JPH0548567U - Noise reduction structure of geared motor - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention relates to a geared motor having a deceleration gear train and a motor incorporated therein. Particularly, noise generated from the motor is reduced by an inexpensive means and the life of the motor is not affected. [Structure] An idle member is loosely fitted to one end of the drive shaft of the motor,
A drive gear is fixed to the tip, the drive gear and the reduction gear train are connected to each other, and an elastic member for urging from the radial direction is brought into contact with the idle member so as to make point contact or curved contact.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a small-sized geared motor, in particular, a drive shaft of a motor, or a slipping member is loosely fitted to the drive shaft, and an elastic member that urges the drive shaft or the slipping member in a radial direction is brought into contact with the motor to drive the motor from the motor. The structure is designed to reduce the noise generated and to buffer the urging force applied to the drive shaft by an elastic material to prolong the life of the motor.

[0002]

[Prior Art]

 In recent years, the geared motor has been used for various purposes such as optical equipment, audio equipment (VTR, audio), automobile equipment (car air conditioner) and peripheral equipment.

In use, noise generated from the geared motor has become a problem. The causes of the noise are noise generated when the motor and the reduction gear train mesh with each other and noise generated when the motor itself rotates. There is.

As a means for reducing the noise of a motor, it has been previously disclosed in Japanese Patent Laid-Open No. 64-74342 (hereinafter referred to as a reference). The structure of the reference is such that the free end of a spring plate having one end fixed thereto is brought into pressure contact with the tip end portion of a pinion fixed to a motor shaft or the top surface of the motor shaft, and a gear mechanism is meshed with the pinion. This is a small DC geared motor with a pinion and gear mechanism installed inside the gearbox. That is, the structure is such that the free end of the spring plate is pressed into contact with the spring plate to suppress rattling of the motor shaft and to reduce the amount of noise.

[0005]

[Problems to be solved by the device]

 However, in the above-mentioned reference, since the tip of the pinion fixed to the motor shaft or the top surface of the motor shaft is directly pressed into contact with the spring plate, a force is applied to the drive shaft in the radial direction and at the same time a large force is applied in the thrust direction. It is a structure to which a load is applied.

The force applied in the radial direction eliminates rattling of the motor shaft and is effective in reducing noise, while the load in the thrust direction is constrained in the thrust direction while the drive shaft is being pushed into the motor. The ring that holds the drive shaft is constantly in pressure contact with the spacer and the bearing that support the drive shaft of the motor, which poses the problem of damaging the spacer and the bearing. There was a problem that the life was shortened.

Further, since the tip of the pinion fixed to the motor shaft or the top surface of the motor shaft is directly pressed against the spring plate, it is difficult to select the thickness, width and material of the spring plate. That is, a spring plate having too much thickness and width causes an overload, and conversely, a thin and narrow spring plate cannot reduce noise.

An object of the present invention is to provide a noise reduction structure for a geared motor, which is capable of reducing the noise of the geared motor, particularly the noise generated from the motor, by an inexpensive means and keeping the life of the motor long.

[0009]

[Means for Solving the Problems]

 In order to achieve the above object, a noise reduction structure for a geared motor according to the present invention comprises a motor, a reduction gear train, and a case that accommodates them. A drive gear is fixed to the tip of the drive shaft of the motor. The idle gear member is loosely fitted to the rear portion of the drive gear, and the elastic member for biasing the idle member in the radial direction is brought into contact with the idle gear member.

[0010]

[Action]

 According to the noise reduction structure of the geared motor of the present invention configured as described above, the idling member is loosely fitted to the drive shaft of the motor or one end of the drive shaft, and the elastic member for biasing is brought into contact with the free end of the drive shaft. By doing so, rattling of the drive shaft is suppressed and noise generation is reduced.

Further, since the drive shaft or the idle member that is loosely fitted is in contact with the radial direction, no load is applied in the thrust direction, and therefore the spacers and bearings inside the motor are not damaged, and The life of the motor can be kept long.

[0012]

【Example】

 Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to this embodiment.

FIG. 1 is a perspective view of a geared motor 10 according to the present invention. The geared motor 10 is mainly composed of a lower case 1, an upper case 2, a motor unit 20 and a reduction gear train 30.

FIG. 2 is a plan view of the motor section 20, FIG. 3 is a front view of the same, and FIG. 4 is an exploded perspective view of a group of parts incorporated in the lower case 1.

First, the motor unit 20 will be described in detail.

Reference numeral 21 is a motor, and 22 is a drive shaft of the motor 21.

A cylindrical pulley 23, which is an idle member, is loosely fitted to one end of the drive shaft 22 so as to be free to rotate, and a groove portion 23b is formed around the center portion of a peripheral wall 23a of the pulley 23. The free end 24a of the elastic member 24 is abutted against 23b in a biased state. A drive gear 25 is fixed to the tip of the drive shaft 22. Here, worm gears are used to improve the meshing of gears in the first stage.

The pulley 23 prevents abrasion of the elastic member 24 that contacts the drive shaft 22 due to the urging force. That is, if the free end 24a of the elastic member 24 is directly contacted with the drive shaft 22 in the radial direction, only the contact portion is worn by the rotational force, and the shaft is thinly broken, resulting in direct contact. It is loosely fitted to prevent it. However, if the material of the drive shaft 22 is changed to a hard material, the elastic member 24 may be directly brought into contact with the drive shaft 22 without loosely fitting the pulley 23. The groove 23b of the pulley 23 is formed to keep the elastic member 24 in contact. That is, the elastic member 24 is prevented from lateral displacement.

The elastic member 24 is formed by bending a linear stainless steel material or a piano wire material as shown in FIG. 4, and its free end 24 a contacts the groove portion 23 b of the pulley 23 and is elastic. The urging force of the material 24 presses the pulley 23 or the drive shaft 22 so as to make point contact with the shaft in the radial direction. Further, in the above description, the urging force of the elastic member 24 presses the pulley 23 or the drive shaft 22, but the drive gear 25 fixed to the drive shaft 22 is also slightly pressed in the direction of the driven first gear 31. Therefore, the engagement with the driven first toothed gear 31 is improved.

The elastic member 24 is not limited to the shape shown in FIGS. 2 to 4, and the tip end 24c has a semi-circular shape that matches the shape of the groove 23b of the pulley 23 as shown in FIG. You may make it contact. Further, as shown in FIGS. 3 and 4, the contact is made from the right side (toward the drawing), but the contact may be made from above or below.

In the motor section 20, the motor 21 to which the drive gear 25 and the pulley 23 are attached is placed on the motor holder section 1a of the lower case 1, and the elastic member 24 is detachably attached to the step section 1b of the lower case 1. To do. Although it is detachable here, one end may be fixed.

The drive gear 25 is located in a protruding state in the semi-hermetically-formed grease container 1c of the lower case 1, and meshes with the first driven gear 31 in the grease container 1c.

Further, since the grease is filled in the grease container 1c, the noise generated from the meshing of the drive gear 25 and the first driven gear 31 is suppressed.

Next, the deceleration gear train 30 will be described in detail.

Reference numeral 31 denotes a driven first gear, which is a lower driven second gear 31a and a center pinion shaft 31b integrally formed of synthetic resin. The 32 output gear is also made of synthetic resin and is fixed to the central output shaft 33.

Each gear of the reduction gear train 30 is housed in the lower case 1. First, the pinion shaft 31b of the driven first gear 31 is inserted into the hole 1d, the lower part of the output shaft 33 is inserted into the hole 1e, and the upper part thereof is inserted into the hole 2e of the upper case 2, respectively. To be worn.

Here, in the deceleration gear train 30 incorporated as shown in FIG. 1, the rotation (torque) of the drive gear 25 fixed to the drive shaft 22 of the motor 21 is decelerated by the first driven gear 31 and further driven. The speed is further reduced by the second gear 31b and the output gear 32, and finally output as torque from the upper output shaft 33.

Further, in the present invention, the sliding plate 34 is fixed to the lower surface of the output gear 32, the notch 40 is formed in a part of the peripheral edge of the sliding plate 34, and the sliding plate 34 is attached to the lower case 1. Abutting contact points 41 and 42 are provided, the contact point 41 is provided at a position where it overlaps with the notch 40, and the contact point 42 is formed so as to always abut the sliding plate 34. Furthermore, the contact point 41 and the contact point 42 are connected in series. A switching mechanism is formed by electrically connecting with.

When the contact 42 comes to the position of the notch 40, this switching mechanism short-circuits the electrical series state and turns off, and keeps the stop position of the output shaft 33 constant. ..

Further, the lower case 1 of the present invention is formed with locking grooves 1f on four sides thereof, and the locking grooves 1f form a locking mechanism to be fitted with the locking hooks 2a provided on the four sides of the upper case 2. is doing.

In this locking mechanism, the lower case 1 and the upper case 2 made of a synthetic resin are integrated by fitting the locking hook 2a and the locking groove 1f, and the motor part incorporated in the lower case 1 is integrated. 20 and the reduction gear train 30 are structured so that they can be securely locked in the case.

[0032]

[Effect of the device]

 A drive gear is fixed to the tip of the drive shaft of the motor, which is composed of a motor, a reduction gear train, and a case that accommodates them. The drive gear and the reduction gear train are connected to each other, and the drive gear is provided at the rear portion of the drive gear. Since the idling member is loosely fitted and the elastic member that urges the idling member in the radial direction is brought into contact with the idling member, the motor is connected by reducing the noise 3 to 5 dB generated by the radial direction of the motor. It has the effect of reducing noise as a geared motor. Further, in the present invention, since the curved free end of the elastic material is in contact, the biasing force can be buffered. Therefore, unlike the reference, no load is applied from the thrust direction, so that components such as the spacers and bearings inside the motor are not damaged and the life of the motor is not affected.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which an upper case of a geared motor according to an embodiment of the present invention is removed.

FIG. 2 is a plan view of a motor unit of the geared motor according to the embodiment of the present invention.

FIG. 3 is a front view of a motor unit of the geared motor according to the embodiment of the present invention.

FIG. 4 is an exploded perspective view of a group of parts incorporated in the lower case of the geared motor according to the embodiment of the present invention.

FIG. 5 is another embodiment of the present invention.

[Explanation of symbols]

 1 Lower Case 2 Upper Case 10 Geared Motor 21 Motor 22 Drive Shaft 23 Pulley 24 Elastic Material 30 Reduction Gear Train

Claims (2)

[Scope of utility model registration request] 1. A drive gear comprising an electric motor, a reduction gear train, and a case accommodating the motor, and a drive gear fixedly attached to a tip of a drive shaft of the motor. A noise reduction structure for a geared motor, wherein an idling member is loosely fitted to a rear portion of the gear, and an elastic member biasing the idling member in a radial direction is brought into contact with the idling member. 2. A motor, a reduction gear train, and a case that accommodates the motor, a drive gear is fixed to a tip of a drive shaft of the motor, and the drive gear and the reduction gear train are connected to each other. A structure for reducing noise in a geared motor, characterized in that an elastic member that urges in a radial direction is brought into contact with a drive shaft at a rear portion of a drive gear.