JP7440368B2 - Flat belt transmission system and its usage - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to a flat belt transmission system with serpentine control pulleys and methods of using the same.

Conventionally, in a transmission system using a flat belt, the flat belt may sometimes meander while running or run unilaterally toward one side of a pulley. This is because flat belts are more sensitive than other flat belts to deviations of the pulley shaft from its normal position, deflection of the pulley shaft due to changes in shaft load, swinging of the pulley, and the like. In order to prevent such meandering and lopsided running, a flat belt meandering control device that prevents meandering of a flat belt is known (for example, see Patent Document 1).

Furthermore, a meandering control pulley having a one-way clutch is known as disclosed in Patent Document 2.

JP2017-25932A Patent No. 6412293

In a flat belt transmission system that includes a fan such as a blower, the fan may rotate in the opposite direction (hereinafter referred to as "reverse rotation") due to wind or the like. In such a case, as described above, the flat belt tends to slip off the pulley, and when the rotation is reversed, the flat belt moves in a meandering direction, and the flat belt comes into contact with the flange of the pulley, damaging the side surface of the belt. Furthermore, in some cases, the flat belt may ride on the flange and fall off the pulley.

Furthermore, there is a need for a simple device that can prevent falling off due to reverse rotation without providing a one-way clutch as in Patent Document 2.

The present invention has been made in view of this problem, and its object is to provide a simple structure that reliably prevents the belt from falling off during reverse rotation.

In order to achieve the above object, in the present invention, the pulley shaft is deliberately misaligned in the opposite direction to that during normal rotation when stopped, so that the meandering prevention function can be exhibited even during reverse rotation.

Specifically, the flat belt transmission system of the first invention includes:
drive pulley;
a driven pulley;
a flat belt that is hung around the drive pulley and the driven pulley;
a meandering control pulley that comes into contact with the flat belt and controls meandering of the flat belt;
a pulley shaft rotatably supporting the meandering control pulley and swingably supporting the meandering control pulley around a pivot;
When the driving pulley is stopped, the pivot axis is arranged at an angle of −15° or more and less than 0° in the forward direction of the meandering control pulley in the normal rotation direction with respect to the direction of the shaft load, when viewed along the direction of the pulley axis. It is tilted at an angle.

Similarly, the method of using the flat belt transmission system of the third invention is as follows:
drive pulley;
a driven pulley;
a flat belt that is hung around the drive pulley and the driven pulley;
a meandering control pulley that comes into contact with the flat belt and controls meandering of the flat belt;
A method of using a flat belt transmission system comprising a pulley shaft rotatably supporting the meandering control pulley and swingably supporting the meandering control pulley around a pivot shaft, the method comprising:
When the driving pulley is stopped, when the pivot shaft is viewed along the direction of the pulley axis, the meandering control pulley has an angle of −15° or more and less than 0° toward the front in the normal rotation direction with respect to the direction of the shaft load. Adjust to tilt at an angle, and
At the time of normal rotation, the pivot shaft is adjusted so that the meandering control pulley is tilted forward in the normal rotation direction at an angle greater than 0° with respect to the direction of the shaft load when viewed along the direction of the pulley axis. shall be.

Normally, the meandering control pulley exhibits a meandering prevention function that prevents the flat belt from meandering by adjusting the inclination of the pulley shaft during forward rotation. However, when the fan rotates in the opposite direction due to strong winds, etc., it cannot perform its function due to its structure, and the meandering control pulley remains tilted in one direction, which causes the belt position to shift and eventually This results in shedding.

In the case of a flat belt transmission system with low overall rigidity, when the drive pulley is stopped before the flat belt is applied, misalignment is taken in the opposite direction to the axial load applied from the flat belt during drive, thereby reducing the load during forward rotation. Adjustments are made so that the misalignment will be 0 when this occurs. However, according to the above configuration, the tilting angle of the pivot when stopped is set at an angle of -15° or more to the front side in the forward rotation direction and smaller than 0° (in other words, it is larger than 0° to the rear side in the forward rotation direction). By setting the tilt angle in the opposite direction to that during normal rotation during reverse rotation with no load applied, the meandering control pulley performs meandering control even during reverse rotation. Therefore, the flat belt will not fall off even during reverse rotation. On the other hand, during normal rotation, the misalignment is not zero but becomes positive toward the front in the normal rotation direction due to the load of the flat belt, so that meandering control can be performed as before in this case as well.

In the second invention, in the first invention,
When the drive pulley rotates in the normal direction, the tension of the flat belt causes the meandering control pulley to move from 0° forward in the normal rotation direction with respect to the direction of the shaft load when viewed along the pulley axis direction. It is also tilted at a large angle.

According to the above configuration, meandering control is possible even during reverse rotation, so there is no need to provide a component such as a one-way clutch to forcibly avoid reverse rotation, and the flat belt does not fall off during normal rotation or reverse rotation.

As described above, according to the present invention, it is possible to obtain a flat belt transmission system that has a simple structure and can control meandering during normal rotation and reverse rotation.

1 is a perspective view showing an overview of a belt transmission system according to an embodiment of the present invention. FIG. 6 is a front view showing the tilt angle of the pivot during normal rotation. FIG. 2B is an enlarged front view of a portion of FIG. 2A. FIG. 7 is a front view showing the tilt angle of the pivot during reverse rotation. FIG. 3A is a partially enlarged front view of FIG. 3A. FIG. 6 is a side view for explaining a change in the distance between the axes during reverse rotation. It is a front view for explaining the details of a meandering control device. 6 is an enlarged sectional view taken along the line VI-VI in FIG. 5. FIG. FIG. 3 is a schematic perspective view of the support rod and its surroundings when the meandering control pulley is in use. FIG. 6 is a view taken in the direction of arrow VIII in FIG. 5; 6 is a view taken in the direction of arrow IX in FIG. 5. FIG.

Embodiments of the present invention will be described below based on the drawings.

1 to 3 show a flat belt transmission system 1 according to an embodiment of the invention. In each figure, the forward rotation direction is shown by arrow F, and the reverse rotation direction is shown by arrow R.

Although not shown in detail, this flat belt transmission system 1 is used as a drive system for, for example, a cooling tower, a blower, etc., and is connected to a drive pulley 2 driven by an actuator such as an electric motor, and a rotating shaft of a fan or the like. It includes a driven pulley 3 and a flat belt 6 that is hung around the driven pulley 3. This flat belt transmission system 1 is not limited to blowers, but can also be used for air conditioners, compressors, and the like. In particular, it targets systems that have no or almost no rotational fluctuations, unlike belt transmission systems that are attached to the output shaft of an engine. The flat belt 6 has a structure in which, for example, a core wire is provided at the center in the thickness direction, and this core wire is held between a top rubber and a bottom rubber. However, the type of flat belt 6 is not particularly limited, nor is the material etc. particularly limited, and belts that tend to meander during running can also be used.

The flat belt transmission system 1 of this embodiment includes a meandering control device 4 that controls the meandering of the flat belt 6 by adjusting the inclination of the meandering control pulley 5 that comes into contact with the transmission surface of the flat belt 6. This meandering control device 4 includes a base portion 4a that is attached to a blower or the like, and a tension arm 4c that is swingably supported by an arm support shaft 4b at one end of the base portion 4a. A pulley shaft 7 that rotatably supports the control pulley 5 is provided.

Specifically, as shown in FIGS. 5 and 6, the meandering control device 4 supports a meandering control pulley 5 around which the flat belt 6 is wound, and the meandering control pulley 5 rotatably around a rotation axis J3. A pulley shaft 7 is provided.

The pulley shaft 7 includes a shaft member 11 that supports the meandering control pulley 5 by a bearing 12, a support rod 13, and a pin 17 forming a pivot shaft C.

The shaft member 11 has an insertion hole 11' that is elongated in plan view and penetrates in the axial direction, and the inner peripheral surface of the insertion hole 11' has flat and mutually parallel sliding surfaces 11a, 11a, Arcuate surfaces 11b, 11b connecting these sliding surfaces 11a, 11a on both sides are formed. Further, a support hole 11c is formed through approximately the center of each sliding surface 11a.

The support rod 13 includes a mounting portion 13a fastened to the tension arm 4c and a support portion 13b inserted into the insertion hole 11' of the shaft member 11. As shown in FIG. 5, the support portion 13b has mutually parallel and flat sliding surfaces 13c, 13c formed so as to face and slidably contact the sliding surfaces 11a, 11a of the shaft member 11. ing. Furthermore, arcuate surfaces 13d, 13d are formed on both sides of the sliding surfaces 11a, 11a of the support portion 13b. Further, the support portion 13b is formed with a through hole 13e that opens approximately at the center of the sliding surfaces 13c, 13c.

The pin 17 of the pulley shaft 7 is fitted into a through hole 13e formed in the support portion 13b of the support rod 13, and both ends of the pin 17 are fitted into support holes 11c formed in the shaft member 11. Therefore, the pin 17 is located near the center in the width direction of the meandering control pulley 5 and is perpendicular to the sliding surfaces 13c, 13c of the support rod 13.

A gap 15 is provided between the arcuate surfaces 11b, 11b of the shaft member 11 and the arcuate surfaces 13d, 13d of the support rod 13, which allow the shaft member 11 to swing together with the meandering control pulley 5 about the pin 17. 15 is formed. Therefore, the meandering control pulley 5 is supported so as to be rotatable around the rotation axis J3 and swingable around the pivot axis C perpendicular to the rotation axis J3.

As shown in FIGS. 2, 5, and 7, the meandering control device 4 moves the pin 17 forward in the normal rotation direction with respect to the direction of the shaft load (load applied to the shaft member 11 by the tension of the flat belt 6) P. , it is used by tilting it by an angle α. In other words, as shown in an enlarged view in FIG. 2B, the axial load P applied to the meandering control pulley 5 is applied between the center of the winding portion of the flat belt 6 that wraps around the meandering control pulley 5 and the axis of the pulley shaft 7. The angular difference from the pin 17 is α. The value of α is calculated when the pin 17 is directed forward in the normal rotation direction with reference to the direction of the axial load P applied to the meandering control pulley 5 with respect to the traveling direction of the flat belt 6 when the motor of the drive pulley 2 is driven. , is a positive value. During normal rotation, the value of α needs to be positive toward the front in the normal rotation direction in order to exhibit the meandering control function. When the value of α becomes negative in the direction opposite to the front side in the normal rotation direction, the flat belt 6 acts to fall off from the center of the meandering control pulley 5. For example, in FIG. 2B, α=8°, and meandering control is activated.

In contrast to FIG. 3B, in the state of FIG. 2B, the tension arm 4c has rotated to the left by about 21 degrees, and the direction of the pin 17 has rotated by that amount. Therefore, in FIG. 3B, α=-13°.

When α=-13°, when the flat belt 6 rotates normally in the F direction, the flat belt 6 falls off, but when it rotates reversely in the R direction, meandering control works and does not fall off.

That is, in the case of FIGS. 3A and 3B, the meandering control pulley 5 exerts its meandering control function even when the fan on the driven pulley 3 side rotates in the opposite direction due to an external force such as strong wind.

In this way, as shown in FIG. 2A, when the normal rotation direction F of the flat belt 6 is clockwise and the meandering control pulley 5 is counterclockwise, the meandering control function is exhibited; is clockwise and the meandering control pulley 5 is clockwise, the meandering control function is not exhibited.

As shown by the solid line in FIG. 8, when the flat belt 6 that has been hanging around the center of the meandering control pulley 5 in the width direction moves from the center of the meandering control pulley 5 to one side of the meandering control pulley 5 as shown by the chain double-dashed line, the axial load is reduced to a pin. From the position 17, the meander control pulley 5 shifts to one side and acts on the shaft member 11. As a result, a rotational moment about the pin 17 (around the pivot C) acts on the shaft member 11, and the shaft member 11 is rotationally displaced around the pin 17 together with the meandering control pulley 5.

That is, as shown in FIG. 7, when the direction of the axial load is parallel to the pin 17 (at P0), no rotation moment is generated around the pin 17. On the other hand, when the direction of the axial load is in the direction P which is inclined by an angle α with respect to the direction of the pin 17, a rotational moment is generated around the pin 17 due to the component force P1, and the shaft member 11 undergoes a rotational displacement. I will do it.

As the meandering control pulley 5 rotates around the tilted pin 17 due to the axial load P, the meandering control pulley 5 rotates so that the side on which the flat belt 6 is biased rotates in the normal rotation direction, as shown by the two-dot chain line in FIG. The flat belt 6 is obliquely crossed so as to be on the front side of F, and the flat belt 6 is shifted to one side as shown by the two-dot chain line in FIG. It is tilted in the direction of the axial load P so that the side from which it comes is lower and the opposite side is higher.

Therefore, the flat belt 6 is subjected to a returning force (a force for returning the offset) due to the meandering control pulley 5 being in an oblique state, and a returning force due to the inclination of the meandering control pulley 5. This prevents the flat belt 6 from shifting to one side. That is, the flat belt 6 runs at a position where the return force caused by the meandering control pulleys 5 intersecting and tilting is balanced with the biasing force acting on the flat belt 6 due to the characteristics of the fan 1 as a whole. become. In this way, the meandering control device 4 is configured to be able to regulate the traveling position of the flat belt 6 to a constant value.

The tension arm 4c also functions as an auto-tensioner by being biased with a predetermined tensile force by a tension spring 4d provided at the other end of the base portion 4a. The meandering control device 4 autonomously controls the running position of the flat belt 6, and tension is stably maintained by the tension spring 4d, so that the flat belt 6 can have a long life and is maintenance-free.

As a feature of this embodiment, the pin 17, which is the pivot of the flat belt transmission system 1, is connected to the pulley shaft 7 when the drive pulley 2 is not driven and the flat belt 6 is stopped, as shown in FIG. When viewed along the direction, the meandering control pulley 5 is inclined forward in the normal rotation direction at an angle β of −15° or more and smaller than 0° with respect to the direction of the axial load. In other words, while the angle α during forward rotation is positive toward the front in the forward rotation direction, the angle β is a negative value meaning the opposite direction from the front in the forward rotation direction (-15°≦β< 0°).

-Operation of flat belt transmission system-
For example, an example in which the flat belt transmission system 1 is used in a blower will be described.

In the stopped state where the electric motor etc. are not driven, as shown in FIGS. 3A, 3B and 4, the flat belt 6 is loosened compared to the normal rotation shown in FIGS. 2A and 2B, and the drive pulley 2 is For example, the rotation axis moves by an angle γ=approximately 3° with a distance L3=5 mm. As shown in FIG. 3, for example, the direction of the axial load is inclined with respect to the direction of the pin 17 by an angle β=−13°.

For example, when the distance between the shafts during forward rotation is L1 = 1295 mm, the distance between the shafts L2 during reverse rotation increases by approximately 5 mm (L3) to approximately 1300 mm. The angle β shown in FIG. 3 at this time is set to β=−13°, for example. This angle β is set to satisfy -15°≦β<0°.

The reason why the distance between the axes changes in this way is that when torque is generated on the drive pulley 2, the tension on the upper span where the meandering control pulley 5 is located does not change significantly, but the tension on the lower span is This is because the axial force applied to the drive pulley 2 increases due to the torque, and the angle γ of the drive pulley changes.

Normally, unstable fixation of the motor shaft should be avoided so that the inclination angle changes due to changes in belt tension, but depending on the mounting position, a large amount of steel may be required to support the motor shaft, so if the strength of the motor support part can be ensured. Support such that the motor itself is moved by belt tension is also permissible.

In this embodiment, even when the flat belt 6 is reversed, it is possible to avoid falling off by using a flexible structure in which the motor shaft changes its inclination angle according to changes in belt tension.

As mentioned above, in the case of FIG. 2B compared to FIG. 3B, the inter-axial distance between the driving pulley 2 and the driven pulley 3 becomes γ = 0°, which is shorter by L3 = 5 mm, but the change in length On the other hand, the tension arm 4c rotates to the left with respect to the arm support shaft 4b, and the meandering control pulley 5 moves downward, thereby applying a predetermined tension to the flat belt 6.

The meandering control pulley 5 exerts its meandering control function even when the fan on the driven side rotates in the opposite direction due to an external force such as strong wind when the fan is stopped. That is, at the time of reverse rotation, the running direction of the flat belt 6 is reversed to that shown in FIG. As in the case where α is positive in the forward rotation direction, when the flat belt 6 tries to meander, the pulley shaft 7 tilts around the pin 17 perpendicular to the pulley shaft 7 and meanders in a direction that reverses the meandering direction. Demonstrates a meandering prevention function that prevents. Then, the flat belt 6 is subjected to a return force (force to restore the offset) due to the meandering control pulley 5 being in an oblique state, and a return force due to the inclination of the meandering control pulley 5, which causes the reverse rotation. This prevents the flat belt 6 from shifting even when the belt is in use.

On the other hand, when the drive motor is driven, a tensile force is applied to the flat belt 6 as shown by the solid line in FIG. get up. Furthermore, the flat belt 6 extends approximately 5.5 mm in total due to tension. Due to the fluctuation of each member due to this force relationship, as shown in FIG. 2, the angle α becomes positive (for example, 11°) toward the front in the normal rotation direction. As shown in FIG. 3, the driving pulley 2 rotates in the normal rotation direction, and the driven pulley 3 rotates. This power causes the fan to rotate. Since the meandering control device 4 also has an auto-tensioner function, the flat belt 6 is maintained at an appropriate tension by the tension of the tension spring 4d.

The meandering control pulley 5 has a meandering control pulley 5 that, when the flat belt 6 meanders during normal rotation, the pulley shaft 7 tilts around a pin perpendicular to the pulley shaft 7 in a direction that restores the meandering, thereby preventing the meandering. Demonstrates prevention function. Then, the flat belt 6 is subjected to a returning force (force to restore the offset) due to the meandering control pulley 5 being in an oblique state, and a returning force due to the tilting of the meandering control pulley 5. This prevents the belt 6 from shifting to one side.

Therefore, according to the flat belt drive device 1 according to the present embodiment, the misalignment angle β at the time of stopping is intentionally set in the opposite direction to that at the time of forward rotation, and during the forward rotation, the angle α becomes positive toward the front side in the forward rotation direction. By doing so, it is possible to secure the meandering prevention function during forward rotation and reliably prevent the flat belt 6 from falling off during reverse rotation with a simple structure. Therefore, a flat belt transmission system that can control meandering during forward and reverse rotation with a simple structure can be obtained. Moreover, the weaknesses peculiar to the meandering control device 4 can be eliminated.

(Other embodiments)
The present invention may have the following configuration for the above embodiment.

That is, the above embodiment is suitable for a flat belt transmission system 1 such as a blower in which there is no rotational fluctuation, but it can also be applied to a case where there is some rotational fluctuation.

Note that the above embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its applications, or uses.

1 Flat belt transmission system
2 Drive pulley
3 Driven pulley
4 Meandering control device
4a Base part
4b Arm support shaft
4c tension arm
4d tension spring
5 Meandering control pulley
6 flat belt
7 Pulley shaft
10 Falling prevention member
11 Shaft member
11' insertion hole
11a Sliding surface
11a, 11a sliding surface
11b, 11b arc surface
11c Support hole
12 Bearing
13 Support rod
13a Mounting part
13b Support part
13c, 13c sliding surface
13d, 13d Arc surface
13e Through hole
15,15 Gap
17 pin (axis C)

Claims (2)

drive pulley;
a driven pulley;
a flat belt that is hung around the drive pulley and the driven pulley;
a meandering control pulley that comes into contact with the flat belt and controls meandering of the flat belt;
a tension arm that is swingably supported on an arm support shaft;
a pulley shaft provided on the tension arm and rotatably supporting the meandering control pulley and swingably supporting the meandering control pulley around a pivot;
When the drive pulley reverses , the end of the pivot near the flat belt rotates in the normal rotation direction of the meandering control pulley with respect to the direction of the shaft load, when viewed along the pulley axis direction. Tilt forward at an angle of -15° or more and less than 0°,
When the drive pulley rotates in the normal direction, the tension of the flat belt causes the pivot shaft to have an end portion close to the flat belt, which is located at the end of the pivot shaft in the direction of the shaft load, when viewed along the pulley axis direction. The meandering control pulley is tilted forward in the normal rotation direction at an angle greater than 0°.
A flat belt transmission system characterized by: drive pulley;
a driven pulley;
a flat belt that is hung around the drive pulley and the driven pulley;
a meandering control pulley that comes into contact with the flat belt and controls meandering of the flat belt;
a tension arm that is swingably supported on an arm support shaft;
A method of using a flat belt transmission system including a pulley shaft provided on the tension arm and rotatably supporting the meandering control pulley and swingably supporting the meandering control pulley around a pivot axis, the method comprising:
When the drive pulley reverses , when the pivot is viewed along the direction of the pulley axis, the end of the pivot near the flat belt rotates in the normal rotation direction of the meandering control pulley with respect to the direction of the shaft load. Adjust it so that it tilts forward at an angle of -15° or more and less than 0°, and
During forward rotation, when the pivot shaft is viewed along the direction of the pulley axis, the end of the pivot shaft closer to the flat belt is 0° forward in the forward rotation direction of the meandering control pulley with respect to the direction of the shaft load. A method of using a flat belt transmission system characterized by adjusting it to tilt at an angle greater than .

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