JPH1181874A - Electric reduction gear for driving shield cutter and electric reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the reduction of torque transmitted to a cutter face by forming the relation of a slide speed and a friction coefficient between clutch plates in such a way that the slide speed is above a fixed slide speed and the friction coefficient is constant or rises slightly. SOLUTION: An electric reduction gear for driving shield cutter X decelerates an output of an electric motor 1 by a planetary reduction gear mechanism 2 to rotate and drive a cutter face 52 from an output shaft 4. The planetary reduction gear mechanism 2 decelerates at three steps by sun gears 13, 18, 23 and a plurality of planetary gears at outer periphery thereof 14, 19, 24. The electric reduction gear X itself is made compact by assembling a wet hydraulic clutch plate 3 in the planetary reduction gear mechanism 2 integrally and arranging it in a case main body 9. A friction plate 31 is made of a material having a high friction coefficient or static friction coefficient close to it. When slide occurs while a steel plate 30 and the friction plate 31 are in pressure-contact, it is possible to drive the cutter face 52 without reducing transmission torque even if a clutch plate 32 begins to slide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric reduction gear for reducing the rotation of a prime mover and transmitting the rotation to an output shaft, and more particularly to an electric reduction gear for driving a shield cutter suitable for a shield type excavator for tunnel excavation. .

[0002]

2. Description of the Related Art Conventionally, an excavator used for tunnel excavation is provided with a cylindrical shield having a cutter face in which excavating cutters are arrayed on a front surface, and continuously rotating the cutter face while advancing the cylindrical seal. There is a shield type excavator that excavates in a regular manner. In order to drive the cutter face of the shield type excavator, the planetary speed reducer, the clutch, and the electric motor are driven with an appropriate rotational output by using an electric speed reducer connected in series in this order. As described above, a powder clutch, a wet clutch, an electromagnetic clutch, and the like are conventionally used as clutches of the electric reduction gear for driving the shield.

[0003]

However, in an apparatus using a powder clutch for an electric reduction gear for driving a shield, when an overload is applied to a cutter face, slippage occurs in the clutch, and the slippage speed exceeds a certain level. At speed, the coefficient of friction between the clutches decreases significantly. Therefore,
If an overload is applied during tunnel excavation, the torque transmitted to the cutter face also decreases due to a decrease in the friction coefficient between the clutches, and the cutter face cannot be driven.

[0004] In the case of using a wet clutch, the output of the electric motor is smoothly transmitted to the planetary reduction gear.
It is simply turned on / off, and when an overload acts on the cutter face, the function of the torque limiter has been achieved by reducing the rise in current due to thermal of the electric motor.
Therefore, the function of the torque limiter is not provided by the wet clutch itself.

[0005] In the case of using an electromagnetic clutch, it is difficult to use it in an atmosphere where explosion proof is required. Further, when the electric reduction gear is connected in series in the order of the planetary reduction gear, the clutch and the electric motor, the electric reduction gear itself becomes larger.

The present invention has been made to solve this problem, and it is an object of the present invention to reduce the size of an electric reduction gear and to drive the cutter face with an appropriate output when an overload is applied to the cutter face.

[0007]

In order to solve the above-mentioned problems, a shielded cutter driving speed reducer according to the present invention is provided with a planetary speed reduction mechanism for reducing the rotation of a prime mover and transmitting the rotation to the cutter face; A wet hydraulic clutch having a number of clutch plates which are connected to a mechanism and which can be pressed by a hydraulically slidable piston. The wet hydraulic clutch has a sliding speed and a coefficient of friction between the pressed clutch plates. The relationship is such that the friction coefficient is constant or slightly increased at a certain sliding speed or higher. As a result, even if the sliding speed between the clutch plates of the wet hydraulic clutch becomes high, the friction coefficient does not decrease, so even if each clutch plate starts sliding due to overload,
The transmission torque transmitted to the cutter face of the shielded excavator is not reduced.

Further, a wet hydraulic clutch is integrally incorporated in the planetary speed reduction mechanism. This eliminates the necessity of serially connecting the reduction gear, the clutch, and the motor as in the related art, and can reduce the size of the electric reduction gear.

Further, in the electric reduction gear of the present invention, a planetary reduction mechanism for reducing the speed of rotation of the prime mover and outputting the same is integrated with the planetary reduction mechanism, connected to the prime mover, and slid by hydraulic pressure. A wet hydraulic clutch having a number of clutch plates that can be freely pressed by a piston, wherein the wet hydraulic clutch determines the relationship between the sliding speed and the friction coefficient between the pressed clutch plates by determining the friction coefficient at a certain sliding speed or higher. Is configured to be constant or slightly increased. As a result, even if the sliding speed between the clutch plates of the wet hydraulic clutch becomes high, the friction coefficient does not decrease, so even if each clutch plate starts sliding due to overload,
The transmission torque output from the planetary reduction mechanism is not reduced.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an electric reduction gear for driving a shield cutter according to an embodiment of the present invention.

In FIG. 1, a plurality of shielded cutter driving electric reducers X (hereinafter, simply referred to as “electric reducers X”) are provided in a shield type excavator Y for tunnel excavation. Drive. The shield type excavator Y has a cylindrical shield 50 and a cylindrical seal 5.
The cutter 0 is provided with a cutter face 52 in which a plurality of excavating cutters 51 are arranged on the front surface, and is advanced by a hydraulic jack (not shown). The electric reduction gear X includes an electric motor 1 (motor), a three-stage planetary reduction mechanism 2, and a wet hydraulic clutch 3 integrated with the planetary reduction mechanism 2. The output of the electric motor 1 is a planetary reduction mechanism. 2, the cutter face 52 is rotationally driven by a ring gear 54 (a ring having an internal gear) that meshes with a pinion 53 at the tip of the output shaft 4 extending into the shield 50.

Next, a specific configuration of the electric reduction gear X will be described with reference to FIGS. 1 and 2,
The electric reduction gear X has a case main body 9 formed by connecting four cylindrical cases 5 to 8 by bolts, and the electric motor 1 is fixed to a plate 10 closing one end of the case main body 9. The rotating shaft 11 of the electric motor 1 penetrates the plate 10 rotatably and protrudes into the case body 9, and is connected to the output shaft 4 via the planetary reduction mechanism 2. Output shaft 4
Is rotatably supported on each of the cases 7 and 8 of the case body 9 via two bearings, and the cutter face of the shielded excavator Y shown in FIG. 52 is connected to the ring gear 54.

The planetary reduction mechanism 2 has three stages of the electric motor 1
A first sun gear 13 formed on a transmission shaft 12 connected to a rotation shaft 11, and a plurality of first planets meshing with the outer periphery of the first sun gear 13. And a gear 14. Each first planetary gear 14
Is meshed with a ring gear 15 (a ring having an internal gear) rotatable between the case body 9 and the rotating shaft 11. Each first planetary gear 14 is rotatably supported by a first carrier 17 fixed to a transmission shaft 16 connected to the transmission shaft 12. A second sun gear 18 is fixed to the transmission shaft 16, and a plurality of second planetary gears 19 mesh with the outer periphery of the second sun gear 18. Each second planetary gear 19 meshes with an internal gear 20 formed on the inner periphery of the case 6 of the case body 9, and a second carrier 22 fixed to a transmission shaft 21 between the output shaft 4 and the transmission shaft 16. Is rotatably supported. A third sun gear 23 is provided on the transmission shaft 21.
Are fixed, and a plurality of third planetary gears 24 mesh with the outer periphery of the third sun gear 23. Each third planetary gear 2
A third carrier 26 meshes with an internal gear 25 on the inner periphery of the case 7 of the case body 9, and is formed on the output shaft 4.
Is rotatably supported. Note that the planetary reduction mechanism 2
The speed is not limited to three-stage deceleration, but may be one-stage, two-stage, four-stage or more, depending on the deceleration condition. Thereby, an appropriate rotation output (power) to the cutter face 52 of the seal type excavator Y can be transmitted.

The wet hydraulic clutch 3 includes a thin annular steel plate 30.
Plate 3 in which a friction material is bonded to a core material of a thin annular steel plate
1 and a plurality of clutch plates 32 and a cylindrical piston 33 slid by hydraulic pressure.
It is integrated into the planetary reduction mechanism 2. As shown in FIG. 3, the steel plates 30 and the friction plates 31 of the clutch plate 32 are located between the case 5 of the case body 9 and the ring gear 15, and are alternately arranged in the axial direction of the input shaft 11. .
Each steel plate 30 is fixed to the inner periphery of the case 5 and
The friction plates 31 are fixed to the outer periphery of the ring gear 15 and protrude toward the case 5 so that the steel plates 30 and the friction plates 31 can be pressed against each other with a predetermined gap therebetween. . The piston 33 is arranged on the electric motor 1 side of the clutch plate 32 and is slidable through a stepped hole 34 on the inner periphery of the case 5 with a seal material 35 (O-ring) interposed therebetween.
The piston 33 defines a pressure oil chamber a between the stepped portion 34a of the stepped hole 34 and is slid toward the clutch plate 32 by the hydraulic pressure supplied to the pressure oil chamber a. The pressure oil chamber a is connected to a hydraulic circuit (not shown) by an introduction hole formed in the case 5. As a result, the wet hydraulic clutch 3
When hydraulic pressure is supplied from the hydraulic circuit to the hydraulic oil chamber a, the piston 3
3 slides toward the clutch plate 32, and presses each steel plate 30 and the friction plate 31 with a pressing force corresponding to the oil pressure in the pressure oil chamber a.

The friction material of the friction plate 31 is selected from the viewpoint of obtaining a high dynamic friction coefficient and a static friction coefficient close to the friction coefficient. For example, a filler is added to a raw paper made of cellulose fiber or the like. A material which is rich in elasticity, has good absorption of lubricating oil for cooling and the like sealed in the case body 9, and has excellent friction characteristics is used. Thus, when the friction material of the friction plate 31 is selected, each steel plate 30 and the friction plate 31
When the slippage occurs in a state where the sliding speed is in a state of being pressed, as shown in FIG. 4, the slipping speed (m / sec) and the friction coefficient (μ) generally indicate the sliding speed (curve A, B) as shown in FIG. m /
sec), the friction coefficient (μ) decreases as the speed increases, but the sliding speed (m / sec)
After c) reaches a constant speed, the friction coefficient (μ) increases at a constant speed or at a small rate as the speed increases. Thereby, even if an overload acts on the shield type excavator Y and the clutch plate 32 of the wet hydraulic clutch 3 starts sliding,
The cutter face 52 of the shielded excavator Y can be driven without reducing the transmission torque regardless of the increase in the sliding speed (m / sec). In addition, as the friction plate 31,
An appropriate amount of tin powder, graphite powder, iron powder, etc., mainly composed of copper powder, may be added, and pressed into a plate and sintered to a metal plate may be used. In short, a high dynamic friction coefficient and similar Any material may be used as long as it has a static friction coefficient and can obtain a relationship between a sliding speed (m / sec) and a friction coefficient (μ) as shown by a curve C in FIG.

Next, an electric reduction gear X for driving the shield cutter
1 will be described with reference to FIG. When the electric motor 1 is driven to rotationally drive the cutter face 52 of the shield type excavator Y, the rotation output is transmitted from the rotation shaft 11 to the planetary reduction mechanism 2. At this time, the wet hydraulic clutch 3
The rotation of the ring gear 15 is stopped by pressing each steel plate 30 and the friction plate 31 with a pressing force corresponding to the oil pressure by the piston 33. The output transmitted from the rotation shaft 11 to the planetary reduction mechanism 2 is the sun gears 13, 18,
23, and the speed is reduced to a predetermined number of revolutions (output) via each of the planetary gears 14, 19, and 24.
3 to the ring gear 53. When the output of the electric motor 1 is transmitted to the ring gear 53, the cutter face 52 is rotated by a predetermined rotation output (power), and the shield 50 is advanced by the hydraulic jack, so that the cutter 51 excavates the tunnel. .

If a load (overload) larger than the output transmitted from the output shaft 4 acts on the cutter face 52 during tunnel excavation by the shield type excavator Y, the rotating shaft 11,
Each shaft 3, 17, 21 of the planetary reduction mechanism 2 excluding the transmission shaft 12
Is locked. In this state, the rotating shaft 1 of the electric motor 1
As the 1 continues to rotate, each first planetary gear 14 rotates around the shaft without transmitting along the inner circumference of the ring gear 15 and transmits the output to the ring gear 15. When the output of the electric motor 1 is equal to or greater than the pressing force of the piston 33,
The ring gear 15 rotates relative to each first planetary gear 14 due to slippage between each steel plate 30 and the friction plate 31, and this rotation causes each shaft 16, 2 via the first planetary gear 14.
The cutter face 53 of the shield type excavator Y is rotationally driven by rotating in the order of 1, 4. At this time, even if the sliding speed (m / sec) between each steel plate 30 and the friction plate 31 of the wet hydraulic clutch 3 becomes high, as shown in FIG.
Since the friction coefficient (μ) does not decrease, even if each steel plate 30 of the wet hydraulic clutch 3 and the friction plate 31 start sliding due to overload, the transmission torque transmitted to the cutter face 52 of the shield type excavator Y is reduced. The cutter face 53 can be driven and tunnel excavation can be performed without reduction.

Further, in the shielded cutter driving electric reduction gear X, the wet hydraulic clutch is integrally incorporated into the planetary reduction mechanism 2 and is disposed in the case body 9, so that the reduction gear, the clutch and the motor are conventionally used. The electric reduction gear X itself can be made more compact and smaller than when serially connected in series. Further, since the wet-type hydraulic clutch 3 is used and the wet-type hydraulic clutch 3 is integrated with the planetary reduction mechanism 2 and disposed in the case main body 9, the excavated soil, water, and the like affect the excavation at the time of tunnel excavation. It is safe and can meet explosion-proof requirements even in an atmosphere.

Although the shielded cutter driving electric reducer X of the present invention has been described as being applied to a shielded excavator Y, the invention is not limited to this, and it is applicable to a device that drives any industrial machine. Is also good.

[0020]

The electric reduction gear for driving the shield cutter according to the present invention has a planetary reduction mechanism for reducing the rotation of the prime mover and transmitting the rotation to the shield, and a friction coefficient constant or slightly higher than a certain sliding speed between the clutch plates. Since it is composed of a wet hydraulic clutch that is raised, even if the sliding speed between the clutch plates of the wet hydraulic clutch increases, the friction coefficient does not decrease, so the clutch plate starts sliding due to overload. In addition, the tunnel excavation can be performed by driving the cutter face without reducing the transmission torque transmitted to the cutter face of the shielded excavator.

Since the wet-type hydraulic clutch is integrated into the planetary reduction mechanism, the electric reduction gear is compared with the conventional case where the reduction gear, the clutch and the motor are connected in series. It can be made smaller. In particular, if a wet hydraulic clutch is used and the wet hydraulic clutch is integrally incorporated into the planetary reduction mechanism, when the tunnel is excavated by the shield of the shield-type excavator, the wet-type hydraulic clutch may be used in an atmosphere affected by excavated earth and sand, water, and the like. It is safe to use and can meet explosion-proof requirements.

The electric reduction gear of the present invention is integrated with a planetary reduction mechanism that reduces the speed of rotation of the prime mover and outputs the same, and has a friction coefficient that is higher than a certain sliding speed between the clutch plates. Since it is composed of a wet hydraulic clutch that is set to be constant or slightly raised, even if the sliding speed between the clutch plates of the wet hydraulic clutch becomes high, the friction coefficient does not decrease. Does not reduce the transmission torque output from the planetary reduction mechanism even if the sliding starts, it is possible to drive any connected industrial machine. In addition, if the wet hydraulic clutch is integrated into the planetary reduction mechanism, the size of the electric reduction gear itself can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of an electric reduction gear for driving a shield cutter and a shield excavator.

FIG. 2 is a cross-sectional view showing a structure of an electric reduction gear for driving a shield cutter.

FIG. 3 is an enlarged view showing a structure of the wet hydraulic clutch shown in FIG. 2;

FIG. 4 is a graph showing a relationship between a sliding speed between each clutch plate and a friction coefficient in a wet hydraulic clutch.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric motor (motor) 2 Planetary reduction gear 3 Wet hydraulic clutch 32 Clutch plate 33 Piston 50 Shield 51 Cutter 52 Cutter face X Shield cutter driving electric reduction gear Y Shield type excavator

Claims (3)

[Claims] 1. A shield type excavator having a cutter face on which cutters for tunnel excavation are arranged, and a shield for rotatably disposing the cutter face, and rotationally driving the cutter face for tunnel excavation. In a shield cutter driving electric reduction gear, a planetary reduction mechanism that reduces the rotation of a prime mover and transmits the rotation to the cutter face; and a large number of sheets that are connected to the prime mover and the planetary reduction mechanism and that can be freely pressed by a hydraulically slidable piston. A wet-type hydraulic clutch having a clutch plate, wherein the wet-type hydraulic clutch increases or decreases the relationship between the sliding speed and the friction coefficient between the pressed clutch plates by a constant or slightly higher than a predetermined sliding speed. An electric reduction gear for driving a shield cutter, which is configured as described above. 2. The electric reduction gear for driving a shield cutter according to claim 1, wherein the wet hydraulic clutch is integrated with the planetary reduction mechanism. 3. A planetary speed reduction mechanism for reducing the speed of rotation of a prime mover and outputting the reduced speed, and a number of sheets which are integrated with the planetary speed reduction mechanism and connected to the prime mover and which can be freely pressed by a hydraulically slidable piston. A wet hydraulic clutch having a clutch plate, wherein the wet hydraulic clutch changes the relationship between the sliding speed and the friction coefficient between the pressed clutch plates so that the friction coefficient is constant or slightly increased at a certain sliding speed or higher. An electric reduction gear characterized by being configured as described above.