Turning device

Abstract

One aspect of the present disclosure provides a turning device for a construction machine, the turning device rotatably supporting an upper turning body on a lower traveling body. The turning device for the construction machine comprises: a lower support body fixed to the lower traveling body; an upper support body rotatable with respect to the lower support body and fixed to the upper turning body; a ring gear installed inside the lower support body so as to rotate; a plurality of motors axially supported by the upper support body and engaged with the ring gear; a first sun gear engaged with the plurality of motors; a second sun gear integrally formed with the first sun gear at the lower portion of the first sun gear and having a diameter different from the diameter of the first sun gear; and a plurality of planetary gears engaged with the second sun gear and the ring gear and axially supported by the lower support body.

Description

Slewing device

[0001] The present disclosure generally relates to construction machinery. In certain embodiments, the present disclosure relates to a slewing device for construction machinery. The present disclosure may be applied to heavy vehicles such as trucks, buses, and construction equipment. While the present disclosure may be described with respect to specific vehicles, the present disclosure is not limited to any specific vehicle.

[0002] Generally, an excavator is a construction machine that performs various tasks at construction sites, such as excavation work to dig the ground, loading work to transport soil, excavation work to build foundations, crushing work to demolish buildings, leveling work to prepare the ground, and leveling work to prepare the ground.

[0003] In general, as shown in FIG. 1, the upper slewing body and the lower traveling body are assembled to be slewing by a slewing drive device (S).

[0004] More specifically, the slewing drive device (S) is fixed to the upper slewing body, a slewing drive gear is provided on the lower side of the slewing drive device (S), and a slewing driven gear (R) is formed on the lower body side. The slewing drive gear meshes internally with the slewing driven gear (R) to achieve gear transmission.

[0005] In addition, the turning joint (TJ) of the construction machine is positioned at the center of the slewing driven gear (R). The turning joint (TJ) ensures that hydraulic pressure is smoothly transmitted to the lower traveling body even when the upper slewing body rotates. The turning joint (TJ) prevents the hydraulic hose from twisting or being damaged, thereby enabling the construction machine to operate stably while rotating at various angles.

[0006] Meanwhile, the trend toward electrification is rapidly spreading within the construction machinery industry as well. Electrification is establishing itself as an essential change to meet the demands for stricter environmental regulations and improved fuel efficiency. For this reason, many construction machinery manufacturers are conducting various research and development efforts to adopt electric motors as slewing drive systems.

[0007] However, electric motors require a larger size to provide the same driving torque as hydraulic motors. Since the upper slewing body is already equipped with many devices such as the cab, engine, oil tank, and control valve, there is a problem in that it is not easy to secure additional installation space.

[0008] According to a first aspect of the present disclosure, a slewing device for a construction machine is provided, comprising: a lower support member fixed to the lower support member; an upper support member slewing with respect to the lower support member and fixed to the upper slewing member; a ring gear installed inside the lower support member and rotating; a plurality of motors axially supported by the upper support member and meshing with the ring gear; a first sun gear meshing with the plurality of motors; a second sun gear formed integrally with the first sun gear at the lower part of the first sun gear and having a diameter different from the diameter of the first sun gear; and a plurality of planetary gears meshing with the second sun gear and the ring gear and axially supported by the lower support member. The first aspect of the present disclosure can provide a slewing device for a construction machine capable of achieving a high reduction ratio of an electric motor. The technical advantage is that it achieves a high reduction ratio while using multiple small motors, thereby distributing power to each motor, reducing machining costs due to smaller gear tooth sizes, and facilitating space utilization.

[0009] Optionally, a through hole may be formed in the center of the first sun gear and the second sun gear.

[0010] Optionally, openings are formed in the lower support and the upper support, and the openings and the through holes may be coaxial with each other.

[0011] Optionally, a turning joint of the construction machine may be disposed to pass through the opening and the through hole.

[0012] Optionally, a gear that meshes with the ring gear and the first sun gear may be formed on the outer circumference of the motor.

[0013] Optionally, a drive gear is provided on the output shaft of the motor, and the drive gear can be engaged with the ring gear and the first sun gear.

[0014] Optionally, a single driver for controlling the operation of the plurality of motors may be further included.

[0015] Optionally, the plurality of motors may be arranged at equal intervals with respect to the center axis of the first sun gear.

[0016] Optionally, the phase difference of the plurality of motors may be equal to the equal angle interval.

[0017] Optionally, the plurality of motors may be arranged symmetrically with respect to a plane passing through the center axis of the first sun gear.

[0018] Optionally, the phase difference between adjacent motors may be equal to the angle difference between motors with respect to the center axis of the first sun gear. The technical advantage is that all motors can be driven by a single motor driver (520) via parallel wiring without the need to apply a driver to each motor individually, which enables system simplification, cost reduction, and efficient power distribution.

[0019] According to a second aspect of the present disclosure, a construction machine including a slewing device can be sought.

[0020] The above-mentioned embodiments, appended claims, and / or examples disclosed herein may be appropriately combined with one another as will be apparent to a person skilled in the art.

[0021] Additional features and benefits are disclosed in the following description, claims, and drawings, and will be readily apparent to a person skilled in the art from them or recognized by practicing the disclosures as described herein.

[0022] With reference to the attached drawings, a more detailed description of the embodiments of the present disclosure cited as examples follows.

[0023] Figure 1 schematically shows a conventional slewing drive device of a construction machine.

[0024] FIG. 2 schematically shows a construction machine according to one embodiment.

[0025] FIG. 3 is a partial cross-sectional view of a slewing device of a construction machine according to one embodiment.

[0026] FIG. 4 is a cross-sectional view of a slewing device of a construction machine according to one embodiment.

[0027] FIG. 5 is a schematic diagram of a motor according to one embodiment.

[0028] FIG. 6 is a cross-sectional view of a slewing device of a construction machine according to another embodiment.

[0029] Figure 7 is a diagram showing the coupling relationship of the ring gear, motor, and first sun gear.

[0030] Figure 8 is a diagram showing the coupling relationship of the ring gear, planetary gear, and second sun gear.

[0031] FIG. 9 is a diagram illustrating motor control by a single driver according to one embodiment.

[0032] FIG. 10 is a diagram illustrating motor control by a single driver according to another embodiment.

[0033] The embodiments described below represent information necessary to enable a person skilled in the art to practice the present disclosure.

[0034] FIG. 2 schematically shows a construction machine according to one embodiment.

[0035] A construction machine (1) according to one embodiment includes a slewing device (100), a lower driving body (200), an upper slewing body (300), a turning joint (400), and a control device (500).

[0036] The undercarriage (200) may be, for example, a crawler or wheel type. For example, the construction machine (1) may drive forward or backward depending on the driving direction of the track or wheel.

[0037] The upper pivot body (300) is pivotably mounted on the lower driving body (200) by means of the pivot device (100) to be described later.

[0038] The turning joint (400) is installed so as to be pivotable in the center of the pivoting device (100) and has an oil passage formed inside to supply oil supplied from the hydraulic supply unit (not shown) to the driving unit of the lower driving body (200) at a constant pressure.

[0039] The turning joint (400) ensures that hydraulic pressure is transmitted smoothly even when the upper swivel body (300) rotates. The turning joint (400) prevents the hydraulic hose from twisting or being damaged, thereby enabling the construction machine (1) to operate stably while rotating at various angles.

[0040] The control device (500) includes a power supply unit (510), a motor driver (520), an ECU (530), and an operating lever (540).

[0041] The power supply unit (510) is a battery and supplies voltage to the motor driver (520).

[0042] The motor driver (520) is configured to drive a swing motor and controls the rotation of the motor by inputting a three-phase voltage signal according to the mechanical angle of the motor to the motor.

[0043] As described below, since the angle between the stator core and the rotator of the motor is the same as the angle between adjacent motors with respect to the center of the swing system, the rotation of multiple motors can be controlled through a single motor driver (520).

[0044] The ECU (530) detects the position or state of the operating lever (540) and generates a corresponding signal. This signal is transmitted to the motor driver (520), causing the motor driver (520) to perform a specific operation according to the signal.

[0045] FIG. 3 is a partial cross-sectional view of a slewing device of a construction machine according to one embodiment, and FIG. 4 is a cross-sectional view of a slewing device of a construction machine according to one embodiment.

[0046] Hereinafter, a pivoting device (100) according to one embodiment is described in detail with reference to FIGS. 3 and FIGS. 4.

[0047] A slewing device (100) according to one embodiment includes an upper support (110), a lower support (120), a sun gear (130), a ring gear (140), a plurality of motors (150) and a plurality of planetary gears (160).

[0048] The upper support body (110) is fixed so that relative movement does not occur with respect to the upper pivot body. An upper opening (111) through which a turning joint can pass is formed approximately in the center of the upper support body (110).

[0049] The lower support body (120) is fixed so that relative movement does not occur with respect to the lower driving body. In addition, the lower support body (120) includes a vertical support member (122) that extends in a vertical direction, and the upper support body (110) is rotatably coupled to the upper part of the vertical support member (122). That is, the lower support body (120) and the upper support body (110) can rotate relative to each other.

[0050] A lower opening (121) through which a turning joint can pass is formed approximately in the center of the lower support (120).

[0051] In addition, a predetermined space is formed between the upper support body (110) and the lower support body (120), and a ring gear (140), a plurality of motors (150), and a plurality of planetary gears (160) are arranged in the space.

[0052] The sun gear (130) includes a first sun gear (131) located at the top and a second sun gear (132) located at the bottom. The first sun gear (131) and the second sun gear (132) may be formed integrally. Additionally, a through hole (133) through which a turning joint can pass is formed in the center of the first sun gear (131) and the second sun gear (132). The first sun gear (131) has a different diameter from the second sun gear (132).

[0053] The upper opening (111), lower opening (121), and through hole (133) can be coaxially aligned. That is, the turning joint can be positioned to pass through the upper opening (111), lower opening (121), and through hole (133). This arrangement allows for more efficient utilization of the internal space of the construction machine (1).

[0054] A ring gear (140) is positioned on the inner side of the vertical support member (122). The ring gear (140) can be roughly divided into an upper and a lower section, with a motor (150) meshing with the upper section and a planetary gear (160) meshing with the lower section.

[0055] A plurality of motors (150) are positioned on the upper side of the ring gear (140) and mesh inwardly with the ring gear (140), and mesh inwardly with the central first sun gear (131). The number of motors (150) can vary as needed. Each motor (150) is axially supported by a motor shaft (151). Additionally, motor carriers (152, 153) that support the motor (150) and receive power may be provided on the upper and lower parts of the motor (150).

[0056] As shown in FIG. 3, a gear that meshes with the first sun gear (131) and the ring gear (140) may be formed on the outer circumference of the motor (150).

[0057] FIG. 5 is a schematic diagram of a motor according to one embodiment, and FIG. 6 is a cross-sectional view of a slewing device of a construction machine according to another embodiment.

[0058] Referring to FIG. 5, the gear (156) on the outer circumference of the motor (150) can rotate in conjunction with the rotation of the rotor (154) inside the motor (150). That is, when the motor (150) is operated, the rotor (154) rotates, and the gear (156) formed on the outer circumference also rotates together. The rotor (154) and stator (155) of the motor (150) can be placed inside the upper support body, and in this case, the space of the upper slewing body of the construction machine can be utilized efficiently.

[0059] However, this is not limited thereto, and as shown in FIG. 6, a drive gear (150g) may be provided on the output shaft of the motor (150), and the drive gear (150g) may be engaged with the first sun gear (131) and the ring gear (140). In this case, to secure space, the stator and rotor of the motor (150), etc., may be positioned on the outer side of the upper support, that is, on the upper side of the drive gear (150g).

[0060] The planetary gear (160) is externally engaged with the second line gear (132) and internally engaged with the ring gear (140). The number of planetary gears (160) can vary as needed.

[0061] Each planetary gear (160) is axially supported by a planetary gear shaft (161). Planetary gear carriers (162, 163) that support the planetary gear (160) and receive power may be provided at the upper and lower portions of the planetary gear (160).

[0062] Figure 7 is a diagram showing the combined relationship of the ring gear, motor, and first sun gear, and Figure 8 is a diagram showing the combined relationship of the ring gear, planetary gear, and second sun gear.

[0063] In FIGS. 7 and 8, four motors (150a, 150b, 150c, 150d) and four planetary gears (160a, 160b, 160c, 160d) are illustrated, respectively, but are not limited thereto.

[0064] The motors (150a, 150b, 150c, 150d) are internally meshed with the ring gear (140) and externally meshed with the central first sun gear (131). Additionally, the planetary gears (160a, 160b, 160c, 160d) are internally meshed with the ring gear (140) and externally meshed with the central second sun gear (132).

[0065] Meanwhile, a high reduction ratio is required to rotate the upper rotating body with a small motor. To this end, the first sun gear (131) has a different diameter from the second sun gear (132).

[0066] In detail, since the linear velocity is the same at the point where the motor (150a, 150b, 150c, 150d), the first sun gear (131), and the ring gear (140) mesh with each other, the relationship can be summarized as follows.

[0067] ω M ·M = -ω S1 ·S1= ω R ·R

[0068] Here, M is the radius of the motor (150a, 150b, 150c, 150d), S1 is the radius of the first sun gear, R is the radius of the ring gear, and ω M is the motor's angular velocity, ω S1 θ is the angular velocity of the first sun gear, ω R represents the angular velocity of the ring gear.

[0069] In addition, since the first sun gear (131) and the second sun gear (132) are formed integrally, their angular velocities are the same.

[0070] That is, ω s1 = ω S2 am.

[0071] Also, the angular velocity ω of the carrier connecting the axes of the planetary gears (160a, 160b, 160c, 160d). c It is equal to the equation below.

[0072]

[0073] Let C be the radius of the carrier, then C = P + S2 = R - P holds true. Here, S2 is the radius of the second sun gear, and P is the radius of the planetary gear.

[0074] ω M, The relationship between S1 and S2 can be summarized as follows.

[0075]

[0076] According to the above equation, the smaller the difference between the radius S1 of the first sun gear (131) and the radius S2 of the second sun gear (132), the lower the angular velocity ω of the second carrier c It can be confirmed that the radius decreases. That is, the smaller the difference between the radius S1 of the first sun gear (131) and the radius S2 of the second sun gear (132), the higher the reduction ratio can be achieved.

[0077] Below, the motor deceleration process is described in detail with reference to FIGS. 7 and FIGS. 8.

[0078] When each motor (150a, 150b, 150c, 150d) operates, the motors (150a, 150b, 150c, 150d) rotate and revolve along the inner circumference of the ring gear (140), and the first sun gear (131) meshed with the motors (150a, 150b, 150c, 150d) also rotates. The second sun gear (132) rotates at the same angular velocity as the first sun gear (131), and as the planetary gears (160a, 160b, 160c, 160d) meshed with the second sun gear (132) and the ring gear (140) also rotate, the rotational speed of the motors (150a, 150b, 150c, 150d) is reduced. The motor carrier supporting the motor (150a, 150b, 150c, 150d) and the upper support rotate at a reduced angular velocity to perform the swing motion of the upper slewing body.

[0079] In this way, using multiple small motors allows the load on each motor to be distributed. Additionally, using small motors enables the design of smaller meshing gear teeth, thereby reducing gear machining costs. Finally, the use of small motors improves the overall space utilization of the system. Since small motors require less installation space compared to conventional large motors, the system design can be made more compact.

[0080] FIG. 9 is a diagram illustrating motor control by a single driver according to one embodiment, and FIG. 10 is a diagram illustrating motor control by a single driver according to another embodiment.

[0081] The driver (520) controls the rotational speed and direction of the motors (150a, 150b, 150c, 150d) through phase control.

[0082] In the present invention, in order to drive a plurality of motors with a single motor driver, the angle between the stator core and the rotator of the motor must be the same as the angle between adjacent motors with respect to the center of the slewing device.

[0083] In detail, the angle at which the motors (150a, 150b, 150c, 150d) are arranged with respect to the center of the pivoting device, that is, the center axis of the through hole (133), and the phase difference of each motor (150a, 150b, 150c, 150d) are the same. That is, the phase difference of the motors (150a, 150b, 150c, 150d) can be arranged to be constant.

[0084] For example, referring to FIG. 9, the motors (150a, 150b, 150c, 150d) are spaced apart radially by 90 degrees with respect to the center axis of the through hole (133), and the phase difference between the motors (150a, 150b, 150c, 150d) is also spaced at 90 degrees.

[0085] However, this is not limited thereto. Referring to FIG. 10, the motors (150a, 150b, 150c, 150d) may be arranged symmetrically with respect to a plane including the center axis of the through hole (133). For example, as shown in FIG. 10, the motors (150a, 150d) and the motors (150b, 150c) may be arranged symmetrically with respect to a plane including the center axis of the through hole (133). In this case, the phase difference between the motors (150a, 150b, 150c, 150d) may be set to be equal to the difference in the angle of arrangement between the motors. For example, if the angle between the motor (150a) and the motor (150d) with respect to the center axis of the through hole (133) is 60 degrees, the phase difference between the motor (150a) and the motor (150d) may also be set to 60 degrees.

[0086] When the slewing device operates, the motors (150a, 150b, 150c, 150d) rotate simultaneously along the sun gear (131) and the ring gear (140), and thus the stator core and rotor of each motor (150a, 150b, 150c, 150d) always maintain the same phase difference.

[0087] Therefore, without the need to apply a driver individually to each motor (150a, 150b, 150c, 150d), all motors can be driven by a single motor driver (520) through parallel wiring. This enables simplification of the control device and cost reduction. However, it is not limited to this, and the driver may be configured in multiple units.

[0088] The terms used herein are used merely to describe specific embodiments and are not intended to limit the disclosure. As used herein, the singular forms “one,” “one,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. As used herein, the term “and / or” includes any combination of one or more of the associated enumerated items. Furthermore, it will be understood that the terms “comprises,” “comprising,” “includes,” and / or “including,” when used herein, specify the presence of the mentioned function, integer, step, action, element, and / or component, but do not exclude the presence or addition of one or more other function, integer, step, operation, element, component, and / or group thereof.

[0089] You will understand that while terms such as first, second, etc. may be used herein to describe various components, these components should not be limited by such terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of this disclosure, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

[0090] Relative terms such as "below," "above," "upper side," "lower side," "horizontal," or "vertical" may be used herein to describe the relationship between one element and another as illustrated in the drawings. It will be understood that these terms and the terms discussed above are intended to include different orientations of the device in addition to the orientations depicted in the drawings. It will be understood that when an element is referred to as being "connected" or "combined" to another element, this may mean that it is directly connected or combined to the other element, or that there may be an intervening element. In contrast, when an element is referred to as being "directly connected" or "directly combined" to another element, there is no intervening element.

[0091] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as generally understood by those skilled in the art to which this disclosure pertains. Furthermore, it will be understood that terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and related technology, and should not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

Claims

1. A slewing device that supports an upper slewing body to a lower driving body so as to enable slewing, A lower support member fixed to the above lower driving body; An upper support member that is pivotable with respect to the lower support member and fixed with respect to the upper pivot member; A ring gear installed on the inner side of the lower support and rotating; A plurality of motors that are axially supported on the upper support and mesh with the ring gear; A first sun gear engaged with the plurality of motors above; A second sun gear formed integrally with the first sun gear at the lower part of the first sun gear, having a diameter different from that of the first sun gear; and A slewing device comprising a plurality of planetary gears that mesh with the second sun gear and the ring gear and are axially supported by the lower support.

2. In Paragraph 1, A slewing device having a through hole formed in the center of the first sun gear and the second sun gear.

3. In Paragraph 2, An opening is formed in the lower support and the upper support, and A pivot device in which the above opening and the above through hole are coaxial with each other.

4. In Paragraph 3, A pivot device in which a turning joint of the construction machine is positioned to pass through the opening and the through hole.

5. In Paragraph 1, A slewing device having a gear formed on the outer circumference of the motor that meshes with the ring gear and the first sun gear.

6. In Paragraph 1, A slewing device having a drive gear provided on the output shaft of the motor, wherein the drive gear meshes with the ring gear and the first sun gear.

7. In Paragraph 1, A slewing device further comprising a single driver that controls the operation of the plurality of motors.

8. In Paragraph 7, A slewing device in which the plurality of motors are arranged at equal angular intervals with respect to the center axis of the first sun gear.

9. In Paragraph 8, A slewing device in which the phase difference of the plurality of motors is the same as the equal angle interval.

10. In Paragraph 7, A slewing device in which the plurality of motors are arranged symmetrically with respect to a plane passing through the center axis of the first sun gear.

11. In Paragraph 7, A slewing device in which the phase difference between adjacent motors is equal to the angle difference between motors with respect to the center axis of the first sun gear.

12. Construction machinery comprising a slewing device according to any one of paragraphs 1 through 11.

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