JP2003299298A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide thinner construction of a thrust pre-load spring fitting cap for a micro motor. <P>SOLUTION: A free end 15a of a hook 22 provided at a pre-load member 14 is interposed from an induction portion 28 wherein an outer periphery of the fitting cap 16 is notched, and a side edge 15d is rotated until it is brought into contact with a wall 26d struck by it. When engaged with a jaw 26, the free end 15a is prevented from moving back to the induction portion 28 by a non-return claw 80 and the pre-load member 14 is not removed. As a direction that the hook 22 is engaged and stopped is not an axial direction, axial accommodation space of the hook 22 is reduced. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preload mechanism for stabilizing a rotor of a small motor in a thrust direction, and more specifically to a fixing means for the preload mechanism.

[0002]

2. Description of the Related Art As shown in FIG.
In the preload mechanism of 0, a steel ball 104 is embedded in the center of a bearing plate 103 slidably fitted in a cap 102 fixed to one motor end surface 101, and a shaft end 106 of a rotor 105 is provided.
The bearing plate 103 is urged toward the rotor 105 by a preload spring 107 incorporated in the cap 102.

Here, the preload spring 107 is attached to the cap 102.
In general, a plurality of fixed hooks 108 are formed integrally with the preload spring 107, and the tips 108a of the fixed hooks 108 are brought into contact with the slopes of the chamfer 109a on the outer circumference of the cap to apply a force from the thrust direction to the outside of the hooks 108. After being temporarily deformed to pass through the jaw 109 provided on the cap 102, the elastic restoring force of the hook 108 engages the jaw 109 to restrain the thrust direction of the preload spring 107, and the elastic biasing force of the preload spring 107. Achieves the incorporation of a preload spring into the cap 102 which acts on the bearing plate 103.

In this configuration, the hook 108 and the jaw 1
In order to facilitate the engagement with 09, the jaw 109 is provided with a chamfer 109a that guides the extension of the tip of the hook 108, and the hook 108 has an inclined portion 108b in which the tip 108a is bent along the slope of the chamfer 109a. This precedes the joint 108c. Therefore, in the cap 102 fixed to the motor end surface 101, the inclined portion 108 that extends to the motor side before the engaging portion 108c after the hook 108 and the jaw 109 are engaged with each other.
Since it is necessary to provide a space 110 in which b can be accommodated, it is necessary to have a thickness corresponding to it.

[0005]

With the recent miniaturization of motors, the axial dimension ratio of the cap plate thickness T, which has nothing to do with the torque performance of the motor, to the overall motor length. growing. Therefore, when the total length of the motor is restricted due to the space, if the cap plate thickness T is the same as it is, the output torque of the motor becomes small, which is a disadvantage.

Therefore, an object of the present invention is to reduce the plate thickness of the mounting cap without impairing the function of the preload spring.

[0007]

In order to achieve the above-mentioned object, a motor according to the present invention is a method for manufacturing a motor having a preload means for abutting against an end surface of a rotor shaft and preloading the rotor shaft in an axial direction. In the above, the preload means includes a preload member having a preload portion, and a second engaging portion fixed to the motor end surface and engaging with a first engaging portion provided on the preload member to fix the preload member. A mounting cap provided with the pre-loading member, and the pre-loading member is axially overlapped and fixed to the pre-loading member so as to apply a pre-load to the rotor end surface. , At least 2 on the motor mounting surface side along the outer periphery of the mounting cap
A groove with a predetermined width that opens to the peripheral side is formed at a location to form a jaw, and one side of this jaw is partially cut away in the axial direction to introduce the first engaging portion to the jaw. After inserting the first engaging portion from the introducing portion, the preload member is rotated to engage the first engaging portion with the second engaging portion.

Here, the first engaging portion has a band-shaped portion that extends symmetrically from the outer periphery of the preload member in the shape of a two-diffraction bend U following the outer shape of the second engaging portion. It is a protrusion defined only by an inward plane. Further, the jaw portion is provided with an abutting portion that restricts rotation of the preload member in the engaging direction. Furthermore, when the first engagement portion is allowed to rotate in the engagement direction at the end portion of the second engagement portion on the introduction portion side, and the first engagement portion engages with the second engagement portion, A non-return pawl is provided to restrict rotation of the engaging portion in a direction opposite to the engaging direction.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a motor according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic external view showing an embodiment of a motor according to the present invention (a).
Is a side view parallel to the motor shaft and the preload member 14 is shown in cross section. (B) is a side view taken along the line BB of (a).
2A and 2B are enlarged views of the preload member 14, where FIG. 2A is a plan view and FIG.
[Fig. 3] is a side view taken along line BB in (a). 3 is an enlarged view of the mounting cap 16, (a) is a plan view,
(B) is a side view taken along the line BB of (a).

In FIG. 1, reference numeral 10 is a motor, and the mounting cap 16 of the preload member 14 is fixed to the end face 12 by a known appropriate means. Bearing 1 which supports the rotor shaft end (not shown) in the thrust direction in the center hole 18 of the mounting cap 16.
9 is slidably inserted. In the preloading member 14, a preloading spring 20 is cut and raised in a cantilever shape as a preloading portion in the center of the preloading member base 14a, and hooks 22 as first engaging portions are integrally formed at two symmetrical positions on the outer circumference. .

The preload spring 20 and the hook 22 are bent in the same direction on the motor side, and the preload spring 20 has a U-shaped punching groove 2
It is separated from the preload member base body 14a by 0a and is bent from the connecting portion 20b in the mounting direction of the motor 10 in a substantially V shape. The hook 22 is a free end 15a of a strip portion 15 that extends symmetrically outward from a bent portion 14c defined by a symmetrical chord 14b on the circular outer circumference of the preload member base 14a.
Bend inward at a right angle to form. Preload member base 14a
The bent portion 14c of the rising arm 15b connected to the free end 15a is curved with a relatively large curvature in accordance with the outer shape of the mounting cap 16 to be described later, so that the deformation stress generated at the time of incorporation into the mounting cap 16 is locally generated. Avoid focusing on.

The tip end 15c of the free end 15a of the hook 22
Is formed in an arc shape following the small diameter side wall 16a of the mounting cap 16 described later, or is formed along the tangent line of the arc formed by the small diameter side wall 16a. The free end 15a is a substantial engagement portion with a jaw portion 26 of the mounting cap 16 described later, and both side edges 15d are formed along a radial line that points to the center of the outer circle of the preload member base body 14a.

The mounting cap 16 is provided with a central hole 18 into which a bearing 19 is slidably inserted, and a groove 24 having a predetermined width W which is opened outward in the radial direction at two locations on the outer periphery facing the motor side when mounted. Is recessed over a predetermined circumference, and the groove bottom is provided with a jaw portion 26.
And One side of each groove 24, which is point-symmetrical to each other, is cut out along the small diameter side wall 16a so as to correspond to the width and shape of the free end 15a of the hook 22, and the introduction portion of the hook 22 which is the first engaging portion. 28. Therefore, both end surfaces 2 of the introduction portion 28
8a is formed along a radial line.

A check claw 30 having a gentle slope 30a is raised at a portion of the jaw 26 facing the introduction portion 28. Check claw 30
Is connected to the jaw 26 on the steep slope 30b, and the connection position 26
A restriction wall 26b is provided along the radius line at a position corresponding to the width of the free end 15a of the hook 22 from a, and serves as an abutting portion. Therefore, the preload member 14 is seated on the jaw 26 with the free end 15a of the hook 22 coming into contact with the regulation wall 26b by turning by a predetermined angle, and the mounting position is automatically set.

The height D from the outer surface 16c of the mounting cap 16 opposite to the motor mounting surface 16b to the check claw top 30c.
1 is the inner surface spacing of the hook 22, that is, the preload member base body 14a
Is greater than the distance S between the facing surfaces of the free end 15a and the free end 15a (D1
> S). The distance D2 from the outer surface 16c to the lower end of the check claw 30 is smaller than the inner surface spacing S of the hook 22 (D2 <S).
The thickness of the jaw portion 26, that is, the distance D3 from the outer surface 16c to the groove surface of the jaw portion 26 is preferably equal to or slightly smaller than the inner surface distance S of the hook 22 (D3≤S). Further, from the check claw top 30c to the motor end surface 12, there is a gap through which the plate thickness d of the preload member 14 can pass due to the difference between the thickness t of the mounting cap 16 and the height D1 from the outer surface 16c of the check claw 30. Yes (d≤t-D1). Then, the plate thickness d of the preload member 14 should be half or more from the jaw 26 to the non-return claw top 30c (1 / 2d≤D1-D3).

The mounting cap 16 is fixed to the motor 10, and the bearing 19 is inserted into the center hole 18 of the mounting cap 16. Then, the free end 15a of the hook 22 protruding laterally of the preload member 14 is inserted from the introduction portion 28 of the mounting cap 16, and the preload member 14 is forced by a force beyond the check claw 30.
Is rotated in the direction of the jaw 26. Free end 15 of hook 22
A is forced to be deformed by the gentle slope 30a of the check claw 30 and sits on the jaw 26 beyond the check claw 30. Preload member 14
The side edge 15d of the free end 15a comes into contact with the regulation wall 26b to prevent the rotation, and is automatically positioned. The preload spring 20 elastically biases the bearing 19 in the thrust direction to support the rotor, and reacts the hook free end 15a with the jaw 2
6 to achieve the incorporation of the preload member 14.

Since the mounting cap 16 and the hook 22 are constructed as described above, it is not necessary for the hook 22 to extend a bent slope 108b for guiding the hook 108 as shown in FIG. The allowable space 110 for accommodating it in the occlusal position can be omitted. For this reason,
The thickness t of the mounting cap 16 is equal to that of the mounting cap 10 of FIG.
Since the thickness can be made sufficiently thinner than the thickness T of 2, the motor can be reduced in size in the axial direction without deteriorating the output characteristics.

Although the embodiment of the motor according to the present invention has been described above with reference to the drawings, the present invention is not limited to the illustrated embodiment, and its shape and configuration deviate from the constituent requirements of the present invention. It is expected that various changes in detail can be made without departing. For example, although the preload spring has two hooks in the above embodiment, it may have three or four hooks. Further, the shape of the mounting cap does not necessarily have to be symmetrical, and as long as the occlusion is established, it is possible to make the hooks function equally without making all hooks the same shape.

[0019]

As is apparent from the above description, the motor according to the present invention has the pre-compression means for contacting the end surface of the rotor shaft and pre-compressing the rotor shaft in the axial direction. In the method of manufacturing a motor having, the preloading means is fixed to a preloading member having a preloading portion and a motor end surface, and is engaged with a first engaging portion provided on the preloading member to fix the preloading member. A mounting cap having two engaging portions, wherein the preload member is axially overlapped with and fixed to the mounting cap to apply a preload to the rotor end surface by the preloading portion. As the two engaging portions, a groove having a predetermined width that is open on the peripheral side is formed in at least two locations on the motor mounting surface side along the outer periphery of the mounting cap to form a jaw portion, and one side of the jaw portion is provided as a shaft. Cut out partly in the direction The first engaging portion is used as an introducing portion that guides the jaw portion, the first engaging portion is inserted from the introducing portion, and then the preload member is rotated to move the first engaging portion to the second engaging portion. By engaging the joint part, the axial bite of the conventional preload member can be avoided, the axial dead space required for the guide member is omitted, and the proportion of the stator part in the whole motor is relatively large. Therefore, the total axial length of the motor can be shortened without reducing the torque output.

Further, the motor according to the present invention is defined by claim 2.
According to the above description, in the first engaging portion, the strip-shaped portion extending symmetrically from the outer circumference of the preload member is formed into a two-diffraction bending U-shape in accordance with the outer shape of the second engaging portion, and has a radius of Since the protrusion is defined only by the plane that faces inward in the direction, the length in the axial direction can be shortened by eliminating the bent portion that guides the occlusion from the hook that is the first engaging portion. Therefore, it is not necessary to provide a space for accommodating the bent portion in the mounting cap, and the plate thickness of the mounting cap can be reduced.

Further, according to the third aspect of the motor of the present invention, the jaw portion is provided with the contact portion for restricting the rotation of the preload member in the engaging direction. Since the mounting position of the preload member is automatically set by constant rotation, the assembling work becomes easy and the quality is stable.

According to a fourth aspect of the motor of the present invention, the end portion of the second engaging portion on the introduction portion side allows the first engaging portion to rotate in the engaging direction. Since the first engagement portion is engaged with the second engagement portion, the check claw for restricting the rotation of the first engagement portion in the opposite direction to the engagement direction is provided. The hook is only deformed temporarily when it crosses the check claw, and elastically returns when it stabilizes at the mounting position, and after engaging with the mounting cap, it does not come off unless a force is applied that exceeds the check claw. The property is improved.

[Brief description of drawings]

FIG. 1 is a schematic external view showing an embodiment of a motor according to the present invention, (a) is a side view parallel to an axis, and (b) is (a).
It is a side view which followed the BB line of FIG.

2A and 2B are enlarged views of a preload spring that constitutes a preload member in a motor according to the present invention, FIG. 2A is a plan view, and FIG. 2B is a side view taken along line BB in FIG.

3A and 3B are enlarged views of a mounting cap in a motor according to the present invention, FIG. 3A is a plan view, and FIG. 3B is a side view taken along line BB in FIG. 3A.

FIG. 4 is a side view showing a preload mechanism in a conventional motor in a cross section taken along an axis.

[Explanation of symbols]

10 motors 14 Preload member 16 mounting cap 19 bearings 20 Preload spring 22 hook 26 jaw 28 Introduction 30 Check claw

Claims (4)

[Claims] 1. A method of manufacturing a motor having a preload means for abutting against an end surface of a rotor shaft and preloading the rotor shaft in an axial direction, wherein the preload means is fixed to a preload member having a preload portion and a motor end surface. A mounting cap provided with a second engaging portion that engages with a first engaging portion provided on the preload member to fix the preload member, and the preload member is axially overlapped with the mounting cap. Fixed by
A configuration for applying a preload to the rotor end surface by the preload portion, wherein the second engaging portion has a groove of a predetermined width that opens at least at two locations on the motor mounting surface side along the outer periphery of the mounting cap. While forming a jaw by recessing,
One side of this jaw is partially cut away in the axial direction to make the first engaging portion an introducing portion that guides the jaw, and after the first engaging portion is inserted from the introducing portion, the preload member A motor for rotating the first engagement portion to engage the second engagement portion. 2. The first engaging portion has a band-shaped portion that extends symmetrically from the outer periphery of the preload member in a U-shaped two-fold bending shape following the outer shape of the second engaging portion. 2. A projection piece defined only by an inward plane.
The motor described in. 3. The motor according to claim 1, wherein the jaw portion is provided with an abutment portion that restricts rotation of the preload member in the engagement direction. 4. The first engaging portion is engaged with the second engaging portion by allowing the end portion of the second engaging portion on the introduction portion side to rotate in the engaging direction. Then, the motor according to claim 1, further comprising a check claw that restricts rotation of the first engaging portion in a direction opposite to the engaging direction.