JPS599479B2 - electric hoist - Google Patents

Description

[Detailed description of the invention] This invention relates to improvements in electric hoists.

Conventionally, the first electric hoist and its control circuit of this type
There was something shown in the figure.

In the figure, 51 is a speed setting device such as a potentiometer operated by a control lever (not shown), etc., 52 is a matching point, 53 is an amplifier, 54 is a phase controller, 55 is a control element such as a thyristor, 56 is an electric motor, 57 is this electric motor 56
58 is a clutch connected to the electric motor 56 when the electric motor 56 rotates in reverse, and 59 is a clutch 58? 60 is an output shaft of a reducer (not shown) connected to the electric motor 56; 61 is an arm having a parallelogram link mechanism; A balance weight 63 is used for balancing, 64 is a load, and a hook 65 for hanging the load 63 is a cooling fan for cooling the electric motor 56.

Next, the operation will be explained.

The voltage e1 set by the speed setting device 51 is
The phase controller 54 outputs a gate signal with a phase angle θ1 proportional to e4 and controls the firing angle of the control element 65, and applies it to the motor 56. Do 1
The charging pressure is controlled to control the torque generated by the electric motor 56.

The electric motor 56 receives an acceleration torque due to the torque difference from the load 63, and rotates while accelerating.

Is that the tachometer generator 57? Voltage e according to rotation speed
2 & output and give negative feedback.

By the way, at the meeting point 52, e1 and e2 are compared, and the rotational speed of the electric motor 56 increases, and when both e and e2 become 0, the electric motor 56 rotates at a constant speed.

Here, when the speed setting device 51 is returned to the neutral point, it becomes e1-0, so the torque generated by the electric motor 56 and the torque from the load 63 are not balanced, so the electric motor 56 rotates in the opposite direction with the torque from the load 63. As a result, the load drop detector 59 connected by the clutch 58 is displaced and the output voltage e
Generates 3.

This e3 is input to the abutting point 52 and rotates the electric motor 56 in the winding direction.

At this point, e3=0 and the electric motor 56 stops.

By repeating this, you become suspended in the air and balance.

Note that the load drop detector 59 only needs to output a predetermined voltage sufficient to rotate the electric motor 56 in the winding direction.
The clutch 58 is engaged until a predetermined rotational angle, that is, the rotational angle at which the load drop detector 59 outputs the predetermined voltage, but when the rotational angle is exceeded, the clutch 58 slips.

Therefore, the output e of the speed setter 51 becomes the same as e3 above.
1 This is the play allowance for the cut speed setting device 51.

By the way, during the lowering operation, since the above-mentioned rotation angle is naturally exceeded, the speed setter 51 is operated by outputting e1 which is larger than e3.

Conventional electric hoists are configured as described above, so when a load is suspended in the air, the electric motor generates torque in a restrained state and is balanced with the load. It has the disadvantage that it requires several times the capacity compared to the previous model, and requires additional cooling using a cooling fan or the like.

Furthermore, in order to maintain the suspended state in a controlled manner, it is necessary to provide a load drop detector and a clutch, and unless a closed loop is formed using a tachogenerator, hunting will occur, which is a practical problem.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it is possible to reduce the capacity of the electric motor, eliminate the need for a load drop J detector, a clutch, etc., and make the structure simple and inexpensive. The purpose is to provide a hoist.

In order to achieve the above object, the present invention provides a structure in which a load side portion of a rotor shaft of the electric motor is supported on a support fixed to a frame of the electric motor that rotates in forward and reverse directions, and a load side end of the rotor shaft is provided with a first helical gear that generates an axial thrust toward the load side when pulling up and toward the free side when pulling down, and further,
It has a second helical gear at one end that meshes with the first helical gear and generates an axial thrust toward the one end when pulling up, and a third helical gear at the other end that generates an axial thrust toward the one end when pulling up. a first gear shaft having a helical gear, a moving means for lifting and lowering a load by suspending it, and a group of gears meshing with the third helical gear to transmit rotational force to the moving means. a braking member disposed concentrically around the outer periphery of the rotor shaft, one side of which abuts against a braking surface formed on the support; a one-way engagement mechanism that engages the braking member; and a one-way engagement mechanism that is fitted to one end of the first gear shaft, and when the first gear shaft receives an axial thrust toward its one end, the braking member and the other A brake butt is provided to press one side of the braking member against the braking surface of the support, and the axial thrust of the third helical gear is greater than the axial thrust of the second helical gear. As a large configuration, a brake mechanism built into the electric hoist allows the electric motor to operate in full force both during lifting and lowering.

Also, a speed command device that outputs a speed command signal, a phase control device that outputs the speed command signal after controlling its phase according to the magnitude thereof, and a firing control device that controls the firing according to the output signal of this phase control device. The motor is equipped with a semiconductor control device that controls the input voltage of the motor, and performs circular control of the motor.

An embodiment of the present invention will be described below with reference to FIGS. 2 to 4.

In FIG. 2, reference numeral 8 indicates a commutator motor 56 (
(hereinafter referred to as electric motor 56), with an opening 8a at one end.
I have k.

Reference numeral 10 denotes a stator core 12 tightly fitted to the inner circumferential surface of the frame 8.
is an armature paired with this stator core 10, 13 is a rotor shaft fitted to this armature 12, and 36 is a hollow paper bracket screwed and fixed to the opening 8a side of the frame 8. The rotor shaft 1 is supported by a support body (hereinafter referred to as a bracket)
The load side (output side) portion of No. 3 is supported by a bracket 36 via a bearing 14, and the free side portion is supported by a frame body 8 via a bearing 15.

36a is a braking surface formed on one side of the bracket 36, 37 is a flat plate portion 37a with one side (right side) in contact with the brake 36a, and the outer peripheral surface of the cylindrical portion 37b in the hollow portion of the bracket This is a braking member that is loosely fitted into the rotor shaft 13 and located concentrically with the rotor shaft 13.

38 is the cylindrical portion 3 of the rotor shaft 13 and the braking member 3γ.
7b, and the winding drum 32 is provided between the rope 34 and the inner peripheral surface of the rope 34.
a one-way engagement mechanism 13 consisting of a one-way roller clutch that engages the rotor shaft 13 and the braking member 37 when the winding drum 37 is lowered and rotated in a direction away from the load drum 32;
a is a left-handed helical gear engraved on the load side end of the rotor shaft 13, which is connected to the flat plate portion 3 of the brake member 37;
It protrudes from the outer end surface of 7 a, and is attached to the load side (
axial thrust is generated to the free side (right side) when lowering.

The winding drum 32 and the rope 34 are means of movement for lifting and lowering the load 63 by suspending it. Configure.

39 has one end screwed to the bracket 36, and the other end fitted into the through hole 1C of the housing 1 and screwed to the left side wall 1e of the housing 1 in FIG. A frame body consisting of a gear box (referred to as the actual lower gear box), 23 is this gear box 39
A first rotatably supported via ball bearings 25 and 26
A gear shaft having a right-handed second helical gear meshing with the first helical gear 13a at one end, and a left-handed third helical gear at the other end. has been done.

Reference numeral 40 denotes a brake butt fitted to one end of the rotating shaft 23, that is, the end on the fitting side of the second helical gear 21; surface).

41 is a second gear shaft installed in the left side wall 1e of the frame 1, 31 is a right-handed fourth helical gear rotatably supported by the second gear shaft 41, and 42 is a right-handed fourth helical gear. A right-handed fifth helical gear 43 is integrally formed with the fourth helical gear 31 and rotatably supported by the second gear shaft 41; This is a left-handed sixth gear that is fitted onto a protruding portion of the winding drum shaft 28 that protrudes from the outer end surface of the wall portion 1e.

The fourth to sixth helical gears 41 to 43 are the third gears.
Is this a gear group that meshes with the helical gear 24 and transmits information to the winding drum 32N? Configure.

In the device configured in this way, as shown in FIG. 4, when hoisting the load 63 suspended on the hook 64 with the rope 34, the speed setting device 51, which is a speed command device, is adjusted and the phase control The conduction angle of the control element 55, which is a semiconductor control device, is controlled by the signal from the electric motor 56.
Speed control is performed by adjusting the voltage.

At this time, the armature 12, rotor shaft 13, and first gear wheel 13a shown in FIG. 2 rotate counterclockwise (leftward) when viewed from the commutator side (right side), and the second Helical gear 2
7 and the third helical gear 24 rotate clockwise (rightward), and the fourth helical gear 31 and the fifth helical gear 4
2 rotates counterclockwise (leftward), and the sixth helical gear 43 and winding drum 32 rotate clockwise (rightward),
The load 63 suspended on the hook 64 in FIG. 4 will be hoisted up.

In this case, the axial thrust on the rotor shaft 13 in FIG. The axial thrust applied to the first gear shaft 23 is the sum of the axial thrust caused by the second helical gear 27 and the axial thrust caused by the third helical gear 24. acts in the right direction, and the braking member 37 hits the braking surface 3 via the brake pad 40.
Press 6a.

However, in this case, the one-way engagement mechanism 38 is disconnected and the braking torque is small, so the rotor shaft 13 overcomes this braking torque and rotates the winding drum 32 in FIG. , the load will be hoisted at variable speed.

Conversely, when driving the electric motor 56 shown in FIG. 4 to lower the load 63 suspended from the hook 64, a motor winding polarity switch (not shown) is switched to output a command for reverse rotation. Then, the rotor shaft 13 and the first helical gear 13a shown in FIG. 3 rotate in the opposite direction to those described above, and the winding drum 32 rotates in the lowering direction, thereby lowering the load.

The axial thrust force applied to the first gear shaft 23 in this case will be explained below.

The armature 12, rotor shaft 13, and first helical gear 13a rotate clockwise (rightward) when viewed from the commutator A side, and the second
The helical gear 27 and the third helical gear 24 rotate counterclockwise (leftward), and the fourth helical gear 31 and the fifth helical gear 42 rotate clockwise (rightward). Rotate to .

In this case, the axial thrust to the rotor shaft 13 is directed to the right (free side) in FIG. 3, the axial thrust by the second helical gear 27 is directed to the left (towards the other end), and The axial thrust by the gear 24 acts in the right direction (towards one end).

Since the relationship is axial thrust by the second helical gear 27 and axial thrust by the third helical gear 24, the resultant axial thrust acts in the right direction in FIG. 3.

This combined axial thrust causes the brake pad 40 to press the other side (left side) of the braking member 37, thereby bringing one side (right side) of the braking member 37 into pressure contact with the braking surface 36a.

In this case, the one-way engagement mechanism 38 engages the rotor shaft 13 and the brake member 37, so the brake member 37 rotates together with the rotor shaft 13 while being pressed against the brake surface 36a.

That is, the electric motor 56 is in continuous operation.

This forward driving operation can be controlled by simple phase control similar to the forward driving operation in the hoisting direction.

Next, as shown in FIG. 4, in the suspended state during the process of hoisting up or lowering the load 63 with the electric motor 56,
Similarly to the lowering direction described above, the brake pad 4 in FIG.
With a brake torque of 0, dog cargo can be easily held.

In this embodiment, a commutator motor is used as the motor, but a reversibly rotatable single-phase or three-phase induction motor may also be used.

Furthermore, the rotational direction control method is not limited to armature winding polarity switching, but may also be polarity switching and current direction switching using a semiconductor switch or the like, and is not particularly limited.

Furthermore, in the above description, the moving means was composed of a winding drum and a rope, but as shown in FIG. 61 and a shaft 60 connected to a rotating body.

As explained above, according to the present invention, the brake mechanism built into the electric point allows the electric motor to operate in full force both during hoisting and when hoisting down. Not only does it eliminate the need for a load drop detector, clutch, and cooling fan, but it also reduces the capacity of the motor, making it more compact and inexpensive. Since the motor is held in place, it is not necessary to operate the electric motor in a restrained state as in the conventional case, and there is an effect of power saving.

Further, the brake butt is fitted onto and held at one end of the first gear shaft, and is located between the one end and the braking member, so that it can be used to connect the brake butt and the first gear shaft. There is no need for any parts for the
- As disclosed in Publication No. 115065, the structure is extremely simple compared to the one in which the brake butt and the drive shaft (corresponding to the above-mentioned first gear shaft) are connected by a coupling, a guide, etc. be.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional device, FIG. 2 is a partially sectional front view showing an embodiment of the present invention, FIG. 3 is an enlarged sectional view of the main part of FIG. 2, and FIG. An embodiment of the invention? FIG. 5 is a block diagram showing another embodiment of the present invention. 13 is a rotor shaft, 13a. 27, 24.31.42.4
3 are first, second, third, fourth, fifth, and sixth rotating bodies, 23 is a first gear shaft, 32 and 34 are moving means, 36 is a support, 36a is a braking surface, 37 38 is a braking member, 38 is a one-way engagement mechanism, 40 is a brake butt, 51 is a speed command device, 54 is a phase control device, 55 is a semiconductor control device, 56
is the electric motor, and 63 is the load. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1. The load end of the rotor shaft of the motor is supported by a support fixed to the frame of the motor that rotates in forward and reverse directions. A first helical gear that generates an axial thrust to each side is provided, and a second helical gear that meshes with the first helical gear at one end and generates an axial thrust to the one end side during pulling. a first gear shaft having a helical gear and a third helical gear at the other end that generates an axial thrust toward one end during pulling; a moving means for lifting and lowering by suspending a load;
a gear group that meshes with the third helical gear and transmits rotational force to the moving means; and a group of gears that are arranged concentrically around the outer periphery of the rotor shaft, and one side of which is in contact with a uniform surface formed on the support. a braking member in contact with the rotor shaft; a one-way engagement mechanism that engages the rotor shaft with the braking member when the rotor shaft rotates in the pulling direction; When one gear shaft receives the same axial thrust at one end, does the braking member move toward the other side? A brake butt that presses one side of the braking member into contact with the braking surface of the support, a speed command device that outputs a speed command signal, and a phase control of the output signal of the speed command device according to its magnitude. The input voltage of the electric motor is controlled according to the output signal of this phase control device, and the input voltage of the motor is controlled according to the output signal of this phase control device. and a semiconductor control device for controlling the electric hoist, wherein the axial thrust of the third helical gear is set to be larger than the axial thrust of the second helical gear.