JP3272627B2 - Motor with clutch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor provided with a clutch mechanism on gears constituting a reduction gear train.

[0002]

2. Description of the Related Art As is well known, a reduction gear train is incorporated in an output shaft of a motor as a drive device for opening / closing a louver of an air conditioner or a drive device for various rotating devices such as an automatic opening / closing valve and a turntable of a microwave oven. A motor with a speed reduction mechanism is widely used. By the way, in a motor in which this kind of reduction mechanism is incorporated, usually, the above-mentioned motor is driven to open and close the air conditioner louver, or to rotate the turntable, but sometimes the operator has In some cases, the louver is forcibly opened and closed manually or the turntable is rotated while the motor is stopped. In such a case, if these rotation operations are performed gently, the reduction gear train rotates in reverse from the output shaft of the motor reduction mechanism, and the rotor of the motor idles. In this case, there is a problem in that an excessive rotational torque greater than a normal driving torque acts on the reduction gear train, thereby causing damage to gears constituting the reduction gear train.

[0003] Conventionally, in this type of motor with a speed reduction mechanism, slip is generated when a forcible and sudden rotation torque is applied to the output shaft of the normal reduction gear train from the outside. In addition, a clutch mechanism for interrupting transmission of the rotational torque to the rotor side of the motor is provided. 6 and 7 show a conventional motor with a clutch of this type. In these figures, this clutch-equipped motor includes a well-known motor 5 in which a rotor having a permanent magnet is rotatably provided in a bobbin 3 around which a coil 2 is wound, at the bottom of a cylindrical casing 1 having a bottom. A reduction gear train 7 composed of a plurality of gears meshing with the gear 4 of the rotor is assembled on an inner lid 6 provided and disposed on the motor 5. Here, the gears are rotatably supported by pins 6a erected on the inner lid 6, respectively.
A pinion is formed on one side and a large diameter spur gear is formed on the other. Each gear is arranged such that its spur gear meshes with the pinion of the gear adjacent to the motor 5 and that the pinion meshes with the spur gear of the gear adjacent to the output shaft 11 of the reduction gear train 7. I have. Further, the final stage gear 9 having only the spur gear 12 is provided with its output shaft 11 protruding from an opening of a lid (not shown) for closing the casing 1. The gear 9 at the last stage is provided with the above-described clutch mechanism.

As shown in FIG. 7, the gear 9 includes a metal output shaft 11, a spur gear 12 formed of a synthetic resin, and two friction plates 13 made of a metal disk member. It is composed of four parts. At one end of the output shaft 11, a key portion 11a is formed which is cut out on both side surfaces and integrally engages with a rotation shaft of a driven member such as a louver of an air conditioner (not shown). A gear mounting portion 11b is formed with one side cut out. A pair of friction plates 13 is mounted on the gear mounting portion 11b with the spur gear 12 interposed therebetween. Here, the hole of the friction plate 13 through which the gear attachment portion 11b is inserted is formed in a non-circular shape that matches the outer shape of the gear attachment portion 11b.
Reference numerals 3 and 13 are configured to rotate integrally with the output shaft 11.

On the other hand, the hole of the spur gear 12 is formed in a circular shape, whereby the spur gear is rotatably mounted on the gear mounting portion 11b. Annular convex portions 12a are formed on the outer peripheral sides of both end surfaces in the axial direction of the spur gear 12, respectively. The spur gear 12 is sandwiched between the friction plates 13, 13,
The center portion 13a of one friction plate 13 is swaged toward the other friction plate 13 so that the free rotation is restricted by the frictional force between the friction plate 13 and the protrusion 12a. , The output shaft 1 via the friction plates 13
It is mounted on the first gear mounting portion 11b. Then, the friction plate 13 and the projection 12a on the output shaft 11
The clutch mechanism in the clutch-equipped motor is constituted by the spur gear 12 formed with.

In the conventional motor with a clutch having the above structure, when the motor 5 is driven, its rotational torque is transmitted to the spur gear 12 of the final gear 9 through the reduction gear train 7, The convex portion 12a and the friction plate 13
The output shaft 11 is integrally rotated by a frictional force between the louver and the louver to drive the opening and closing of the louver via a link and to rotate the valve shaft and the turntable. Also, when the output shaft 11 is very slowly rotated from the outside, such as when the louver is slowly opened and closed manually when the motor 5 is stopped, the motor 5 rotates integrally with the output shaft 11. The frictional force between the friction plate 13 and the convex portion 12a of the spur gear 12 also rotates the spur gear 12 integrally, and this rotation is transmitted to the gear 4 of the rotor via the reduction gear train 7, and the rotor becomes idle. It is designed to rotate. When a rotational torque larger than the rotational torque at the time of the drive is instantaneously applied to the output shaft 11 from the outside, such as when the louver is rapidly opened and closed, the friction plate 13 and the protrusion 12a And as a result, the rotation of the motor 5 to the rotor side is cut off to prevent the gears in the reduction gear train 7 from being damaged.

[0007]

In such a conventional motor with a clutch, if the caulking force of the friction plate 13 is weak, the projection 12a and the friction plate are not rotated even when the motor 5 is driven to rotate. There is a risk of slippage between the friction plate 13 and the convex portion 12a even when a large rotational torque is applied from the outside if the crimping force is too strong. There is a problem that the gears are damaged without acting smoothly. For this reason, there has been a problem that the work for finding the optimum caulking force on the friction plate 13 is troublesome and troublesome, and the assembling thereof is also troublesome, resulting in poor productivity.
In addition, in order to constitute the above-described clutch mechanism, in addition to the spur gear 12, a metal friction plate 1 which is an additional component is provided.
The necessity of 3 and 13 causes a problem that the structure becomes complicated and the number of parts increases, which leads to complicated parts management and an increase in the manufacturing unit price.

The present invention has been made to effectively solve the problems of the conventional motor with a clutch, and has a simple structure, a reduced number of parts, and easy and reliable assembly. Another object of the present invention is to provide a motor with a clutch that can prevent damage to the reduction gear train and can freely set the torque for attaching and detaching the clutch.

[0009]

According to a first aspect of the present invention, there is provided a motor with a clutch according to the present invention, wherein a reduction gear train including a plurality of gears is meshed with a rotor gear of the motor, and a final stage of the reduction gear train. A motor with a clutch provided with a clutch mechanism for interrupting transmission of the rotational torque to the rotor side of the motor when excessive rotational torque acts on an output shaft provided and connected to a driven member. The output shaft provided with the clutch mechanism is formed of an elastic body.
It is, and Rutotomoni is friction plate formed on an outer peripheral portion, the friction
A shaft member having a space formed inside the rubbing plate, and a gear that meshes with the reduction gear train is provided on the outer peripheral portion of the shaft member so as to be relatively slidably mounted on the friction plate. The formed gear member and the friction plate incorporated in the space portion
And a biasing member that applies a frictional force to the gear member by pressing the gear member radially outward .

Here, the invention described in claim 2 is the above-mentioned invention .
The biasing member is assembled into the space with the
It is characterized in that a spring that presses the serial friction plate radially outward.

In the motor with the clutch according to the first or second aspect , the output shaft of the reduction gear train provided with the clutch mechanism is connected to the friction plate of the shaft member having the friction plate formed on the outer periphery. frictional force between with the gear to the exterior of the gear member formed freely slide relative, by the urging member, and the friction plate and the gear member to press the friction plates radially outer side When the motor is driven, or when the output shaft is very slowly rotated from the outside, the shaft member and the gear member are separated by the frictional force generated by the urging member. Rotate together,
As a result, the rotation is transmitted to the output shaft side or, conversely, to the motor side.

Then, from the outside, the shaft member of the output shaft is
When a rotational torque larger than the frictional force is suddenly applied, the gear member side is connected to the rotor side of the motor via a reduction gear train and resists the rotational torque. Excessive rotational torque exerted by the shaft member causes the friction plate of the shaft member to slide with respect to the gear member, and only the shaft member instantaneously slips smoothly by a certain angle. As a result, the transmission of the rapid rotation to the rotor side of the motor is cut off, and the gears in the reduction gear train are prevented from being damaged. At this time, by appropriately setting the area and surface roughness of the friction plate contacting the gear member, the material of the urging member, and the like, the degree of external force acting on the output shaft, the driving torque of the motor itself, Alternatively, the operating conditions of the clutch mechanism when an excessive rotational force is applied from the outside can be freely set according to various use conditions such as the gear strength in the reduction gear train.

Therefore, according to the motor with clutch, the structure is simple, the number of parts can be reduced, the assembly is easy, and the torque for attaching and detaching the clutch can be freely selected. In addition, since an elastic body is used as the shaft member, and a biasing member that presses the friction plate radially outward is incorporated in a space formed inside the friction plate, the biasing member is a gear member. Side, and the entire output shaft is more compact than when the gear member is pressed against the friction plate side of the shaft member. Further, even when the same urging member is used, it is possible to change the above-mentioned clutch attaching / detaching torque only by adjusting the installation position of the urging member in the space, in other words, the operation position with respect to the friction plate. Becomes possible.

Further, as in the embodiment described in claim 2, as the biasing member, by using an inexpensive spring general purpose, it is possible to achieve more cost reduction of,
It is easy to assemble, and the torque for attaching and detaching the clutch can be freely set by appropriately selecting the material, thickness, diameter, or length of the spring and changing the biasing force. It is more suitable for

[0015]

1 to 5 show a main part of a first embodiment of a motor with a clutch according to the present invention. Other structures are the same as those shown in FIG. For this reason, the same reference numerals are used in the description, and the description is omitted. In this motor with a clutch, an output shaft 20 provided with a clutch mechanism is provided instead of the output shaft 11 of the reduction gear train 7 shown in FIG. As shown in FIGS. 1 to 5, the output shaft provided with the clutch mechanism includes a shaft member 21 that engages with a driven member, and a spur gear that meshes with the outermost gear of the last stage of the reduction gear train 7 on the outer periphery. (Gear) 22 formed thereon, and a spring (biasing member) 24 for biasing the shaft member 21 toward the gear member 23 and applying a frictional force therebetween. is there.

The shaft member 21 is a columnar member having a hole 25 formed at the center thereof into which a pin 6a erected on the inner lid 6 is inserted. The shaft member 21 is an elastic body such as POM (polyoxymethylene). It is molded integrally with the engineering plastics of Japan. At the upper end of the shaft member 21,
A key portion 26 integrally formed with a rotation shaft of a driven member such as an air conditioner louver is formed, and a large diameter portion 27 and a smaller diameter than the large diameter portion 27 are sequentially formed below the key portion 26. A shaft 28 is formed. On the lower surface of the large-diameter portion 27, two cylindrical flexible portions 29 each having a central angle in a range of about 120 ° to 130 ° surround the shaft portion 28 so as to be aligned with the central axis. It is formed symmetrically.
As a result, a space 30 is formed between the flexible portion 29 and the shaft 28. At the lower end of the flexible portion 29 in the figure, the friction plate 3 slightly larger than the large-diameter portion 27 is provided.
1 is formed. Incidentally, in the shaft member 21, the portion where the friction plate 31 is formed is enlarged in diameter, so that the shaft member 21 opens the gear member 23 or an opening of a lid (not shown) for closing the casing 1. It has a structure that does not fall out.

On the other hand, the gear member 23 is a member having a substantially cylindrical shape as shown in FIG. 4, in which a main body 23a and a spur gear 22 formed on the outer peripheral portion are integrally formed by a sintered body. Incidentally, the gear member 23 may be made of a material having sufficient strength to oppose the urging force acting from the spring 24 via the flexible portion 29 of the shaft member 21. Depending on the conditions, a hard synthetic resin or various types of metal can be used. The length of the gear member 23 in the axial direction is the same as that of the flexible portion 29.
Is set substantially equal to the length dimension of the main body 2
The inner peripheral surface 23b of the flexible portion 29 and the friction plate 3
It is formed in a shape corresponding to 1. FIG. 5 shows a spring 24, in which a cylindrical outer periphery is cut out in the axial direction, thereby generating an urging force outward when the diameter is reduced. The spring 24 is formed of a metal having a desired urging force such as SUS in accordance with a required urging force, and its length is longer than the length of the space 30 in the axial direction. It is formed short.

As shown in FIG. 1, the output shaft 20 has a gear member 23 inserted from the key portion 26 side of the shaft member 21 and is relatively slidably mounted on the outer periphery of the flexible portion 29. At the same time, the spring 24 is inserted into the space 30 of the shaft member 21 in a contracted state and is assembled integrally. Thereby, the flexible portion 29 of the shaft member 21 is urged radially outward by the spring 24, and the friction plate 3
By pressing 1 on the inner peripheral surface 23b of the gear member 23, a predetermined frictional force is applied between the friction plate 31 and the inner peripheral surface 23b of the gear member 23. The output shaft 20 thus configured is rotatably disposed on the inner lid 6 by the pin 6a, and the spur gear 22 of the gear member 23 meshes with the last gear of the reduction gear train 7; The key portion 26 of the shaft member 21 is assembled into the casing 1 in a state where the key portion 26 protrudes from the opening of the lid that closes the casing 1.

In the clutch-equipped motor having the above structure, the output shaft 20 of the reduction gear train 7 provided with the clutch mechanism is connected to the friction plate 31 of the shaft member 21 and the gear member 23 having the spur gear 22 formed on the outer periphery. Are relatively slidably mounted, and the flexible portion 29 of the shaft member 21 is urged toward the gear member 23 by the spring 24 so that the friction plate 3 is
Since a frictional force is given between the gear 1 and the gear member 23,
When the ordinary motor 5 is driven, the shaft member 21 and the gear member 23 rotate integrally by the frictional force generated by the spring 24, and as a result, the air conditioner of the air conditioner is connected via the link engaged with the shaft member 21. The louver is driven to open and close, or the valve shaft and the turntable are driven to rotate. Similarly, when the output shaft 20 is very slowly rotated from the outside, such as when the louver is slowly opened and closed manually when the motor 5 is in a stopped state, the same applies to the shaft. Member 21 and gear member 2
Since the rotation of the output shaft 3 is performed integrally, the rotation of the output shaft 20 is transmitted to the gear 4 of the rotor via the reduction gear train 7, and the rotor idles.

On the other hand, the reduction gear train 7
When a rotational torque larger than the frictional force is suddenly applied to the shaft member 21 of the output shaft 20, the gear member 23 side is connected to the rotor 4 side of the motor 5 via the reduction gear train 7. As a result, the excessive rotational torque acting from the shaft member 21 causes
The friction plate 31 of the shaft member 21 is
Sliding upward, only the shaft member 21 instantaneously smoothly idles by a certain angle. As a result, the transmission of the rapid rotation of the motor 5 to the rotor 4 is interrupted, and the gears in the reduction gear train 7 are prevented from being damaged.

As described above, according to the motor with the clutch having the above-described structure, the structure is extremely simple as compared with the conventional motor, and the number of parts can be reduced to reduce the manufacturing cost. In addition to being easy to assemble, even when an excessive rotational force acts on the shaft member 21 side of the output shaft 20 from the outside, it is possible to reliably prevent the reduction gear train 7 at the subsequent stage from being damaged.

In addition, the area and surface roughness of the friction plate 31 in contact with the gear member 23, as well as the material, thickness, diameter, and length of the spring 24 are appropriately selected to change the urging force thereof. By adjusting the frictional force generated between the friction plate 31 and the gear member 23, various kinds of external force acting on the output shaft 20, the driving torque of the motor itself, or the gear strength in the reduction gear train 7, etc. The operating condition of the clutch mechanism when an excessive torque is applied from the outside can be freely set according to the use condition. Further, even when the springs 24 having the same shape are used, the above-described clutch mounting / detaching torque is appropriately changed only by adjusting the installation depth position of the springs 24 in the space portion 30, that is, the operation position on the flexible portion 28. You can also. In this shaft member 21,
Since the diameter of the portion of the flexible portion 29 where the friction plate 31 is formed is increased, the shaft member 21 is reliably prevented from falling out of the gear member 23 or the opening of the lid that closes the casing 1. can do.

In the above embodiment, only the case where two flexible portions 29 and two friction plates 31 of the shaft member 21 are formed has been described. However, the present invention is not limited to this case. In the case where three or more shaft members 21 are formed as appropriate according to the external force to be applied, or when the shaft member 21 is formed of a soft material having high elasticity, the flexible portion is formed in a cylindrical shape, and the flexible portion is entirely formed. An annular friction plate extending around the periphery may be formed.

[0024]

As described above, claim 1 or claim 2
According to the motor with a clutch described in (1), the structure can be simplified, the number of parts can be reduced, the assembly is easy, and damage in the reduction gear train can be reliably prevented. The operating condition of the clutch mechanism when an excessive torque is applied from the outside can be freely set according to the use condition. Moreover,
Ru can constitute the entire output shaft more compact.
Further , according to the second aspect of the present invention, since a general-purpose and inexpensive spring is used, it is possible to obtain an effect that the cost can be further reduced and the cost is low.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a clutch mechanism part in an embodiment of a motor with a clutch according to the present invention.

FIG. 2 is a longitudinal sectional view showing the shaft member of FIG.

FIG. 3 is a bottom view of FIG. 2;

FIG. 4 is a longitudinal sectional view showing the gear member of FIG. 1;

FIG. 5 is a perspective view showing the spring of FIG. 1;

FIG. 6 is a partially cutaway perspective view showing a conventional motor with a clutch.

FIG. 7 is a sectional view showing a clutch mechanism part of FIG. 6;

[Explanation of symbols]

 Reference Signs List 4 rotor gear 5 motor 6a pin 7 reduction gear train 20 output shaft 21 shaft member 22 spur gear (gear) 23 gear member 24 spring (elastic member) 29 flexible portion 30 space portion 31 friction plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02K 7/10 F16H 1/20 F16H 35/10

Claims (2)

(57) [Claims] An excessive rotation torque is applied to an output shaft, which is provided with a reduction gear train composed of a plurality of gears on a rotor gear of a motor and is provided at the last stage of the reduction gear train and to which a driven member is connected. A clutch-equipped motor provided with a clutch mechanism for interrupting transmission of the rotational torque to the rotor side of the motor when actuated, wherein an output shaft provided with the clutch mechanism is formed of an elastic body.
Friction plates are formed are formed, and the outer peripheral portion Te Rutotomo
A shaft member having a space formed inside the friction plate ;
A gear member, which is provided on the friction plate of the shaft member so as to be relatively slidable and is provided with a gear meshing with the reduction gear train on an outer peripheral portion, and is incorporated in the space portion,
A motor with a clutch, comprising: a biasing member that presses the friction plate radially outward to apply a frictional force to the gear member. 2. The urging member according to claim 1, wherein said urging member is in a contracted state.
It is assembled in the space and presses the friction plate radially outward .
Clutched motor according to claim 1, wherein the spring der Rukoto that.