JP7158432B2 - Rotating electric machine - Google Patents

Description

The present application relates to a rotating electric machine.

The technical background is described (see Patent Documents 1 and 2).
2. Description of the Related Art In recent years, an increasing number of electric power steering devices are mounted near a rack shaft of a vehicle steering device. This type of electric power steering apparatus transmits the power of a drive motor to a rack shaft by a transmission mechanism such as a belt transmission mechanism. The drive motor frequently reverses the direction of rotation because it is necessary to turn the vehicle right or left according to the driver's intention. In order to realize comfortable steering at this time and improve steering feeling, a transmission mechanism with helical teeth (for example, a pulley and belt, or a pair of gears, etc.) is adopted.

However, when a pulley or belt with helical teeth is employed, an axial reaction force acts on the rotating shaft when the drive motor is driven. The direction of this reaction force is similarly reversed as the direction of rotation of the drive motor is reversed. Therefore, when the direction of the reaction force is reversed, an impact is applied to the bearings that support the rotating shaft. It has been found that this impact puts a burden on the bearing. In order to reduce the load on the bearing, the diameter of the bearing should be increased. However, the size of the drive motor also increases in the radial direction, which is not preferable in terms of mountability on the vehicle.

Therefore, as a method of reducing the load on the bearing without changing the size of the bearing, an axial space is provided between the bearing and the case, and a multiple helical coil as described in Patent Document 1 is provided in that space. It is conceivable to attach a wave washer to absorb the impact.

The multiple helical wave washer must be installed between the outer ring of the bearing and the case, but if the frame is installed with the opening end facing upward, the space in the case will open downward. As a result, when the case is assembled with the multiple helical wave washer temporarily placed on the bearing, it becomes difficult to position the multiple helical wave washer.

Japanese Patent No. 6468009 Japanese Patent No. 4527145

The rotary electric machine described in the above-mentioned conventional patent document 1 includes a frame fitted with a stator having windings, a core to which a first bearing and a magnet are fixed, a shaft into which a second bearing is press-fitted, and a clearance fit of the second bearing. , a case to be press-fitted and fixed to the frame, and multiple helical wave washers between the second bearing and the case. The multiple helical wave washer and the case are temporarily fixed to the frame, but since the space in the case opens toward the ground, the multiple helical wave washer is temporarily placed on top of the second bearing before the case is removed. need to be assembled. However, since the multiple helical wave washer presses the outer ring of the second bearing, it is necessary to provide a gap from the inner ring of the second bearing.

In addition, if the shaft is assembled with the multiple helical wave washer temporarily fixed with the space of the case opened upwards, and then the shaft is rotated and assembled, the multiple helical wave washer may or may not be present depending on the product usage environment. Therefore, it is necessary to change the assembly process depending on the presence or absence of the multiple helical wave washer, resulting in an increase in equipment costs.

In addition, the conventional rotary electric machine described in Patent Document 2 described above has a structure in which the resin part and the inside of the wave washer are fixed by snap fitting and the resin part and the case are press-fitted and fixed. An increase in cost is required due to the addition of the assembly process. Moreover, there is a problem that the axial length becomes longer by the thickness of the resin part.

The present application discloses a technique for solving the above-described problems, and the purpose thereof is to provide a rotating electric machine capable of improving the assembling efficiency of the wave washer and stabilizing the pressurization by the wave washer. It is something to do.

A rotating electrical machine disclosed in the present application is a rotating electrical machine in which an output shaft is held by an output side bearing and a non-output side bearing, and includes a non-output side bearing box in which the non-output side bearing is accommodated and held. a wave washer disposed between the bearing box and an end surface of the outer ring of the non-output side bearing housed in the bearing box and configured by spirally winding a narrow thin plate; and the wave washer. An end winding body press-fitted and held between an end surface of the outer ring of the non-output side bearing housed in the anti-output side bearing box and between the wave washer and the anti-output side bearing box, respectively. The end winding body is continuous with the end portion of the wave washer and is wound in a plane with a winding number of 3/4 or more .

According to the rotating electric machine disclosed in the present application, it is possible to obtain a rotating electric machine that can improve the ease of assembly of the wave washer and stabilize the pressurization by the wave washer.

1 is a cross-sectional view showing a rotating electric machine according to Embodiment 1; FIG. 2 is a perspective view showing a wave washer in the rotary electric machine according to Embodiment 1; FIG. 1 is a cross-sectional view showing a main part of a rotating electric machine according to Embodiment 1; FIG. 2 is a side view showing a wave washer and an end winding body in the rotary electric machine according to Embodiment 1; FIG.

Embodiment 1.
FIG. 1 is a cross-sectional view showing a rotating electric machine according to Embodiment 1. FIG. FIG. 2 is a perspective view showing a wave washer in the rotary electric machine according to Embodiment 1. FIG. FIG. 3 is a cross-sectional view showing a main part of the rotating electrical machine according to Embodiment 1. FIG. FIG. 4 is a side view showing the wave washer and the end winding body in the rotary electric machine according to Embodiment 1. FIG.

The rotary electric machine 1 includes a frame 4 fitted with a stator 3 having windings 2, an output-side bearing 6 housed and held in a bearing box 5 on the output side, and a bearing box 7 on the counter-output side. and an output shaft 10 into which a core 9 to which a magnet (not shown) is fixed is press-fitted, and the output shaft 10 to which the counter-output side bearing 8 is loosely fitted is press-fitted into the frame 4 and fixed, and a case 11 fixed to the frame 4 by screws (not shown); The anti-output side bearing 8 is composed of an outer ring 8a, an inner ring 8b, and balls 8c.

The wave washer 12 applies an axial pressure to the outer ring 8a of the non-output side bearing 8 on the non-output side. is attached to the
Furthermore, an end winding body 13 manufactured by winding a flat portion is press-fitted between the wave washer 12 and the outer ring 8a of the non-output side bearing 8 and between the wave washer 12 and the non-output side bearing box 7, respectively. retained.

By pressing and holding the end winding body 13 between the wave washer 12 and the outer ring 8a of the non-output side bearing 8 and between the wave washer 12 and the non-output side bearing box 7, the non-output side bearing The wave washer 12 does not come off even when the space of the box 7 is directed toward the ground, and the anti-output side bearing 8 can be assembled.

In addition, by setting the outer diameter d1 of the end winding body 13 to the outer diameter d2 of the wave washer 12 in a state where the maximum load (for example, full compression) of the wave washer 12 is generated, d1>d2. The space of the bearing box 7 on the output side and the wave washer 12 can be arranged coaxially, and the outer ring 8a of the anti-output side bearing 8 can be stably pressurized.

FIG. 2 shows a wave washer 12 made of a coiled wave spring made by spirally winding a narrow thin plate, and an end winding body 13 made by winding a narrow thin plate flat on the end of a wave washer 12. is doing. The end winding body 13 can be manufactured on both sides or one side by changing the program of the processing equipment for spirally winding the wave washer 12 composed of a coiled wave spring. Since the production equipment for the wave washer 12 composed of .

FIG. 3 shows the end winding body 13 of the present application between the wave washer 12 composed of a coiled wave spring and the outer ring 8a of the non-output side bearing 8, and between the wave washer 12 composed of the coiled wave spring and the non-output side. is a cross-sectional view showing a state in which the bearing box 7 and the bearing box 7 are press-fitted and held. When the end winding body 13 is press-fitted, it is necessary to push the end face of the wave washer 12 to press-fit. adjust the inner diameter 14 of the

FIG. 4 is a side view showing the relationship between the outer diameter d1 of the end winding body 13 and the outer diameter d2 of the wave washer 12 composed of a coiled wave spring. When a load is applied to the wave washer 12, the outer diameter of the wave washer 12 is deformed in an expanding direction, and becomes maximum when fully compressed. By setting the outer diameter of the end winding body 13 so that d1>d2, where d2 is the outer diameter at the time of full compression, more stable characteristics can be obtained.
The required number of turns of the end winding body 13 is 3/4 or more.

Next, the operation and effects of the rotating electrical machine of the present application configured as described above will be described.
In rotating electric machines such as electric rotating machines that require noise reduction, metal hammering noise caused by the internal clearance of the bearing, abnormal noise caused by misalignment of joints (not shown) due to reaction force generated in the axial direction, etc. There is something to point out. At that time, it is necessary to pressurize the outer ring of the bearing to suppress the internal clearance of the bearing.

A wave washer 12 composed of the coiled wave spring of the present application is fixed by being press-fitted into the bearing box 7 on the non-output side, thereby making it possible to share equipment with the bearing box 7 on the non-output side without setting the wave washer 12. As a result, the cost can be reduced, and the coaxiality of the wave washer 12, the bearing box 7 on the non-output side, and the bearing 8 on the non-output side is ensured, so that a stable pressurization can be generated.

The rotary electric machine of the present application can be easily assembled by assembling the rotary electric machine in a state in which the wave washer 12 is preconfigured in the bearing box 7 on the counter-output side. Therefore, it is possible to improve the assemblability of the wave washer 12 without increasing the number of parts, stabilize the positional accuracy after assembly, and stabilize the pressurization by the wave washer 12 at a low cost. can be done. In the present application, the case 2 is configured on the non-output side, but if the frame 4 is configured on the non-output side, the bearing box on the non-output side of the frame 4 and the A similar effect can be obtained by providing a space with the bearing and fixing the wave washer 12 in the space by press-fitting.

In the rotary electric machine of the present application, it is desirable that the wave washer 12 is composed of a coiled wave spring. Since the coiled wave spring is manufactured by spirally winding one narrow thin plate, the end winding body 13 can be configured on both sides or one side only by changing the programming, and can be manufactured at low cost. .

If the wave washer 12 is fixed by press-fitting, it may lose its function as a spring and may not be able to apply pressure. By making it larger than the outer diameter d2 of 12, it is possible to maintain the function as a spring. Since the outer diameter of the wave washer 12 expands when a load is applied, the outer diameter d2 of the wave washer 12 is the outer diameter when fully compressed.

The end roll 13 is press-fitted and fixed in the bearing box 7 on the counter-output side, but if the end roll 13 bends, an appropriate pressurization cannot be applied. Therefore, bending of the end winding body 13 is suppressed by setting the end winding portion of the end winding body 13 of the wave washer 12 used in the present application to be 3/4 or more of the circumference. This makes it possible to continue applying appropriate pressurization.

In the embodiment of the present application, bending is suppressed by forming the end turn portion of the end turn body 13 around 3/4 or more. 7 may be in contact with each other, and the load may be received by the bearing box 7 on the anti-output side to prevent deflection.

By the way, in the above-described embodiment, the case where the end winding body 13 is configured at both end portions of the wave washer 12 has been described, but the end winding body 13 is not limited to this, and the end winding body 13 may be any of the wave washers 12. It suffices if it is configured at one end, and the same effects as in the above-described embodiment can be obtained.

While this application describes various exemplary embodiments and examples, various features, aspects, and functions described in one or more embodiments may not apply to particular embodiments. can be applied to the embodiments singly or in various combinations.
Accordingly, numerous variations not illustrated are envisioned within the scope of the technology disclosed herein. For example, modification, addition or omission of at least one component, extraction of at least one component, and combination with components of other embodiments shall be included.

INDUSTRIAL APPLICABILITY The present application is suitable for realization of a rotating electric machine capable of improving the assemblability of the wave washer and stabilizing the pressurization by the wave washer.

1 rotary electric machine, 6 output side bearing, 7 non-output side bearing box, 8 non-output side bearing, 8a outer ring, 10 output shaft, 12 wave washer, 13 end winding body, d1 outer diameter of end winding body, d2 wave washer outer diameter of

Claims (2)

In a rotating electric machine in which an output shaft is held by an output-side bearing and a non-output-side bearing, a bearing box on the non-output side in which the non-output-side bearing is accommodated and held; A wave washer arranged between the end face of the outer ring of the accommodated non-output side bearing and configured by spirally winding a narrow thin plate; an end roll press-fitted between the end face of the outer ring of the non-output side bearing and between the wave washer and the bearing box on the non-output side, wherein the end roll is A rotary electric machine, wherein the wave washer is continuously wound on the end of the wave washer so that the number of turns is 3/4 or more and is wound in a plane. 2. The electric rotating machine according to claim 1, wherein d1>d2, where d1 is the outer diameter of said end winding body and d2 is the outer diameter of said wave washer when a maximum load is generated.

Images