JPH03212140A - Bearing mounting structure for molded motor - Google Patents

Abstract

PURPOSE:To reduce assembly steps, and to prevent generation of noise due to the play of a bearing by integrally providing spring means for pressing the outer race of the bearing axially agent the opposed contact side of a bearing stop ring with the bearing, and holding the bearing between the means and a stop ring engaged with the outside position of the bearing. CONSTITUTION:A bearing engaging ring 7 has semicircular protrusions 72 corresponding to a cutout groove 59 at three positions of a predetermined interval on the outer peripheral edge. Further, cut pieces erected in the same axial direction are provided as spring parts 71 between the protrusions 72. The parts 71 are brought into contact with the outer race of a bearing 58 mounted outside a bearing engaging ring 70, and further engaged by a stop ring 51 mounted at the other bearing 58. Accordingly, the part 71 axially presses the outer race of the bearing 58, and the ring 51 axially presses the inner race. That is, the play of the bearing can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bearing mounting structure for a molded motor.

[Conventional technology and problems to be solved 1. A stator with wires wound around an annular core is molded with a molding material such as resin, and a rotor shaft is inserted into the inner cavity of the molded body. There is a so-called molded motor that is supported by bearings arranged at openings at both ends of a molded body.

In such a molded motor, bearing brackets are attached to openings at both ends of the molded body to hold a bearing that supports the rotor shaft. A circular attachment is formed by expanding into the openings at both ends of the molded body and is fitted onto the surface.

In this case, it is necessary to align the mounting surface of the bearing bracket with the axis of the stator, but since the diameter of the mounting surface is larger than the inner diameter of the central rotor housing space, both of these must be aligned during molding. The mounting surface cannot be molded together with the rotor housing space in one mold; for example, one mounting surface is molded together with the rotor housing space using a core metal, and the other mounting surface is molded using an upper mold. It had to be molded in a mold.

However, when molding both mounting surfaces using separate molds, it is difficult to align the axes of both mounting surfaces due to the combination structure of the upper and lower molds and the core metal. There is a problem that misalignment easily occurs.

Therefore, in the molded motor described above, the inventor formed the opening at one end of the inner cavity of the molded body in which the stator was molded as a bearing mounting space having a diameter smaller than that of the rotor housing space. The above problem is solved by forming the rotor housing space in the center and the mounting space for the bearing bracket in the opening on the other end so that their diameters become larger in sequence, and by forming each of these spaces with a single core metal. It was decided to.

In this case, since the bearing is directly mounted in the bearing mounting space with the smallest diameter, a means for regulating the movement of the bearing in the axial direction is required.

As a means for this, as shown in FIG. 6, axial notch grooves are provided at several locations on the inner circumferential surface of the bearing mounting space at required intervals in the circumferential direction, leaving the innermost end. A ring plate-shaped stopper member having a protrusion on its outer periphery corresponding to the protrusion is placed at an inner position of the bearing by fitting the protrusion into the notch and engaging with the inner open end. The bearing was held between a retaining ring attached to the rotor shaft on the outside.

In this case, the bearing that supports the rotor shaft (generally a ball bearing) usually has a slight play between the outer ring, the inner ring, and the ball sandwiched between the two rings. If this happens, vibration and noise will occur during rotation, so the inner ring of the bearing is locked to a retaining ring attached to the rotor shaft, and the outer ring is pressed in the direction of the retaining ring to eliminate the play. need to be eliminated. Therefore, it is conceivable to interpose a corrugated washer between the stopper member and the bearing member.

However, using a wave washer in this way requires two parts, a stopper member and a wave washer.
This increases the amount of time required to assemble the motor, and also makes parts management troublesome.

In view of the above, the present invention solves the above problems and reduces the number of parts when a bearing that supports a rotor shaft is directly fitted into the inner peripheral surface of the minimum diameter opening of a molded body of a stator. To provide a mounting structure capable of reducing the number of assembly steps by reducing the number of steps required for assembly, and capable of holding a bearing without fear of generating noise due to play in the bearing.

[Means for solving the problem] The stator is molded with a molding material such as resin, and the inner circumferential surface of at least one end side opening in the inner cavity of the molded body is
In a molded motor in which a bearing to be supported on a rotor shaft is fitted, a notched groove extending in the axial direction from the opening end is formed on the inner circumferential surface of the opening that serves as the bearing mounting surface of the molded body, leaving the innermost end. A bearing locking ring provided at several locations in the circumferential direction and having protrusions on the outer periphery that correspond to the notch grooves is arranged so that the protrusions fit into the notch grooves and engage with the innermost end of the bearing. The outer ring of the bearing is pressed in the axial direction, and a spring means is integrally provided on the side of the bearing locking ring that is in contact with the bearing. The bearing is held between the retaining ring and the retaining ring.

[Function] In the bearing mounting space configured as described above, the bearing locking ring including a spring means locks on the inner back end, presses the outer ring of the bearing outward, and presses the outer ring of the bearing to the outside. On the other hand, the retaining ring fitted on the outside of the bearing ends up pressing the inner ring of the bearing inward. Due to these axial pressures, there is no play between the balls arranged in the bearing and the outer ring and the inner ring, and no noise or vibration is generated.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 1, 4B is a rotor core, 48 is a rotor shaft, and these core 46 and shaft 48 constitute a rotor. 52 and 58 are bearings that rotatably support this rotor. Further, 5o is a drawn bearing bracket made of a disk, and the bearing 52 is held by this bearing bracket 50. 51.5
Reference numeral 1 denotes a C-type or E-type retaining ring that restricts the axial movement of the bearings 52 and 58, and is fitted into a groove 53 provided in the circumferential direction of the rotor shaft 48.

Further, in FIG. 2, IO is a stator arranged on a circular diameter, and this stator IO has a coil 16 wound in a toroidal shape in each slot 14 provided in the stator core 12. A plurality of teeth 18 are formed at the inner end of the stator core 12. This stator 10 is molded with a molded material such as resin.
The molded body 20 is molded so as to be buried leaving the inner surface of the molded body 8 intact.

FIG. 3 shows a cross-sectional view of the molded body 20.

22 is a cylindrical bearing mounting space in which the bearing 58 is attached; 24 is a cylindrical rotor housing space formed with a diameter larger than that of the rotor by the amount of the air gap; 2B is a space in which the periphery of the bearing bracket 50 is engaged; The fitting cylindrical bearing bracket is mounted in a space. Since the rotor housing space 24 is formed to have a larger diameter than the bearing mounting space 22, and the bearing bracket mounting space 2B is formed to have a larger diameter than the rotor housing space 24, each of the spaces 22, 24, 2B is formed as one core. It can be formed from gold 21.

Reference numeral 59 indicates a notch groove extending in the axial direction, and reference numeral 60 indicates an end portion on the inner deep open side. A deep opening side end portion 60 is left.

Further, FIG. 4 is a perspective view of a bearing locking ring 70 that fits in the notch groove 59. This bearing locking ring 70
has semicircular protrusions 72 corresponding to the notch grooves 59 at three locations on the outer periphery at regular intervals, and furthermore, between each of the protrusions 72 provided at the three locations, , the spring portion 71 has a section rising in the same axial direction.

This spring portion 71 is in contact with the outer ring of the bearing 58 attached to the outside of the bearing retaining ring 70, and is further fitted into the engagement state by the retaining ring 51 attached to the other side of the bearing 58.
As a result, the spring portion 71 serves as the outer ring of the bearing 58 and the retaining ring 5.
1 presses the inner rings in the axial direction. therefore,
Bearing play can be eliminated.

A molded body 20 is formed by molding the stator lO with resin.
When forming, as shown in FIG. 3, first, the core metal 21 is fitted into the lower mold, the stator lO is arranged around the core metal 21,
Furthermore, the upper mold is fitted into the lower mold, and an injection port (not shown) is inserted into the space formed by the lower mold, the upper mold, and the core bar 21.
Inject the resin through. After this resin is solidified and cooled, the upper mold is separated from the lower mold, and the core bar 21 is pulled out from one side.

Next, the internal installation of this motor will be explained in terms of structure.

As shown in FIG. 1, first, the rotor shaft 48 to which the rotor core 4B is fixed is inserted from the bearing bracket mounting space 2B. At this time, the rotor core 46 is held at a position corresponding to the stator core 12. Further, in this installation, the bearing 52 supporting the rotor shaft 48 is press-fitted into the bearing bracket 5° after the bearing bracket 50 is locked to the inner peripheral surface of the space 26. Then, insert a C-type or E-type retaining ring 5 from the outside.
1 is attached to the rotor shaft 48. The retaining ring 51 prevents the bearing 52 from moving in the axial direction, and fits into a circumferential groove 53 provided at a predetermined position of the rotor shaft 48 .

On the other hand, as shown in FIG. 5, the inserted rotor shaft 48 protrudes from the bearing mounting space 22, which is the other opening.

A notched groove 59 provided on this rotor shaft 48 during molding.
A bearing locking ring 70 having a protrusion corresponding to the outer peripheral edge thereof is fitted into the space 22 so that the spring 71 of the ring 70 is on the outside, and the end portion 60 left inside is This bearing locking ring 70 is locked. A bearing 58 is inserted into the outside of this bearing locking ring 70, and a retaining ring 51 that comes into contact with the inner ring of the bearing 58 is placed further outside.
It is fitted into the groove 53 provided in the rotor shaft 48.

[Effects of the Invention] As described above, in the present invention, the stopper that prevents the movement of the bearing is provided with a spring means, so the number of parts can be reduced, and the assembly process of the molded motor can be facilitated. Therefore, it is possible to reduce costs and time for manufacturing the motor, and moreover, it is possible to reduce the troublesomeness of parts management. Furthermore, the spring means and the outer retaining ring eliminate play in the bearing and eliminate the risk of noise and vibration.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the mounting structure of the present invention, Fig. 2 is a perspective view of the stator, Fig. 3 is a sectional view of the molded body, and Fig. 4 is a bearing locking ring of the present invention. FIG. 5 is a perspective view showing how the bearing is mounted in space, and FIG. 6 is a sectional view showing the structure of the conventional bearing. 10... Stator, 12... Stator core, 16...
... Winding wire, 20 ... Mold body, 21 ... Core metal, 2
2... Bearing mounting space, 24... Rotor housing space,
26... Bearing bracket installation is space, 46...
・Rotor core, 48... Rotor shaft, 50... Bearing bracket, 51... Retaining ring, 52, 511.
... Bearing, 59 ... Notch groove, 60 ... Inner back end,
70...Bearing locking ring, 71...Spring portion of bearing locking ring, 72...Protrusion of bearing locking ring.

Claims (1)

[Claims] 1. The stator is molded with a molding material such as resin, and a bearing for supporting the rotor shaft is fitted onto the inner peripheral surface of at least one end side opening in the inner cavity of the molded body. In the molded motor, the inner circumferential surface of the opening that serves as the bearing mounting surface of the molded body is provided with notched grooves extending in the axial direction from the opening end, leaving the innermost end at several locations in the circumferential direction, and the notched grooves and A bearing locking ring having a corresponding protrusion on the outer periphery is disposed inside the bearing so that the protrusion fits into the notch groove and engages with the inner inner end, and the bearing locking ring A spring means for pressing the outer ring of the bearing in the axial direction is integrally provided on the side facing the bearing, and the bearing is placed between the spring means and a retaining ring that is secured to the outer side of the bearing on the rotor shaft. A bearing mounting structure for a molded motor, characterized in that the bearing is held in place.