JPS5918852Y2 - motor rotor - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a motor rotor.

Conventionally, for example, the rotor of a motor, which is a driving means of a watch, has been fixed by press-fitting an annular magnet into a rotor shaft made of a non-magnetic material.

However, when the magnets are press-fitted, the rotor shaft is actually scraped to a small extent, producing cutting powder, and the magnets are being scraped, producing magnet powder, and these cutting powder and magnet powder can enter the bearing after the rotor is assembled. This impairs rotor rotation and is one of the causes of spontaneous stop.

Furthermore, with the mounting means for press-fitting the magnets, the magnets may crack, so it is necessary to improve the dimensional accuracy between the rotor shaft and the shaft hole of the magnets.

Therefore, this invention attempts to eliminate the above drawbacks.
An embodiment of the present invention will be described in detail below with reference to the drawings.

In Figures 1 and 2, reference numeral 1 denotes a rotor shaft made of a highly rigid non-magnetic material, and both ends of this shaft are attached to bearing portions 2a of the base plates 2 and 3.
, 3b for rotation.

Further, on the outer circumferential surface of the rotor shaft 1, a plurality of (four in the drawing) grooves 1a are carved at equal intervals along the axial direction over almost the entire length of the rotor shaft. .

Further, as shown in FIGS. 1 to 3, the rotor shaft 1 has a bottomed cylindrical holding part 4 made of a non-magnetic material such as elastic plastic such as polyester elastomer, and is integrated with this holding part below. The molded rotor pinion 5 and the shaft hole 6
are fitted and connected via.

The inner wall surface of the shaft hole 6 has protrusions 5a, . . . along the axial direction.
. . . are provided, and each protrusion engages with an engagement groove 1a of the rotor shaft 1.

The holding portion 4 and the rotor pinion 5 are prevented from rotating around the rotor shaft 1 by the engagement groove 1a and the protrusion 5a that engages with this groove. and is positioned at the end of this groove.

Since the holding portion 4 and the rotor pinion 5 have elasticity, they are reliably connected to the rotor shaft 1, and the rotor pinion and a gear meshing with the pinion, for example, a second gear (not shown), are connected to the rotor shaft 1.

) can suppress the impact noise generated when meshing with the

The holding portion 4 is concentric with the rotor shaft 1, and surrounds the rotor shaft, and an annular rotor magnet 8 is housed inside the holding portion 4 by passing through the rotor shaft 1 through a center hole 8a.

The end face of the rotor magnet 8 in the axial direction is located inside the opening edge of the holding part 4 and is housed so as to sink low. A space 9 is formed.

An adhesive 10 is injected into the opening space 9 to seal and fix the rotor magnet 8 within the holding portion 4.

The adhesive 10 flows into the groove 1a of the rotor shaft 1, and also flows into the small gap 11 between the rotor shaft and the center hole 8a of the rotor magnet 8, and is attached to the rotor magnet. The adhesive area is increased and the adhesive strength is increased.

This is even more effective if, for example, a cyan adhesive is used as the adhesive.

12 is a stator.

Note that the engagement groove 1a may be provided on the inner wall surface of the shaft hole 6, and the protrusion 5a may be provided on the rotor shaft side, and their positional relationship is relative.

Further, the rotor according to the present invention is not limited to the driving means of a timepiece.

As explained above, according to the present invention, the holding part and the rotor pinion are made of a highly elastic member, and are connected to the rotor shaft by engaging the protrusion extending in the axial direction and the retaining groove. Therefore, the two are firmly connected to each other in a non-rotatable manner, and the impact noise generated when the rotor pinion meshes with the gear that meshes with it can be suppressed to a low level.

In addition, since the rotor magnets are not attached to the rotor shaft by press-fitting, assembly is easy, no cracks occur, and no cutting dust is generated as in conventional methods, so the rotation of the rotor is not impaired and it can be inserted into the rotor shaft. Not only is it acceptable even if there is an accuracy error due to some loosening of the dimensions of the rotor magnet, but also the adhesive gets into the large gap formed between the rotor magnet and the rotor by the ridges or engagement grooves. So,
The practical effects are significant, such as increasing the adhesive strength of the adhesive.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a partially cutaway sectional view showing the state of use, FIG. 2 is an enlarged sectional view taken along the line ■■-■■ in FIG. It is an enlarged sectional view taken along the line III-III. 1......Rotor shaft, 1a...
・Engagement groove, 4...... Holding part, 5...
...Rotakana, 5a...Protrusion, 6
......Shaft hole, 8...Rotor magnet, 9...Opening space, 10...
·····glue.

Claims (1)

[Scope of utility model registration request] A rotor shaft, a bottomed cylindrical holding part and rotor pinion connected to the rotor shaft through a shaft hole and integrally molded from a highly elastic non-magnetic material, and either one of the rotor shaft and the shaft hole. A protrusion extending in the axial direction is formed on one side, a retaining groove is formed on the other side and engages with the protrusion, and the rotor shaft is inserted into the holding part and is housed in the holding part from the opening edge of the holding part. an annular rotor magnet whose axial end face is located inside;
A rotor for a motor, comprising an adhesive injected into an opening space of the holding part and a gap between the rotor magnet and the rotor shaft to seal and fix the rotor magnet in the holding part.