JP3783435B2 - Gear mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gear mechanism, and more particularly to a gear mechanism applied to the rotation of a mode cam of a DAT (Digital Audio Tape Recorder) streamer used as a large-capacity external storage device of a computer device.
The DAT streamer uses a DAT tape cassette, and recording and reproduction of information on the magnetic tape is performed by a rotating drum (rotating head) that rotates at a high speed, and the magnetic tape is driven by being pinched by a capstan and a pinch roller. In addition, the mode cam is rotated by the mode motor, and various mechanisms are operated according to the rotation of the mode cam. Transmission of rotation from the mode motor to the mode cam is performed by a gear mechanism.
[0002]
The DAT streamer is required to be small, and the gear mechanism that transmits the rotation from the mode motor to the mode cam is also required to be compact. Further, it is desirable that the gear mechanism has a configuration that can be easily assembled.
[0003]
[Prior art]
6A and 6B show a gear mechanism 10 that transmits rotation from the worm 11a of the mode motor 11 of the conventional DAT streamer to the mode cam 12. FIG. The gear mechanism 10 is a reduction gear mechanism, and includes gears 13, 14, 15, which are rotatably fitted and supported by shafts 17, 18, 19 implanted in the chassis 16. Yes. The mode motor 11 is screwed and attached to a bracket 16a integral with the chassis 16.
[0004]
[Problems to be solved by the invention]
The gears 13, 14, and 15 are all supported by shafts 17, 18, and 19 that are implanted in the chassis 16, and the distance between the shafts is accurately determined. However, all the gears 13, 14, and 15 are made of the same member. Since it is attached to a certain chassis 16, the degree of freedom of design is limited, and the workability when assembling is not good. Further, since all the gears 13, 14, and 15 are arranged in a plane, it is difficult to reduce the size.
[0005]
Here, the mode motor 11 and a part of the plurality of gears are attached to the bracket, the remaining gears are attached to the chassis, and the mode motor 11 and a part of the plurality of gears are attached to the chassis. It is also possible. In this way, the number of gears attached to the chassis is smaller than in the conventional case, and it is sufficient to attach the mode motor 11 and the bracket to which the gears are previously attached to the chassis, and the workability during assembly is improved. Moreover, the height is also utilized, and the gear mechanism is partly three-dimensional and compact.
[0006]
However, in this case, there is a risk that the accuracy of the gap between the gear on the bracket and the gear on the chassis may not be good, and a device that keeps the accuracy of the gap between the gear on the bracket and the gear on the chassis good. Is required.
Then, an object of this invention is to provide the gear mechanism which solved the said subject.
[0007]
[Means for Solving the Problems]
The invention of claim 1 is a gear mechanism having a first gear and a second gear which are engaged and transmit rotation.
The first gear 52 is rotatably supported by a first gear shaft 62 that is implanted in the first support plate 61b.
The second gear 53 is rotatably supported by a second gear shaft 63 that is implanted in a second support plate 70 that is a member different from the first support plate,
The first support plate is provided with a positioning shaft 64 in addition to the first gear shaft. The first gear shaft and the positioning shaft are engaged with each other. It is in a relationship corresponding to the positional relationship with the second gear,
The second gear shaft has a positioning hole 63a formed on the tip side,
With the second support plate attached, the distal end side of the positioning shaft 64 is fitted in the positioning hole 63a on the distal end side of the second gear shaft, and thereby the first gear shaft and The positional relationship with the second gear shaft is determined.
[0008]
The positional relationship between the first gear shaft and the positioning shaft on the first support plate is determined with high accuracy, and the configuration in which the distal end side of the positioning shaft is fitted in the positioning hole on the distal end side of the second gear shaft is as follows: A first gear is rotatably supported by a first gear shaft that is implanted in the first support plate, and the second gear is a second member that is different from the first support plate. In a configuration in which the second gear shaft is rotatably supported by the second gear shaft, the positional relationship between the first gear shaft and the second gear shaft is accurately determined. Accordingly, the first gear and the second gear are configured to be rotatably supported on a gear shaft in which both the first gear and the second gear are implanted in the second support plate. It is possible to engage with the same accuracy.
[0009]
The invention of claim 2 is a gear mechanism having a first gear and a second gear which are engaged and transmit rotation.
The first gear 52 is rotatably supported by a first gear shaft 62 that is implanted in the first support plate 61b.
The second gear 53 is rotatably supported by a second gear shaft 63A implanted in a second support plate 70 which is a member different from the first support plate,
In addition to the first gear shaft, a positioning shaft 64A is implanted on the first support plate, and the first gear and the positioning shaft are engaged with each other. It is in a relationship corresponding to the positional relationship with the second gear,
The positioning shaft has a positioning hole 64Aa on the tip side,
With the second support plate attached, the distal end side of the second gear shaft 63A is fitted into the positioning hole 64Aa on the distal end side of the positioning shaft, and thereby the first gear shaft and The positional relationship with the second gear shaft is determined.
[0010]
The positional relationship between the first gear shaft on the first support plate and the positioning shaft is accurately determined, and the positioning hole on the tip side of the positioning shaft is fitted with the tip side of the second gear shaft. The first gear is rotatably supported by a first gear shaft implanted in the first support plate, and the second gear is a member different from the first support plate. In the structure rotatably supported by the second gear shaft implanted in the second support plate, the positional relationship between the first gear shaft and the second gear shaft is determined with high accuracy. Accordingly, the first gear and the second gear are configured to be rotatably supported on a gear shaft in which both the first gear and the second gear are implanted in the second support plate. It is possible to engage with the same accuracy.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
For convenience of explanation, a DAT streamer to which a gear mechanism according to an embodiment of the present invention is applied will be described first. FIG. 3 shows the DAT streamer 30. A magnetic tape 32 is drawn from the attached DAT tape cassette 31 by loading poles 33 and 34 and wound around a rotating drum 35. The magnetic tape 32 travels while being driven by a pinch roller 36 and a capstan 37, and information is recorded on the magnetic tape 42 by the rotary head 38, or the information recorded on the magnetic tape 42 is reproduced by the rotary head 38.
[0012]
In the DAT streamer 30, the mechanism is moved by the mode cam 56 rotating to a predetermined position according to the operation, and the operation mode is set according to the operation. The mode cam 56 is rotated by the mode motor 50 via the worm 51, the worm wheel 52, and the gears 53, 54, and 55.
1 and 2A, 2B and 2C show a gear mechanism 60 according to an embodiment of the present invention. The main part of the present invention is in the rotation transmission portion from the worm wheel 52 to the gear 53.
[0013]
Reference numeral 61 denotes a bracket, which is a vertical motor mounting portion 61a, an upper horizontal projecting portion 61b that projects horizontally from the upper end of the motor mounting portion 61a, and a lower horizontal that projects horizontally to both sides from the lower end of the motor mounting portion 61a. It has the overhang | projection part 61c, 61d.
A gear shaft 62 for the worm wheel 52 is implanted in the upper horizontal projecting portion 61b and projects downward.
[0014]
A gear shaft 63 for the gear 53 is implanted in the chassis 70 of the DAT streamer 30 and protrudes upward. A positioning hole 63 a is formed at the center of the upper end surface of the gear shaft 63. A gear 53 is fitted to the gear shaft 63 and is rotatably supported.
The gear portion 52a of the worm wheel 52 and the gear 53 are engaged with each other, and the distance between the center of the worm wheel 52 and the center of the gear 53 in the engaged state is A.
[0015]
A positioning shaft 64 for the gear shaft 63 is implanted on the upper horizontal projecting portion 61b of the bracket 61 and projects downward. The distance between the gear shaft 62 and the positioning shaft 64 is a distance A equal to the distance A between the center of the worm wheel 52 and the center of the gear 53 in the above-described meshed state. The diameter of the lower end of the positioning shaft 64 is a value that just fits into the positioning hole 63a.
[0016]
The motor mounting portion 61a of the bracket 61 is formed with a U-shaped cutout portion 61a1 having an opening on the upper end side.
A worm 51 is fixed to the spindle 50 a of the mode motor 50.
Gears 53, 54, and 55 are incorporated on the chassis 70. The gears 54 and 55 are fitted to another shaft on the chassis 70. A sub chassis 71 is fixed above the chassis 70.
[0017]
In the worm wheel assembly 80, the mode motor 50 with the worm 51 is fixed to the motor mounting portion 61 a of the bracket 61 with a screw, and the worm wheel 52 is fitted to the gear shaft 62 so that it cannot be removed by the screw 64. The worm wheel 52 is engaged with the worm 51.
The gear 53 is fitted to the gear shaft 63.
[0018]
The worm wheel assembly 80 has the lower horizontal projecting portions 61c and 61d in a state where the lower end portion of the positioning shaft 64 is fitted into the positioning hole 63a of the gear shaft 63 and the gear portion 52a of the worm wheel 52 is engaged with the gear 53. Is attached to the sub chassis 71 by being screwed to the sub chassis 71. The gear mechanism 60 is configured as described above.
[0019]
The worm wheel 52 corresponds to a “first gear” according to claim 1 of the claims, the gear 53 corresponds to a “second gear”, and the upper horizontal projecting portion 61 b of the bracket 61 corresponds to a “first gear”. The chassis 70 corresponds to the “second support plate”, the gear shaft 62 corresponds to the “first gear shaft”, and the gear shaft 63 corresponds to the “second gear shaft”. The positioning shaft 64 corresponds to the “positioning shaft”, and the positioning hole 63a corresponds to the “positioning hole”.
[0020]
Here, the projecting portion 61b is a flat surface, there is no step between the gear shaft 62 and the positioning shaft 64, the accuracy of the dimension A between the positioning shaft 64 and the gear shaft 62 is good, and Since the positioning shaft 64 is fitted in the positioning hole 63a of the gear shaft 63, the distance between the gear shaft 62 and the gear shaft 63 is accurately determined by the dimension A. Therefore, the gear portion 52a and the gear 53 of the worm wheel 52 mesh with the same accuracy as that obtained by the conventional configuration in which the worm wheel 52 and the gear 53 are both fitted to the shaft on the chassis 70. Transmission of rotation of the gear 53 from the gear portion 52a of the gear 52 is normally performed.
[0021]
Further, since the worm wheel assembly 80 to which the mode motor 50 with the worm 51 and the worm wheel 52 are attached is attached on the subchassis 71, compared with the structure in which the gear and the motor are exclusively assembled to the chassis 70. Thus, the assembly work is easy and the repair work is easy.
Further, since the worm wheel assembly 80 to which the mode motor 50 with the worm 51 and the worm wheel 52 are attached is attached on the sub chassis 71, a part thereof is three-dimensional and uses the height. The gear mechanism 60 is smaller than the configuration in which the gear and the motor are exclusively assembled to the chassis 70. Further, the gear mechanism 60 has a higher degree of design freedom than a configuration in which gears and motors are exclusively assembled to the chassis 70.
[0022]
Further, since it is not necessary to pass the worm wheel 52 through the hole of the bracket 61, the worm wheel 52 is prevented from hitting the hole of the hole of the bracket 61 and being damaged when the worm wheel 52 is passed through the hole of the bracket 61.
If the bracket 61 is a synthetic resin molded product, the portion corresponding to the upper horizontal overhanging portion 61 b may have a stepped portion between the gear shaft 62 and the positioning shaft 64.
[0023]
4 and 5 show a gear mechanism 60A according to another embodiment of the present invention. In the gear mechanism 60A, the positioning shaft 64A has a positioning hole 64Aa at the lower end, the gear shaft 62A has a thin portion 62Aa at the upper end, and the positioning hole 64Aa of the positioning shaft 64A is opposite to the gear mechanism 60 described above. The gear shaft 62A is configured to be fitted to a thin portion 62Aa at the tip, and the distance between the gear shaft 62A and the gear shaft 63 is accurately determined by the dimension A.
[0024]
A configuration is also conceivable in which a positioning hole is formed in a portion of the bracket 61 where the positioning shaft 64A is planted, and the tip of the gear shaft 62A is fitted into the positioning hole for positioning. However, if this is done, the length (height) of the gear shaft 62A becomes too long, and the influence of the tilting of the gear shaft 62A is likely to appear in the distance between the gear shaft 62A and the gear shaft 63. It becomes difficult to accurately determine the distance between the shaft 62A and the gear shaft 63.
[0025]
On the other hand, in the present embodiment, the gear mechanisms 60 and 60A described above have medium lengths (heights) of the gear shafts 62 and 62A, and the gear shafts 62 and 62A are hardly affected by tilting. The distance between the gear shaft 62 and the gear shaft 63 and the distance between the gear shaft 62A and the gear shaft 63 are accurately determined as the dimension A.
[0026]
【The invention's effect】
As described above, according to the first aspect of the present invention, in the gear mechanism having the first gear and the second gear which are engaged and transmit rotation, the first gear is attached to the first support plate. The second gear is rotatably supported by the first gear shaft that is implanted, and the second gear is implanted on a second support plate that is a member different from the first support plate. The first support plate is provided with a positioning shaft in addition to the first gear shaft, and the relationship between the first gear shaft and the positioning shaft is supported by the gear shaft in a rotatable manner. And the second gear shaft has a positioning hole formed on the tip side thereof, and has a relationship corresponding to the positional relationship between the first gear engaged with the second gear and the second gear. The positional relationship between the first gear shaft and the positioning shaft is accurately determined, and the distal end side of the positioning shaft is positioned on the distal end side of the second gear shaft. Since it is the structure fitted to the hole, the first gear is rotatably supported by the first gear shaft implanted in the first support plate, and the second gear is the first support plate. In the structure rotatably supported by the second gear shaft implanted in the second support plate which is a member different from the above, the positional relationship between the first gear shaft and the second gear shaft is The first gear and the second gear can be rotated on a gear shaft in which both the first gear and the second gear are implanted in the second support plate. It can be meshed with the same accuracy as the supported configuration.
[0027]
Further, the first gear is supported by the first support plate, the second gear is supported by the second support plate which is a member different from the first support plate, and the first support Since the plate is attached to the second support plate, it is easier to assemble and repair than the configuration in which the first gear and the second gear are supported by the second support plate. In addition, it can be three-dimensional and compact.
[0028]
According to the second aspect of the present invention, the positioning shaft has a positioning hole formed at the distal end side, and the second gear shaft is attached to the distal end side of the positioning shaft with the second support plate attached. Since the positioning relationship between the first gear shaft and the second gear shaft is determined by being fitted in the positioning hole, the first gear has the first support. A first gear shaft that is implanted in the plate is rotatably supported, and the second gear is implanted in a second support plate that is a member different from the first support plate. In the structure rotatably supported by the second gear shaft, the positional relationship between the first gear shaft and the second gear shaft can be determined with high accuracy, and the same effect as that obtained by the invention of claim 1 can be obtained. Have
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a gear mechanism according to an embodiment of the present invention.
FIG. 2 is a view showing the gear mechanism of FIG. 1;
FIG. 3 is a plan view schematically showing a DAT streamer to which the gear mechanism of FIGS. 1 and 2 is applied.
FIG. 4 is an exploded perspective view of a gear mechanism according to another embodiment of the present invention.
FIG. 5 is a diagram showing the gear mechanism of FIG. 4;
FIG. 6 is a view showing a conventional gear mechanism.
[Explanation of symbols]
30 DAT streamer 50 mode motor 51 worm 52 worm wheel 53, 54, 55 gear 56 mode cam 60, 60A gear mechanism 61 bracket 61b upper horizontal overhang 62, 63, 63A gear shaft 63a positioning hole 64, 64A positioning shaft 64Aa positioning hole 70 Chassis 71 Subchassis 80 Worm wheel assembly

Claims (2)

In a gear mechanism having a first gear and a second gear which are engaged and transmit rotation,
The first gear is rotatably supported by a first gear shaft implanted in the first support plate;
The second gear is rotatably supported by a second gear shaft that is implanted in a second support plate that is a member different from the first support plate,
In addition to the first gear shaft, a positioning shaft is implanted on the first support plate, and the first gear and the first gear in which the relationship between the first gear shaft and the positioning shaft is engaged. In relation to the positional relationship with the gear 2
The second gear shaft has a positioning hole on the tip side,
With the second support plate attached, the distal end side of the positioning shaft is fitted into the positioning hole on the distal end side of the second gear shaft, whereby the first gear shaft and the first gear shaft are fitted. A gear mechanism having a configuration in which the positional relationship with the second gear shaft is determined. In a gear mechanism having a first gear and a second gear which are engaged and transmit rotation,
The first gear is rotatably supported by a first gear shaft implanted in the first support plate;
The second gear is rotatably supported by a second gear shaft that is implanted in a second support plate that is a member different from the first support plate,
In addition to the first gear shaft, a positioning shaft is implanted on the first support plate, and the first gear and the first gear in which the relationship between the first gear shaft and the positioning shaft is engaged. In relation to the positional relationship with the gear 2
The positioning shaft has a positioning hole on the tip side,
With the second support plate attached, the distal end side of the second gear shaft is fitted into the positioning hole on the distal end side of the positioning shaft, whereby the first gear shaft and the first gear shaft are fitted. A gear mechanism having a configuration in which the positional relationship with the second gear shaft is determined.

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