JP3713137B2 - Geared actuator - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a geared actuator used for an information device, a measuring instrument, an automobile air conditioner, and the like, and more particularly to reduction of sliding loss and mechanical noise of a stepping motor used for the geared actuator.
[0002]
[Prior art]
A conventional stepping motor has a configuration as shown in FIG. FIG. 3 is a cross-sectional view of the main part of the stepping motor. In FIG. 3, a metal 23 is fixed to the upper plate 21 and the lower plate 22 by press fitting or the like, and a shaft rotatably supported by the upper and lower metals 23. A ring-shaped magnet 26 is arranged at 24 via a magnet holder 25.
[0003]
On the other hand, a stator is disposed on the magnet 26 with a predetermined gap therebetween, and this stator is configured in two stages so that the coils 27 and 28 are covered with yokes 29 and 30, respectively.
One end of the shaft 24 protrudes outward from the housing formed by the upper and lower plates 21 and 22, and a gear 31 made of synthetic resin is press-fitted into the protruding portion, and the motor output is transmitted to the outside. is there.
In the stepping motor configured as described above, a washer 32 is inserted on one end side of the shaft 24 and a spring material is interposed between the upper plate 21 and the rotor on the other end side in order to suppress the rampage of the rotor due to thrust backlash. 33 is arranged, and the rotor is urged toward the lower plate 22 via the washer 32 by the action of the spring member 33.
[0004]
[Problems to be solved by the invention]
However, in the configuration as described above, the rotor is always in contact with the lower plate side (washer 32), resulting in loss at that portion. Depending on the loss, it may lead to deterioration of characteristics such as torque reduction as a motor. Therefore, it is necessary to strictly control the urging force by selecting the material and shape of the spring material 33.
In addition, as described above, since the rotor is in contact with the lower plate side, sliding noise at that portion becomes a problem, and in solving these problems, another process such as grease application must be added, This leads to a decrease in productivity and an increase in cost.
[0005]
SUMMARY OF THE INVENTION Accordingly, the present invention is to provide a geared actuator that solves the above-described problems and can reduce the motor loss that has occurred while suppressing the runaway of the rotor in the thrust direction.
[0006]
[Means for Solving the Problems]
In the present invention, the rotor is biased in the thrust direction by the spring material disposed in the motor housing, and the end in the biasing direction is brought into contact with the case constituting the actuator, so that a gap is formed between the housing and the rotor. Thus, the above-described problem can be solved. This eliminates the need for a conventional washer, suppresses the rotor from moving in the thrust direction, and reduces the motor loss.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The geared actuator of the present invention accommodates in a case a stepping motor consisting of a stator arranged in a housing made up of upper and lower plates and a rotor arranged in the housing with a predetermined gap in the stator. In the geared actuator, the urging member disposed in the housing urges the rotor in the thrust direction, and the urging direction end is brought into contact with the case, so that the gap between the housing and the rotor is A gap is formed.
Further, it is preferable that the rotor is rotatably supported via a sleeve-like metal disposed so as to face a recess formed in the holder.
[0008]
[Example 1]
FIG. 1 is a cross-sectional view of a main part of a geared actuator according to an embodiment of the present invention.
In the drawing, an upper plate 1 and a lower plate 2 constitute a housing, and a rotor is arranged in the housing with a predetermined gap between the stator and the stator. As in the prior art, the stator is configured in two stages so as to cover the coils 7 and 8 with yokes 9 and 10, respectively.
[0009]
On the other hand, the rotor has a magnet holder 5 made of synthetic resin and a magnet 6 disposed on the outer periphery of the magnet holder 5, and a gear portion 5 a is integrally formed in the magnet holder 5 and partly. It is formed to have a recess 5b. Here, a sleeve-like metal 3 fixed to a part of the housing is arranged so as to face the recess 5b, and the magnet holder 5 is attached to the shaft 4 rotatably supported through the metal 3. Is fixed.
[0010]
Reference numeral 11 denotes a spring material for urging the rotor in the thrust direction. The spring material 11 abuts the output end of the rotor against the case 12 constituting the actuator. A gap a is formed between the magnet holder 5 and the magnet holder 5.
Reference numeral 16 denotes a transmission gear for transmitting the output of the stepping motor. The transmission mechanism after that is omitted. In this embodiment, the metal 3 is directly fixed to the housing. It may be configured via a holder or the like.
[0011]
This eliminates the contact between the motor housing and the rotor, eliminates the need for the washer previously interposed in that portion, and reduces motor loss while preventing the rotor from moving in the thrust direction. It becomes possible. In this case, the output end of the motor and the case 12 come into contact with each other, but the contact friction is small because of the pivot support type, and it does not substantially affect motor loss.
[0012]
[Example 2]
FIG. 2 is a cross-sectional view of a main part of a geared actuator according to another embodiment of the present invention.
In other words, the rotor is supported at both ends by the metal 13 in the figure, and both ends of the shaft 4 protrude outward from the housing composed of the upper and lower plates 1 and 2. Then, by bringing the spring material 11 disposed in the housing into contact with the magnet holder 15, the rotor is urged in the thrust direction. The shaft end located on the biasing direction side is brought into contact with the case side wall 12 of the actuator so that a gap b is formed between the housing and the rotor.
[0013]
The other configurations are the same as those in the above embodiment, and thus the same reference numerals are given and description thereof is omitted. However, in this case, a gear train may be formed on the opposite shaft protruding portion that contacts the case 12. In this way, the same effects as those of the above embodiment can be obtained.
[0014]
In addition, this invention is not limited to said each Example, In the range which does not deviate from the main point of this invention, it can change suitably and can implement. For example, in addition to the configuration in which the stepping motor itself is housed in the case and one end of the rotor is brought into contact with the case, there is no problem even if the end portion in the urging direction of the rotor is covered with the case.
[0015]
【The invention's effect】
As described above, according to the present invention, the urging member disposed in the motor housing urges the rotor in the thrust direction, and the urging direction end is brought into contact with the case constituting the actuator, Since the gap is formed between the housing and the rotor, a conventional washer is not required, and the rotor in the thrust direction is prevented from being violated, and thus the motor loss that has occurred can be reduced. In addition, the sliding noise generated in the washer mounting portion is eliminated, and it is not necessary to add a grease application process or the like. Therefore, it is possible to improve productivity and reduce costs.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of a geared actuator according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a main part of a geared actuator according to another embodiment of the present invention.
FIG. 3 is a cross-sectional view of a main part of a conventional stepping motor.
[Explanation of symbols]
1, 21 ... Upper plate 2, 22 ... Lower plate 3, 13, 23 ... Metal 4, 24 ... Shaft 5, 15, 25 ... Magnet holder 11, 33 ... Spring material (biasing member)
12 ... Case 32 ... Washer a, b ... Gap

Claims (2)

In a geared actuator in which a stepping motor including a stator disposed in a housing composed of upper and lower plates and a rotor disposed in the housing through a predetermined gap is accommodated in a case.
The rotor is urged in the thrust direction by a spring material arranged in the housing, and the end in the urging direction is brought into contact with the case to form a gap between the housing and the rotor. Geared actuator characterized by The geared actuator according to claim 1, wherein the rotor is rotatably supported via a sleeve-like metal disposed so as to face a recess formed in the upper and lower plates .

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