JPS60167645A - Bearing mechanism of motor - Google Patents

Abstract

PURPOSE:To suppress the loss of a torque and the fluctuation of a motor shaft by supporting the motor shaft by bearings disposed outside of a motor body. CONSTITUTION:A bearing mechanism of a motor 18 is disposed at a bearing mounting body 21 secured to a chassis 2 in front of a motor body 19, and supported by bearings 29, 31 mounted in the body 21 of a motor shaft 20 formed integrally with a lead screw 35. Accordingly, since the shaft 20 is supported at the portions projected from the body 19 and hence at both ends of the portion formed with the lead screw 35 by bearing members 29, 31, at least the rotating speed for moving the lead screw 35, i.e., a movable member can be extremely stabilized.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a novel motor bearing mechanism.

Specifically, in a motor having a motor shaft in which a part of the lead screw is integrally formed, torque loss and vibration of the motor shaft are suppressed by supporting the motor shaft with a bearing section disposed outside the motor body. It is an object of the present invention to provide a novel bearing mechanism for a motor, which is capable of making it possible to perform the following operations, and also allows highly accurate movement of an actuated member that is actuated by a portion of a lead screw.

Background Art and Problems Therein, for example, in relatively small electronic devices, etc., as a moving means for moving a certain moving member in a predetermined direction with high precision, a lead screw that is engaged with the moving member is rotated by a motor. In many cases, the movable member is moved minutely. In such moving means, a bearing mechanism is used to rotatably support the lead screw, but the conventional bearing mechanism of this type of motor has many problems.

1 and 2 show an example of a conventional motor bearing mechanism in a magnetic recording device, for example, a recording device that performs recording and reproduction using a magnetic disk as a recording medium.

First, the item a shown in FIG. 1 will be briefly explained.

In the figure, b indicates a motor body fixed to the chassis C, and a stator (not shown) is disposed inside the motor body. Reference numeral d designates a motor shaft, and a lead screw part e is integrally formed in approximately half of the motor shaft, and is made to protrude from the motor body. The remaining approximately half of the motor shaft d is rotatably supported by pole bearings f, f provided in the motor body. Note that a rotor (not shown) is fixed to a portion of the motor shaft d that is inserted into the motor body. Nut member g is screwed onto lead screw portion e, and nut member g is fixed to a moving body (not shown) supported movably with respect to chassis C. When the motor shaft d is rotated, the nut member g is moved in the direction shown by the arrow in the drawing, thereby causing the moving body to move in the direction shown by the arrow.

According to such a motor bearing mechanism a, the motor shaft d has bearings f and f at twelve locations in the axial direction.
Despite being supported by the lead screw part e, the tip end of the lead screw part e becomes slightly bent in the direction perpendicular to the axial direction due to impact forces received from the outside, fluctuations in the load applied to the lead screw part e, etc. .

Next, the item h shown in the $2 diagram will be explained.

In the figure, the same members as those in the bearing mechanism a of the motor shown in FIG. 1 are designated by the same reference numerals as in FIG. 1, and a description thereof will be omitted. i is a motor shaft, and the tip of the portion protruding from the motor body is formed to be thin. Reference character j denotes a lead screw, both ends of which are formed thin, and one end of which is rotatably supported by a pole bearing 1 provided on a support wall k erected from the chassis C. The tip of the motor shaft i and the other end of the lead screw shaft j are connected by a coupling m so as to be located coaxially with each other. Note that n and n are bearing metals that support the motor shaft i throughout the motor body. However,
When the motor shaft i is rotated, the lead screw j is also rotated integrally with the lead screw j, thereby causing a moving body (not shown) to move in the direction indicated by the arrow in the same manner as described above.

Although such a motor bearing mechanism uses a large number of parts, it has many problems.

That is, since the motor shaft i is supported at substantially both end positions in the axial direction by the bearing metals n and -n,
There are few operational problems such as bending or wobbling, but the lead screw j has a support structure at the other end that is connected to the coupling m.
This is because the structure is directly connected to motor shaft j via.

A so-called "radial runout" occurs at the other end. Furthermore, a slight misalignment inevitably occurs between the metal bearings n, n, which support the motor shaft i, and the pole bearing 1, which supports one end of the lead screw shaft j, and this misalignment causes the coupling m to This is absorbed by the flexibility of the connections used, but this causes considerable losses in rotational torque.

As mentioned above, according to the conventional motor bearing mechanism,
Misalignment, wobbling, and deflection inevitably occur, and these things cause the movement accuracy of the moving member to be disrupted.

Purpose of the Invention The present invention has been made in view of the above-mentioned problems, and provides a motor in which a part of the lead screw is integrally formed, in which the motor shaft is supported by a bearing portion disposed outside the motor body. By doing so, it is possible to suppress torque loss and vibration of the motor shaft, and
It is an object of the present invention to provide a novel motor bearing mechanism that allows highly accurate movement of an actuated member operated by a portion of a lead screw. In order to achieve the above purpose, a bearing mounting body that is fixed to the chassis part is arranged at the front of the motor body, and a part of the lead screw protrudes from the motor body of the integrally formed motor shaft. It is characterized in that both ends of the portion are supported by bearing members attached to the bearing mounting body.

EMBODIMENTS Below, details of the bearing mechanism of the motor of the present invention will be explained according to embodiments shown in the accompanying drawings. The drawing shows an example of an embodiment in which the motor bearing mechanism of the present invention is applied as a motor bearing mechanism in a recording device. In the drawing, l indicates the recording device, and 2 indicates the chassis. When viewed from above, the chassis 2 has a substantially longitudinal direction (
In FIG. 3, the direction to the right is the front, and the direction to the left is the rear. Further, in the figure, the upper side is the right side, and the lower side is the left side. The orientation in the following description is also based on this direction. ), and the chassis 2 is formed of die-cast aluminum in this embodiment. Reference numeral 3 denotes a fourth section formed approximately at the center in the left-right direction of the upper surface of the chassis 2, and at a position offset toward the rear edge, and a motor, a head support, etc., which will be described later, are arranged in the recessed section 3. There is. Reference numeral 4 denotes a front panel section provided at the front end of the chassis 2, and a cassette insertion opening 5 is formed in the upper part. Reference numeral 6 denotes a door body disposed on the rear surface of the cassette insertion opening 5 so as to be openable and closable, and is opened by inserting a magnetic disk cassette to be described later.

Reference numeral 7 denotes a spindle (see FIGS. 3 and 87), which is arranged at a position slightly forward of the position where the recess 3 of the chassis 2 is formed, and whose upper end surface is slightly above the upper surface of the chassis 2. It is located so that it protrudes from the top. Further, the upper end surface of the spindle 7 is provided with various elements for coupling with a magnetic disk, which will be described later, but they are not shown. This spindle 7 is a flat plate motor 8.
is fixed to the center of the rotor 9.

10 is a cassette carrier (see Figures 6 and 7);
It is supported so as to be movable in the vertical direction by guide parts (not shown) provided on the left and right sides of the upper surface of the chassis 2, and when the magnetic disk cassette 11 is not installed, it is indicated by a two-dot chain line in FIG. (hereinafter, this position will be referred to as the "non-loading position"), and when the magnetic disk cassette 11 is loaded, it will be guided by the guide section and moved to the position shown by the solid line in FIG. 7 (hereinafter, this position will be referred to as the "non-loading position"). (referred to as the "loading completion position."), and this state is stabilized by a triggering means (not shown). The cassette insertion opening 5 formed in the front panel section 4 is located at the same height as the cassette carrier 10 when it is in the non-loading position, and the magnetic disk cassette 11 By inserting this from the cassette insertion opening 5, the cassette carrier 1
0.

The magnetic disk cassette 11 (see FIG. 7) is formed into a thin casing, and a central opening 13 is formed approximately in the center of the lower surface of the cassette casing 12. Reference numeral 14 denotes a magnetic disk rotatably housed inside the cassette housing 12, and a center core 15 is provided at the center, and the center core 15 is exposed to the outside through the central opening 13. ing. A window 16.
6 is formed so that a head section, which will be described later, can come into contact with the recording surface of the magnetic disk 14 through this window 16.16.

Thus, the magnetic disk cassette 11 is loaded onto the cassette carrier 10 as described above. When the cassette carrier 10 reaches the loading completion position, the magnetic disk cassette 11 is inserted into the positioning holes (not shown) formed on the left and right sides of the cassette housing 12 in the positioning holes provided upright on the chassis 2. The magnetic disk 14 is positioned at a predetermined set position with respect to the recording device 1 by inserting the storage bin 17.17, and the magnetic disk 14 is magnetically attracted to the upper end surface of the spindle 7. It is positioned so that it can rotate integrally with the spindle 7.

Reference numeral 18 indicates a part of the motor (see FIGS. 3 to 5). The motor part 18 consists of a motor main body 19, a motor shaft 20, and a bearing mounting body 21, and is arranged in a portion offset to the right of the recess 3 formed on the upper surface of the chassis 2.

The motor main body 19 has a case 22 formed in a substantially cylindrical shape, and openings 23 and 24 are formed in the center of each end face of the case 22. A stator 25 is provided along the circumferential surface. Although the detailed structure of the stator 25 is omitted in the drawings, the stator 25 is provided with electromagnetic induction means divided into many parts for step-driving a rotor fixed to the motor shaft 20 and described later. ing.

The bearing mounting body 21 includes a chassis-side fixing part 26 that is rectangular in shape and long in the front-rear direction when viewed from above, and a substantially disc-shaped motor-side fixing part that is integrally formed at the rear end of the chassis-side fixing part 26. 27, and the rear end of the chassis-side fixing part 26 is connected to the lower part of the front end surface of the motor-side fixing part 27 so as to abut on the lower part thereof. 28 is the motor side fixing part 27
A bearing mounting hole 28 is formed approximately in the center of the bearing mounting hole 28, and an oil-less metal 29 is mounted in the bearing mounting hole 28 by fixing means such as press fitting or caulking. Reference numeral 30 denotes a bearing mounting piece integrally formed in an upright manner from approximately the center of the front end edge of the chassis side fixing portion 26, and an oil-less metal 31 is fixed to the bearing mounting piece 30. Thus, the bearing mounting body 21 is integrally connected to the motor main body 19 by fixing its motor side fixing portion 27 to the front surface of the motor case 22 with screws 32, 32, 32. In this state, the oil-less metal 29.3 provided on the shaft center of the motor case 22 and the bearing mounting body 21
1 and the axial center are now arranged in a straight line. In addition, 3
3 is a protection plate disposed between the front surface of the motor case 22 and the motor side fixing portion 27 of the bearing mounting body 21. As shown in FIG.

The rear end of the motor shaft 20 is inserted into a motor case 22, and a rotor 34 is fixed to the portion inserted into the motor case 22. Although the detailed structure of the rotor 34 is omitted in the drawings,
The rotor 34 is provided with electromagnetic induction means corresponding to the electromagnetic induction means (not shown) provided on the stator 25. 35 is the motor case 22 of the motor shaft 20
A guide groove 36 is formed on the outer peripheral surface of the motor shaft 20 in a spiral manner along the axial direction of the motor shaft 20. By doing so, it is formed integrally with the motor shaft 20. Thus, both ends of the portion of the motor shaft 20 protruding from the motor body 19 are supported by bearing members provided on the bearing mounting body 21, that is, oil-less metals 29 and 31. That is, the motor shaft 20
The part slightly closer to the rear end side from the central part in the axial direction is inserted into the oilless metal 29, and the tip part is inserted into the oilless metal 31; It is rotatably supported at the attached part.

In the motor bearing mechanism of the present invention, the motor shaft is rotatably supported by the bearing member disposed outside the motor body. The rear end of the motor shaft 20 slightly protrudes rearward from the motor case 22 through a seal ring 37 attached to an opening 24 formed at the rear end of the motor case 22. 38 is a protection plate attached to the rear end of the motor case 22.

Thus, the motor portion 18 described above is attached to the chassis 2 in the following manner. That is, 39 is a substantially square opening formed in the recess 3 of the chassis 2, and the lower end of the motor case 22 of the motor main body 19 passes through the opening 39 and extends below the lower surface of the chassis 2. be arranged to be located; The bearing mounting body 21 is attached to the upper surface of the chassis 2 by fixing its chassis-side fixing portion 26 to the chassis 2 with screws 40 and 40.

Thus, the motor main body 19 drives the rotor 34 in steps by passing a driving current through the stator 25 in accordance with a predetermined pulse. Therefore, the motor shaft 20 is driven in minute steps at every predetermined rotation angle.

41 is a head support (see FIGS. 3, 6, and 7). The head support 41 is attached to a lower carriage 42a.
and an upper carriage 42b, the upper carriage 42b is rotatably connected to the lower carriage 42a via a connecting shaft 43 at its base end, and the upper carriage 42b and the lower carriage 42b are carriage 42a of
The frame is always elastically biased by a tension spring 44 that is passed between the carriage 42a so that its tip tends to move toward the tip of the lower carriage 42a.

45 is a guide shaft that guides the movement of the head support 41, and both ends of the guide shaft 45 are connected to the recess 3 of the chassis 2.
A support block 46.46 and a support block 46.4 that are spaced apart from each other in the front-rear direction at a position near the left end of the support block 46.46.
It is held by a presser piece 47.47 made of a leaf spring material attached to 6.

Therefore, the head support 41 is attached to the lower carriage 42a.
By inserting the guide shaft 45 into a guide hole 48 formed in the guide shaft 45, the guide shaft 45 is movably held by the guide shaft 45 and guided in the moving direction by the guide shaft 45.

Reference numeral 49 denotes a retaining pin formed to protrude substantially horizontally from the side surface of the lower carriage 42a on the motor part 18 side toward the right side, and the engagement pin 49 is connected to the lead screw part of the motor shaft 20. The guide groove 35 is engaged with a portion of the guide groove 36 located on the side facing the chassis 2 . When the retaining pin 49 is engaged with the guide groove 36 of the lead screw portion 35, the proximal end of the leaf spring 50 is fixed to the lower carriage 42a by a fixing means such as a screw. is held by resiliently contacting a portion of the screw portion 35 located on the side opposite to the chassis 2. That is, the engagement pin 49 is elastically moved from below into the guide groove 36 of the lead screw portion 35 by the upward elastic force of the lower carriage 42a urged by the elastic force of the leaf spring 50. engaged.

When the motor main body 19 is driven in steps as described above, the motor shaft 20 is rotated in a predetermined direction, and the engagement pin is moved along the axial direction of the motor shaft 20. This causes the head support 41 to move in the direction shown by the arrow in FIG.

In addition, 51 is a magnetic head for recording and reproduction provided on the upper surface of the tip of the lower carriage 42a, and 52 is a magnetic head made of a material such as felt provided on the lower surface of the tip of the upper carriage 42b. Rat with a presser. When the cassette carrier 10 is in the non-loading position, the upper carriage 42b is in the position shown by the two-dot chain line in FIG. When the cassette carrier 10 reaches the loading completion position, it is brought to the position shown by the solid line in FIG. 7 by the tensile force of the tension spring 44 described above.

When the magnetic disk cassette 11 is set in a predetermined position as described above, the carriage 42a on the lower side of the head support 41 is moved as shown by the solid line in FIG.
The magnetic head 51 provided in the window 1 of the cassette housing 12
6 to contact the recording surface of the magnetic disk 14, and the suppressor 52 provided on the upper carriage 42b is brought into elastic contact from above with the portion of the magnetic disk 14 that is contacted from below by the magnetic head 51. Become. Therefore, for example, when a recording operation is started, the magnetic head 14 is rotated integrally with the spindle 7 as described above, thereby forming an annular track at a predetermined position on the recording surface of the magnetic disk 14. At the same time, a predetermined signal is magnetically recorded. When the recording operation in the i-rack is completed, the motor main body 19 is driven in steps, and the head support 41 is pitch-fed until the magnetic head 51 is located on a predetermined track.

In this embodiment, the axial position of the motor shaft 20 of the motor portion 18 described above can be finely adjusted. That is, 54 and 55 are wall portions that are erected at positions near the right side of the recess 3 of the chassis 2 and spaced apart in the front-rear direction, and one wall 54 provided along the rear end of the recess 31 A leaf spring 56 is attached to the front surface, and an adjustment screw 57 is screwed into the other wall portion 55. At the center of both end surfaces of the motor shaft 20, substantially convex hemispherical contact tips 58a and 58b are formed. Thus, the rear end of the motor shaft 20 is brought into elastic contact with the leaf spring 56 via the contact tip 58a, and the front end thereof is brought into elastic contact with the tip of the adjustment screw 57 through the contact tip 58b. There is. Therefore, if the g4M screw 57 is turned in the screwing direction, the motor shaft 20 will be moved rearward, and if the adjusting screw 57 is turned in the unscrewing direction, the motor shaft 20 will be moved by the push of the leaf spring member 56. Forced to move forward by pressure.

Effects of the Invention As is clear from the above description, the bearing mechanism of the motor of the present invention is such that the bearing mounting body fixed to the chassis portion is disposed at the front of the motor body, and a portion of the lead screw is integrated with the bearing mechanism of the motor of the present invention. The motor shaft is characterized in that both ends of a portion of the motor shaft protruding from the motor body are supported by bearing members attached to the bearing mounting body.

Therefore, according to the present invention, since both ends of the motor shaft protrude from the motor body, that is, the portion where the lead screw part is formed, are supported by the bearing members, at least the lead screw part is supported by the bearing member. The rotary part for moving the movable member is journalled in such a way that it can rotate very stably. Therefore, there is no bending or wobbling of a portion of the lead screw, and the lead screw can rotate in an extremely stable state.

Further, since the motor shaft is supported only at two points in the axial direction, problems such as misalignment do not occur, and therefore, loss of rotational torque can be suppressed.

Incidentally, in the above-described embodiment, the bearing mounting body fixed to the chassis part was integrally fixed to the front part of the motor body, but by doing so, the motor shaft is supported. Since the axis of the bearing member and the axis of the motor body can be placed coaxially with each other with high precision, the positional relationship between the motor shaft and the motor body can be determined correctly, and the rotational movement of the motor shaft can be adjusted. The motor can be made more stable, and furthermore, the work of attaching the motor to the chassis can be performed extremely easily. As shown in the embodiments described above, the motor can be constructed at low cost by using a relatively inexpensive member such as oil-less metal as the bearing member on which the motor shaft is supported.

In the above-mentioned embodiment, the bearing mechanism of the motor of the present invention was applied as a bearing mechanism of a motor for moving a head support in a recording device. It can be widely applied as a bearing mechanism for a motor in various devices that operate a predetermined operated member.

[Brief explanation of drawings]

FIG. 1 is a side view of a main part showing an example of a conventional motor bearing mechanism with a part cut away; FIG. 2 is a side view of a main part showing another example of a conventional motor bearing mechanism with a part cut away; 3 to 7 show an example of an embodiment in which the motor bearing mechanism of the present invention is applied as a motor bearing mechanism in a recording device, and FIG. 3 is a plan view showing the entire recording device with some parts omitted; FIG. 4 is a perspective view of the main parts of the recording device with some parts omitted, FIG. 5 is a sectional view taken along line A-A in FIG. 3, and FIG. 6 is a sectional view taken along line BB in FIG. 3. , FIG. 7 is a sectional view taken along the line C--C in FIG. 3 with the magnetic disk cassette installed. Explanation of symbols 2... Chassis part, 19... Motor body, 2C
1 --- Motor shaft, 21 --- Bearing mounting member, 29
．． 31... φ bearing member, 3511@Conflict screw part Fig. 1 Fig. 2

Claims (1)

[Claims] A bearing mounting body that is fixed to the chassis portion is arranged at the front of the motor body, and both ends of the portion of the motor shaft that is integrally formed with the lead screw that protrudes from the motor body are attached to the bearing mounting body. A bearing mechanism for a motor, characterized in that it is supported by a bearing member attached to a motor.