Variable speed gearbox

Abstract

To suppress influence on a power system by suppressing an increase of an activation power when starting a variable-speed increasing gear.SOLUTION: A variable-speed increasing gear comprises: an electrically-driven apparatus; a speed change gear; and a power supply part that supplies a power of a constant rated frequency supplied from an electric power source to the electrically-driven apparatus in the case where the electrically-driven apparatus is started. The electrically-driven apparatus includes: a rated dynamo-electric motor having a rated rotor rotating a rated input shaft of the speed change gear; and a variable-speed dynamo-electric motor which has a variable-speed rotor connected to a variable-speed input shaft of the speed change gear and functions as a dynamo-electric motor in a dynamo-electric motor mode while functioning as a power generator in a power generator mode. The power supply part is connected to the rated dynamo-electric motor and the variable-speed dynamo-electric motor, and when the electrically-driven apparatus is started, the power generated in the variable-speed dynamo-electric motor which becomes the power generator mode is supplied to the rated dynamo-electric motor after an activation power is supplied to the rated dynamo-electric motor and the variable-speed dynamo-electric motor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure provides a variable speed On the spot Regarding. [Background technology]

[0002] Patent Document 1 discloses a variable speed step-up gear for driving a rotary machine such as a compressor, which includes an electric device having a constant speed motor and a variable speed motor, and a planetary gear transmission. The constant speed motor rotates a fixed speed shaft to generate rotational driving force. The fixed speed shaft rotates a constant speed input shaft of the planetary gear transmission. The variable speed motor rotates a variable speed rotor. The variable speed rotor rotates a variable speed input shaft of the planetary gear transmission. The planetary gear transmission changes the speed of the rotational driving force transmitted to the constant speed input shaft and the variable speed input shaft and transmits it to the rotary machine. In a variable speed step-up gear configured in this way, the rotation speed of the output shaft of the transmission connected to the rotary machine is changed by changing the rotation speed of the variable speed motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 217483 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the configuration described in Patent Document 1, when the variable speed step-up gear is started, starting the constant speed motor may generate a large starting power exceeding the rated power, which may cause disturbances such as voltage drops in the power supply system, such as a commercial power supply, that supplies power to the constant speed motor.

[0005] The present disclosure has been made to solve the above-mentioned problems, and provides a variable speed step-up gear that can suppress an increase in starting power and suppress an impact on a power supply system when starting a variable speed step-up gear. The machineThe purpose is to provide. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, a variable speed step-up gear according to the present disclosure includes an electric device that generates a rotational driving force, a speed change device that changes the speed of the rotational driving force transmitted from the electric device to a constant speed input shaft and a variable speed input shaft and transmits the changed speed to a driven object via an output shaft, and a power supply unit that supplies electric power of a constant rated frequency that is supplied from a power source to the electric device when starting the electric device, wherein the electric device includes a constant speed motor having a constant speed rotor that rotates the constant speed input shaft of the speed change device, and a variable speed motor having a variable speed rotor connected to the variable speed input shaft of the speed change device, and functioning as a generator in a generator mode and as a motor in a motor mode, wherein the constant speed rotor, the variable speed rotor, the constant speed input shaft, the variable speed input shaft, and the output shaft are arranged on the same axis, and the power supply unit is connected to the constant speed motor and the variable speed motor, and a control device for controlling switching between the first switch and the second switch. In this case, after supplying starting power to the constant speed motor and the variable speed motor, the power supply unit supplies power generated by the variable speed motor in the generator mode to the constant speed motor, and the power supply unit includes: an inverter connected to the power source and generating power to be supplied to the constant speed motor and the variable speed motor; a first wiring connecting the inverter and the variable speed motor; a second wiring branching from the first wiring between the inverter and the variable speed motor and connected to the constant speed motor; a first switch arranged on the second wiring and capable of switching between an on state and an off state of power supply from the inverter to the constant speed motor; a third wiring connecting the power source and the constant speed motor; a second switch arranged on the third wiring and capable of switching between an on state and an off state of power supply from the power source to the constant speed motor; The variable speed motor is supplied with power only from the first wiring, and the first wiring is not provided with a switch that can switch the power supply state between an on state and an off state. . [Effects of the Invention]

[0008] According to the variable speed step-up gear and the starting method for the variable speed step-up gear of the present disclosure, when starting the variable speed step-up gear, it is possible to suppress an increase in starting power and thereby suppress the impact on the power supply system. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a variable speed step-up gear according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view showing the configuration of an electric device for the variable speed step-up gear. [Figure 3] FIG. 2 is a functional block diagram of a control device for the variable speed step-up gear. [Figure 4] 3 is a flowchart showing the steps of a method for starting a variable speed step-up gear according to an embodiment of the present disclosure. [Figure 5] 10A and 10B are diagrams illustrating steps of supplying power from an inverter and a variable speed motor to a constant speed motor in a starting method for a variable speed step-up gear according to an embodiment of the present disclosure. [Figure 6] 10 is a diagram showing a process of supplying drive power from a commercial power source to a constant speed motor in a starting method for a variable speed step-up gear according to an embodiment of the present disclosure. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments for carrying out a variable speed step-up gear and a starting method for a variable speed step-up gear according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to only these embodiments.

[0011] (Configuration of variable speed step-up gear) As shown in FIG. 1, the variable speed step-up gear 1 of this embodiment includes an electric device 50 that generates a rotational driving force, a speed changer 10 that changes the speed of the rotational driving force generated by the electric device 50 and transmits it to a driven object, and a power supply unit 100. The variable speed step-up gear 1 can be applied to a fluid machinery system such as a compressor system, for example. The variable speed step-up gear 1 is installed in advance in an area where the variable speed step-up gear 1 will be installed, such as a factory, and is driven by power supplied from a commercial power source (power supply) 200 that can supply power at a constant rated frequency. The variable speed step-up gear 1 and the commercial power source 200 constitute part of the fluid machinery system. The driven object of the variable speed step-up gear 1 of this embodiment is, for example, a compressor C.

[0012] The electric device 50 has a constant-speed motor 51 having a constant-speed rotor 52 that rotates at a constant speed, and a variable-speed motor 71 having a variable-speed rotor 72 that rotates at any rotational speed. The constant-speed rotor 52 and the variable-speed rotor 72 are each connected to a transmission 10.

[0013] The constant speed motor 51 is supported on the base 90 by a constant speed motor support part 51S. The variable speed motor 71 is supported on the base 90 by a variable speed motor support part 71S. The transmission 10 is supported on the base 90 by a transmission support part 10S. These supports enable the electric device 50 and the transmission 10, which are heavy objects, to be securely fixed.

[0014] The transmission 10 changes the speed of the rotational driving force generated by the electric device 50 and transmits it to a driven object. The transmission 10 of this embodiment is a planetary gear transmission having multiple planetary gears (not shown) composed of external gears and internal gears, and a sun gear (not shown). The transmission 10 has a constant-speed input shaft Ac that rotates at a constant speed by the driving force of the constant-speed electric motor 51, and a variable-speed input shaft Av that rotates at a desired rotation speed by the driving force of the variable-speed electric motor 71. The constant-speed input shaft Ac is inserted inside the cylindrical variable-speed input shaft Av. The transmission 10 changes the speed of the rotational driving force obtained by the constant-speed input shaft Ac, which is rotated at a constant speed by the constant-speed electric motor 51, and the variable-speed input shaft Av, whose rotational speed is controlled by the variable-speed electric motor 71, using gears and transmits it to the output shaft Ao. That is, the variable speed step-up gear 1 can change the rotation speed of the output shaft Ao of the transmission 10 connected to the driven object by changing the rotation speed of the variable speed motor 71.

[0015] Hereinafter, the direction in which the axis Ar extends will be referred to as the axial direction Da. One side of the axial direction Da in the variable speed step-up gear 1 will be referred to as the output side Do, and the side opposite the output side Do will be referred to as the input side Di. The radial direction centered on the axis Ar will be simply referred to as the radial direction Dr. In the variable speed step-up gear 1 of this embodiment, the electric device 50 is arranged on the input side Di in the axial direction with respect to the speed change device 10. Furthermore, the speed change device 10 is arranged on the output side Do with respect to the electric device 50. The compressor C is arranged on the output side Do with respect to the variable speed step-up gear 1.

[0016] As shown in FIG. 2, constant speed motor 51 has a constant speed rotor 52 that rotates about axis Ar and is connected to constant speed input shaft Ac of transmission 10, and a constant speed motor casing 61.

[0017] The constant speed rotor 52 has a constant speed rotor shaft 53 that is cylindrical and has an axis Ar as its center, and a conductor 56 that is fixed to the outer periphery of the constant speed rotor shaft 53 .

[0018] Constant speed stator 66 is disposed on the outer side Dro in the radial direction Dr of conductor 56 of constant speed rotor 52. Constant speed stator 66 is formed of a plurality of coils.

[0019] Constant speed motor casing 61 has a cylindrical shape centered on axis Ar and includes a constant speed motor casing main body 62 to which a constant speed stator 66 is fixed on the inner circumferential side, and lids 63i, 63o that close both ends in the axial direction Da of cylindrical constant speed motor casing main body 62. Constant speed rotor bearings 65i, 65o that support constant speed rotor shaft 53 rotatably about axis Ar are attached to each of lids 63i, 63o.

[0020] The input side end of constant speed rotor shaft 53 protrudes from input side cover 63i of constant speed motor casing 61 toward the input side.

[0021] The variable speed motor 71 has a variable speed rotor 72 that rotates about an axis Ar and is connected to a variable speed input shaft Av, a variable speed stator 86 that is arranged on the outer periphery of the variable speed rotor 72, and a variable speed motor casing 81 to which the variable speed stator 86 is fixed on the inner periphery.

[0022] The variable speed rotor 72 has a variable speed rotor shaft 73 and a conductor 76 fixed to the outer periphery of the variable speed rotor shaft 73. The variable speed rotor shaft 73 is cylindrical and has an axis Ar as its center, and has a shaft insertion hole 74 that penetrates in the axial direction Da. A constant speed input shaft Ac is inserted through the shaft insertion hole 74 of the variable speed rotor shaft 73. An annular flange 73o that widens toward the outer side Dro in the radial direction Dr is formed on the output side end of the variable speed rotor shaft 73.

[0023] The variable speed stator 86 is disposed on the outer side Dro in the radial direction Dr of the conductor 76 of the variable speed rotor 72. The variable speed stator 86 is formed by a plurality of coils.

[0024] Variable speed motor casing 81 has a cylindrical shape centered on axis Ar and includes variable speed motor casing main body 82 with variable speed stator 86 fixed to its inner periphery, an output side lid 83o that closes the output side end of cylindrical variable speed motor casing main body 82, and an inlet side lid 83i that is positioned on the input side of variable speed stator 86 and fixed to the inner periphery of cylindrical variable speed motor casing main body 82. Variable speed rotor bearings 85i, 85o that support variable speed rotor shaft 73 rotatably about axis Ar are attached to inlet side lid 83i and output side lid 83o, respectively.

[0025] In the variable speed step-up gear 1 of this embodiment, the constant speed rotor 52, the variable speed rotor 72, the constant speed input shaft Ac, the variable speed input shaft Av, and the output shaft Ao are arranged on the same axis.

[0026] 1, constant speed motor 51 is configured to rotate constant speed rotor 52 (internal gear 17) in a first direction R1, which is the circumferential direction of axis Ar, when power is supplied from an external source. When constant speed rotor 52 rotates in first direction R1, constant speed input shaft Ac rotates in first direction R1.

[0027] The output shaft Ao of the transmission 10 is set to rotate in the first direction R1 by the constant speed rotor 52 of the constant speed motor 51 rotating in the first direction R1 at the maximum rotation speed. That is, the forward rotation of the constant speed motor 51 is the first direction R1, and the forward rotation of the output shaft Ao of the transmission 10 is the first direction R1. The forward rotation of the output shaft Ao allows the compressor C to operate normally.

[0028] The variable speed motor 71 can rotate the variable speed rotor 72 in a first direction R1 and a second direction R2 circumferentially about the axis Ar. That is, the variable speed motor 71 is capable of forward and reverse rotation. By increasing the rotation speed of the variable speed rotor 72 in the first direction R1, the rotation speed of the output shaft Ao of the transmission 10 in the second direction R2 increases.

[0029] The variable speed motor 71 functions as a generator by generating electric power when the variable speed rotor 72 is rotated by an external force. The state in which the variable speed motor 71 functions as a generator is called a generator mode.

[0030] When power is supplied to the variable speed motor 71, the variable speed motor 71 functions as an electric motor by rotating the variable speed rotor 72. The state in which the variable speed motor 71 functions as an electric motor is called the electric motor mode.

[0031] The power supply unit 100 is electrically connected to the commercial power source 200, the constant-speed motor 51, and the variable-speed motor 71. Therefore, as shown in FIG. 1 , the power supply unit 100 supplies power supplied from the commercial power source 200 or the variable-speed motor 71 to the constant-speed motor 51 or the variable-speed motor 71. When starting the electric device 50, the power supply unit 100 supplies, as starting power, to the electric device 50, power required to start the electric device 50, which is supplied from the commercial power source 200 and has a constant rated frequency. Thereafter, during normal operation, the power supply unit 100 supplies, to the constant-speed motor 51, power generated by the variable-speed motor 71 in generator mode. The power supply unit 100 of this embodiment includes an inverter 101, a first wiring 111, a second wiring 112, a third wiring 113, a first switch 121, a second switch 122, and a control device 150.

[0032] The inverter 101 converts the frequency of the power supplied from the commercial power source 200 and the variable-speed motor 71 based on instructions from the control device 150. The inverter 101 is connected to the commercial power source 200. The inverter 101 generates, for example, three-phase AC power. When starting the constant-speed motor 51 and the variable-speed motor 71, the inverter 101 supplies starting power to the constant-speed motor 51 and the variable-speed motor 71. During normal operation after starting is complete, the inverter 101 supplies drive power, the frequency of which is different from the starting power, only to the variable-speed motor 71, which operates the variable-speed motor 71 at its rated speed. Specifically, the inverter 101 supplies power of a frequency instructed by the control device 150 to the variable-speed motor 71. The variable-speed rotor 72 of the variable-speed motor 71 rotates at a rotational speed corresponding to this frequency. As the rotational speed of the variable-speed rotor 72 changes in this way, the rotational speed of the variable-speed input shaft Av of the transmission 10, which is connected to the variable-speed rotor 72, also changes. As a result, the rotation speed of the output shaft Ao of the transmission 10 changes.

[0033] The first wiring 111 connects the inverter 101 and the variable-speed stator 86. The second wiring 112 branches off from the first wiring 111 between the inverter 101 and the variable-speed motor 71. The second wiring 112 is connected to the first wiring 111 and the constant-speed stator 66. The third wiring 113 is connected to the commercial power supply 200 and the constant-speed stator 66. In this embodiment, the third wiring 113 merges with the second wiring 112 and is connected to the constant-speed stator 66. The third wiring 113 supplies power of a constant rated frequency supplied from the commercial power supply 200 directly to the constant-speed motor 51 without passing through the inverter 101. The power from the commercial power supply 200 is supplied from the third wiring 113 to the constant-speed motor 51 as drive power for rotating the constant-speed rotor 52 of the constant-speed motor 51 at a constant rotational speed.

[0034] The first switch 121 is disposed midway along the second wiring 112. The first switch 121 is capable of switching the state of power supply from the inverter 101 to the constant speed motor 51 between an on state and an off state. That is, when the first switch 121 is in the on state, power is supplied from the inverter 101 to the constant speed motor 51 via the second wiring 112. On the other hand, when the first switch 121 is in the off state, power from the inverter 101 to the constant speed motor 51 via the second wiring 112 is cut off.

[0035] The second switch 122 is disposed midway along the third wiring 113. The second switch 122 is capable of switching the state of power supply from the commercial power source 200 to the constant speed motor 51 between an on state and an off state. That is, when the second switch 122 is in the on state, power is supplied from the commercial power source 200 to the constant speed motor 51 via the third wiring 113. On the other hand, when the second switch 122 is in the off state, power from the commercial power source 200 to the constant speed motor 51 via the third wiring 113 is cut off.

[0036] The control device 150 controls the power supply unit 100. The control device 150 of this embodiment controls the operations of the inverter 101, the first switch 121, and the second switch 122. The control device 150 is configured with a computer. As shown in FIG. 3 , the control device 150 has a reception unit 151, an interface 152, a switch control unit 153, and an inverter control unit 154.

[0037] The reception unit 151 receives instructions directly from an operator or receives instructions from a higher-level control device. The interface 152 receives instruction signals to the reception unit 151 and transmits instruction signals to the inverter 101, the first switch 121, and the second switch 122.

[0038] The switch control unit 153 controls the opening and closing operations of the first switch 121 and the second switch 122 in accordance with instructions received by the receiving unit 151 .

[0039] Inverter control unit 154 controls inverter 101 in accordance with instructions etc. received by reception unit 151. Inverter control unit 154 changes the frequency of power supplied from commercial power supply 200. Constant-speed rotor 52 of constant-speed motor 51 and variable-speed rotor 72 of variable-speed motor 71, to which power is supplied from inverter 101, rotate at a rotation speed according to this frequency.

[0040] (Procedure for starting a variable speed gearbox) Next, a method for starting the variable speed step-up gear of this embodiment will be described. As shown in Figure 4, the method for starting the variable speed step-up gear S10 of this embodiment includes step S11 of receiving a start command, step S12 of supplying power from the inverter to the constant speed motor and the variable speed motor, step S13 of increasing the frequency of the power to the rated frequency, and step S14 of supplying drive power to the constant speed motor 51 only from a commercial power source.

[0041] In step S11 of receiving a start instruction, the reception unit 151 receives an instruction from an operator or a higher-level control device to start the variable speed step-up gear 1. When the reception unit 151 receives the start instruction, the process proceeds to step S12.

[0042] In step S12 of supplying power from the inverter to the constant-speed motor and the variable-speed motor, power is supplied from the inverter 101 to the constant-speed motor 51 and the variable-speed motor 71, and then power generated by the variable-speed motor 71, which is in generator mode, is supplied to the constant-speed motor 51. Specifically, as shown in FIG. 1 , the first switch 121 is turned on (closed), and the second switch 122 is turned off (open). In step S12, the power supplied from the commercial power supply 200 to the inverter 101 is supplied from the inverter 101 to the constant-speed motor 51 and the variable-speed motor 71 as three-phase AC starting power. The constant-speed rotor 52 and the variable-speed rotor 72 begin to rotate due to the starting power supplied from the inverter 101. Thereafter, as the variable-speed rotor 72 rotates, the variable-speed motor 71 is switched to generator mode and generates power. The electric power generated by the variable speed motor 71 is regenerated to the constant speed motor 51 via the first wiring 111 and the second wiring 112. As a result, as shown in Fig. 5 , the constant speed motor 51 is supplied with electric power supplied from the inverter 101 and regenerated electric power from the variable speed motor 71. Therefore, the electric power supplied from the inverter 101 to the constant speed motor 51 is reduced by the amount of regenerated electric power from the variable speed motor 71.

[0043] In step S13 of increasing the frequency of the power to the rated frequency, inverter control unit 154 controls inverter 101 so as to increase the frequency of the power supplied from inverter 101 to constant speed motor 51 and variable speed motor 71 at an appropriate rate (ramp rate). Inverter control unit 154 increases the frequency of the starting power supplied from inverter 101 to constant speed motor 51 and variable speed motor 71 so as to synchronize with the rated frequency of the power supplied from commercial power supply 200. When the frequency of the power supplied from inverter 101 to constant speed motor 51 and variable speed motor 71 reaches the rated frequency, the frequency of the power supplied from inverter 101 via first wiring 111 and second wiring 112 is synchronized with the frequency of the power to be supplied from commercial power supply 200 via third wiring 113.

[0044] In step S14 of supplying drive power to the constant speed motor 51 only from the commercial power supply 200, as shown in FIG. 6, the switch control unit 153 turns the first switch 121 to the OFF state. This stops the supply of startup power from the inverter 101 to the constant speed motor 51. At the same time, the switch control unit 153 turns the second switch 122 to the ON state. This causes the constant speed motor 51 to be supplied with power at a constant rated frequency only from the commercial power supply 200 through the third wiring 113, without going through the inverter 101. Meanwhile, the variable speed motor 71 continues to operate in the power generation mode, and the inverter 101 receives power from the commercial power supply. In this state, rated operation continues.

[0045] (Action and effect) In the variable-speed step-up gear 1 and the starting method thereof configured as described above, when starting the electric device 50, first, starting power is supplied to the constant-speed motor 51 and the variable-speed motor 71 via the inverter 101. As a result, the variable-speed motor 71 operates in generator mode to generate electric power. The electric power generated by the variable-speed motor 71 is supplied to the constant-speed motor 51. Because the electric power generated by the variable-speed motor 71 is supplied to the constant-speed motor 51, the starting power supplied to the constant-speed motor 51 from the commercial power supply 200 via the inverter 101 is prevented from increasing to a level that exceeds the rated power. This prevents disturbances such as voltage drops in the commercial power supply 200. As a result, when starting the variable-speed step-up gear 1, it is possible to suppress an increase in starting power and thereby reduce the impact on the power supply system, including the commercial power supply 200.

[0046] Furthermore, when starting the electric device 50, turning the second switch 122 off can cut off the direct supply of power from the commercial power source 200 to the constant-speed motor 51. In this state, turning the first switch 121 on allows power to be supplied from the inverter 101 to the constant-speed motor 51 via the second wiring 112. As a result, starting power is supplied from the inverter 101 to the constant-speed motor 51 and the variable-speed motor 71 via the first wiring 111 and the second wiring 112. Furthermore, after starting of the electric device 50 is completed, turning the first switch 121 off cuts off the supply of electricity from the inverter 101 to the constant-speed motor 51. Turning the second switch 122 on in this state supplies the constant-speed motor 51 with drive power necessary to continue operation from the commercial power source 200. The constant-speed rotor 52 can be driven to rotate at a constant speed by drive power at a constant rated frequency supplied from the commercial power source 200. On the other hand, the rotation speed of the variable speed rotor 72 of the variable speed motor 71 can be controlled by supplying power controlled by the inverter 101. In this way, the power supply source at the start of the variable speed step-up gearbox 1 can be switched with a simple configuration.

[0047] Furthermore, inverter control unit 154 can synchronize the frequency of the power generated by inverter 101 with the frequency of the drive power supplied from commercial power supply 200 when starting of electric device 50 is completed. Therefore, when switching is made so that power is supplied directly to constant speed motor 51 from commercial power supply 200 without going through inverter 101, fluctuations in the rotation speed of constant speed rotor 52 can be suppressed. This allows for smooth switching of the power supply system.

[0048] (Other embodiments) The above describes in detail the embodiments of the present disclosure with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present disclosure.

[0049] In the above embodiment, the configuration of each part of the variable speed step-up gear 1 has been described, but the configuration of each part may be changed as appropriate. For example, the gear configuration of the transmission 10 may be a configuration using any gear, such as internal gears or external gears.

[0050] <Additional Notes> The variable speed step-up gear 1 and the method for starting the variable speed step-up gear 1 described in the embodiment can be understood, for example, as follows.

[0051] (1) A variable speed step-up gear 1 according to a first aspect includes an electric motor 50 that generates a rotational driving force, a transmission 10 that changes the speed of the rotational driving force transmitted from the electric motor 50 to a constant speed input shaft Ac and a variable speed input shaft Av and transmits the changed speed to a driven object via an output shaft Ao, and a power supply unit 100 that supplies electric power of a constant rated frequency supplied from a power source to the electric motor 50 when starting the electric motor 50. The electric motor 50 includes a constant speed motor 50 having a constant speed rotor 52 that rotates the constant speed input shaft Ac of the transmission 10. and a variable-speed motor 71 having a constant-speed rotor 72 connected to a variable-speed input shaft Av of the transmission 10, the variable-speed motor 71 functioning as a generator in a generator mode and as a motor in a motor mode, the power supply unit 100 being connected to the constant-speed motor 51 and the variable-speed motor 71, and supplying starting power to the constant-speed motor 51 and the variable-speed motor 71 when starting the electric device 50, and then supplying power generated by the variable-speed motor 71 in the generator mode to the constant-speed motor 51.

[0052] When starting the electric device 50, the variable speed step-up gear 1 first supplies power to the constant speed motor 51 and the variable speed motor 71 via the power supply unit 100. As a result, the variable speed motor 71 operates in generator mode to generate power. The power generated by the variable speed motor 71 is supplied to the constant speed motor 51. Because the constant speed motor 51 is supplied with the power generated by the variable speed motor 71, the power supplied from the power source to the constant speed motor 51 via the power supply unit 100 is prevented from increasing to a level that exceeds the rated power. This prevents disturbances such as voltage drops from occurring in the power source. As a result, when starting the variable speed step-up gear 1, it is possible to suppress an increase in starting power and thereby reduce the impact on the power supply system, including the power source.

[0053] (2) A variable speed step-up gear 1 according to a second aspect is the variable speed step-up gear 1 of (1), wherein the power supply unit 100 includes an inverter 101 connected to the power source to generate power to be supplied to the constant speed motor 51 and the variable speed motor 71, a first wiring 111 connecting the inverter 101 and the variable speed motor 71, a second wiring 112 branching from the first wiring 111 between the inverter 101 and the variable speed motor 71 and connected to the constant speed motor 51, and a first switch 112 arranged on the second wiring 112 and capable of switching the supply state of power from the inverter 101 to the constant speed motor 51 between an on state and an off state. 121, a third wiring 113 connecting the power source and the constant speed motor 51, a second switch 122 arranged on the third wiring 113 and capable of switching the state of power supply from the power source to the constant speed motor 51 between an on state and an off state, and a control device 150 for switching the first switch 121 and the second switch 122, and when starting the electric device 50, the control device 150 turns the first switch 121 on and the second switch 122 off, and then turns the second switch 122 on and the first switch 121 off.

[0054] According to this configuration, when starting the electric device 50, turning the second switch 122 off can cut off the direct power supply from the power source to the constant-speed motor 51. In this state, turning the first switch 121 on allows power to be supplied from the inverter 101 to the constant-speed motor 51 via the second wiring 112. As a result, starting power is supplied from the inverter 101 to the constant-speed motor 51 and the variable-speed motor 71 via the first wiring 111 and the second wiring 112. After starting the electric device 50 is complete, turning the first switch 121 off cuts off the supply of electricity from the inverter 101 to the constant-speed motor 51. In this state, turning the second switch 122 on supplies the constant-speed motor 51 with the drive power required to continue operation from the power source. The constant-speed rotor 52 can be driven to rotate at a constant speed by the drive power at a constant rated frequency supplied from the power source. On the other hand, the rotation speed of the variable speed rotor 72 of the variable speed motor 71 can be controlled by supplying power controlled by the inverter 101. In this way, the power supply source at the start of the variable speed step-up gearbox 1 can be switched with a simple configuration.

[0055] (3) The variable speed gearbox 1 of the third aspect is the variable speed gearbox 1 of (2), in which, when the frequency of the power generated by the inverter 101 is synchronized with the frequency of the driving power supplied from the power source, the control device 150 changes the second switch 122 from an off state to an on state and changes the first switch 121 from an on state to an off state.

[0056] This suppresses fluctuations in the rotation speed of constant speed rotor 52 when switching is made to supply power directly from the power supply to constant speed motor 51 without passing through inverter 101. Therefore, the power supply system can be switched smoothly.

[0057] (4) A starting method S10 of a variable speed step-up motor 1 according to a fourth aspect is a starting method S10 of a variable speed step-up motor 1 according to any one of (1) to (3), and includes a step of supplying power from the power supply unit 100 to a constant speed motor 51 and the variable speed motor 71, and then supplying the power generated by the variable speed motor 71 in the generator mode to the constant speed motor 51, and a step of supplying power to the constant speed motor 51 only from the power source.

[0058] As a result, the constant speed motor 51 is supplied with power generated by the variable speed motor 71, and the power supplied from the power source to the constant speed motor 51 via the power supply unit 100 is prevented from increasing to a level that exceeds the rated power. This prevents disturbances such as voltage drops from occurring in the power source. As a result, when starting the variable speed step-up gear 1, it is possible to suppress an increase in starting power and reduce the impact on the power supply system, including the power source. [Explanation of symbols]

[0059] 1...Variable speed increaser 10...Gearbox 50...Electric device 51...Constant speed electric motor 51S…Constant speed motor support part 52...Constant speed rotor 53...Constant speed rotor shaft 56...conductor 61...Constant speed motor casing 62...Constant speed motor casing body 63i, 63o…Lid 65i...Constant speed rotor bearing 65o...Constant speed rotor bearing 66...Constant speed stator 71...Variable speed motor 71S...Variable speed motor support 72...Variable speed rotor 73...Variable speed rotor shaft 73o...flange 74...Shaft insertion hole 76...conductor 81...Variable speed motor casing 82...Variable speed motor casing body 83i…Entrance side lid 83o...Output side cover 85i...Variable speed rotor bearing 85o...Variable speed rotor bearing 86...Variable speed stator 90...mounting stand 100…Power supply section 101...Inverter 111…First wiring 112…Second wiring 113…Third wiring 121...First switch 122...Second switch 150...Control device 151…Reception 152...Interface 153...Switch control section 154...Inverter control unit 200…Commercial power supply Ac...Constant speed input shaft Ao...Output shaft Ar…Axis line Av...Variable speed input shaft C...Compressor Da...Axial direction Di...input side Do...Output side Dr…Radial direction Dri…inside Dro...outside R1…first direction R2…Second direction S10...Starting method for variable speed step-up gear S11: Step of receiving a start instruction S12: A step of supplying power from the inverter to the constant speed motor and the variable speed motor S13: A process of increasing the power frequency to the rated frequency S14: A process of supplying power to the constant speed motor only from the power source

Claims

1. an electric device that generates a rotational driving force; a transmission that changes the speed of the rotational driving force transmitted from the electric device to the constant speed input shaft and the variable speed input shaft and transmits the rotational driving force to a driven object via an output shaft; a power supply unit that supplies power at a constant rated frequency from a power source to the electrically driven device when the electrically driven device is started; The electrically powered device is a constant speed motor having a constant speed rotor that rotates the constant speed input shaft of the transmission; a variable speed motor having a variable speed rotor connected to the variable speed input shaft of the transmission device, the variable speed motor functioning as a generator in a generator mode and as a motor in a motor mode; the constant speed rotor, the variable speed rotor, the constant speed input shaft, the variable speed input shaft, and the output shaft are arranged on the same axis; the power supply unit is connected to the constant speed motor and the variable speed motor, and when starting the electric device, supplies starting power to the constant speed motor and the variable speed motor, and then supplies power generated by the variable speed motor in the generator mode to the constant speed motor; The power supply unit an inverter connected to the power source to generate power to be supplied to the constant speed motor and the variable speed motor; a first wiring that connects the inverter and the variable speed motor; a second wiring branching from the first wiring between the inverter and the variable speed motor and connected to the constant speed motor; a first switch disposed on the second wiring and capable of switching a state of power supply from the inverter to the constant speed motor between an on state and an off state; a third wiring connecting the power supply and the constant speed motor; a second switch disposed on the third wiring and capable of switching the state of power supply from the power source to the constant speed motor between an on state and an off state; a control device that controls switching of the first switch and the second switch, The variable speed motor is supplied with power only from the first wiring, and the first wiring does not have a switch that can switch the power supply state between an on state and an off state.

2. 2. A variable speed step-up gear as described in claim 1, wherein the control device changes the second switch from an off state to an on state and the first switch from an on state to an off state when the frequency of the power generated by the inverter is synchronized with the frequency of the drive power supplied from the power source.

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