JPH05340465A - Gear device - Google Patents

Abstract

PURPOSE:To provide a gear device which copes with any fluctuation in a backlash during working and prevents trouble, such as breakage of a gear, even when precision is increased. CONSTITUTION:A compression coil spring 31 and a positioning means 35 nipped between gears 13 and 14 through energization of the compression coil spring are arranged between a main gear 13, engaged with a first gear 11 and relatively rotatable, and an auxiliary gear 14. A fundamental backlash is set to a low value by means of a regulating bolt 33, thermal deformation of the gears 13 and 14 is offset through expansion and contraction of a thermoelement 34 by means of heat and when an unreasonable force is exerted, the gears 13 and 14 allowed to escape therefrom through the force of the compression spring 31.

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 transmission mechanism such as a plate cylinder of an offset printing machine, which requires high accuracy.

[0002]

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

That is, if the backlash is too large, the precision of the transmitted rotation is reduced, and the operating precision of the machine operated by the transmitted rotation is reduced. On the other hand, if the backlash is too small, the effects of manufacturing error, tooth profile error, etc. become apparent, and an unreasonable force is applied to each tooth, which makes the rotation unstable or damages the gears.

In order to properly adjust such backlash, a gear device having a backlash adjusting mechanism using a double gear has been conventionally used. 4 and 5, the gear device 90 has first and second gears 91 and 92 meshing with each other, and the second gear 92 is composed of a main gear 93 and a sub gear 94.

The main gear 93 and the auxiliary gear 94 are gears having the same tooth shape and arranged coaxially with the shaft 95, and both of them are the first gear 91.
Is meshed with. 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 rotatable relative to each other.

A long 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 long hole 96, and the tip of the bolt 97 is screwed to the 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, that is, in a phase within the elongated hole 96.

In such a gear device 90, the bolt
97 is loosened so that the sub gear 94 can freely rotate with respect to the main gear 93, and then the main gear 93 and the sub gear 94 are relatively rotated to change the phase, so that each first gear 91 By changing the meshing state for the first and second gears 91, 92
Adjust the backlash between.

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

Then, 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 are
By fixing 94 and the current phase, a proper 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 or the like of a mechanical device requiring accuracy. For example, in an offset rotary printing press, if the backlash between the plate cylinder and the blanket cylinder is large, printing misalignment occurs, and if the backlash is small, printing failure due to uneven rotation or tooth expansion due to thermal expansion occurs. Since the restraint occurs, the above-described gear device 90 is adopted as the rotation transmission mechanism between the plate cylinder and the blanket cylinder.

In FIG. 6, an offset rotary printing machine transfers ink from a printing plate wound around a plate cylinder 81 onto a blanket cylinder 82, rolls the blanket cylinder 82 onto a sheet, and transfers the ink onto the sheet. It is for printing. For this, the plate cylinder 81
The blanket cylinder 82 and the blanket cylinder 82 are required to rotate synchronously. The plate cylinder 81 and the blanket cylinder 82 are rotatably supported by the frame 80 on both sides of the respective shafts 83 and 84, and are arranged so as to be rollable with each other. The shafts 83, 84 are linked by a gear unit 90 between the outer ends of the frame 80.

Here, a rubber blanket for transferring ink is stretched on the surface of the blanket cylinder 82. When the blanket cylinder 81 is pressed against the plate cylinder 81, the rubber sheet is elastically deformed so that the respective surfaces are brought into close contact with each other. It Therefore, the contact states of the plate cylinder 81 and the blanket cylinder 82 are not constant only by the contact of their respective surfaces themselves. For that purpose, bearers 85 and 86 having the same diameter as that of the plate cylinder 81 and the blanket cylinder 82 are attached to both ends of the cylinder 81 and the blanket cylinder 82, respectively.
By making rolling contact of 85 and 86 with each other, the distance between the shafts is regulated to a constant value, and the close contact state of the surfaces during rolling can be maintained constant.

In such an offset rotary printing press, the first and second gears 9 in the gear device 90 are controlled by the above-mentioned bearers 85 and 86 which regulate the distance between the shafts to a constant value.
The meshed state of 1, 92 is also constant, and if the gear device 90 is fixed in advance by adjusting the backlash, a good meshed state is maintained. In addition, the bearer 85,
Even when the shaft distance between the plate cylinder 81 and the blanket cylinder 82 fluctuates due to wear of 86, and the meshing state of the gear device 90 changes, the back adjustment is performed by the adjustment procedure described above when the printing machine is stopped. Re-adjustment of the lash can be sufficient.

[0014]

By the way, in the above-mentioned offset rotary printing press, there is a problem that it is possible to sufficiently cope with a long-term backlash fluctuation, but it is not possible to sufficiently cope with a short-term fluctuation. ..

For example, in a printing press, the machine temperature changes with the lapse of time from the start of operation, and each part deforms according to the temperature. Gear device in operation due to such thermal deformation
Backlash variation occurs at 90. In addition, when the "clip to cylinder" operation is performed to separate the plate cylinder 81 and the blanket cylinder 82 at a time other than during printing, the backlash of the gear device 90 may fluctuate due to the operation, or the other gear may be restricted from other gears. In the case of immobility, each tooth may be overloaded.

Further, in order to finely adjust the printing register in a direction oblique to the axis of the plate cylinder, the shaft 83 of the plate cylinder 81 or the blanket cylinder 82.
An adjustment called "plate twist" is performed by displacing an end position of one of the shafts 84 of the shaft 84 opposite to the gear device 90 and tilting the axes of the cylinders 81, 82. Even if it is carried out, the backlash of the gear device 90 fluctuates due to the inclination of the axis.

With respect to these short-term fluctuations in backlash, it is difficult to make adjustments by stopping the printing machine one by one, and since these are fluctuations that occur in the operating state, backlash adjustment is performed in the stopped state. It is difficult for the conventional gear device 90 to carry out, and it is almost impossible to deal with the fluctuation due to the thermal deformation which changes from moment to moment.

From the above, if the backlash is set to be small in order to improve the printing accuracy, inconveniences such as malfunctions and damages of gears may occur due to backlash fluctuations during operation, and in consideration of safety. If the backlash is large, the printing accuracy cannot be obtained, and there is a problem that printing defects occur.

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

[0020]

According to the present invention, there is provided a main gear and a sub gear which are meshed with the same other gear and are relatively rotatable,
Energizing means for urging the auxiliary gear in the respective relative rotation directions with respect to the main gear, and positioning for being held between the main gear and the auxiliary gear to restrict relative rotation of each gear due to the urging. The positioning means has an adjusting mechanism capable of adjusting the length in the relative rotation direction by an external operation, and a thermoelement which expands and contracts in the relative rotation direction by heat. ..

[0021]

[Operation] In the present invention as described above, the backlash between the main gear and the sub gear is adjusted by rotating the main gear and the sub gear relative to each other to adjust the phase of each gear. To be done. At this time, the main gear and the auxiliary gear are relatively rotated by the urging force of the urging means until the positioning means is clamped, and the position is regulated in that state. Therefore, the phase of the main gear and the auxiliary gear can be adjusted by adjusting the length of the positioning means in the relative movement direction of the main gear and the auxiliary gear.

Further, the positioning means can adjust the phases of the main gear and the auxiliary gear by automatically following the fluctuation of the backlash due to the thermal deformation by appropriately setting the thermal deformation characteristics of the thermoelement. Therefore, it is possible to reliably deal with the backlash variation due to thermal deformation.

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

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2, the gear device of the present embodiment
Reference numeral 10 is a gear device of the offset rotary printing press shown in FIG.
Instead of 90, the plate cylinder 81 and the blanket cylinder 82 rotate synchronously.

The gear unit 10 has first and second gears 11 and 12 meshing with each other, of which 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 of the same tooth shape that are coaxially arranged on the shaft 15, and both mesh with the first gear 11.

The main gear 13 is directly fitted to the shaft 15 and fixed in a state in which the relative rotation is restricted by the key 16. The sub gear 14 is fitted to the cylindrical step portion 17 of the main gear 13 so as to be rotatable relative to it, and is held by a pressing member 18 screwed to the end portion of the shaft 15.
It is prevented from falling off.

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

The first receiving member 23 is arranged in the vicinity of the counterclockwise side end of the first concave portion 21, and its clockwise side surface is the first receiving surface 25, and the first receiving surface 25 faces the first receiving surface 25. The inner side surface of the recess 21 on the clockwise side end is a second receiving surface 26.

The second receiving member 24 is arranged in the vicinity of the clockwise end of the second concave portion 22, and the counterclockwise side surface thereof serves as the third receiving surface 27. The inner surface of the recess 22 on the counterclockwise side end serves as a fourth receiving surface 28.

Between the first receiving surface 25 and the second receiving surface 26, substantially along the direction of relative rotation between the main gear 13 and the auxiliary gear 14,
A biasing means using a compression coil spring 31 is interposed.
In order to position the compression coil spring 31, a guide pin 32 that is inserted into the end of the compression coil spring 31 is planted 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 direction of relative rotation between the main gear 13 and the auxiliary gear 14,
Adjustment bolt 33 and thermoelement 34, which are adjustment mechanisms
The positioning means 35 having the above is interposed. Adjusting bolt
33 is screwed to the third receiving surface 27 of the second receiving member 24, and is rotated from the outside through the window portion 36 formed on the side surface of the auxiliary gear 14 to project 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, one end of which is fixed to the fourth receiving surface 28 and the other end of which abuts on the tip of the adjusting bolt 33. Has been done.

In this embodiment thus constructed, the compression coil spring 31 has the first and second receiving surfaces 25, 26.
Since it acts to separate the auxiliary gear 14 from the main gear 13
1 is rotated relative to the clockwise direction in FIG. On the other hand, since the positioning means 35 is interposed between the third and fourth receiving surfaces 27, 28, the main gear 13 and the auxiliary gear 14 stop relative rotation with the positioning means 35 being sandwiched. To be done. That is,
The phase of the relative rotation between the main gear 13 and the auxiliary gear 14 is the positioning means.
It is determined by the length of the adjusting bolt 33 of 35 and the thermoelement 34.

Therefore, if the adjusting bolt 33 is operated while the gear device 10 is stopped and the amount of protrusion thereof is changed, the compression coil spring 31 follows the length of the positioning means 35 and the auxiliary gear 13 and the auxiliary gear. The phase with the gear 14 changes, which allows a basic backlash adjustment between the first and second gears 11, 12.

On the other hand, the thermoelement 34 thermally expands due to the temperature rise when the gear device 10 is operated, so that the main gear 13 and the auxiliary gear 14 are made to follow the length of the positioning means 35 by the compression coil spring 31. , The backlash between the first and second gears 11, 12 is automatically adjusted according to the temperature. For this reason, if the thermal expansion characteristics of the thermoelement 34 are set so as to cancel the variation due to the temperature of the backlash between the first and second gears 11 and 12, the first element will not be affected regardless of the temperature state. And the second gear 11,
The backlash between 12 can be maintained at a preset predetermined value.

Further, since the main gear 13 and the sub gear 14 are made to follow the length of the positioning means 35 by the compression coil spring 31, they can receive an external force in the direction opposite to the biasing force of the compression coil spring 31. The relative rotation is appropriately made in the direction of the external force. Therefore, even if the backlash between the first and second gears 11 and 12 is set small in advance, the main gear 13 and the auxiliary gear 13 are subject to sudden thermal deformation or plate twisting or plate peeling.
If an unreasonable force is applied to 14, the gears 13, 14 will escape against the urging force of the compression coil spring 31, and the respective gears 13, 14 due to the unreasonable force.
Inconveniences such as breakage of 14 can be reliably avoided.

Therefore, according to this embodiment, the influence of thermal deformation on the backlash between the first and second gears 11 and 12 can be avoided, and the thermal deformation or plate twisting or plate peeling can be used to prevent Even if an unreasonable force is applied to the gears 13 and 14, the gears 13 and 14 can be released to avoid damage and the like, and it is possible to cope with backlash fluctuations during operation. For this reason,
There is no need to set a large backlash in advance in anticipation of fluctuations during operation as in the past, and the backlash set in advance can be minimized.
As a result, it is possible to improve the operation accuracy.

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

First, the thermoelement 34 sets the thermal expansion characteristic so as to cancel the variation due to the temperature 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 thermal expansion coefficient A of the material, and the difference between the temperature during assembly and the temperature during operation Assuming an increase 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.

Further, assuming that the length L of the thermoelement 34, the average diameter r and the coefficient of thermal expansion B, the elongation is BLθ.
However, the second recess 22 that houses the thermoelement 34 is also AL
Since the thermal expansion is performed by θ, the effective elongation amount of the thermoelement 34 is ΔEo = BLθ−ALθ. Converting this on the pitch circle of the gear 12, ΔE = R / r (BLθ−ALθ).

Here, in order to make the thermoelement 34 capable of canceling out the variation due to the temperature of the backlash between the first and second gears 11 and 12, the effective elongation amount ΔEo of the thermoelement 34 and the back It is sufficient that the rush reduction amount ΔD becomes equal. Therefore, from ΔEo = ΔD, 2ARθsin
α = R / r (BLθ-ALθ), which is the size of the gear
B = A {1 + (2r / L) s irrespective of R and temperature rise θ
in α} holds. That is, it is important that this equation does not include R and θ.

As a concrete example, the thermal expansion coefficient of the gears 11 and 12 A = 10.7 × 10 ⁻⁶ / deg, the pressure angle α = 20 °, the length L of the thermoelement 34 L = 81.16 mm, and the average diameter r = 68.5. mm, assembly temperature is 20 ° C, operating temperature is 60 ° C, temperature rise θ
= 40deg, B = 10.7 × 10 ^-6 (1 + (2 × 68.
5 / 8.16.sin 20 °) = 16.88 × 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
17.1 × 10 ^-6 / deg beryllium copper C1720 (1.9% Be, 0.2% N
If the thermoelement 34 is created using (i, remaining Cu), the effective elongation amount ΔEo and the backlash decrease amount ΔD of the thermoelement 34 will be obtained regardless of the values of the pitch circle radius R of the gears 11 and 12 and the temperature rise θ. It is always the same, and the above-mentioned backlash cancellation can be realized.

Next, the compression coil spring 31 is set as follows. If the assembly temperature is 20 ° C, the operating temperature is 60 ° C, and the temperature rise is θ = 40deg, the backlash decrease is ΔD = 2ARθsin α = 2
X 10.7 x 86.9 x 40 x sin 20 ° = 0.0254 mm.

When the above-mentioned beryllium copper is used for the thermoelement 34, the longitudinal elastic modulus of beryllium copper is E
≈13300kgf / mm ² , length of thermoelement 34 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, when a 56 kgf spring is used as the compression coil spring 31, the proportional calculation yields 40 × 56 / 811.6 = 2.76 deg, and the temperature rise starts to be dealt with at 2.76 deg. As described above, when setting the compression coil spring 31, basically, the escape operation by the external force may be basically considered, but since it is also related to the operation of the thermo element 34, it should be selected in consideration thereof. Is desirable.

The present invention is not limited to the above embodiments, and the following modifications and the like are also included in the present invention. That is, the main gear provided on the second gear 12.
The structures of 13 and the sub gear 14 are arbitrary, 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, but a tension spring or a helical spring may be used if the main gear 13 and the auxiliary gear 14 can be biased in the direction in which the positioning means 35 is clamped. Alternatively, it may be installed with an appropriate engaging 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-described embodiment, and the adjusting bolt 33 may have another structure as long as the length can be adjusted by an external operation. The combination state and the like may be appropriately selected.

Further, the constitution of the first and second recesses 21, 22 and the first and second receiving members 23, 24 for installing the biasing means such as the compression coil spring 31 and the positioning means 35 is also arbitrary. The urging means and the positioning means 35 may be put together in the same recess or the like. Then, 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 transmission mechanism between the plate cylinder and the blanket cylinder of the offset rotary printing machine, but may be a gear mechanism of another mechanical device, and the present invention is required to have meshing accuracy. It can be widely applied to gear mechanism parts.

[0051]

As described above, according to the present invention, it is possible to cope with an unreasonable force by the escape of the biasing means, and it is also possible to automatically cope with thermal deformation by the thermoelement. By implementing these measures to deal with backlash fluctuations during operation, it is possible to avoid inconveniences such as gear damage even if accuracy is increased. Further, since one type of thermoelement can be commonly applied regardless of the size of the gear and the temperature rise, it is very advantageous in the management and maintenance of parts.

[Brief description of 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 cutaway front view showing a conventional example.

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

FIG. 6 is a schematic diagram 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 33 as biasing means 33 Adjustment bolt as adjusting means 34 Thermo element 35 Positioning means

Claims (1)

[Claims] 1. A main gear and an auxiliary gear that are meshed with another same gear and are capable of relative rotation, and an urging means for urging the auxiliary gear in the respective relative rotation directions with respect to the main gear, And a positioning means that is sandwiched between the main gear and the auxiliary gear to regulate the relative rotation of each gear due to the bias, and the positioning means can adjust the length in the relative rotation direction by an external operation. And a thermo-element that expands and contracts in the relative rotation direction by heat.