JPH10285869A - Geared motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the vibrating amplitude of an overhang mode by forming a connected part of a reduction gear and a motor for a bracket into a double cylindrical structure, and connecting an outer cylindrical part with the housing of the motor through a plurality of ribs rising in the rotating shaft direction of the motor disposed radially between the cylindrical parts. SOLUTION: A bracket 3 is constituted of a flange 16, a connected part 18 for connecting to the flange 16, and a bearing housing 14 for retaining a bearing. The flange 16 is provided with a bolt hole 17 for fixing on a main casing. The connected part 18 is a double cylindrical structure consisting of an outer cylindrical part 19 and an inner cylindrical part 20, between which a rib 21 rising in the rotating shaft direction of the motor is provided radially, and the outer cylindrical part 19 is connected to the housing of the motor 6. Even if it vibrates by itself with exciting force generated by driving a geared motor, it is possible to minimize the vibrating amplitude of an overhang mode, and radiation of magnetic noise or engaging noise resulting from vibration to its surrounding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a geared motor, and more particularly, to a magnetic motor which is excited by a magnetic exciting force generated by driving the geared motor and an exciting force generated by meshing of a gear pair. The present invention relates to a geared motor having a structure capable of minimizing radiated vibration and harsh magnetic noise and meshing noise generated due to the vibration.

[0002]

2. Description of the Related Art A geared motor includes a motor that generates a rotational force in response to a predetermined electric input and a speed reducer having a function of reducing the speed of a motor rotating shaft by a plurality of gear pairs. The casing of the machine generally has a structure including a main casing for accommodating a gear pair, and a bracket disposed at a position connecting the main casing and the motor, and supporting a part of the motor rotation shaft via a bearing. As a structure of a portion excluding a gear pair, for example, JP-A-6-24128
There is one disclosed in Japanese Patent Publication No.

[0003]

The problematic noise in a geared motor will be described. The excitation force generated by driving the geared motor is roughly classified into two types.
One is a magnetic component of the motor, and the other is a meshing component resulting from meshing of the gear pair. The vibrations of the respective parts of the geared motor are excited by these exciting forces, generating unpleasant magnetic sounds and meshing sounds and radiating them to the surroundings.
In particular, when the frequency of the excitation force matches the natural frequency of the geared motor (hereinafter, such a case is referred to as resonance).
In this case, the sound level becomes relatively high. Also, among the plurality of vibration modes, when the bracket resonates in a vibration mode in which the bracket is relatively largely deformed and the entire motor vibrates rigidly (hereinafter, referred to as an overhang mode), the vibration amplitude and the sound amplitude are reduced. Due to the size of the radiation area, the sound level becomes extremely high regardless of the type of the excitation force. This is no exception in the prior art geared motor.

[0004] In general, when reducing noise generated from equipment, two major issues are to avoid resonance and to reduce the level of excitation force. However, in the case of a geared motor, it is extremely difficult to achieve the former in a situation where a large number of exciting forces exist and the frequency changes due to variable speed operation.
In addition, the latter is a problem that is contradictory to miniaturization and weight reduction that leads to cost reduction, and it is often difficult to achieve the latter. Therefore, in the case of a geared motor, apart from the above problem, it is necessary to efficiently increase the rigidity of each part in order to reduce the vibration amplitude of the vibration mode.

However, in the prior art geared motor described above, if the mode is limited to the overhang mode, measures such as increasing the rigidity of the bracket to reduce the vibration amplitude are not taken. It is hard to say that sufficient consideration has been given to the generation of radiation and radiation to the surroundings.

The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the vibration amplitude of the overhang mode even when the vibration itself is generated by driving a geared motor. It is an object of the present invention to provide a geared motor including a bracket having a structure capable of suppressing radiation to the surroundings of magnetic noise and meshing noise generated due to vibration.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to provide a double-cylinder structure comprising an outer cylinder and an inner cylinder at a connecting portion for connecting the speed reducer of the bracket and the motor, wherein the motor is provided between the outer cylinder and the inner cylinder. This is achieved by a geared motor characterized in that a plurality of ribs that stand up in the direction of the rotation axis are radially arranged and the outer cylinder and the motor housing are connected.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a geared motor according to the present invention will be described below with reference to FIGS.

FIG. 1 is a partial longitudinal sectional view of a side surface of a geared motor 1 according to the present invention.

A bracket 3 is fixed to a surface of the main casing 2 opposite to a surface from which the output shaft 5 projects, using fastening means such as a bolt (not shown). A motor 6 is fixed to an end of the bracket 3. ing. The leg 4 is integrally formed with the main casing 2 so that the geared motor 1 can be fixed to a fixed surface (not shown).

A stator 13 is fitted inside the housing 7 using fitting means such as shrink fitting or press fitting, and a motor bracket 9 is fixed to an end thereof. A through bolt 11 is used to fix the motor bracket 9, and the motor 6 is fixed to the bracket 3 by fastening the bolt to the bracket 3. However, if equivalent performance is obtained, the method of fixing the bracket 3 and the motor 6 need not be limited to the above. Two bearings 15 are fitted to the motor rotating shaft 12 using fitting means such as press-fitting, and the bearings 14 provided on the bracket 3 and the motor bracket 9 hold them, so that the motor rotating shaft 1
2 allows rotation inside the stator 13.

A pinion (not shown) is formed at the end of the motor rotation shaft 12 and meshes with a part of a plurality of gear pairs (not shown) appropriately arranged in the speed reducer 25, and finally the motor rotation shaft A power transmission system from 12 to the output shaft 5 is configured. This makes it possible to reduce the speed of the motor rotation shaft 12 rotating at a predetermined rotation speed according to a reduction ratio determined by the number of gear pairs (not shown) and the gear ratio.

FIG. 2 is a front view of the bracket 3 provided in the geared motor 1 of the present invention.

The bracket 3 comprises a flange 16, a connecting portion 18 for connecting to the housing 7, and a bearing housing 14 for holding a bearing 15. The flange 16 has a bolt hole 17 for fixing to the main casing 2. Is provided. The connecting portion 18 has a double cylindrical structure composed of an outer cylinder 19 and an inner cylinder 20, and a motor rotating shaft 1
Ribs 21 rising in two directions are provided radially.

Here, the connecting portion 18 provided on the bracket 3
The necessity and the problem of are explained.

In general, the geared motor 1 includes a motor 6 having a partially modified standard motor which functions independently.
In many cases, a manufacturer that manufactures the standard motor and the geared motor 1 in parallel is often used for reasons of cost reduction. However, since each of the standard motors is configured to function independently, when the standard motors are mounted on the geared motor 1, it is necessary to consider the bracket 3 in accordance with the structure.
One of them is the installation of the connection portion 18, which is provided mainly for correcting the length of the housing 7, and is an indispensable portion when configuring the geared motor 1.

In determining the structure of the bracket 3, it is necessary to consider making the rigidity of the connecting portion 18 as large as possible. This is because, as shown in FIG. 8, there is a vibration mode in which the connecting portion 18 is relatively largely deformed and the entire motor 6 rigidly vibrates, and the vibration amplitude greatly depends on the rigidity of the connecting portion 18. Because it is. However, in order to increase the rigidity, for example, integrating the connecting portion 18 and the bearing housing 14 or increasing the outer diameter of the connecting portion 18 leads to an increase in the mass and the manufacturing cost of the geared motor 1 in the bracket 3. Therefore, it is not always an effective method. As the structure of the connecting portion 18, it is desirable that the members are appropriately arranged within a range that does not increase the mass and the manufacturing cost, and that the necessary rigidity can be secured.
There is a bracket 3 provided in the geared motor 1 of the present invention shown in FIG.

The bracket 3 provided in the geared motor 1 according to the present invention will be described with reference to FIGS. Note that the same parts as those in FIG.

FIG. 3 shows a front view of the bracket 3. Radial fins 22 are provided on the outer periphery of the connecting portion 18 and extend in the direction of the motor rotation shaft 12.

FIG. 4 is a front view of another bracket 3.
A plurality of fins 2 adjacent to each other are arranged on the outer periphery of the connecting portion 18 at positions where the fins are divided into four in the circumferential direction.
Each of the fin groups 23 includes two fin groups 23. Each fin 22 extends in the direction of the motor rotation shaft 12.

The bracket 3 shown in FIG. 3 and FIG.
As with the bracket 3 shown in FIG. 1, the rigidity required for suppressing the vibration amplitude can be secured, and the cooling performance of the geared motor 1 can be improved. Note that the shapes of the fins 22 and the fin group 23 may be changed from the direction of the motor fins 8 and the motor rotation shaft 12 provided in the motor 2 so as not to obstruct the flow of cooling air (not shown) generated by the rotation of the fan 10. It is desirable that the shape is almost the same as the shape seen, but this is not the case if the desired performance for cooling is obtained.

FIG. 5 shows a front view of the bracket 3. A plurality of protrusions 24 extending in the direction of the motor rotation shaft 12 are provided on the outer periphery of the connection portion 18.

FIG. 6 shows a front view of another bracket 3.
The thickness of the connecting portion 18 is continuously changed at a portion where the connecting portion 18 is divided into four in the circumferential direction.

The bracket 2 shown in FIGS. 5 and 6 secures the rigidity required to suppress the vibration amplitude, and
In order to keep the mass of the connecting portion 18 small, the thickness of the connecting portion 18 is partially increased or decreased.

FIG. 7 shows a front view of the bracket 3. The leg 4 for fixing the geared motor 1 to a fixing surface (not shown) is provided integrally with the connection portion 18. In this case, the main casing 2 does not need to include the legs 4.

The bracket 3 is provided with a leg 4 serving as a reinforcing member at a connecting portion 18 having a small rigidity and easily deformable as compared with the speed reducer 25 and the motor 6, and this is not shown when the geared motor 1 is constructed. Since the vibration amplitude is fixed to the fixed surface, the vibration amplitude can be suppressed to be small.

[0027]

According to the present invention, the connecting portion for connecting the speed reducer and the motor of the bracket has a double cylindrical structure composed of an outer cylinder and an inner cylinder, and the motor is connected between the outer cylinder and the inner cylinder in the direction of the motor rotation axis. A plurality of raised ribs are radially arranged, and the outer cylinder and the motor housing are connected, so even if the vibration itself generated by the excitation force generated by driving the geared motor,
The vibration amplitude of the overhang mode can be suppressed to a small value, and the radiation of the magnetic sound and the meshing sound generated due to the vibration to the surroundings can be suppressed to a small value.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view showing an embodiment of a geared motor according to the present invention.

FIG. 2 is a front view of a bracket provided in the geared motor of the present invention.

FIG. 3 is a front view of a bracket provided in the geared motor of the present invention.

FIG. 4 is a front view of a bracket provided in the geared motor of the present invention.

FIG. 5 is a front view of a bracket provided in the geared motor of the present invention.

FIG. 6 is a front view of a bracket provided in the geared motor according to the present invention.

FIG. 7 is a front view of a bracket provided in the geared motor of the present invention.

FIG. 8 is a diagram illustrating a vibration mode of the geared motor according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Geared motor, 2 ... Main casing, 3 ... Bracket, 4 ... Leg, 5 ... Output shaft, 6 ... Motor, 7 ... Housing, 8 ... Motor fin, 9 ... Motor bracket, 10 ...
Fan, 11: Through bolt, 12: Motor rotating shaft, 13
... stator, 14 ... bearing housing, 15 ... bearing, 16 ...
Flange, 17 ... bolt hole, 18 ... connection part, 19 ... outer cylinder, 20 ... inner cylinder, 21 ... rib, 22 ... fin, 23 ...
Fin group, 24: convex part, 25: reduction gear.

Claims (4)

[Claims] 1. A motor having a function of reducing the speed of a rotating shaft of a motor by a plurality of gear pairs, the motor having a function of reducing the speed of a rotating shaft of the motor by receiving a predetermined electric input. A geared motor having a structure including a main casing for accommodating a gear pair, and a bracket disposed at a position connecting the main casing and the motor and supporting a part of a motor rotation shaft via a bearing, wherein a reduction gear of the bracket and a motor are provided. The connecting portion connecting the outer cylinder and the inner cylinder has a double cylindrical structure comprising an outer cylinder and an inner cylinder. A geared motor characterized by being combined with a housing. 2. A motor for generating a rotational force in response to a predetermined electric input, and a speed reducer having a function of reducing the speed of a motor rotating shaft by a plurality of gear pairs, and a casing of the speed reducer is provided. A geared motor having a structure including a main casing for accommodating a gear pair, and a bracket disposed at a position connecting the main casing and the motor and supporting a part of the motor rotation shaft via a bearing, wherein a reduction gear of the bracket and a motor are provided. A plurality of fins are arranged on an outer peripheral surface of a connecting portion for connecting the motor and the motor. 3. A motor, which generates a rotational force in response to a predetermined electric input, and a speed reducer having a function of reducing the speed of the motor rotating shaft by a plurality of gear pairs. A geared motor having a structure including a main casing for accommodating a gear pair, and a bracket disposed at a position connecting the main casing and the motor and supporting a part of a motor rotation shaft via a bearing, wherein a reduction gear of the bracket and a motor are provided. The thickness of the connecting part that connects
Alternatively, a geared motor characterized by being changed intermittently. 4. A motor, which generates a rotational force in response to a predetermined electric input, and a speed reducer having a function of reducing the speed of a motor rotating shaft by a plurality of gear pairs. A geared motor having a structure including a main casing that accommodates a gear pair, and a bracket that is disposed at a position connecting the main casing and the motor and that supports a part of the motor rotation shaft via a bearing, the bracket being provided with legs. A geared motor characterized in that: