JPH064478B2 - Electric hoist - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electric hoisting device such as an electric chain block.

[Problems to be Solved by Conventional Techniques and Inventions]

Generally, in electric hoisting equipment, the limit switch for upper limit and lower limit is provided to stop the chain, but this limit switch is abolished in small and simple electric hoisting equipment Instead, a torque limiter with adjustable torque is often used.

For example, Japanese Patent Publication No. 57-25475 and Japanese Unexamined Patent Publication No.
In the torque limiter described in Japanese Patent Laid-Open No. 1-197395, the cover has to be removed every time the torque setting is changed and adjusted, which is troublesome. In addition, a special tool is required for this torque adjustment, and it is necessary to apply a large torque,
The work was even more troublesome.

Then, this invention aims at solving the said problem.

[Means for Solving the Problems]

In order to achieve the above object, the present invention relates to an electric hoisting device in which a load sheave is driven by a motor through a reduction gear mechanism, and a motor output shaft and a single shaft that meshes with the motor output shaft. A friction gear that rotates around the center, a pair of holding plates that sandwich the friction gear via friction plates, and a substantially conical taper that is arranged in a direction orthogonal to the one axis and has an inner end portion. A torque adjusting shaft with a threaded portion, and a spherical cover that contacts the outer surface of the tapered portion to change the pressing force of the torque adjusting shaft at a right angle and presses one of the holding plates toward the friction gear. A contact member and a reaction force elastic member that intermittently presses the other pressing plate toward the friction gear, and the rotation concave portion at the outer end of the torque adjusting shaft is always outside the machine body. Exposed.

[Action]

Since the rotation recess at the outer end of the torque adjustment shaft with a screw arranged in the direction orthogonal to the one axis is always exposed to the outside, immediately (without removing the cover etc.) It can be rotated with a tool. Also,
Even if another object hits the rotating recess, there is no risk that the torque adjustment shaft will rotate unintentionally. When the torque adjustment shaft is screwed with a general tool such as a screwdriver, the taper part presses the spherical contacted body in the direction of the uniaxial center orthogonal to the torque adjustment shaft, and the spherical contacted body presses one pressing plate. And press it further toward the friction gear side through the friction plate. The other pressing plate is elastically pressed by the reaction force elastic member, and is pressed in the opposite direction by the same force by the reaction. To reduce the torque, conversely, the torque adjusting shaft may be screwed back.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIGS. 1, 2, and 3 show an embodiment of the electric hoisting device according to the present invention. The electric hoisting device includes a machine body 12 having a reduction gear mechanism and the like built therein, a motor 7 laterally mounted to the machine body 12, a switch base 14 mounted laterally opposite thereto, and a switch therefor. The cover 15, the chain 42 suspended from the machine body 12, and the load hook at the lower end of the chain 42
43 and an operation push button switch 17 hanging from the switch base 14. Reference numeral 19 is a hook for suspending the electric hoist on a ceiling or the like. 18 is a chain storage bag of the wound load sheave 8. Reference numeral 13 is a power cable, and 16 is a wiring cable from the switch base 14 to the motor 7. Road sheave 8 inside the fuselage 12 (see Fig. 3)
In addition, the chain 42 is suspended.

FIG. 3 shows the reduction gear mechanism and the torque adjusting device. The electric hoisting device of the present embodiment includes a motor output shaft 5, a driven shaft 26 parallel to the motor output shaft 5, a friction gear 4 rotatably fitted on the driven shaft 26, and a pair of annular rings contacting both surfaces of the motor output shaft 5. The friction plates 6 and 6 and one of the friction plates 6 are fixed to each other, and serrations are formed on the inner peripheral surface of the driven shaft 26 so that the friction plates 6 are externally fitted to the serrated portion of the driven shaft 26. The substantially annular holding plate 10 and the other friction plate 6 are fixed to each other, and the substantially annular holding plate 11 has serrations on the inner peripheral surface thereof so as to be externally fitted to another serration portion of the driven shaft 26.
A threaded torque adjusting shaft 1 which is disposed in a direction orthogonal to the axis l of the driven shaft 26 and has a substantially conical taper portion 2 formed at its inner end, and a threaded portion of the shaft 1. A torque adjusting collar 20 having a screw hole 40 into which 1a is screwed and a circumferential projection 39 is formed, and the pressing force of the torque adjusting shaft 1 is changed to a right angle by coming into contact with the outer surface of the taper portion 2. Spherical contacted body 3, holding disc 22 having a recess 23 formed in the center, and thrust bearing abutting this
24, a ball bearing 25 adjacent thereto, and a reaction force elastic member 9 such as a disc spring. The torque adjusting shaft 1 has a circumferential groove 38 formed in an intermediate portion thereof.
An O-ring 21 for sealing is externally fitted on the 38, and a rotation concave portion 41 of one character or a cross is formed on the upper end edge,
It is always exposed to the outside of the airframe 12. The torque adjusting collar 20 is fixed to the machine body 12 with bolts 36, 36, and the screw portion 1a of the torque adjusting shaft is inserted in the screw hole 40 so as to be able to advance and retract. Thus, the axis m of the torque adjusting shaft 1 is orthogonal to the axis l of the driven shaft 26, and the rotation recess 41 at the outer end thereof is always exposed to the outside of the machine body 12.

Friction gear 4 meshing with the motor output shaft 5
Is mounted rotatably around the axis l of the driven shaft 26, and the friction gear 4 is provided with a pair of pressing plates 1 through friction plates 6 and 6.
It is held between 0 and 11.

The torque adjustment is performed by moving the screwed torque adjustment shaft 1 back and forth. That is, when the tip of the driver is inserted into the rotation concave portion 41 at the outer end exposed to the outside of the torque adjusting shaft 1 and rotated and screwed, the tapered portion 2 presses the spherical contacted body 3. As a result, the pressing force is redirected at a right angle. Next, the spherical contacted body 3 presses the holding disk 22, and the holding disk 22 presses the inner ring 25a of the ball bearing 25 via the thrust bearing 24. That is, there is a minute gap between the outer ring and the thrust bearing 24. Next, the inner ring 25a of the ball bearing 25 presses the circumferential ridges 37 of the pressing plate 10 to press the friction plate 6 of the pressing plate 10 against the friction gear 4. Since the pressing plate 11 is elastically pressed by the reaction force elastic member 9, it is pressed against the friction gear 4 by a reaction (via the friction plate 6). On the contrary, in order to weaken the torque, similarly, the tip of the driver may be inserted into the rotating portion 41 and the torque adjusting shaft 1 may be screwed back along the screw hole 40.

The rotation of the motor output shaft 5 is transmitted to the friction gear 4 and further transmitted to the driven shaft 26 via the friction plates 6 and 6 and the pressing plates 10 and 11. The rotation of the driven shaft 26 is transmitted to the load gear 28 by the pinion gear 27, rotates the load sheave shaft 29, and the load sheave 8 rotates. 33 is a ratchet wheel and 34 is a disc hub. 35 is an oil seal.

If excessive load is applied to the load sheave 8 due to the upper and lower limits of hoisting and unwinding the chain 42,
Sliding occurs on the contact surface between the friction gear 4 and the friction plates 6 and 6, and the rotation of the motor output shaft 5 is not transmitted to the pressing plates 10 and 11 but cut off. This protects the motor 7 without burning.

It should be noted that the present invention is not limited to the above-described embodiments, and design changes can be freely made without departing from the gist of the present invention. For example,
Fix the friction plates 6 and 6 on both sides of the friction gear 4,
When an excessive load is applied to the load sheave 8 between the friction plate 6 and the pressing plate 10 and between the friction plate 6 and the pressing plate 11, slippage occurs and the driving force is cut off. That also
desirable.

〔The invention's effect〕

Since the present invention is configured as described above, it has the significant effects described below.

When rotating the torque adjustment shaft 1 with a screw, the motor and the switch cover, which are located outward in the direction of the uniaxial center l, can be kept out of the way and can be easily and quickly externally removed without removing those covers. Torque can be adjusted.

Even if another object hits the outer end portion of the threaded torque adjustment shaft 1, the shaft 1 can be prevented from rotating unexpectedly, and the torque adjustment error can be prevented.

(Because the reaction force of the force that presses the pressing plate 10 acts in the direction orthogonal to the direction in which the threaded torque adjustment shaft 1 moves forward and backward) The shaft 1 can be rotated with a small force, and torque adjustment is facilitated. You can do it.

Compared with the displacement of the threaded torque adjustment shaft 1 in the screw advancing / retreating direction, the displacement of the spherical contacted body 3 in the direction of the uniaxial center l can be smaller, and the torque can be finely adjusted.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention, FIG. 2 is a side view, and FIG. 3 is an enlarged main part sectional plan view for explanation. 1 ... torque adjusting shaft with screw, 2 ... taper part, 3 ...
Spherical contacted object, 4 ... Friction gear, 5 ... Motor output shaft, 6 ... Friction plate, 7 ... Motor, 8 ... Road sheave, 9 ...
Repulsive elastic member, 10, 11 ... Presser plate.

Claims (1)

[Claims] 1. An electric hoisting machine in which a load sheave 8 is driven by a motor 7 via a reduction gear mechanism, wherein a motor output shaft 5 and a uniaxial center l around which the motor output shaft 5 meshes. And a pair of pressing plates that sandwich the friction gear 4 via friction plates 6 and 6.
10, 11 and a threaded torque adjusting shaft 1 which is disposed in a direction orthogonal to the one axis l and has a substantially conical taper portion 2 formed at the inner end thereof, and the outside of the taper portion 2. The spherical contacted body 3 that abuts against the side surface to change the pressing force of the torque adjusting shaft 1 to a right angle and presses the one pressing plate 10 toward the friction gear 4 side, and the other pressing plate 11 to the friction gear. 4 is a reaction force elastically pushing member 9 that elastically presses to the 4 side, and the rotation recess 41 at the outer end of the torque adjusting shaft 1 is always exposed to the outside of the machine body 12. An electric hoist.