JP2008008422A - Power transmission and working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a revolving unit of a working machine and a power transmission appropriate for the working machine, which are produced inexpensively in a simple structure and capable of developing low and high torque while controlling the waste of energy. <P>SOLUTION: In the power transmission, rotation of a drive source is reduced by a reduction gear and outputted. The transmission includes a hydraulic motor 20 as a first driving source, an electric motor 70 as a second drive source, a sun gear 81 to which energy of rotation of the electric motor 70 is transferred, a plurality of planetary gears 82 meshed with the sun gear 81, a carrier 83 which rotationally supports the plurality of planetary gears 82 to receive transferred rotational energy of the hydraulic motor 20, an internal gear 84 freely rotatably meshed with the plurality of planetary gears 82, and a reduction gear 80 of the planetary-gear mechanism having an output shaft 85 to which energy of rotation of the internal gear 84 is transferred. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power transmission device and a work machine including a hydraulic motor and an electric motor as drive sources, which are suitable for use in a swivel device of a swivel work machine such as a hydraulic excavator.

Generally, a rotating work machine uses a reduction gear of a planetary gear mechanism (hereinafter referred to as a planetary gear reduction device) as a power transmission device of a turning device.
As shown in FIG. 4, a hydraulic excavator 1, which is a typical example of a revolving work machine, includes a lower traveling body 2, an upper revolving body 3 that is pivotably coupled to the lower traveling body 2, and an upper revolving body 3. It is comprised from the working apparatus 4 attached so that it might extend ahead.

Then, the upper swing body 3 is swung with respect to the lower travel body 2 by a swiveling device 10 disposed between the lower travel body 2 and the upper swing body 3.
The lower traveling body 2 includes a traveling frame (not shown) as a skeleton thereof, and a large-diameter ring-shaped circular body 2a provided on the upper surface of the central portion of the traveling frame.
The upper swing body 3 has a swing frame 3a as a skeleton thereof, an engine (not shown) mounted on the swing frame 3a, a hydraulic pump 5 (see FIG. 6) that is driven by the engine and discharges hydraulic oil, and an operation. It has a hydraulic oil tank 6 (see FIG. 6) for storing oil, a cab 7 on which an operator gets on, and the like.

  As shown in FIG. 5, the swivel device 10 has a lower end 11 a mounted on the swivel frame 3 a and a stepped cylindrical housing (reduction gear body) 11 disposed on the upper end 11 b side of the housing 11. A hydraulic motor (swing motor) 20 serving as a rotation source (drive source), a planetary gear reducer 30 disposed in the housing 11 for reducing the rotation of the hydraulic motor 20, and a lower end 11b of the housing 11 projecting downward. The pinion gear 40 to which the rotational energy decelerated by the planetary gear reducer 30 is transmitted, and the swivel wheel formed in a ring shape to which the rotational energy of the pinion gear 40 (hereinafter also referred to as rotational energy) is transmitted ( Slewing bearing) 50. Here, the hydraulic motor 20 and the planetary gear reducer 30 constitute a power transmission device.

  The planetary gear reducer 30 is connected to the hydraulic motor shaft 21 of the hydraulic motor 20 via a spline or the like (spline coupled), and connected to the input shaft 31 to transmit the rotational energy of the hydraulic motor 20. The sun gear 32, the plurality of planetary gears 33 arranged on the outer periphery of the sun gear 32 and meshing with the sun gear 32, and the rotation shafts (pivot axes) of the plurality of planetary gears 33 are rotatably supported around the sun gear 32. Rotational energy is transmitted to the carrier 34, the inner gear 35 formed on the inner peripheral surface of the housing 11 and meshed with the plurality of planetary gears 33, and the pinion gear 40 connected to the carrier 34 via a spline or the like (that is, the planetary gear reduction gear). And an output shaft 36 that outputs the rotation decelerated by the machine 30.

The swivel wheel 50 is provided between the round body 2a and the swivel frame 3a, and an inner ring 51 formed in a ring shape and fixed to the upper surface of the round body 2a, and a ring shape formed on the lower surface of the swivel frame 3a. The outer ring 52 is fixed, and a plurality of steel balls 53 are disposed between the inner ring 51 and the outer ring 52.
Inner teeth 51 a with which the pinion gear 40 meshes are formed on the inner peripheral side of the inner ring 51. Then, when the outer ring 52 rotates around the inner ring 51, the turning frame 3 a attached to the outer ring 52, that is, the upper turning body 3 turns on the lower traveling body 2 around the turning axis.

  The operation of the turning device 10 will be described in detail. When hydraulic oil is supplied to and discharged from the hydraulic motor 20 to rotate the hydraulic motor 20, rotational energy is generated. This rotational energy is transmitted to the sun gear 32 via the input shaft 31. The sun gear 32 rotates. Then, the planetary gear 33 that meshes with the sun gear 32 rotates. At this time, since the planetary gear 33 is also meshed with the internal gear 35, rotational energy is transmitted to the internal gear 35. However, since the internal gear 35 is formed and fixed on the inner peripheral surface of the housing 11, the planetary gear is provided. 33 also performs a revolving motion. That is, each planetary gear 33 revolves around the sun gear 32 while rotating around the pivot supported by the carrier 34.

The energy of the revolving motion of the planetary gear 33 is transmitted to the carrier 34 that supports the planetary gear 33, and the rotational energy is transmitted to the pinion gear 40 disposed on the lower end side of the output shaft 36 connected to the carrier 34.
Since the pinion gear 40 meshes with the inner teeth 51a of the inner ring 51 of the turning wheel 50, the pinion gear 40 revolves around the center of the inner ring 51 while receiving the rotation energy and rotating along the inner teeth 51a. The revolution force of the pinion gear 40 is transmitted to the turning frame 3a to which the planetary gear speed reducer 30 to which the pinion gear 40 is connected is attached, and the outer ring 52 fixed to the turning frame 3a is applied to the round body 2a of the traveling frame. The turning frame 3a, that is, the upper turning body 3 turns on the lower traveling body 2 by rotating around the fixed inner ring 51.

  That is, the planetary gear reducer 30 decelerates the rotation of the hydraulic motor 20 transmitted from the input shaft 31 and rotates the pinion gear 40 provided on the output shaft 36 with a large torque. The pinion gear 40 revolves while rotating along the inner teeth 51a of the turning wheel 50, and the upper turning body 3 turns on the lower traveling body 2 by the revolution force at this time.

Here, as described above, the hydraulic motor 20 is generally used as the rotation source of the turning device 10, that is, the power transmission device. However, the hydraulic motor 20 has an energy loss during turning acceleration or turning deceleration. There is a problem that (power loss) is large.
In other words, the hydraulic circuit C ₁ of the power transmission device will be described with reference to FIG. 6. The hydraulic circuit C ₁ is configured such that hydraulic oil discharged from the hydraulic pump 5 driven by engine output passes through the control valve 8. The hydraulic fluid supply circuit 20 has a discharge passage where hydraulic oil flows from the hydraulic pump 5 to the hydraulic motor 20 and a return passage where the hydraulic oil 20 returns to the hydraulic oil tank 6. Relief valves 9 a and 9 b built in the hydraulic motor 20 are interposed in a passage communicating the discharge passage and the return passage between the control valve 8 and the hydraulic motor 20.

In the hydraulic circuit C ₁ , at the time of turning acceleration, in order to properly accelerate the hydraulic motor 20, some hydraulic oil is operated by the relief valves 9 a and 9 b so as to keep the maximum value of the load pressure of the hydraulic motor 20 constant. By returning to the oil tank 6, smooth acceleration characteristics are obtained while protecting the hydraulic motor 20 from excessive load pressure. In other words, the relief valves 9a and 9b convert hydraulic energy corresponding to the differential pressure before and after and the passage flow rate into heat energy. The return oil from the relief valves 9a and 9b is collected in the hydraulic oil tank 6 via an oil cooler for cooling the hydraulic oil, but the heat energy generated in the relief valves 9a and 9b is in the atmosphere when passing through the oil cooler. The energy is lost.

  At the time of turning deceleration, a smooth deceleration characteristic is obtained while protecting the hydraulic motor 20 from excessive load pressure by controlling the load pressure of the hydraulic motor 20 to be constant by the relief valves 9a and 9b as braking force. Therefore, as in turning acceleration, hydraulic energy is converted into thermal energy by the relief valves 9a and 9b, and the thermal energy is released into the atmosphere from the oil cooler, resulting in energy loss.

Further, in such a conventional planetary gear speed reducer 30, the reduction ratio is fixed. Therefore, when performing a fine operation, the flow rate to the hydraulic motor 20 must be precisely controlled, and there is a problem that it is expensive.
In response to these problems, for example, a technique for replacing the rotation source of the turning device from a hydraulic motor to an electric motor has been developed, as in the techniques described in Patent Document 1 and Patent Document 2.

If an electric motor is applied as the rotation source of the swivel device, it is possible to control the current to the electric motor, thereby suppressing energy loss and engine output, and obtaining smooth acceleration characteristics and deceleration characteristics. Operability can be ensured.
JP 2001-12274 A JP 2004-190845 A

However, if an electric motor is used to turn a hydraulic excavator, the electric motor cannot output high torque in continuous operation. Necessary work is difficult.
In addition, in order to obtain the aforementioned acceleration characteristics and deceleration characteristics with an electric motor, a large electric motor with a large capacity is required, which is expensive.

  The present invention has been devised in view of such a problem, and can be manufactured at a low cost with a simple configuration, and can output a small torque and a large torque while suppressing energy loss. An object of the present invention is to provide a power transmission device and a work machine.

  In order to achieve the above object, a power transmission device according to a first aspect of the present invention is a power transmission device that decelerates and outputs rotation of a drive source by a reduction gear, and is a hydraulic motor as a first drive source. An electric motor as a second drive source, a sun gear to which rotation energy of the electric motor is transmitted, a plurality of planetary gears arranged on the outer periphery of the sun gear and meshing with the sun gear, the plurality of planets Each rotation shaft of the gear is rotatably supported around the sun gear, and a carrier to which the rotational energy of the hydraulic motor is transmitted, is arranged on the outer periphery of the plurality of planetary gears, and is rotatable with the plurality of planetary gears. It is characterized by comprising a meshing internal gear and a planetary gear mechanism reduction gear having an output shaft to which the rotational energy of the internal gear is transmitted.

  A power transmission device according to a second aspect of the present invention is a power transmission device that outputs the drive source by decelerating the rotation of the drive source with a speed reducer, as a first drive source and a second drive source. An electric motor, a sun gear to which rotation energy of the hydraulic motor is transmitted, a plurality of planetary gears arranged on the outer periphery of the sun gear and meshing with the sun gear, and the rotation axes of the plurality of planetary gears A carrier that is rotatably supported around a gear and transmits rotational energy of the electric motor, an internal gear that is disposed on an outer periphery of the plurality of planetary gears and is rotatably meshed with the planetary gears, and the internal gear And a reduction gear of a planetary gear mechanism having an output shaft to which the rotation energy is transmitted.

  A power transmission device according to a third aspect of the present invention is the power transmission device according to the first aspect, wherein the hydraulic motor has a hydraulic motor shaft for inputting rotational energy of the hydraulic motor to the carrier. The electric motor has an electric motor shaft for inputting energy of rotation of the electric motor to the sun gear, and the electric motor shaft has a hollow portion formed hollow at a central portion in a radial direction, The hydraulic motor shaft is disposed so as to penetrate the hollow portion of the electric motor shaft.

According to a fourth aspect of the present invention, there is provided a power transmission device according to the present invention, wherein a hydraulic motor as a first drive source, an electric motor as a second drive source, and the power of the hydraulic motor and the electric motor are combined and input. And a speed reducer that decelerates and outputs the input power of the hydraulic motor and the electric motor.
A work machine according to a fifth aspect of the present invention is a turning device having the power transmission device according to any one of the first to fourth aspects, a lower traveling body, and a turn on the lower traveling body by the turning device. It is characterized by having an upper revolving body coupled freely.

According to the power transmission device of the first or second aspect of the present invention, two drive sources, that is, a hydraulic motor and an electric motor can be provided with a simple and inexpensive configuration with respect to a reduction gear of one planetary gear mechanism. .
Moreover, a hydraulic motor and an electric motor can be used alone or in combination. In other words, the maximum torque can be output over a long period of time without rotating the hydraulic motor (that is, in a stationary state), so that a large torque can be output favorably by driving the hydraulic motor, and the electric motor can be driven. Thus, it is possible to output a small torque while suppressing energy loss.

Further, if the total output of the electric motor and the hydraulic motor is equivalent to that of the hydraulic motor of the prior art, a component with a small output can be used without changing the airframe performance, and the cost can be further reduced.
According to the power transmission device of the third aspect of the present invention, the hydraulic motor shaft can be disposed so as to penetrate through the hollow portion at the central portion in the radial direction of the electric motor shaft, whereby a more compact configuration can be achieved.

According to the power transmission device of the present invention as set forth in claim 4, two drive sources of a hydraulic motor and an electric motor can be provided with a simple and inexpensive configuration with respect to one speed reducer.
Moreover, a hydraulic motor and an electric motor can be used alone or in combination. In other words, the maximum torque can be output for a long time without rotating the hydraulic motor, so that a large torque can be output satisfactorily by driving the hydraulic motor, and energy loss can be suppressed by driving the electric motor. A small torque can be output.

Further, if the total output of the electric motor and the hydraulic motor is equivalent to that of the hydraulic motor of the prior art, a component with a small output can be used without changing the airframe performance, and the cost can be further reduced.
According to the work machine of the present invention as set forth in claim 5, in response to the turning request of the turning device, the turning operation of the high torque can be prolonged for a long time by driving the hydraulic motor, and the energy loss is caused by the driving of the electric motor. A small torque can be output and fine operability can be ensured.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[One Embodiment]
1 to 3 show a power transmission device according to an embodiment of the present invention. FIG. 1 is a schematic sectional view of a turning device having the power transmission device, and FIG. 2 is an arrow AA in FIG. FIG. 3 is an electric / hydraulic circuit diagram of the power transmission device. Note that members similar to those in the prior art are denoted by the same reference numerals and will be described with reference to FIG. 4 as appropriate.
In the present embodiment, a power transmission device applied to a swing device for a hydraulic excavator will be described.

<Configuration>
As shown in FIG. 4, the excavator 1 is attached to the lower traveling body 2, the upper revolving body 3 that is pivotably coupled to the lower traveling body 2, and the front revolving body 3 so as to extend forward. And the working device 4.

Then, a turning device 60 (indicated by reference numeral 10 in FIG. 4) disposed between the lower traveling body 2 and the upper turning body 3 is provided. 2 to turn.
The lower traveling body 2 includes a traveling frame (not shown) as a skeleton thereof, and a large-diameter ring-shaped circular body 2a provided on the upper surface of the central portion of the traveling frame.

The upper swing body 3 has a swing frame 3a as a skeleton thereof, an engine (not shown) mounted on the swing frame 3a, a hydraulic pump 5 (see FIG. 3) driven by the engine and discharging hydraulic oil, and an operation. It has a hydraulic oil tank 6 (see FIG. 3) for storing oil, a cab 7 on which an operator gets on, and the like.
As shown in FIG. 1, the swivel device 60 has a lower end mounted on the swivel frame 3 a and a stepped cylindrical housing 11, and a hydraulic pressure as a rotation source disposed on the upper end side of the housing 11. A motor 20 and an electric motor 70, a planetary gear reducer 80 disposed in the housing 11 and decelerating and outputting the rotation input from the hydraulic motor 20 and the electric motor 70, and projecting downward from the lower end of the housing 11, It is mainly composed of a pinion gear 40 to which the rotational energy decelerated by the gear reducer 80 is transmitted, and a turning wheel 50 formed in a ring shape to which the rotational energy of the pinion gear 40 is transmitted. Here, the hydraulic motor 20, the electric motor 70, and the planetary gear reducer 80 constitute a power transmission device. The hydraulic motor 20 rotates, for example, with clockwise rotation as normal rotation and counterclockwise rotation as reverse rotation. Similarly, the electric motor 70 rotates in the clockwise direction as the forward rotation and the counterclockwise direction as the reverse rotation.

  The electric motor 70 is configured as an electric motor / generator, and the power transmission device supplies electric power for rotationally driving the electric motor 70 to the electric motor 70 and charges the electric power generated by the electric motor 70. (Accumulator) 90 (see FIG. 3) and an inverter 91 (see FIG. 3) for controlling the current (frequency of alternating current) between the electric motor 70 and the battery 90 are further provided.

Further, a shaft (hereinafter referred to as an electric motor shaft) 71 of the electric motor 70 has a hollow portion 71a formed hollow at the central portion in the radial direction. A shaft (hereinafter referred to as a hydraulic motor shaft) 21 of the hydraulic motor 20 passes through the hollow portion 71 a of the electric motor shaft 71.
As shown in FIG. 2, the planetary gear speed reducer 80 is arranged at the radial center of the housing 11 and is connected to the electric motor shaft 71 to transmit the rotational energy (first rotational energy) of the electric motor 70. 81, a plurality (four in this case) of planetary gears 82 arranged on the outer periphery of the sun gear 81 and meshing with the sun gear 81, and the pivot axes of the plurality of planetary gears 82 are rotatably supported around the sun gear 81. In addition, the carrier 83 is connected to the hydraulic motor shaft 21 and transmits the rotational energy (second rotational energy) of the hydraulic motor 20, and is disposed on the outer periphery of the plurality of planetary gears 82 so as to freely mesh with the plurality of planetary gears 82. A gear 84 and an output shaft 85 connected to the internal gear 84 and transmitting the rotation of the internal gear 84 as rotational energy to the pinion gear 40 for output. It is.

The internal gear 84 is not fixed unlike the prior art planetary gear reducer 30 shown in FIG. 5, and therefore the planetary gear reducer 80 includes two input shafts, an electric motor shaft 71 and a hydraulic motor shaft 21. , One output shaft 85.
The turning wheel 50 is provided between the round body 2a and the turning frame 3a. The inner ring 51 fixed to the upper surface of the round body 2a, the outer ring 52 fixed to the lower surface of the turning frame 3a, the inner ring 51, A plurality of steel balls 53 are provided between the outer ring 52 and the outer ring 52.

Inner teeth 51 a with which the pinion gear 40 meshes are formed on the inner peripheral side of the inner ring 51. Then, when the outer ring 52 rotates around the inner ring 51 fixed to the round body 2a, the turning frame 3a attached to the outer ring 52, that is, the upper turning body 3 turns on the lower traveling body 2 around the turning axis. It is supposed to be.
Here, the hydraulic / electric circuit C ₂ of the power transmission device of the turning device 60 will be described with reference to FIG. 3. In the hydraulic / electric circuit C ₂ , the hydraulic oil discharged from the hydraulic pump 5 passes through the control valve 8. A hydraulic circuit C ₃ (indicated by a solid line in FIG. 3) supplied to the hydraulic motor 20 and an electric circuit C ₄ having an electric motor 70 (indicated by a broken line in FIG. 3) are provided. In the hydraulic / electric circuit C ₂ , the hydraulic motor 20 and the electric motor 70 are connected in parallel to the planetary gear speed reducer 80, and the turning device 60 includes the planetary gear speed reduction even if each of the hydraulic motor 20 and the electric motor 70 is independent. The upper turning body 3 can be turned via the machine 80, and the upper turning body 3 can be turned via the planetary gear speed reducer 80 by combining the hydraulic motor 20 and the electric motor 70.

The hydraulic circuit C ₃ includes a discharge passage from which the hydraulic oil flows from the hydraulic pump 5 to the hydraulic motor 20, a return passage through which the hydraulic oil 20 returns to the hydraulic oil tank 6, a discharge passage drawn from the control valve 8, and a return passage An upstream communication passage and a downstream communication passage communicating with the passage are provided.
A no-load valve 12 is interposed on the upstream communication path. The no-load valve 12 can communicate with the discharge passage and the return passage drawn from the control valve 8 by short-circuiting. That is, the no-load valve 12 is normally in a closed state (closed state), but is opened when the hydraulic motor 20 needs to be idled, and the supply of hydraulic oil to the hydraulic motor 20 is shut off. Be able to.

In addition, relief valves 9 a and 9 b that are incorporated in the hydraulic motor 20 and return a part of the hydraulic oil to the hydraulic oil tank 6 so as to control the load pressure of the hydraulic motor 20 to be constant are provided on the downstream communication path. It is intervened.
On the other hand, the electric circuit C ₄ includes an electric motor 70, a battery 90, and an inverter 91 that is interposed between the electric motor 70 and the battery 90 and controls current.

  The inverter 91 charges the battery 90 by causing the electric motor 70 to function as a generator according to the charging state of the battery 90 during steady turning when the planetary gear speed reducer 80 is driven by the hydraulic motor 20, and at the time of turning deceleration, By causing 70 to function as a generator, the battery 90 is charged by converting turning kinetic energy (inertial energy) into electric energy.

<Action and effect>
Since the power transmission device and the turning device having the power transmission device according to the embodiment of the present invention are configured as described above, the following operations and effects are obtained.
In the power transmission device, the electric motor shaft 71 is splined to the sun gear 81, and the hydraulic motor shaft 21 is splined to the carrier 83. The rotational energy of two different rotational sources of the electric motor 70 and the hydraulic motor 20 can be input. That is, since one planetary gear speed reducer 80 is shared by the electric motor 70 and the hydraulic motor 20, a speed reducer dedicated to the electric motor 70 and a speed reducer dedicated to the hydraulic motor 20 are not required, and the apparatus can be downsized. The weight can be reduced and the cost can be reduced.

Further, since the hydraulic motor shaft 21 passes through the hollow portion 71a of the electric motor shaft 71, a more compact configuration can be achieved.
Further, the electric power transmission device can rotate both the electric motor 70 and the hydraulic motor 20 independently or in combination with each other depending on the situation, so that the power transmission device can provide both the advantages of the electric motor 70 and the advantages of the hydraulic motor 20. And can output a large torque and output a small torque without energy loss.

  Then, the swing device 60 of the hydraulic excavator 1 having the power transmission device controls the no-load valve 12 to be in an open state (by communicating the upstream communication path) during the first fine operation during swing acceleration. If the supply of hydraulic oil to the motor 20 is cut off and only the electric motor 70 is driven to rotate and the output of the electric motor 70 is controlled, energy loss from the relief valves 9a and 9b of the hydraulic motor 20 is eliminated. Can be. Further, if the no-load valve 12 is opened for a moment immediately after the electric motor 70 is started, backlash of the planetary gear reducer 80 can be suppressed.

When the vehicle is accelerated to some extent, the no-load valve 12 is controlled to be closed (without connecting the upstream communication path) to supply hydraulic oil to the hydraulic motor 20, and the hydraulic motor 20 is also combined to rotate. Then, increase the rotation speed and torque.
Furthermore, at the time of steady turning where acceleration has advanced and reached steady rotation, only the hydraulic motor 20 can be driven to rotate, and the electric motor 70 can act as a generator to charge the battery 90 with excess energy from the hydraulic motor 20. If the hydraulic motor 20 is used during steady turning, the hydraulic motor 20 has a characteristic capable of outputting the maximum torque for a long time without rotating (that is, in a stationary state). Work requiring high torque such as can be performed for a long time.

Further, at the time of turning deceleration, only the hydraulic motor 20 is driven to rotate, and the electric motor 70 is made to act as a generator so that inertial energy related to turning of the upper turning body 3 can be charged to the battery 90, thereby suppressing energy loss. Can do.
When the electric motor 70 is operated as a generator during turning deceleration, the no-load valve 12 is opened when the inertial energy due to the braking force exceeds the capacity of the electric motor 70 as a generator. The electric motor 70 can be protected by operating the relief valves 9 a and 9 b of the hydraulic motor 20.

Further, at the time of fine operation, the hydraulic motor 20 is driven to rotate in one direction and the electric motor 70 is driven to rotate in the opposite direction to the hydraulic motor 20 (for example, the hydraulic motor 20 is driven forward and the electric motor 70 is driven reversely. By doing so, a continuously variable transmission can be obtained, and fine operability can be further improved.
That is, when the hydraulic motor 20 is rotationally driven by supplying and discharging hydraulic oil to the hydraulic motor 20 during fine operation, second rotational energy is generated, and the second rotational energy is transmitted from the hydraulic motor shaft 21 to the carrier 83. Rotate. Then, the planetary gear 82 supported by the carrier 83 performs a revolving motion. At the same time, when an electric current is passed through the electric motor 70 and the electric motor 70 is rotationally driven, first rotational energy is generated. The first rotational energy is transmitted from the electric motor shaft 71 to the sun gear 81, and the sun gear 81 rotates. Then, the planetary gear 82 that meshes with the sun gear 81 rotates. That is, the planetary gear 82 rotates and revolves.

Since the internal gear 84 is not fixed, the internal gear 84 is rotated by the rotation and revolution of the planetary gear 82. Here, by appropriately setting the directions and magnitudes of the first rotational energy and the second rotational energy, the rotational direction and the rotational speed of the internal gear 84 connected to the output shaft 85 can be determined.
That is, by controlling the current to the electric motor 70 in addition to the flow control to the hydraulic motor 20, the reduction ratio and the rotation direction by the planetary gear reducer 80 can be determined. It can be a stepped transmission.

The rotational energy whose reduction ratio is determined in this way is transmitted to the pinion gear 40 disposed on the lower end side of the output shaft 85 connected to the internal gear 84.
Since the pinion gear 40 meshes with the inner teeth 51a of the inner ring 51 of the turning wheel 50, the pinion gear 40 receives the rotation energy and rotates while revolving along the inner teeth 51a. The revolution force of the pinion gear 40 is transmitted to the turning frame 3 a to which the planetary gear speed reducer 80 to which the pinion gear 40 is connected is attached, and the outer ring 52 fixed to the turning frame 3 a is connected to the round cylinder via the rigid ball 53. The turning frame 3a, that is, the upper turning body 3 can be turned on the lower traveling body 2 by rotating around the inner ring 51 fixed to 2a.

Further, if the total output of the electric motor 70 and the hydraulic motor 20 is equal to the output of the hydraulic motor 20 alone used in the conventional turning device 10, a component with a small output is used without changing the airframe performance. And cost can be further reduced.
Here, the planetary gear reducer 80 has been described by taking a single-stage planetary gear reducer having four planetary gears 82 as an example. However, the planetary gear reducer is not limited to this. The number of planetary gears, the number of teeth of each gear, the number of steps, etc. are preferably set as appropriate.

[Others]
As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various deformation | transformation is possible in the range which does not deviate from the meaning of this invention.
For example, in the above-described embodiment, the first rotational energy of the electric motor 70 is transmitted to the sun gear 81, and the second rotational energy of the hydraulic motor 20 is transmitted to the carrier 83. The energy may be transmitted to the carrier 83, and the second rotational energy of the hydraulic motor 20 may be transmitted to the sun gear 81. In this case, the motor shaft 21 of the hydraulic motor shaft 20 has a hollow portion formed hollow at the center in the radial direction, and the electric motor shaft 71 is disposed so as to penetrate the hollow portion of the hydraulic motor shaft 21. Is preferred.

  In the above embodiment, the planetary gear mechanism is used as the speed reducer. However, the structure of the speed reducer is not limited to this. For example, a speed reducer composed of a hydraulic torque converter having a pump impeller, a turbine runner, a stator, and the like is used. It may be modified as appropriate, a multi-stage transmission that includes several types of gears and switches and selects gears, or a continuously variable transmission including pulleys, belts, and the like may be employed.

Moreover, in the said embodiment, although the battery 90 and the inverter 91 are provided and the electric power generated with the electric motor 70 can be charged to the battery 90, the battery 90 like especially the said embodiment is not provided, but an electric The motor 70 simply functions as an electric motor, and may be driven to rotate by being supplied with power from a power source not limited to the battery 90.
Moreover, although the case where the power transmission device of the present invention was applied to the swing device 10 of the excavator 1 was described in the above embodiment, the power transmission device of the present invention is applied to a work machine such as a crane or other swing mechanism. Can also be applied.

It is typical sectional drawing which shows the turning apparatus which has the power transmission device which concerns on one Embodiment of this invention. It is a figure which shows the turning apparatus which has the power transmission device which concerns on one Embodiment of this invention, Comprising: It is AA arrow sectional drawing of FIG. 1 is an electric / hydraulic circuit diagram of a power transmission device according to an embodiment of the present invention. It is a perspective view which shows the hydraulic excavator carrying the turning apparatus which has a power transmission device based on a prior art. It is sectional drawing which shows the turning apparatus which concerns on a prior art. It is a hydraulic circuit diagram of the power transmission device according to the prior art.

Explanation of symbols

1 Excavator (work machine)
DESCRIPTION OF SYMBOLS 2 Lower traveling body 2a Round body 3 Upper revolving body 3a Revolving frame 4 Working device 5 Hydraulic pump 6 Hydraulic oil tank 7 Cab 8 Control valve 9a, 9b Relief valve 10 Turning device 11 Housing (reduction gear body)
12 No-load valve 20 Hydraulic motor (swing motor, one component of power transmission device)
21 Hydraulic motor shaft (input shaft)
30 planetary gear reducer (one component of power transmission device)
31 Input shaft 32 Sun gear 33 Planetary gear 34 Carrier 35 Internal gear 36 Output shaft 40 Pinion gear 50 Slewing wheel (slewing bearing)
51 Inner ring 51a Inner tooth 52 Outer ring 53 Steel ball 60 Turning device 70 Electric motor (a component of the turning motor and power transmission device)
71 Electric motor shaft (input shaft)
80 planetary gear reducer (component of power transmission device)
81 sun gear 82 planetary gear 83 carrier 84 internal gear 85 output shaft 90 battery (capacitor)
91 Inverter

Claims (5)

A power transmission device that decelerates and outputs the rotation of a drive source with a speed reducer,
A hydraulic motor as a first drive source;
An electric motor as a second drive source;
A sun gear to which energy of rotation of the electric motor is transmitted, a plurality of planetary gears arranged on the outer periphery of the sun gear and meshing with the sun gear, and the rotation shafts of the plurality of planetary gears are rotated around the sun gear. A carrier that is capable of supporting and transmitting rotational energy of the hydraulic motor, an internal gear that is disposed on an outer periphery of the plurality of planetary gears and rotatably meshes with the planetary gears, and a rotational energy of the internal gear is A power transmission device comprising a planetary gear mechanism reduction gear having an output shaft to be transmitted. A power transmission device that decelerates and outputs the rotation of a drive source with a speed reducer,
A hydraulic motor as a first drive source;
An electric motor as a second drive source;
A sun gear to which the energy of rotation of the hydraulic motor is transmitted, a plurality of planetary gears arranged on the outer periphery of the sun gear and meshing with the sun gear, and the rotation shafts of the plurality of planetary gears are rotated about the sun gear. A carrier capable of supporting and transmitting rotational energy of the electric motor, an internal gear disposed on the outer periphery of the plurality of planetary gears and rotatably meshing with the planetary gears, and rotational energy of the internal gears. A power transmission device comprising a planetary gear mechanism reduction gear having an output shaft to be transmitted. The hydraulic motor has a hydraulic motor shaft for inputting rotational energy of the hydraulic motor to the carrier,
The electric motor has an electric motor shaft for inputting rotation energy of the electric motor to the sun gear,
The electric motor shaft has a hollow portion formed hollow at the center in the radial direction,
The power transmission device according to claim 1, wherein the hydraulic motor shaft is disposed so as to penetrate the hollow portion of the electric motor shaft. A hydraulic motor as a first drive source;
An electric motor as a second drive source;
The power of the hydraulic motor and the electric motor is input in combination, and a speed reducer that decelerates and outputs the power of the input hydraulic motor and the electric motor. Power transmission device. A turning device having the power transmission device according to any one of claims 1 to 4,
A lower traveling body,
A work machine comprising: an upper swing body that is pivotably coupled to the lower traveling body by the swing device.

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