a valve (not shown) of the water heater.
And are stored. An intermediate plate 23 that separates the lower case 21 from the upper case 22 is attached to the lower case 21 using, for example, a fixing screw, and the DC motor 1 is pressed from above by the intermediate plate 23.

A first gear (first gear) 10 composed of a worm gear is attached to the output shaft 2 of the DC motor 1 by, for example, press fitting. The first gear 10 meshes with a second gear (second gear) 11 rotatably supported on the shaft 5, and the second gear 11 is concentric with the second gear 11.
A third gear 12 having fewer teeth than one is integrally formed. The third gear 12 has more teeth than the third gear 12 and meshes with a fourth gear 13 rotatably supported on the shaft 6. The fourth gear 13 is concentric with the fourth gear 13. The fifth gear 14 having fewer teeth than the fourth gear 13 is integrally formed. The fifth gear 14 has more teeth than the fifth gear 14 and meshes with a sixth gear 15 rotatably supported on the shaft 5. The sixth gear 15 is concentric with the sixth gear 15. To 6
A seventh gear 16 having fewer teeth than the number gear 15 is integrally formed. The seventh gear 16 has a larger number of teeth than the seventh gear 16 and has an eighth gear 17 rotatably supported on the shaft 7.
The ninth gear 18 having a smaller number of teeth than the eighth gear 17 is formed integrally with the eighth gear 17. Further, the ninth gear 18 meshes with an output tenth gear 19 having more teeth than the ninth gear 18.

The rotation of the DC motor 1 is reduced at a predetermined reduction ratio by the reduction mechanism 3 including the first to tenth gears 10 to 19 and transmitted to the valve. In addition, shaft 5
7 are inserted into shaft holes 21a and 22a provided in the lower case 21 and the upper case 22, respectively, and are positioned between the lower case 21 and the upper case 22. On the surface of the 10th gear 19 facing the middle plate 23, a substantially cylindrical convex portion 19 a is protruded coaxially with the gear, and this convex portion 19 a is inserted into a shaft hole 23 a provided in the middle plate 23. ing. Further, a cylindrical portion 19 b protrudes from the other surface of the 10th gear 19 and is inserted into an opening 22 b provided in the upper case 22. The 10th gear 19 is formed by the upper case 22 and the middle plate 23. It is rotatably supported.

Here, the intermediate plate 2 facing the tenth gear 19
The printed circuit board 31 is attached to the portion 3 by an attachment screw 34. Two Hall ICs 32 for detecting the rotation angle of the 10th gear 19 are mounted on the printed circuit board 31, and a permanent magnet 33 is embedded in the 10th gear 19. Two Hall ICs 32 and permanent magnets 33 make up one
A sensor for detecting the rotation angle of the 0th gear 19 is configured, and a desired detection angle can be obtained by changing the arrangement of the Hall IC 32. In the present embodiment, two Hall ICs 32 are arranged on the printed circuit board 31. However, the number of the Hall ICs 32 is not limited to two, and three or more Hall ICs 32 may be provided.
The number and arrangement of the Hall ICs 32 may be changed so as to obtain a desired detection angle. Reference numeral 35 in FIG. 4 denotes a lead wire for supplying power to the DC motor 1 and for outputting a signal from the Hall IC 32.

When power is supplied to the DC motor 1 by a signal from an external circuit (not shown), the DC motor 1 rotates, and the rotation of the DC motor 1 is controlled by the first to tenth gears 1.
The speed is reduced at a predetermined reduction ratio by the speed reduction mechanism 3 composed of 0 to 19, transmitted to the valve of the water heater, and the valve is opened and closed.

In the driving device according to the present embodiment, FIGS.
As shown in FIG. 3, a rib 24 having a recess 24a into which the tip of the output shaft 2 of the DC motor 1 is inserted is protruded from the lower case 21, and a portion of the output shaft 2 to which the first gear 10 is attached. A washer 30 for receiving the thrust of the first gear 10 is attached to a portion between the leading end inserted into the recess 24a. Here, a slit 24 b running in a direction substantially perpendicular to the axial direction of the output shaft 2 is formed in the rib 24.
Are formed at both ends of the bottom of the slit groove 24b, and a stepped portion 24c which is one step higher than the central portion is provided. A substantially linear wire spring (spring member) 4 having elasticity is arranged in the slit groove 24b so as to be bridged between the two stepped portions 24c, and as shown in FIG. Is higher than the height position of the output shaft 2, the wire spring 4 is bent downward by the output shaft 2 in FIG.

Therefore, the output shaft 2 of the DC motor 1 is pressed upward in FIG. 1 by the spring return force of the wire spring 4, and the vibration of the output shaft 2 is reduced by pressing the output shaft 2. Here, the wire spring 4 is composed of the first gears 10 and 2
Since the output shaft 2 is pressed in a direction substantially perpendicular to the direction in which the # 11 gear meshes with the # 1 gear, 1
Even if the meshing between the second gear 10 and the second gear 11 varies, the influence on the meshing between the first gear 10 and the second gear 11 is small, and the first gears 10 and 2 are reduced by the spring return force of the wire spring 4. Since the preload with the # 11 gear does not increase, the # 1 gear 10 and the # 2 gear 11 can be smoothly rotated.

Further, for example, when the meshing between the first gear 10 and the second gear 11 is jammed due to the eccentricity of the second gear, 1
If the wire spring 4 presses the output shaft 2 in a direction substantially parallel to the direction in which the # 10 gear and the # 2 gear 11 mesh with each other,
The wire spring 4 may be deformed by the influence of the eccentricity of the second gear, and the force applied to the output shaft 2 may be changed by the wire spring 4, and the life of the wire spring 4 is shortened by the expansion and contraction of the wire spring 4. In this embodiment, the wire spring 4 presses the output shaft 2 in a direction substantially orthogonal to the direction in which the first gear 10 and the second gear 11 mesh with each other. Even when the meshing with the second gear 11 is jammed, the wire spring 4 is not affected by the eccentricity of the second gear 11.

The side wall 24d of the rib 24 and the lower case 21
And the rib 21b protruding from the wire spring 4b restricts the movement of the wire spring 4 in the longitudinal direction.

Since the output shaft 2 of the DC motor 1 generally uses a large amount of SUS material, it is desirable to use a different material such as phosphor bronze for the wire spring 4. In addition, since lubricating grease is applied to a contact portion between the output shaft 2 and the wire spring 4, even if an iron-based material such as a piano wire is used as the material of the wire spring 4, the contact between the output shaft 2 and the wire spring 4 can be prevented. Sliding resistance and wear can be reduced, and there is no practical problem.

In this embodiment, the output shaft 2 of the DC motor 1 is directly pressed by the linear wire spring 4,
There is no other necessary member, and a mechanism for reducing the vibration of the DC motor 1 can be realized with a small number of components. Since the number of components is small, it is inexpensive, has good assemblability, improves reliability, and can reduce assembly errors. Moreover, since the wire spring 4 can be formed only by cutting the wire material, the working is extremely easy, and since the shape is simple, the working can be performed with high accuracy, and a mechanism for reducing the noise of the DC motor 1 can be realized at very low cost. Can be. A similar effect can be obtained by using a leaf spring instead of the wire spring 4 as the spring member. However, a metal mold for forming the leaf spring is required, and the manufacturing cost is increased. desirable. Further, since the wire spring 4 for pressing the output shaft 2 of the DC motor 1 is provided outside the DC motor 1, it is not necessary to use a special motor provided with a mechanism for reducing vibration, and it is inexpensive. It is possible to use a DC motor 1 which is highly reliable and easily available.
Since the wire spring 4 is provided outside the C motor 1, the assembly state of the wire spring 4 can be visually confirmed from the outside, and the wire spring 4 can be easily replaced.

[0020]

As described above, the first aspect of the present invention comprises at least a DC motor, a first gear provided on an output shaft of the DC motor, and a second gear meshing with the first gear. A transmission mechanism for transmitting the rotation of the DC motor to the outside, and a case for accommodating the DC motor and the transmission mechanism. It is characterized in that a linear spring member that presses the output shaft in a direction substantially orthogonal to the case is provided, and the vibration of the output shaft is suppressed by pressing the output shaft with the spring member.
Since the noise generated by the DC motor can be reduced and the spring member directly presses the output shaft of the DC motor, there is no necessary member other than the spring member. Since the number of parts is small, there is an effect that it is inexpensive, has good assemblability, improves reliability, and can reduce assembly errors. Moreover, since the spring member is straight and can be formed only by cutting the wire material, processing is extremely easy, and since the shape is simple, processing can be performed with high precision. A mechanism for reducing the noise of the DC motor is extremely inexpensive. There is an effect that it can be realized. Furthermore, D
Since the spring member for pressing the output shaft of the C motor is provided outside the DC motor, there is no need to use a special motor provided with a mechanism for reducing vibration, and it is inexpensive, highly reliable, and highly available. Since the DC member can be used, and the spring member is provided outside the DC motor, the assembly state of the spring member can be visually checked from the outside, and the replacement operation of the spring member can be performed. There is an effect that it can be easily performed. In addition, since the spring member presses the output shaft in a direction substantially orthogonal to the direction in which the first and second gears mesh, the meshing of the first and second gears varies due to variations in parts. However, the influence on the meshing of the first and second gears is small, and
When the engagement between the first and second gears is jammed, the first
When the spring member presses the output shaft in a direction substantially parallel to the direction in which the second gear meshes, the force generated by the meshing is applied to the spring member, and the spring member may be deformed. There is also a possibility that the life of the spring member may be shortened due to expansion and contraction of the spring member, but the spring member presses the output shaft in a direction substantially orthogonal to the direction in which the first and second gears mesh with each other. Therefore, the spring member is not affected by the jamming of the first and second gears.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of a driving device according to an embodiment viewed from a side.

FIG. 2 is an enlarged view of a main part of the driving device as viewed from above.

FIG. 3 is a top view of the same drive device with an outer case, a speed reduction mechanism, and a middle plate removed.

FIG. 4 is a top view of the above driving device.

FIG. 5 is a cross-sectional view of the same driving device as viewed from the side.

FIG. 6 is a view of the drive device of the above, with the upper case removed, as viewed from above.

FIG. 7 is a developed view of the speed reduction mechanism of the drive device as viewed from the side.

FIG. 8 is an explanatory diagram of a conventional driving device.

[Explanation of symbols]

 2 output shaft 4 wire spring 21 lower case 24 rib 24a recess 24b slit groove 24c stepped portion

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[Procedure amendment]

[Submission date] July 10, 2000 (2007.1.
0)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

A first gear (first gear) 10 composed of a worm gear is attached to the output shaft 2 of the DC motor 1 by, for example, press fitting. The first gear 10 meshes with a second gear (second gear) 11 rotatably supported on the shaft 5, and the second gear 11 is concentric with the second gear 11.
A second pinion 12 having fewer teeth than one is integrally formed. 2nd pinion 12, No. 2 many number of teeth than the pinion 12, and then third gear 13 meshes which is rotatably supported by a shaft 6, the third gear 13 third gear 13 is concentric No. 3 pinion 1 with fewer teeth than No. 3 gear 13
4 are integrally formed. The third pinion 14 is 3
Ban pinion 14 many number of teeth than the meshes and fourth gear 15 that is rotatably shaft 5 pivotally supported, than the fourth gear 15 concentrically with the fourth gear 15 is in fourth gear 15 The fourth pinion 16 having a small number of teeth is integrally formed. No. 4
Anion 16, often the number of teeth than the fourth pinion 16, has fifth gear 17 meshes which is rotatably supported by a shaft 7, coaxially with fifth gear 17 to the fifth gear 17 5 # 1 gear
A fifth pinion 18 having fewer teeth than seven is integrally formed. In addition, the fifth pinion 18 is the fifth pinion
And the sixth gear 19 for output having more teeth than the gear 18.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

Thus, the first to sixth gears 10 , 11, 1
3,15,17,19 and 2nd-5th pinion 12,1
DC by the reduction mechanism 3 composed of 4, 16, and 18
The rotation of the motor 1 is reduced at a predetermined reduction ratio and transmitted to the valve. Note that both ends of the shafts 5 to 7 are inserted into shaft holes 21a and 22a provided in the lower case 21 and the upper case 22, respectively.
It is positioned between lower case 21 and upper case 22. On the surface of the sixth gear 19 facing the middle plate 23, a substantially cylindrical protrusion 19 a is projected coaxially with the gear, and this protrusion 19 a is inserted into a shaft hole 23 a provided in the middle plate 23. ing. In addition, a cylindrical portion 19 b protrudes from the other surface of the sixth gear 19, and an opening 2 provided in the upper case 22.
The 6th gear 19 is rotatably supported by the upper case 22 and the middle plate 23.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

Here, the intermediate plate 23 facing the sixth gear 19
The printed circuit board 31 is attached to the portion by a mounting screw 34. On the printed circuit board 31, the sixth gear 19
Two Hall ICs 32 for detecting the rotation angle of the second gear 19 are mounted, and a permanent magnet 33 is embedded in the sixth gear 19. A sensor for detecting the rotation angle of the sixth gear 19 is constituted by the two Hall ICs 32 and the permanent magnet 33, and a desired detection angle can be obtained by changing the arrangement of the Hall ICs 32. In the present embodiment, two Hall ICs 32 are arranged on the printed circuit board 31. However, this is not intended to limit the number of Hall ICs 32 to two, and three or more Hall ICs 32 may be provided. The number and arrangement of the Hall ICs 32 may be changed so as to obtain the detection angle of. Reference numeral 35 in FIG. 4 denotes a lead wire for supplying power to the DC motor 1 and for outputting a signal from the Hall IC 32.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

When power is supplied to the DC motor 1 by a signal from an external circuit (not shown), the DC motor 1 rotates, and the rotation of the DC motor 1 is controlled by the first to sixth gears 1.
0,11,13,15,17,19 and 2-5 pinio
The speed is reduced at a predetermined reduction ratio by a speed reduction mechanism 3 composed of components 12, 14, 16, and 18 and transmitted to the valve of the water heater, and the valve opens and closes.

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Claims (1)

[Claims] 1. A transmission for transmitting the rotation of a DC motor to an outside having at least a DC motor, a first gear provided on an output shaft of the DC motor, and a second gear meshing with the first gear. And a case for accommodating the DC motor and the transmission mechanism.
A linear spring member for pressing the output shaft in a direction substantially orthogonal to the direction in which the gears mesh with each other.