JP3970494B2 - Hollow shaft parallel gear reducer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hollow shaft type parallel gear reduction device in which a hollow shaft is used as an output member and an input axis is parallel to a final output axis, and particularly, a mechanical torque limiter is rationally attached. The present invention relates to a parallel gear reduction device that can perform the same.
[0002]
[Prior art]
Conventionally, when designing a hollow shaft type parallel gear reduction device of this type, generally a parallel gear device such as a spur gear set or a helical gear set is used.
[0003]
With this type of parallel gear device, the input shaft and the output shaft can be easily paralleled at a position shifted (not coaxial), and the distance between the input and output shafts can be set to a predetermined amount. This is because the output member can be easily formed into a hollow shaft if secured.
[0004]
[Problems to be solved by the invention]
However, the conventional parallel gear device as described above has several problems.
[0005]
First, with this type of parallel gear device alone, a large reduction ratio cannot be secured in a compact state.
[0006]
Secondly, in connection with the fact that a large reduction ratio cannot be ensured, when taking a safety measure against this excessive load on this type of parallel gear device, the magnitude of the load is generally determined by the current value of the motor that is the drive source. As a result, when the load is estimated to be above the specified level, the motor power must be turned off.
[0007]
In this type of parallel gear device, the transmission torque to be handled is small (because the reduction ratio is not so large), and therefore it is difficult in terms of accuracy to construct a limiter function by detecting the torque mechanically, and This type of parallel gear device has no member that “receives only torque in a fixed state”, and therefore, mechanical torque detection is difficult in practice.
[0008]
However, the method for estimating the magnitude of the load with the motor current value is as follows: (1) When the motor load factor is low, the current varies greatly. (2) Following the voltage fluctuation, the current also changes regardless of the load. (3) It is vulnerable to noise, (4) Current is difficult to follow the load, (5) Failures such as disconnection and short-circuiting are likely to occur, and reliable and highly accurate safety measures can be taken. There was no problem.
[0009]
In other words, in order to solve this limiter problem, first, in order to achieve a high reduction ratio, a spur gear set, a helical gear set, etc. are combined in multiple stages, thereby increasing the transmission torque handled by the parallel gear device and increasing it. Only when an external load (torque) is detected, there is no choice but to take safety measures by estimating the overload from the current value of the motor that is the drive source.
[0010]
However, if the spur gear set or the like is combined in multiple stages such as three stages, four stages, etc., the entire apparatus is greatly increased in size, and the first problem is not solved at all. There was a certain limit to increasing In addition, since the handleable transmission torque increases, a large external load can be easily detected by the motor current value, but it is still not reliable with respect to noise and disconnection. Furthermore, safety measures may be required to protect the counterpart machine even for a relatively small external load. In this case, the (small) external load can be accurately estimated with the motor current value. It was difficult.
[0011]
Therefore, in spite of diversifying needs in the current market, there is no hollow shaft type parallel gear reduction device with “compact, high reduction ratio, high accuracy limiter function”, and In fact, no proposal has been made.
[0012]
In consideration of the above circumstances, the present invention can provide a highly accurate safety measure against changes in the magnitude of the load, and a hollow shaft type orthogonal gear reduction device capable of realizing a hollow shaft in two stages. The purpose is to provide.
[0013]
[Means for Solving the Problems]
According to the first aspect of the present invention, in the hollow shaft type parallel gear reduction device in which a hollow shaft is used as the output member and the input axis is parallel to the final output axis, the internal gear is used as the first gear. and an outer gear that is inscribed in the internal gear, have a output unit at the other end and having an input section at one end of the input axis and rotatable with said internal gear relative to the fixed housing A held internal meshing planetary gear device is provided, and as a second-stage gear device, the output of the internal meshing planetary gear device is converted into an output rotation around an axis parallel to the input axis at a position shifted from the input axis. A mechanical torque limiter provided with a gear device and operating when a load of the parallel gear reduction device acts more than a specified value, a dog bar protruding from the outer periphery of the internal gear, and the dog Against the stick A coil spring arranged, a cam provided at the tip of the dog bar, and when the dog bar collapses overcoming the urging force of the coil spring due to a load exceeding the specified value, A mechanical torque limiter provided with a limit switch incorporated so as to operate is attached to the first-stage inscribed mesh planetary gear device, thereby solving the above-mentioned problem.
[0014]
In this gear reduction device, the torque of the hollow shaft is transmitted from the parallel gear device to a mechanical torque limiter attached to the intermeshing planetary gear device, and when the torque limiter detects a torque exceeding a specified value, for example, the drive motor The power transmission is cut off to protect the machine.
[0015]
The intermeshing planetary gear unit has a compact configuration and a high reduction ratio and handles a large amount of torque, and there are internal gears that receive only torque in an originally fixed state, as will be described later. By making this slightly rotatable, a high-performance limiter mechanism can be constructed by accurately detecting torque mechanically. In addition, since it is a mechanical type, there is no fear of failure due to disconnection or the like or malfunction due to noise, and it is extremely reliable. Moreover, since the actual torque can be directly reflected, the accuracy of the limiter operation is high even with a low external load. In addition, as will be described later, the mechanical torque limiter can realize a simple and accurate operation by using a dog bar protruding from an internal gear and utilizing the tilt of the dog bar (described later).
[0016]
Moreover, since the parallel gear device is provided in the “second stage”, it can be easily made into a large diameter hollow shaft, and it is greatly compact by combining with the first-stage internally meshing planetary gear device. And cost reduction.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0018]
1 and 2 are external views showing a state in which a motor M is attached to the parallel gear reduction device 100 of the embodiment, and FIG. 3 is a side sectional view showing an internal structure thereof.
[0019]
This parallel gear reduction device 100 corresponds to an intermeshing planetary gear reduction device (“internal meshing planetary gear device” in the claims) as a first-stage reduction gear (first-stage gearing), as shown in the figure. And a parallel gear reducer (hereinafter referred to as “parallel gear device” in the claims) as a first-stage reduction device (second-stage gear device). , Hereinafter referred to as “helical gear set”) 2 are integrally connected via a connecting base 3.
[0020]
A motor M is connected to the input portion of the swing reduction gear 1, and the input axis LN of the motor M and the axis (output axis) LS of the hollow shaft 24 of the helical gear set 2 are parallel to each other at a shifted position. A mechanical torque limiter 5 is attached to the oscillating speed reducer 1 as a safety device.
[0021]
As shown in FIG. 3, the oscillating speed reducer 1 has a known basic structure, and an eccentric body shaft 12 serving as an input portion is provided on one end side on the input axis LN, and an output is provided on the other end side. The motor shaft 11 is connected to the center hole of the eccentric body shaft 12. An external gear 14 is fitted to the eccentric body shaft 12 via a bearing 13, and the external gear 14 is internally meshed with an internal gear 15 having internal teeth including pins 16, and the internal gear 15 is The fixed housing 40 is rotatably held. A plurality of inner roller holes are provided in the external gear 14, and an inner pin 18 and an inner roller 17 are fitted into each inner roller hole. The inner pin 18 penetrating the external gear 14 is connected to a fixed housing 40 with a bearing 41, 42 is fixed to the flange portion of the low-speed shaft 19 supported rotatably.
[0022]
In this oscillating speed reducer 1, when the motor shaft 11 makes one revolution, the external gear 14 tries to oscillate around the input axis LN by the rotation of the eccentric body shaft 12. Since rotation is constrained, the external gear 14 almost only swings while being inscribed in the internal gear 15, and the external gear 14 rotates the internal gear every rotation of the motor shaft 11. The number of teeth rotates with respect to 15. This rotation of the external gear 14 is absorbed by the gap between the inner roller hole and the inner pin 18 (inner roller 17), and only the rotation component is transmitted to the low-speed shaft 19 via the inner pin 18. Thus, the rotation of the motor M is decelerated and output.
[0023]
The helical gear set 2 includes an input shaft 21 that is rotatably arranged by two bearings 22 so as to penetrate one side of the box 28, and an input shaft 21 that penetrates both sides of the box 28. A hollow shaft 24 (as an output shaft) rotatably arranged by bearings 25 and 26 in parallel relation, a helical pinion 23 provided on the input shaft 21, and a hollow shaft 24 so as to mesh with the helical pinion 23. And a helical gear 27 provided on the outer periphery.
[0024]
The input shaft 21 of the helical gear set 2 is connected to the low-speed shaft 19 of the oscillating speed reducer 1 by a pin joint 31 inside the connection base 3. That is, the flange 31a attached to the low speed shaft 19 of the swing reduction gear 1 and the flange 31b attached to the input shaft 21 of the helical gear set 2 are coupled by the pin 32, so that the low speed shaft 19 and the input shaft 21 are integrated. And rotate.
[0025]
Thereby, the rotation of the low speed shaft 19 of the swing reduction gear 1 is further decelerated and transmitted to the hollow shaft 24. In this case, the helical gear set 2 is arranged in the “second stage” and its output member is made into a hollow shaft, so that it can be a large-diameter hollow shaft and can be directly connected directly to the drive shaft of the load side device. can do.
[0026]
Further, as shown in FIGS. 3, 4, and 5, the mechanical torque limiter 5 includes a dog bar 51 projecting from the outer periphery of the internal gear 15 and a reaction force generated when the internal gear 15 transmits power. When rotating, the coil spring 53 disposed in the direction in which the dog bar 51 falls, the spring receiver 54 provided at the tip of the coil spring 53 to transmit the force of the coil spring 53 to the dog bar 51, and the protrusion of the spring receiver 54 A spring case 52 that defines a limit, an adjustment screw 55 that adjusts the set load of the coil spring 53, a cam 57 provided at the tip of the dog bar 51, and an actuator 58a abutting against the cam 57. The dog bar 51 is held in the neutral position by the force of the coil spring 53 when the load is small. It has been.
[0027]
In the torque limiter 5, the parallel gear reduction device 100 has only one rotation direction, and therefore the coil spring 53 is disposed only on one side and a stopper 56 is provided on the opposite side. However, when the rotation direction is on both sides, the stopper 56 is removed and a coil spring is added on the opposite side.
[0028]
Next, the operation will be described focusing on the torque limiter 5 portion.
[0029]
In this gear reduction device 100, the (reaction force) torque of the hollow shaft 24 is transmitted to the low-speed shaft 19 of the oscillating reduction gear 1 through the helical gear 27 → helical pinion 23 → input shaft 21 → pin joint 31 in this order. Since the torque of the low-speed shaft 19 is always transmitted to the internal gear 15 via the external gear 14, when a load is applied to the low-speed shaft 19, the internal gear 15 causes the low-speed shaft due to the torque reaction force of the external gear 14. 19, the dog bar 51 pushes the coil spring 53. When a load greater than that previously set by the set load of the coil spring 53 is applied, the cam 57 at the upper end of the dog bar 51 operates the limit switch 58, thereby turning off the motor M. Therefore, the drive is stopped, and further increase in load is prevented, and the machine is protected.
[0030]
The torque for operating the limit switch 58 is very large because it is taken out from the internal gear 15 of the oscillating speed reducer 1 and completely corresponds to the load applied to the hollow shaft 24 of the helical gear set 2 and the mechanical type. Therefore, a highly accurate limiter function can be realized. When the motor M stops, the dog bar 51 returns to the neutral position by the force of the coil spring 53.
[0031]
In the case of this speed reduction device 100, since the mechanical torque limiter 5 is attached to the swing reduction gear 1, unlike the case where the torque is estimated by the current value of the motor M, it is possible to deal with an excessive load with high accuracy. .
[0032]
In addition, since the oscillating speed reducer 1 and the helical gear set 2 are connected using the connecting table 3, various combinations of the oscillating speed reducer 1 and the helical gear set 2 can be obtained. It is possible to respond flexibly to the requirements in the specifications such as size, reduction ratio, or transmission torque.
[0033]
In the above embodiment, the gear ratio of the helical gear set 2 is set for reduction, but it is not always necessary to set the gear ratio as a reduction gear.
[0034]
Moreover, although the helical gear set 2 was employ | adopted as a parallel gear apparatus in the said embodiment, you may make it employ | adopt other parallel gear apparatuses, such as a parallel gear set.
[0035]
【The invention's effect】
As described above, according to the present invention, in a parallel shaft type gear reduction device using a large-diameter hollow shaft as a final output member, it is possible to reliably detect the magnitude of a load and protect the machine. There is an effect.
[Brief description of the drawings]
1 is a side view showing the appearance of an embodiment of the present invention. FIG. 2 is a view taken along the line II-II in FIG. 1. FIG. 3 is a side sectional view of the embodiment of the present invention. Different)
4 is a cross-sectional view taken along arrow IV in FIG. 3. FIG. 5 is a cross-sectional view taken along arrow V in FIG.
1 ... Oscillating speed reducer (internal mesh planetary gear)
2. Helical gear set (parallel gear device)
5 ... Mechanical torque limiter 12 ... Eccentric body shaft (input unit)
19 ... Low speed shaft (output unit)
24 ... Hollow shaft

Claims (1)

In the hollow shaft type parallel gear reduction device in which a hollow shaft is used as the output member and the input axis is parallel to the final output axis.
As a first stage gear, an outer gear that is inscribed in the internal gear and internal gear, have a output unit at the other end and having an input section at one end of the input axis, and wherein the teeth An intermeshing planetary gear device in which the gear is rotatably held with respect to the fixed housing is provided;
A parallel gear device that converts the output of the intermeshing planetary gear device into an output rotation around an axis parallel to the input axis is provided as a second gear device, and
A mechanical torque limiter that operates when a load of the parallel gear reduction device is applied more than specified, a dog bar projecting on the outer periphery of the internal gear, and a coil spring disposed with respect to the dog bar And a cam provided at the tip of the dog bar, and when the load exceeding the specified value acts and the dog bar overcomes the biasing force of the coil spring and falls down, the cam is operated via the cam. A hollow shaft type parallel gear reduction device , wherein a mechanical torque limiter including an incorporated limit switch is attached to the first-stage inscribed mesh planetary gear device.

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