JPH04312338A - Geared motor - Google Patents

Abstract

PURPOSE:To assemble the motor section and the gear mechanism section of a geared motor integrally of reduced number of components and to reduce assembly manpower. CONSTITUTION:The support and case for motor components(stator 5, rotor 6) and gear components 14, 17 are constituted of a main case 1, a bearing plate 2 and a subcase 3. The subcase 3 has bearing function for both the rotor shaft 7 and the gear components 14, 17. Outer tube 50 of the stator 5 is positioned by means of the tubular protrusion 51 of the bearing plate 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a geared motor that integrally combines a small-sized motor with a gear mechanism for changing speed.

0002

[Prior Art] The structure of a conventional geared motor is that a motor is a self-contained motor housed in a case, and a gear head, which has a gear mechanism with a predetermined gear ratio built into a small case, is combined with the motor, and both are screwed together. It is connected and fixed using a separate connecting metal fitting.

0003

[Problems to be Solved by the Invention] In a structure in which a geared motor is constructed by connecting and fixing a motor and a gear head, each of which has an independent structure, the number of parts as a whole is large, and the number of man-hours required to assemble each motor and gear head is large. When the number of man-hours for assembling the gear head and motor and screwing them together is included, the number of man-hours required for assembly as a whole is extremely large, resulting in high costs.

The present invention was made in view of the above-mentioned conventional problems, and its purpose is to realize an inexpensive and small geared motor that integrates a motor and a gear mechanism with fewer parts and fewer assembly steps. It is in.

[0005]

[Means for Solving the Problems] A geared motor according to the present invention includes a main case having a cylindrical motor storage portion with one end open, and a stator that is fitted and stored in the motor storage portion of the main case. A rotor is assembled in the stator and one end of the rotor shaft is supported by the bearing part of the main case, and a rotor is fitted and attached to the main case so as to close the opening of the motor storage part, and the rotor shaft has one end supported by the bearing part of the main case. a bearing plate that is supported with the other end thereof being penetrated; a sub-case that is fitted and attached to the main case so as to cover the bearing plate and forms a gear storage section;
The rotor is rotatably supported in a predetermined arrangement by the subcase and the bearing plate, and includes a gear mechanism for changing the speed of rotation of the rotor shaft.

Further, as means for positioning the stator with high precision, a cylindrical protrusion that coaxially enters the motor housing is formed on the bearing plate, and this cylindrical protrusion aligns the stator in the motor housing. It is configured to fit into the upper end protrusion of the outer circumferential cylindrical body for positioning.

[0007]

[Operation] A motor portion is constructed by attaching the stator and rotor to the main case and fitting the bearing plate. By further fitting and mounting the sub-case to this main case, a gear storage section is formed, and the gear mechanism is disposed therein. The bearing means that rotatably supports each gear of the gear mechanism is constituted by a bearing plate and a sub-case, which also bear the bearing of the rotor shaft.

[0008] The stator is temporarily positioned by being housed in the motor storage portion, but is positioned even more accurately by the cylindrical protrusion of the bearing plate combined with the main case. Since the rotor shaft is supported by a bearing plate, the positional relationship between the stator and the rotor is extremely accurate.

[0009]

[Embodiment] Fig. 1 is a plan view of a geared motor according to an embodiment of the present invention with the subcase removed, and Fig. 2 is a sectional view taken along line A--I of Fig. 1 with the subcase attached. . In both figures, 1 is a main case, 2 is a bearing plate, and 3 is a sub-case, each of which is made of a plastic molded product.

The main case 1 has a cylindrical motor accommodating portion 4 that is open at the upper end, and a claw-pole stator 5 of a stepping motor is fitted and fixed inside the cylindrical motor storage portion 4. A magnetic rotor is housed in a rotatable manner. A bearing hole 8 into which the rotor shaft 7 fits is formed at the center of the inner surface of the bottom of the motor housing portion 4, and the lower end of the rotor shaft 7 is supported by this bearing hole 8. However, the main case 1 does not have a function of supporting the upper end side of the rotor shaft 7.

The outer cylinder 50 of the stator 5 is made of a magnetic material and forms part of a claw pole yoke. The lower part of the stator 5 is positioned in the main case 1 by fitting the center hole 50a on the bottom surface of the outer circumferential cylinder 50 into the circular protrusion 4a on the inner bottom surface of the motor housing section 4. Further, the upper end side of the outer circumferential cylinder 50 is open straight.

With the stator 5 and rotor 6 housed in the motor housing 4, the bearing plate 2 is fitted onto the upper surface of the main case 1 so as to close the opening of the motor housing 4. Details of the bearing plate 2 are shown in FIG. The bearing plate 2 is formed with a bearing hole 9 that supports the upper end of the rotor shaft 7 in a penetrating state, and also has two small positioning holes 10 formed therein. On the other hand, two positioning protrusions 11 (FIG. 1) corresponding to the positioning holes 10 are formed on the main case 1.
The bearing plate 2 is assembled to the main case 1 by press-fitting the bearing plate 1 into the two holes 10. The bearing plate 2 is now attached to the main case 1 at an accurate position, and the upper end side of the rotor shaft 7 passes through the bearing hole 9. At this time, the lower surface of the bearing hole 9 comes into contact with the diameter step of the rotor shaft 7, and the rotor 6 is positioned in the thrust direction.

The peripheral portion of the bearing hole 9 of the bearing plate 2 is a cylindrical protrusion 51 that protrudes downward, and when the bearing plate 2 is assembled to the main case 1 as described above, the cylindrical protrusion 51 The cylindrical protrusion 5 enters into the motor accommodating portion 4 and tightly fits into the upper end opening of the outer circumferential cylindrical body 50 of the stator 5 . The upper part of the stator 5 is now positioned on the bearing plate 2. Therefore, the positional relationship between stator 5 and rotor 6 is maintained with extremely high precision.

The rotor shaft 7 is a molded plastic product, and a first gear 12 is formed at the upper end portion of the bearing plate 2 that projects upward. In addition, bearing plate 2
A rectangular protrusion 13 is formed on the lower surface of the holder. A terminal section is formed next to the motor storage section 4 in the main case 1, and the wiring window section of the terminal section is connected to the bearing plate 2.
It is designed to be closed by a protruding piece 13.

A bearing hole 16 for supporting the lower end of a gear shaft 15 for a gear component 14 is formed on the upper surface side of the bearing plate 2, and a bearing hole 16 for rotatably supporting another gear component 17 is formed. A gear shaft 18 is integrally provided in a protruding manner. The gear parts 14 and 17 are both molded plastic products, and the gear part 14 is formed with a large-diameter second gear 19 that meshes with the first gear 12 and a smaller-diameter third gear 20. The component 17 includes a fourth gear 21 that meshes with the third gear 20, and a fifth gear 22 having a smaller diameter than the fourth gear 21. This fifth gear 22 is an output gear.

With the gear parts 14 and 17 mounted on the upper surface of the bearing plate 2, the sub-case 3 is attached to cover the box-shaped upper surface of the main case 1 from above. The detailed configuration of this subcase 3 is shown in FIG. Two positioning protrusions 23 and three locking claws 24 are formed on the lower surface of the periphery of the sub-case 3. On the other hand, on the upper surface side of the peripheral wall portion of the main case 1, there are two positioning holes 25 corresponding to the positioning protrusions 23 and three positioning holes corresponding to the locking claws 24.
A number of locking holes 26 are formed. Protrusion 23 and hole 25
By fitting, the sub case 3 is positioned relative to the main case 1, and the locking pawl 24 is elastically caught in the locking hole 26, so that the sub case 3 is not easily removed.

A bearing hole 27 for supporting the upper end of the gear shaft 15 for the gear component 14 is formed on the lower surface side of the sub-case 3. That is, the lower end of the gear shaft 15 is supported by the bearing plate 2, and the upper end is supported by the subcase 3. A gear component 14 is rotatably mounted on the gear shaft 15, and is positioned between small cylindrical portions forming a bearing hole 16 and a bearing hole 27 to position the gear component 14 in the thrust direction.

Furthermore, a gear shaft 18 integrated with the bearing plate 2
The drum-shaped gear part 17 attached to the is housed in the cylindrical part 28 of the sub-case 3, and the fifth gear 22 at the upper end thereof
protrudes from the upper end opening of the cylindrical portion 28. Cylindrical part 28
The gear component 17 is positioned in the radial direction, and the gear component 17 is also positioned in the thrust direction by the upper surface side of the fifth gear 22 and the lower surface side of the cylindrical portion 28 coming into contact with each other.

[0019]

Effects of the Invention The geared motor of the present invention forms the case and the support for the motor parts and the gear parts of the transmission gear mechanism by combining three parts: the main case, the sub-case, and the bearing plate. In particular, the bearing plate has a bearing function for the rotor housed in the main case, and also performs a positioning and bearing function for a gear mechanism disposed between the main case and the sub-case. With this structure, it is possible to realize a geared motor in which the motor part and the gear mechanism part are integrated in a very compact manner with a small number of parts. Furthermore, since the number of parts is small and assembly is easy, this type of geared motor can be mass-produced at low cost.

Furthermore, since the stator and rotor are positioned with extremely high precision by the main case and the bearing plate, the motor rotates smoothly and is highly reliable.

[Brief explanation of drawings]

FIG. 1 is a plan view of a geared motor according to an embodiment of the present invention with a subcase removed.

FIG. 2 is a sectional view taken along line E in FIG. 1 of the geared motor with a subcase attached.

FIG. 3 is a plan view, a sectional view, and a bottom view of a bearing plate of the geared motor.

FIG. 4 is a plan view, a sectional view, and a bottom view of a subcase of the geared motor.

[Explanation of symbols]

1 Main case 2 Bearing plate 3. Sub case 4 Motor storage section 5 Stator 6 Rotor 7 Rotor shaft 12 1st gear 14 Gear parts 15 Gear shaft 17 Gear parts 18 Gear shaft 50 Outer cylindrical body 51 Cylindrical protrusion

Claims (1)

[Claims] Claims: 1. A main case having a cylindrical motor housing with one end open, a stator fitted and housed in the motor housing of the main case, and a rotor shaft assembled within the stator. a rotor whose one end side is supported by a bearing portion of the main case, and a rotor that is fitted and attached to the main case so as to close an opening of the motor storage portion;
a bearing plate that supports the other end of the rotor shaft in a penetrating state; a sub-case that is fitted and attached to the main case so as to cover the bearing plate to form a gear storage section; and a gear mechanism that is rotatably supported in a predetermined arrangement by a bearing plate and changes the speed of rotation of the rotor shaft, and the bearing plate has a cylindrical protrusion that coaxially enters the motor housing,
A geared motor characterized in that the cylindrical protrusion fits into a protruding upper end portion of the outer circumferential cylindrical body of the stator in the motor storage portion to position the same.