JPH0679362B2 - Record player - Google Patents

Description

TECHNICAL FIELD The present invention relates to a record player capable of preventing vibration of a rotary shaft of a turntable and obtaining high sound quality.

“Prior Art” Conventionally, a record player is known in which a turntable is rotated by a motor and an electric signal is taken out from a record placed on the turntable via a pickup. In this record player, as shown in FIG. 4, the ball 3 is placed under the lower end center of the turntable shaft 2 in order to reduce the rotational friction of the turntable shaft 2 which is the rotation shaft of the turntable 1 and to receive the thrust load. The turntable shaft 2 is provided so as to be rotatable within the guide hole 5 of the bearing 4.

[Problems to be Solved by the Invention] However, in the bearing 4, since it is necessary to provide lubricating oil between the guide hole 5 and the turntable shaft 2,
A very small gap (5 to 6 μ) is formed between the guide hole 5 and the turntable shaft 2. Therefore, when the turntable shaft 2 rotates, the turntable shaft 2 makes a rubbing motion with the center of the lower end surface as a fulcrum, and the turntable shaft 2 swings, which adversely affects the durability of the record and the cartridge. Further, there is a drawback that the sound quality of reproduction is deteriorated due to the generation of noise such as so-called noise in the performance of the record and the function of the record player cannot be fully exerted.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a record player that solves the above problems of the conventional one.

"Means for Solving Problems" The present invention has the following configuration in order to achieve the above object. That is, in a record player in which a turntable is rotated by a motor and an electric signal is taken out from a record on the turntable through a pickup, one side of the outer circumference of a turntable shaft made of a magnetic material is attached to both ends of a roller shaft. A pair of bearing rollers of the same shape and size having a flange roller made of a magnetic material and having the same diameter are rotatably arranged at a predetermined distance from each other, and the flange rollers of the pair of bearing rollers are magnetized to form the flanges. The turntable shaft is rotatably magnetically attached to the roller.

"Operation" The turntable shaft is rotatably magnetically attached to the outer periphery of each flange roller of the pair of bearing rollers, thereby preventing the turntable shaft from swinging or scoring, and causing noise such as so-called jumble. To prevent the occurrence of high quality sound.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. In FIG. 1 and FIG. 2, 11 is a record player main body, and this record player main body 11 has a base plate 12 on its upper part. The base plate 12 is the bottom plate 13 of the main body 11.
It is said to be parallel to.

A mounting member made of rubber at a predetermined position on the lower surface of the base plate 12.
A motor 15 is attached via 14. The rotating shaft 16 of the motor 15 is perpendicular to the upper surface 12a of the base plate 12, that is, oriented in the vertical direction.

An extension shaft 17 made of a magnetic material (iron) is connected to the rotary shaft 16 on its axis by a rubber coupling 16a. The extension shaft 17 is fitted into the mounting member 14 via a metal (bearing) 18 and is rotatable integrally with the rotary shaft 16.

On the other hand, a bearing box 20 is attached to the base plate 12 via a stepped ring-shaped attachment ring 19. The bearing box 20 has a shape in which the upper and lower ends of a cylinder 21 are closed by discs 22 and 23, and shaft holes 24 and 25 are formed at the centers of the discs 22 and 23, respectively. The discs 22 and 23 are made of a non-magnetic material.

A cup-shaped shaft support box 26 is fixedly attached to the shaft hole 25. A screw 27 having a recess 27a is screwed into the bottom of the shaft support box 26. In the shaft hole 24 and the shaft support box 26, a turntable shaft 29, which is a rotation shaft of the turntable 28, is rotatably loosely fitted. At the upper end of the turntable shaft 29, a pin 29a into which a center hole of a record board (not shown) is fitted, and a flange 29 located at the base of the pin 29a.
b and are formed. The turntable shaft 29 is made of tool steel (magnetic material) and is hardened, then polished, hard-plated, and lapped. Turntable axis
29 is provided perpendicularly to the upper surface 12a of the base plate 12, and a ball 30 for reducing the rotational friction resistance of the turntable shaft 29 is provided between the lower end of the turntable shaft 29 and the bottom surface of the recess 27a of the screw 27. It is provided. 31 is a seal member.

Also, on one side of the outer circumference of the turntable shaft 29, the bearing box 20
Two roller shafts 32, 33 are rotatably attached to the roller shaft and are spaced from each other. These roller shafts 32, 33 are made of iron (magnetic material). The roller shafts 32, 33 are oriented in the same direction as the turntable shaft 29 and are provided apart from each other. Both ends of each of the roller shafts 32 and 33 are attached to the adjusting screws 34 and 35, which are screwed into the discs 22 and 23 of the bearing box 20, to the bearings 36 and 3, respectively.
It is rotatably attached via 6. The adjusting screws 34 and 35 and the roller shaft 32 are located on the same axis, and the adjusting screws 34 and 35 and the roller shaft 33 are located on the same axis. In addition, the adjusting screw 34, 35 has a nut 3
7 is screwed in, loosen this nut 37 and adjust screws 34, 35
By rotating, the roller shafts 32, 33 can be moved to their desired positions in the axial direction, and the nuts 37 can be tightened to fix the roller shafts 32, 33 to those positions. Flanges are formed on both ends of each of the roller shafts 32 and 33.

At both ends of the roller shaft 32, a disk-shaped flange roller 3 coaxially with the roller shaft 32 and rotatable integrally with the roller shaft 32 is provided.
Disc-shaped flange rollers 39, 39 are attached to both ends of the roller shaft 33 coaxially with the roller shaft 33 and integrally rotatable with the roller shaft 33. The flange rollers 38, 38 are detachably fixed to the flanges at both ends of the roller shaft 32 with screws, and the flange rollers 39, 39 are detachably fixed to the flanges at both ends of the roller shaft 33 with screws. The flange rollers 38 and 39 have the same diameter and are larger than the outer diameter of the turntable shaft 29. In this embodiment, the ratio of the outer diameter of the turntable shaft 29 to the outer diameter of the flange rollers 38, 39 is determined to be about 1: 5.5.

The flange roller 38 and the flange roller 39 are spaced apart and adjacent to each other, and a turntable shaft 29 is located between the outer peripheries of these flange rollers 38, 39. The turntable shaft 29 is a flange roller as will be described later. They are magnetically attached to 38, 39 and supported by these flange rollers 38, 39.

The outer peripheral surfaces of the flange rollers 38, 39 are, as shown in FIG. 3, central portions C in the axial direction of the flange rollers 38, 39.
Chamfers M are formed on both sides of the central portion C so that only the contact table 29 is brought into contact with the turntable shaft 29. This reduces the contact area of the turntable shaft 29 with the flange rollers 38, 39, and reduces the turntable shaft 29 and the flange roller 3
This is to prevent dust from getting in between 8 and 39 as much as possible, and to prevent runout of the turntable shaft 29 as much as possible, which also reduces wear of the turntable shaft 29. The flange rollers 38, 39 are made of tool steel (magnetic material) and hardened, but have a hardness slightly lower than that of the turntable shaft 29.

The roller shaft 32 and the two flange rollers 38 form a bearing roller 38a, and the roller shaft 33 and the two flange rollers 39 form a bearing roller 39a.

Further, a turntable 28 provided thereon is screwed to the flange 29b of the turntable shaft 29. A ring 40 made of a magnetic material (electromagnetic mild steel) is concentrically fixed to the turntable shaft 29 at the lower part of the turntable 28.

Between the roller shafts 32 and 33, two bar magnets (permanent magnets) 41 and 42 which are orthogonal to the roller shafts 32 and 33 are vertically separated from each other. Both ends of each of the bar magnets 41 and 42 are formed into concave arc surfaces, and a slight gap is provided between both ends of the bar magnets 41 and 42 and the roller shafts 32 and 33.
Both ends of the bar magnet 41 and the bar magnet 42 are connected by connecting members 43 and 44 made of a non-magnetic material. These connecting members 43 and 44 are attached to a substantially U-shaped attaching member 46 attached to a tie rod 45 provided between the bottom plate 13 and the base plate 12 and supported at predetermined positions.

The bar magnets 41, 42 are magnetized so that the N magnetic pole appears at each end on the roller shaft 32 side and the S magnetic pole appears at each end on the roller shaft 33 side.

Therefore, an S magnetic pole appears on the roller shaft 32 in a portion adjacent to the N magnetic poles of the bar magnets 41, 42, and on the roller shaft 33, the bar magnets 41, 4 are formed.
The N magnetic pole appears in the portion adjacent to the S magnetic pole of 2. Further, an N magnetic pole appears at the contact portion with the turntable shaft 29 on both flange rollers 38, and an S magnetic pole appears at the contact portion with the turntable shaft 29 on both flange rollers 39.

As a result, the S magnetic pole appears at the contact portion of the turntable shaft 29 with the flange roller 38, and the N magnetic pole appears at the contact portion of the turntable shaft 29 with the flange roller 39. As a result,
The turntable shaft 29 is magnetically attached to each of the flange rollers 38 and 39.

On the other hand, a cylindrical magnet (permanent magnet) 47 is rotatably attached to the upper end of the extension shaft 17 and the ring 40 provided on the turntable 28 by an unillustrated actuating means. Thereby, the rotation of the rotary shaft 16 of the motor 15 is transmitted to the turntable 28. The magnet 47 is made of samarium cobalt and is magnetized in its axial direction. In addition,
48 and 49 are tie rods, 50 is a dust removing felt piece attached to the tie rods 48 and 49 and lightly touching the outer circumference of the flange rollers 38 and 39, 51 is a rotary encoder, and 52 is a groove for inserting a tool.

Next, the operation of the record player configured as described above will be described.

When the motor 15 is driven, the rotation of the rotary shaft 16 of the motor 15 is transmitted to the turntable 28 via the extension shaft 17, the magnet 47, and the ring 40, and the turntable 28 rotates. At this time,
As described above, the bar magnets 41 and 42 are magnetized so that the N magnetic pole appears at each end on the roller shaft 32 side and the S magnetic pole appears at each end on the roller shaft 33 side. Has a bar magnet 4
The S magnetic pole appears in the portion adjacent to the 1,42 N magnetic pole, and the roller shaft
33, an N magnetic pole appears in a portion adjacent to the S magnetic poles of the bar magnets 41, 42, and an N magnetic pole appears in a contact portion with the turntable shaft 29 on both flange rollers 38, so that both flange rollers 39
Of the turntable shaft 29, an S magnetic pole appears at the contact portion of the turntable shaft 29, and an S magnetic pole appears at the contact portion of the turntable shaft 29 with the flange roller 38. Since the N magnetic pole appears, the turntable shaft 29 is rotatably attached to each of the flange rollers 38 and 39.

Therefore, even if the outer circumference of the turntable shaft 29 wears for a long time and the diameter decreases, the turntable shaft
9 is rotatably magnetically attached, and the turntable shaft 29 does not shake like a rubbing motion. Therefore, it is possible to prevent the occurrence of noise such as burrs due to the swing of the turntable shaft 29.

Further, since the outer diameter ratio between the turntable shaft 29 and the flange rollers 38, 39 is about 1: 5.5, the flange roller 38, 39
Since the rotation of 39 is relatively slow, the flange rollers 38,39
It also prevents so-called noise noise caused by the rotation of the.

From the above, the durability of the record, the cartridge, etc. is improved, and the reproduction sound quality with high fidelity in the record performance is obtained (first embodiment).

In the above embodiment, the bar magnets 41, 42 provided between the pair of roller shafts 32, 33 are brought close to the roller shafts 32, 33 in a non-contact state, and the bar magnets 41, 42 are used to form the flange roller 38. , 39, and the turntable shaft 29 is magnetically attached to the flange rollers 38, 39, but the present invention is not limited to this. For example, the flange roller 38 is formed by permanent magnets brought into contact with the roller shafts 32, 33, respectively. , 39 may be magnetized so that the turntable shaft 29 is magnetically attached to the flange rollers 38, 39 (second embodiment). It may be a permanent magnet composed of a ring fitted to the holes 33 and 33 (third embodiment).

Further, in each of the above-mentioned embodiments, the flange rollers 38, 39 are magnetized by the permanent magnets attached to the roller shafts 32, 33, but the present invention is not limited to this. For example, the roller shafts 32, 33 are magnetized and the permanent magnets are magnetized. Flange roller 38,3
The turntable shaft 29 may be magnetically attached to these flange rollers 38, 39 by magnetizing 9 (fourth embodiment),
Further, only the flange rollers 38, 39 may be magnetized into permanent magnets without magnetizing the roller shafts 32, 33, and the turntable shaft 29 may be magnetically attached to these flange rollers 38, 39 (fifth embodiment). Example).

[Advantages of the Invention] According to the present invention, in a record player that rotates a turntable by a motor to extract an electrical signal from a record on the turntable through a pickup, the outer circumference of a turntable shaft made of a magnetic material is used. On one side, a pair of bearing rollers of the same shape and size having flange rollers made of a magnetic material and having the same diameter at both ends of the roller shaft are rotatably arranged at a predetermined distance from each other. Since the flange rollers are magnetized so that the turntable shafts are rotatably magnetically attached to the respective flange rollers, even if the outer circumference of the turntable shaft is worn and the diameter is reduced, the flange roller is always fitted with the turntable shaft. It can be magnetically attached, so that it is possible to reliably prevent the occurrence of run-out such as the rubbing movement of the turntable shaft. It prevents the occurrence of noise such as burrs due to the swing of the table axis,
It is possible to improve the durability of the record and the cartridge and obtain a reproduction sound quality with high fidelity in the record performance.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention,
1 is a cross-sectional plan view of an essential part, FIG. 2 is a sectional view taken along line II-II of FIG. 1, FIG. 3 is a partial sectional view showing a relationship between a flange roller and a turntable shaft, FIG. 4 is a sectional view showing a bearing structure of a conventional record player. 15 …… motor, 28 …… turntable, 29 …… turntable shaft, 32,33 …… roller shaft, 38,39 …… flange roller, 38a, 39a …… bearing roller, 41,42 …… bar magnet ( permanent magnet).

Claims (6)

[Claims] 1. In a record player for rotating a turntable by a motor to extract an electric signal from a record on the turntable through a pickup, a roller shaft is provided on one side of an outer circumference of a turntable shaft made of a magnetic material. A pair of bearing rollers of the same shape and size having flange rollers made of a magnetic material and having the same diameter are rotatably arranged at a predetermined distance from each other, and the flange rollers of the pair of bearing rollers are magnetized. A record player in which the turntable shaft is rotatably magnetically attached to each of the flange rollers. 2. The record player according to claim 1, wherein each of the flange rollers is magnetized by a magnet provided between the pair of roller shafts. 3. The record player according to claim 1, wherein each of the flange rollers is magnetized by a magnet brought into contact with the roller shaft. 4. The record player according to claim 1 or 3, wherein each of the flange rollers is magnetized by a magnet formed of a ring fitted to the roller shaft. 5. The record player according to claim 1, wherein each of the flange rollers is magnetized by magnetizing the roller shaft. 6. The record player according to claim 1, wherein each of the flange rollers is magnetized to be a permanent magnet.