JP3130126B2 - Gear device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear device, and can be used for a rotation transmitting mechanism such as a plate cylinder of an offset printing press requiring high accuracy.

[0002]

2. Description of the Related Art Conventionally, a meshing gear transmission mechanism has been frequently used for transmitting a driving force and an operation of a rotating portion in a mechanical device. In such a gear transmission mechanism, it is important to adjust the backlash between the gears in the meshing state.

[0003] That is, if the backlash is too large, the accuracy of the transmitted rotation is reduced, and the operation accuracy of the machine operated by the transmitted rotation is reduced. On the other hand, if the backlash is too small, the effects of manufacturing errors and tooth profile errors become apparent, and excessive force is applied to each tooth, causing unstable rotation or gear breakage.

[0004] In order to appropriately adjust such backlash, a gear device having a backlash adjusting mechanism using a double gear has conventionally been used. 4 and 5, a gear device 90 has first and second gears 91 and 92 that mesh with each other, and the second gear 92 includes a main gear 93 and a sub gear 94.

[0005] The main gear 93 and the auxiliary gear 94 are gears of the same tooth shape coaxially arranged on a shaft 95, and both are first gears 91 and 91.
Is engaged. The main gear 93 is fixed to the shaft 95, while the auxiliary gear 94 is fitted to the main gear 93 so as to be relatively rotatable.

An elongated hole 96 extending in the circumferential direction is formed on the side surface of the auxiliary gear 94.
A bolt 97 is inserted into the elongated hole 96, and the tip of the bolt 97 is screwed to a side surface of the main gear 93. By tightening the bolt 97, the auxiliary gear 94 can be fixed to the main gear 93 at an arbitrary angular position or phase within the range of the long hole 96.

In such a gear device 90, the bolt
After loosening 97 so that the auxiliary gear 94 can freely rotate with respect to the main gear 93, the main gear 93 and the auxiliary gear 94 are relatively rotated to change the phase, and each first gear 91 By changing the meshing state with respect to the first and second gears 91 and 92,
Perform backlash adjustment during

For example, when the main gear 93 is brought into contact with the first gear 91 in a counterclockwise direction and the auxiliary gear 94 is brought into contact with the first gear 91 in a clockwise direction, the backlash becomes substantially zero. The backlash can be gradually increased by returning the auxiliary gear 94 counterclockwise.

When the backlash can be adjusted to an appropriate amount, the bolt 97 is tightened again, and the main gear 93 and the auxiliary gear 93 are tightened.
By fixing 94 to the current phase, an appropriate adjusted backlash is set between the first and second gears 91 and 92.

The gear device 90 with such a backlash adjusting mechanism is applied to a gear transmission mechanism of a mechanical device requiring high accuracy. For example, in an offset-type rotary printing press, when the backlash between the plate cylinder and the blanket cylinder becomes large, printing deviation occurs, and when the backlash becomes small, poor printing due to uneven rotation occurs, and the tooth expansion due to thermal expansion occurs. Due to the restraint, the gear device 90 described above is employed for the rotation transmitting mechanism between the plate cylinder and the blanket cylinder.

In FIG. 6, the rotary offset printing press transfers ink from a printing plate wrapped around a plate cylinder 81 to a blanket cylinder 82, and rolls the blanket cylinder 82 onto paper to transfer ink to the paper. This is for printing. For this, the printing cylinder 81
The blanket cylinder 82 and the blanket cylinder 82 need to rotate synchronously, and the plate cylinder 81 and the blanket cylinder 82 are rotatably supported on both sides of the respective shafts 83 and 84 by the frame 80 so as to be rollable with each other. The shafts 83, 84 are linked by a gearing 90 between the outer ends of the frame 80.

Here, a rubber blanket for transferring ink is provided on the surface of the blanket cylinder 82. When the blanket is pressed against the plate cylinder 81, the rubber sheet is elastically deformed and the respective surfaces are brought into close contact. You. For this reason, the contact state of the plate cylinder 81 and the blanket cylinder 82 is not constant only by the contact of each surface itself. For this purpose, both ends of the plate cylinder 81 and the blanket cylinder 82 are provided with bearers 85 and 86 of the same diameter, respectively.
By bringing the 85 and 86 into rolling contact with each other, the distance between the shafts is regulated to be constant, and the state of close contact of the surface during mutual rolling can be kept constant.

In such an offset rotary printing press, the first and second gears 9 in the gear unit 90 are controlled by the above-mentioned bearers 85 and 86 that regulate the distance between the shafts.
The meshing state of the gears 1 and 92 also becomes constant, and a good meshing state is maintained if the backlash adjustment of the gear device 90 is performed and fixed in advance. In addition, the bearer 85,
86, etc., and the inter-axis distance between the plate cylinder 81 and the blanket cylinder 82 fluctuates to change the meshing state of the gear device 90. By adjusting the rush, it is possible to respond sufficiently.

[0014]

By the way, the above-described offset rotary printing press has a problem that it can sufficiently cope with long-term fluctuations of backlash but cannot sufficiently cope with short-term fluctuations. .

For example, in a printing press, the machine temperature changes with the lapse of time from the start of operation, and each part is deformed according to the temperature. Gearing in operation due to such thermal deformation
90 has backlash fluctuations. Also, when performing a `` peeling off '' operation for separating the plate cylinder 81 and the blanket cylinder 82 other than during printing, the backlash of the gear device 90 fluctuates due to the operation, and the other gear is restrained from others. In the case of immobility or the like, the teeth of each other may be overloaded.

Further, in order to finely adjust the printing register obliquely to the axis of the plate cylinder, the shaft 83 of the plate cylinder 81 or the blanket cylinder 82 is finely adjusted.
An adjustment called a “plate twist” is performed in which the end of the shaft 84 on the opposite side to the gear device 90 is displaced and the axes of the cylinders 81 and 82 are tilted. Even when the operation is performed, the backlash of the gear device 90 varies due to the inclination of the axis.

For these short-term fluctuations in backlash, it is difficult to stop the printing press one by one and make adjustments. In addition, since these are fluctuations that occur in the operating state, the backlash adjustment is performed in the stopped state. It is difficult to cope with the conventional gear device 90 to be performed, and in particular, it can hardly cope with fluctuation due to thermal deformation that changes every moment.

From the above, if the backlash is set small in order to enhance the printing accuracy, fluctuations in the backlash during operation cause inconveniences such as operation failure and gear damage, and safety is taken into consideration. If the backlash is large, there is a problem that printing accuracy cannot be obtained and printing failure occurs.

An object of the present invention is to provide a gear device which can cope with fluctuations in backlash during operation and which can avoid inconveniences such as gear breakage even if the accuracy is improved.

[0020]

SUMMARY OF THE INVENTION The present invention provides a main gear and a sub gear which are meshed with the same other gear with a backlash and are rotatable relative to each other; Biasing means for biasing in the direction of relative rotation, and positioning means sandwiched between the main gear and the auxiliary gear to regulate the relative rotation of each gear by the bias, the positioning means , substantially offsetting the adjusting mechanism capable of adjusting the thermal variation of the backlash by the optimum amount of backlash occurs so <br/> external operation the length of the relative rotational direction of the gears
To the main gear,
And a thermo element for changing the biasing position of the auxiliary gear .

[0021]

According to the present invention, the main gear and the auxiliary gear are relatively rotated to adjust the respective phases, so that the backlash between the other gears meshed with each other is adjusted. Is done. At this time, the main gear and the sub gear rotate relative to each other by the urging of the urging means until the positioning means is sandwiched, and the position is regulated in that state. Therefore, by adjusting the length of the positioning means in the direction of relative movement between the main gear and the auxiliary gear, the phase of the main gear and the auxiliary gear can be adjusted.

The positioning means can adjust the phase of the main gear and the auxiliary gear by automatically following the backlash fluctuation caused by the thermal deformation by appropriately setting the thermal deformation characteristics of the thermoelement. Thus, it is possible to reliably cope with fluctuations in backlash due to thermal deformation.

Further, since the main gear and the auxiliary gear are rotated by the urging means to the position regulated by the positioning means, the urging force of the urging means is appropriately set. Even if an excessive force is applied to each gear due to sudden thermal deformation or plate twisting or peeling, the main gear and the auxiliary gear escape against the urging force of the urging means, Inconveniences such as breakage of gears can be reliably avoided. As a result, it is possible to cope with fluctuations in the backlash during operation, and it is possible to avoid inconveniences such as gear breakage even if the accuracy is improved, and thus the above-mentioned object is achieved.

[0024]

An embodiment of the present invention will be described below with reference to the drawings. 1 and 2, a gear device according to the present embodiment is shown.
10 is a gear device of the offset rotary printing press shown in FIG. 5 described above.
In place of 90, synchronous rotation with the plate cylinder 81 and blanket cylinder 82 is performed.

The gear device 10 has first and second gears 11 and 12 that mesh with each other. The second gear 12 is composed of a main gear 13 and a sub gear 14. The main gear 13 and the auxiliary gear 14 are gears having the same tooth shape coaxially arranged on the shaft 15, and are both meshed with the first gear 11.

The main gear 13 is directly fitted on the shaft 15 and is fixed in a state where the relative rotation is regulated by the key 16. The auxiliary gear 14 is relatively rotatably fitted to a cylindrical step 17 of the main gear 13, and a holding member 18 screwed to an end of the shaft 15.
It is prevented from falling off.

The auxiliary gear 14 has first and second concave portions 21 and 22 formed along the back side of the tooth surface. Main gear 13
First and second receiving members 23 and 24 projecting into the respective recesses 21 and 22 are fixed to the step 17.

The first receiving member 23 is disposed near the counterclockwise end of the first recess 21, and its clockwise side surface is a first receiving surface 25. The inner surface at the clockwise end of the recess 21 is a second receiving surface 26.

The second receiving member 24 is disposed in the vicinity of the clockwise end of the second concave portion 22, and its counterclockwise side is a third receiving surface 27. The inner surface at the counterclockwise end of the concave portion 22 is a fourth receiving surface 28.

Between the first receiving surface 25 and the second receiving surface 26, substantially along the direction of relative rotation of the main gear 13 and the auxiliary gear 14,
An urging means using a compression coil spring 31 is interposed.
In order to position the compression coil spring 31, a guide pin 32 inserted into an end of the compression coil spring 31 is implanted on the first receiving surface 25 of the first receiving member 23.

Between the third receiving surface 27 and the fourth receiving surface 28, substantially along the relative rotation direction of the main gear 13 and the auxiliary gear 14,
Adjustment bolt 33 and thermoelement 34, which are adjustment mechanisms
Is positioned. Adjustment bolt
33 is screwed into the third receiving surface 27 of the second receiving member 24, and is externally rotated through a window 36 formed on the side surface of the auxiliary gear 14 to protrude from the third receiving surface 27. Is adjustable. The thermoelement 34 is a rod-shaped member such as an alloy set so as to obtain a predetermined coefficient of thermal expansion, and has one end fixed to the fourth receiving surface 28 and the other end in contact with the tip of the adjustment bolt 33. Have been.

In this embodiment constructed as described above, the compression coil spring 31 is provided with the first and second receiving surfaces 25, 26.
Act on the main gear 13
Is rotated clockwise in FIG. On the other hand, since the positioning means 35 is interposed between the third and fourth receiving surfaces 27 and 28, the relative rotation of the main gear 13 and the auxiliary gear 14 is stopped while the positioning means 35 is sandwiched. Is done. That is,
The phase of the relative rotation between the main gear 13 and the auxiliary gear 14 is determined by the positioning means.
It is determined by the length of the adjustment bolt 33 and the thermoelement 34.

Therefore, when the adjusting bolt 33 is operated while the gear device 10 is stopped to change the amount of protrusion, the main gear 13 and the auxiliary gear 13 that follow the length of the positioning means 35 by the compression coil spring 31 are changed. The phase with the gear 14 changes, so that a basic backlash adjustment between the first and second gears 11, 12 can be performed.

On the other hand, the thermoelement 34 thermally expands due to a temperature rise when the gear device 10 is operated, so that the main gear 13 and the sub gear 14 which follow the length of the positioning means 35 by the compression coil spring 31 And the backlash between the first and second gears 11, 12 is automatically adjusted according to the temperature. For this reason, if the thermal expansion characteristic of the thermoelement 34 is set so as to offset the fluctuation of the backlash between the first and second gears 11 and 12 due to the temperature, the first temperature can be obtained regardless of the temperature state. And the second gear 11,
The backlash during twelve can be maintained at a preset predetermined value.

Since the main gear 13 and the auxiliary gear 14 follow the length of the positioning means 35 by the compression coil spring 31, the main gear 13 and the auxiliary gear 14 receive an external force opposite to the urging force of the compression coil spring 31. The relative rotation is appropriately performed in the direction of the external force. For this reason, even if the backlash between the first and second gears 11 and 12 is set to be small in advance, the main gear 13 and the sub gear 13 due to sudden thermal deformation or plate twist or plate peeling.
If an excessive force is applied to the gears 14, the gears 13, 14 escape against the urging force of the compression coil spring 31, and the gears 13, 14
Inconveniences such as breakage of 14 can be reliably avoided.

Therefore, according to the present embodiment, the effect of thermal deformation on the backlash between the first and second gears 11 and 12 can be avoided, and each of the gears can be subjected to thermal deformation, plate twist, plate peeling, or the like. Even if an excessive force is applied to the gears 13 and 14, the gears 13 and 14 can be released to avoid breakage and the like, and can cope with fluctuations in backlash during operation. For this reason,
It is not necessary to set a large backlash in advance in anticipation of fluctuations during operation as in the prior art, and it is possible to minimize the backlash to be set in advance.
Operation accuracy can be improved.

The compression coil spring in the above embodiment
The material, performance, etc. of the thermoelement 31 and the thermoelement 34 may be set as appropriate, and these settings may be made in the following procedure, for example.

First, the thermo-element 34 is set so that the thermal expansion characteristic cancels out the temperature fluctuation of the backlash between the first and second gears 11 and 12. That is, as shown in FIG. 3, the pitch circle radius R of the first and second gears 11 and 12, the pressure angle α, the coefficient of thermal expansion A of the material, and the difference between the temperature at the time of assembly and the temperature at the time of operation are represented by the temperature. If the rise is θ, the amount of backlash reduction due to the thermal expansion ΔR (= ARθ) of each gear 11, 12 is ΔD = 2ΔR sin α = 2ARθ sin α.

Assuming that the length L, the average diameter r, and the coefficient of thermal expansion B of the thermoelement 34 are BLθ, the elongation is BLθ.
However, the second concave portion 22 for accommodating the thermoelement 34 is also AL.
Since thermal expansion is performed by θ, the effective elongation of the thermoelement 34 is ΔEo = BLθ−ALθ. When this is converted into the pitch circle of the gear 12, ΔE = R / r (BLθ−ALθ).

Here, in order to make the thermoelement 34 such that the fluctuation of the backlash between the first and second gears 11 and 12 due to the temperature can be offset, the effective elongation ΔEo of the thermoelement 34 and the backlash It suffices if the rush reduction ΔD is equal. Therefore, 2ARθsin from ΔEo = ΔD
α = R / r (BLθ−ALθ)
B = A ｛1 + (2r / L) s regardless of R and temperature rise θ
inα｝ holds. That is, it is important that this formula does not include R and θ.

As specific examples, the thermal expansion coefficients A of the gears 11 and 12 are A = 10.7 × 10 ⁻⁶ / deg, the pressure angle α = 20 °, the length L of the thermoelement 34 is 81.16 mm, and the average diameter r is 68.5. mm, assembling temperature is 20 ° C, operating temperature is 60 ° C and temperature rise θ
= 40deg, B = 10.7 × 10 ^-6 (1+ (2 × 68.
5 / 81.16) sin20 °) = 16.88 x 10 ^-6 / deg.

That is, the thermal expansion coefficient of the thermoelement 34
B may be about 17 × 10 ⁻⁶ / deg, for example, the coefficient of thermal expansion is
17.1 × 10 ⁻⁶ / deg beryllium copper C1720 (1.9% Be, 0.2% N
i, the remaining Cu), the effective elongation ΔEo and the backlash reduction ΔD of the thermoelement 34 can be obtained irrespective of the values of the pitch radii R of the gears 11 and 12 and the temperature rise θ. It is always the same, and the above-described cancellation of the backlash can be realized.

Next, the compression coil spring 31 is set as follows. Here, assuming that the temperature at the time of assembly is 20 ° C, the temperature at the time of operation is 60 ° C, and the temperature rise is θ = 40deg, the backlash reduction is ΔD = 2ARθsin α = 2
× 10.7 × 86.9 × 40 × sin20 ° = 0.0254 mm.

When the aforementioned beryllium copper is used for the thermoelement 34, the longitudinal elastic modulus of beryllium copper is E
≒ 13300kgf / mm ² , Thermo element 34 length L = 81.16m
m, the sectional area S = a 15 × 13 = 195mm ^2, a force corresponding than Hooke's law backlash decrease [Delta] D = 0.0254 mm F
Is calculated, F = ΔD × ES / L = 0.0254 × 13300 × 19
5 / 81.16 = 811.6kg.

Therefore, if a 56 kgf spring is used as the compression coil spring 31, the proportional calculation will be 40 × 56 / 811.6 = 2.76 deg, and the response to the temperature fluctuation will be started at a temperature rise of 2.76 deg. As described above, when setting the compression coil spring 31, it is basically sufficient to consider the escape operation due to the external force, but since it is also related to the operation of the thermoelement 34, it is necessary to take this into consideration. Is desirable.

The present invention is not limited to the above-described embodiment, but includes the following modifications and the like. That is, the main gear provided on the second gear 12
The structure of the auxiliary gear 13 and the auxiliary gear 14 is optional, for example, the main gear 13
May be fixed to the shaft 15 and the auxiliary gear 14 may be rotatably provided on the shaft 15.

The biasing means provided on the second gear 12 is not limited to the compression coil spring 31. If the main gear 13 and the auxiliary gear 14 can be biased in the direction of sandwiching the positioning means 35, a tension spring, a helical spring, Alternatively, it may be installed with an appropriate engagement structure using a leaf spring or the like.

Further, the positioning means 35 provided on the second gear 12 is not limited to the structure of the above embodiment, and the adjusting bolt 33 may have another structure as long as the length can be adjusted by an external operation. May be selected as appropriate.

The configuration of the first and second concave portions 21 and 22 and the first and second receiving members 23 and 24, in which the urging means such as the compression coil spring 31 and the positioning means 35 are installed, are also optional. Alternatively, the urging means and the positioning means 35 may be collectively housed in the same recess or the like. The number and arrangement of the biasing means such as the compression coil spring 31 and the positioning means 35 may be appropriately selected for implementation.

Further, the present invention is not limited to the rotation transmitting mechanism between the plate cylinder and the blanket cylinder of the offset rotary printing press, but may be a gear mechanism of another mechanical device. The present invention can be widely applied to a gear mechanism portion.

[0051]

As described above, according to the present invention, it is possible to cope with an unreasonable force by escaping the urging means, and to automatically cope with thermal deformation by means of the thermoelement. By realizing the response to the backlash fluctuation during the operation, it is possible to avoid inconveniences such as gear breakage even if the accuracy is improved. Also, since one type of thermoelement can be applied in common regardless of the size of the gear and the temperature rise, it is very advantageous in parts management and maintenance.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing the embodiment.

FIG. 3 is a schematic diagram showing a setting procedure of the embodiment.

FIG. 4 is a partially broken front view showing a conventional example.

FIG. 5 is a sectional view showing the conventional example.

FIG. 6 is a schematic view showing a portion to which the conventional example and the present invention are applied.

[Explanation of symbols]

 10 Gear device 11 First gear 12 Second gear 13 Main gear 14 Secondary gear 31 Compression coil spring as urging means 33 Adjusting bolt as adjusting means 34 Thermoelement 35 Positioning means

Claims (1)

(57) [Claims] 1. Having the same other gear and backlash
A main gear and an auxiliary gear meshed in a state and relatively rotatable, an urging means for urging the auxiliary gear with respect to the main gear in a relative rotational direction, and between the main gear and the auxiliary gear. is sandwiched and a positioning means for restricting relative rotation of the gear by the urging, the positioning means, the optimum amount of Ba
An adjustable adjusting mechanism Tsu crash occurs as in the relative rotational direction of the gears length by an external operation, back
The biasing position of the auxiliary gear with respect to the main gear is changed by expanding and contracting in the relative rotation direction by an amount that substantially offsets the heat fluctuation of the rush.
And a thermoelement to be formed.