JPS6173569A - Prime mover drive power transmission - Google Patents

Abstract

PURPOSE:To efficiently rotate a load by using two rotors which relatively rotate, electromagnetically coupling them, driving a load by electromagnetically coupling by a prime mover, and further using a wound-rotor type induction motor. CONSTITUTION:An armature winding is provided in one 3 of two opposed rotors 2, 3 which relatively rotate, and the rotors 2, 3 are coupled by an electromagnetic joint 1. a rotor 3 is coupled by a gear unit 8 with the rotor of a rotary electric machine 7 having a stator, and also coupled with a load 11. The machine 7 drives the load 11 by power received by the joint 1. A wound-rotor type induction motor is used in the machine 7, and a resistor 16 is connected to the secondary circuit.

Description

[Detailed Description of the Invention] When transmitting power from a prime mover to a load, an attempt was made to transmit power while decelerating by using an electromagnetic mechanical connection without using a gear device, as shown in Patent Application Publication No. 62 of 1971, etc. However, when the rotational speed of the load is low, the size of the rotating electrical machine connected to the electromagnetic coupling becomes very large, which not only results in an uneconomical device but also reduces efficiency. . In order to improve this problem, Japanese Patent Application Publication No. 56-29500 cleverly combined a gear device between an electromagnetic coupling and a rotating electric machine. According to this, one of the rotors of an electromagnetic coupling having two opposing rotors that rotate relative to each other is coupled to the rotor of a rotating electric machine having a stator through a gear system. It is also mechanically coupled to a load, further arranged so that the other rotor of the electromagnetic coupling is driven and rotated by a prime mover, and electrically connected between the rotating electric machine and both armature windings of the electromagnetic coupling. are doing.

Let's take ship propulsion as an example. To save energy,
The main type of marine propulsion engine has become the diesel engine, but there are two types of diesel engines: a 4-stroke engine with a speed of about 400 rpm, and a 1-cycle engine with a speed of about 400 rpm.
Two-cycle engines with a speed of about 1,000 rpm are considered to be the two types of current large-capacity diesel engines. The recent trend is to reduce the rotation speed of the propeller of a ship driven by such a diesel engine by half the rotation speed of the diesel engine, to about 200 rpm from 400 rpm, and about 50 rpm from 100 rpm.

The present invention relates to a power transmission device in which a load is driven by such a prime mover.

This will now be explained with reference to FIG. 1, which is an example of a specific electrical connection diagram of the present invention. In FIG. 1, one rotor 2 of the electromagnetic coupling 1 is driven by the prime mover 4. When driven at a rotational speed of rpm, the other rotor 3 rotates at n2. -n2 speed difference n1
As a result, the electromagnetic coupling 1 outputs the generated power to the outside of the slip ring 6, and the rotating electrical machine 7 receives the power. A current flows through the armature winding of the rotor 3, and an electromagnetic joint action is established between it and the field poles of the rotor 1, and the rotational speed n of the prime mover 4 increases.

Torque is transmitted from the load side rotor 3 of the electromagnetic coupling 1 through the shaft 14 directly toward the load 11 by n2 of the
Electric power is supplied from the electromagnetic coupling 1 to the rotating electric machine 7.

If the rotating electrical machine 7 is now a synchronous motor, the following relationship holds true.

n1=n0-n2 (1) 120f=
p1n1 (2) n2×r=n3
(3) n3p2=120f
(4) Where, f is the frequency of the AC power in the electrical connection line 15, p1 and p2 are the numbers of poles of the electromagnetic coupling 1 and the rotating electrical machine 1, respectively, and n3 is the rotational speed of the rotating electrical machine 7.
r is the reduction ratio of the gear device 8. Substituting equation (3) into equation (4) and comparing it with equation (2), n1=n2×r×p2
/p1 (5) From equations (1) and (5), n0=n2 (r×p2/p1+1) (6) Reverse the connection between the electromagnetic coupling 1 and the armature windings of the rotating electrical machine 7 using the electrical connection wire 15. When connected in phase order, the rotation direction of the prime mover 4 and the rotation direction of the load 11 are opposite to each other, and equation (1) becomes n0+n2.
= n1, and equation (6) is n0 = n2 (r×p2/p
1-1). However, in order to obtain such a situation, certain conditions are required, as will be described later.

When the rotational speed of the prime mover 4 is 100 rpm and the rotational speed of the load 11 is 50 rpm, in the above equation (6), r=
8, p1=32, p2=4. That is, when transmitting power from the low-speed prime mover 4 to the low-speed load 11,
Only the electromagnetic coupling 1 is a multi-pole machine, and the rotating electric machine 7 can be easily manufactured as a small-pole machine, making it a low-cost, high-efficiency machine.

In this way, the method disclosed in Patent Application Publication No. 56-29500 can in principle produce a good power transmission device, but as explained above, the rotational speed n0 of the prime mover 4 and the rotational speed n2 of the load 11 are When the speed ratio is around 2:1, (6)
According to the formula, the value of r×p2/p1 must be close to 1. In other words, the torque output from the load-side rotor of the electromagnetic coupling 1 and the torque output from the output shaft of the rotating electric machine 7 via the gear device 8 to the load 11 are approximately equal. Although such a situation is preferable when the rotational direction of the load 11 is the same as the rotational direction of the prime mover 4, it is not preferable when the rotational direction of the load 11 is reversed. At the time of reversal, it is preferable that the value of rxp2/p1 be 3 or more, as seen from the equation n0=n2 (rxp2/p1-1) described above. In other words, unless the value of n0/n2 becomes greater than 2,
In the case of a ship's propeller, its output exceeds the engine's running output. However, when moving forward, r×p2/p
If the value of 1 is 1, and the value of r×p2/p1 at the time of reverse rotation is 3 or more, the number of poles of the electromagnetic coupling 1 or the rotating electrical machine 7 is changed, and the number of poles is changed by the armature winding. This also requires complicated pole number conversion, which requires the provision of double wires. In particular, changing the number of poles of the electromagnetic coupling 1 is not preferable because it requires doubling not only the slip ring 6 of the rotor 3 but also the slip ring 5 of the rotor 2. It is extremely preferable to change the rotational direction of the load 11 without changing the rotational direction of the prime mover 4 using a device as simple as possible. Moreover, it is preferable that the efficiency is as high as possible when the rotation direction of the prime mover 4 and the rotation direction of the load 11 are the same direction.

An object of the present invention is to produce a power transmission device that drives a load 11 from a prime mover 4, and to efficiently rotate the prime mover when the rotation direction of the prime mover 4 and the rotation direction of the load 11 are driven in the same direction. It is an object of the present invention to implement an arrangement in which the direction of rotation of the load 11 and the direction of rotation of the load 11 can be reversed with the simplest possible device.

In order to achieve such an object, the present invention has two rotors 2 and 3 facing each other, which rotate relative to each other, as shown in FIG. Either rotor 2 or 3 (3 in the diagram)
One of the rotors 3 of the electromagnetic coupling 1 is provided with an armature winding, and one rotor is driven to rotate relative to the other rotor. and is mechanically coupled to the load 11 through the gear device 8, and is further arranged so that the other rotor 2 of the electromagnetic coupling 1 is driven and rotated by the prime mover 4, thereby A load 11 is driven from the prime mover 4 through the electromagnetic coupling 1, and an electrical connection is made between both armature windings of the rotating electrical machine and the electromagnetic coupling, so that the rotating electrical machine 7 is driven by the electromagnetic coupling 1. In the arrangement in which the load is driven by the electric power generated, the rotary electric machine 7 is a wound induction motor, and the arrangement is such that the resistor 16 is connected to the secondary circuit thereof.

Now, let's think about what kind of effect it would have if we had an array like this. For example, when the rotation speed of the prime mover 4 is 400 rpm and the rotation speed of the load 11 is 200 rpm, the load 1
If the rotation direction of the motor 1 is the same as the rotation direction of the prime mover 4, then r×p2/p1=1 from equation (6), and the electromagnetic coupling 1
The output of the load-side rotor 3 and its electrical output, that is, the output of the motor 7, are approximately equal. That is, the output torque to the output shaft 14 to the load 11 is that the torque given from the output shaft 17 of the rotor 3 of the electromagnetic coupling 1 and the torque given from the rotating electric machine 7 via the gear device 8 are approximately equal. Gear device 8
obtains a reduction ratio r by the large gear 9 and pinion 10 that constitute it. Excitation current is supplied from the outside to the field winding through the slip ring 5 of one rotor 2 of the electromagnetic coupling 1. In this way, when the load 11 rotates in the normal direction, the output of the rotating electric machine 7 takes on 1/2 of the output of the entire prime mover 4, but if this is a wound induction motor, the output is The torque applied to the load 11 is shown as t1 in FIG. In this case, equation (4) is n3p2=
120f(1-S). However, S is slip.

In Fig. 2, the horizontal axis represents slip, and the vertical axis represents torque T.

t1 in FIG. 2 is a torque curve, and T0 in the torque curve is its operating point. On the other hand, in order to reverse the rotational direction of the load 11 without changing the rotational direction of the prime mover 4, the number of poles of the wound induction motor 7 is changed. The pole conversion is shown in FIG. 3 with its primary winding. In the previous example, r=8, p1=
32, an example of p2=4 was shown during normal rotation, but this p2
is 8. When the pole number ratio is 1:2, such as 4 poles to 8 poles, the winding connection is simple, and as shown in FIG. 3, it is as follows. In other words, in the case of a four-pole structure with a small number of poles, T1, T2, and T3 are the terminals in the three-phase winding shown in Figure 3, and T
4. Make a delta connection with T5 and T6 open as they are,
In the case of eight poles, which have a large number of poles, T4, T5, and T6 are used as terminals, and T1, T2, and T3 are shorted to form a double star connection. In this way, the wound induction motor 7 has a torque characteristic of t1 in FIG. 2 when the number of poles is small, whereas it has a torque characteristic of t2 in FIG. 2 when the number of poles is large. load 1
1 is the same as the rotation direction of the prime mover 4, the torque output from the output shaft 17 of the rotor 3 of the electromagnetic coupling 1 is approximately equal to the torque T0 output through the gear device 8 of the wound induction motor 7, as described above. Since it is considered that they are equal, in such a situation, the switchgear for reverse phase connection provided in the electrical connection line 15 is not shown in the figure, but through it the reverse phase connection can be made and the number of poles can be changed as described above. If the electromagnetic coupling 1 and the wound induction motor 7 are connected using The torque from the output shaft 17 of the rotor 3 of No. 1, that is, T0, is larger than that, and the torque of the wound induction motor 7 causes the load-side rotor 3 of the electromagnetic coupling 1 to rotate in the opposite direction. The torque curves t2 to t5 in FIG. 2 can be adjusted by controlling the value of the resistor 16 connected to this secondary circuit by a control device 13 provided in the circuit exiting from the slip ring 12 of the wound induction motor 7. Therefore, at the beginning of forward/reverse conversion, if the value of the resistor 16 to be inserted is adjusted to place it on the curve from t5 to t4 where the highest torque value is reached at the point S>1, the load 11 can be easily reversed. Become.

In this way, the forward/reverse conversion of the wound induction motor 7 can be easily performed by changing the number of poles to the simplest 1:2 pole number ratio and inserting a secondary circuit resistor, but this is in an extremely transient state. A little loss is not a problem. However, during steady state when the rotational direction of the load 11 is the same as the rotational direction of the prime mover 4, the operating efficiency is a problem. Therefore, it is preferable that the secondary circuit of the wound induction motor 7 is supplied with a DC excitation current from a DC power supply 15 as shown in FIG. In Fig. 1, in the secondary three-phase winding of the wound induction motor 7, the two-phase winding terminals are short-circuited, a DC voltage is applied between this and the other single-phase winding, and a DC excitation current is generated. supply In this way, during steady state, the wound induction motor 7 can be efficiently operated as a synchronous motor having field poles excited by direct current. In the case of a synchronous motor whose field poles are DC-excited in steady state, it can be operated relatively efficiently even if the gap distance between the stator and rotor is somewhat large. Therefore, even if the capacity of the wound induction motor 7 becomes large, for example, 500 KW or 1000 KW, it can be easily manufactured.

The effects of the present invention can be summarized as follows.

(1) When the load 11 is driven by the prime mover 4 as shown in FIG. The rotational direction of the load 11 can be changed smoothly in a transient state in which the rotational direction of the load 11 is opposite to the rotational direction of the prime mover 4 while increasing the motion efficiency in a steady state where the driving direction is the same as the rotational direction of the prime mover 4. It can be reversed.

(2) The above-mentioned operation can be realized with a simple device and the device can be inexpensive.

[Brief explanation of the drawing]

Fig. 1 is an example of a specific electrical connection diagram of the present invention, Fig. 2 is an example of a characteristic diagram of an induction motor used in the device of the present invention, and Fig. 3 is a wound wire induction motor used in the device of the present invention. FIG. 3 is a diagram for explaining switching of armature winding connections of a motor. In addition, the symbols representing the main parts in the figure are as follows. 1: Electromagnetic coupling, 2, 3: Electromagnetic coupling rotor, 4: Prime mover, 5: Slip ring, 6: Slip ring, 7
: Wound induction motor, 8: Gear device, 9: Large gear forming gear device 8, 10: Pinion forming gear device 8, 11: Load, 12: Slip ring of wound induction motor 7, 13: Winding Control device for linear induction motor 7, 14: Output shaft, 15: Electrical connection line, 16: Resistor,
17: Load side rotor output shaft of electromagnetic coupling 1, T1, T
2, T3, T4, T5, T6: terminal, T0: operating point on torque curve, t1, t2, t3, t4, t5: torque curve

Claims (1)

[Claims] An electromagnetic joint that has two rotors that rotate relative to each other, and that has an armature winding on at least one of the rotors, and drives and rotates one rotor relative to the other rotor. One of the rotors of the electromagnetic coupling is coupled to the rotor of a rotating electric machine having a stator through a gear system, and is also mechanically coupled to the load, and the other rotor of this electromagnetic coupling is The rotary electric machine is arranged so as to be driven and rotated by a prime mover, thereby driving a load from the prime mover via the electromagnetic coupling, and the rotary electric machine and the armature windings of the electromagnetic coupling are electrically connected to each other. In an arrangement in which the rotating electric machine drives a load using electric power received from an electromagnetic coupling, the rotating electric machine is a wound induction motor,
A prime mover drive power transmission device arranged in such a way that a resistor is connected to its secondary circuit.