JPH0138144Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to an improvement of an electric hoist.

[Conventional technology]

FIG. 1 is a sectional view showing the prior art disclosed in Japanese Utility Model Application Publication No. 55-113388.
1 is a motor for hoisting and lowering, 2 is a frame of this motor 1, 3 is a load-side bracket screwed to one end surface of this frame 2, and 4 is fitted to the inner peripheral surface of the frame 2. 5 is a stator winding wound around this stator core 4, 6 is a rotor core that is paired with the stator core 4, and 7 is a rotating shaft fitted to this rotor core 6. One end of the child shaft is rotatably supported by a load side bracket 3 via a ball bearing 8. 9 is a frame to which the electric motor 1 is screwed on one end and the gear box 11 of the gear reduction gear 10 is screwed on the other end;
12 is a first shaft joint fitted to one end of the rotor shaft 7; 13 is a long intermediate shaft fitted to the other end of the first shaft joint 12; and 50 is this intermediate shaft 13. The second shaft joint is fitted with a toothed portion 50 on the outer periphery.
a is formed. 51 is a planetary gear engaged with this tooth portion 50a, 52 is an internal gear engaged with this planetary gear 51, 53 is an internal gear that is engaged with the planetary gear 51, and 54 is connected with this internal gear 53. a connecting shaft 55, a bearing supporting the connecting shaft 54;
Reference numeral 56 denotes a winding drum connected to the connecting shaft 54; 57 has one end connected to the winding drum 56 and a middle part wound around it, suspending the hook block, and the other end connected to the frame 9; The wire rope 58 is a brake shaft whose one end is fitted into the second shaft joint 50, and whose center is supported by a bearing 59. 60 is a shaft sealing device fitted to the brake box 61, and 62 is a shaft sealing device fitted to the end of the connecting shaft 54.

Next, the operation of the device configured as described above will be explained. For example, when a winding push button of a push button switch is closed, the rotor shaft 7 of the electric motor 1 rotates in the winding direction. The rotation of the rotor shaft 7 is as follows: rotor shaft 7 → first shaft joint 12 → intermediate shaft 13 → second shaft joint 50
The deceleration is transmitted to the tooth section 50a, the planetary gear 51, the internal gear 53, the connecting shaft 54, and the winding drum 56, and the wire rope 57 is wound around the winding drum 56 and hoists the load suspended on the hook block. Further, when the lowering pushbutton of the push button switch is closed, the rotor shaft 7 of the motor 1 rotates in the lowering direction and lowers the load suspended from the hook block through the above-mentioned path.

[The problem that the idea aims to solve]

As described above, in the conventional electric hoist, both ends of the intermediate shaft 13 are connected to the rotor shaft 7 and the planetary gear 51 via the first shaft joint 12 and the second shaft joint 50. Since the shaft sealing member 62 and the intermediate shaft 13 are formed in a long length, it is easy to run out during rotation, and as a result, the sliding contact portion of the shaft sealing member 62 with the intermediate shaft 13 is damaged early, and lubricant leaks from the gear type transmission 10. There was a problem. Further, since it is necessary to polish the sliding contact portion of the intermediate shaft 13 with the shaft sealing member 62, there is a problem that workability is extremely poor due to the long length.

This invention was made in an attempt to eliminate these drawbacks, and the purpose is to provide an electric hoist that can prevent abnormal damage to the shaft seal member and that can significantly facilitate polishing of the sliding part of the shaft seal member. do.

[Means to solve the problem]

The electric hoist according to this invention includes a frame that houses a hoisting drum and has a gear box connected to one end to drive the hoisting drum, a hoisting motor connected to the other end of the frame,
A long intermediate shaft connected to the rotor shaft of the electric motor through a first shaft joint; a hollow shaft housing the intermediate shaft and rotatably supported in the gear box; one end connected to the winding drum; a connecting shaft, a second shaft joint coupled to an end of the intermediate shaft within the connecting shaft, a pair of bearings provided at the other end of the connecting shaft and the gear box, and supported by the pair of bearings. a short drive gear shaft coupled to the second shaft joint; a gear transmission mechanism coupled to the drive gear of the drive gear shaft to transmit rotational force to the other end of the coupling shaft; and the pair of bearings. Among them, a shaft sealing member is provided close to the hoisting motor side of the bearing on the connecting shaft side and sealing between the inner circumferential surface of the connecting shaft and the drive gear shaft.

[Effect]

In the electric hoist according to this invention, the drive gear shaft is supported at two points by a pair of bearings to prevent runout, and abnormal damage to the inner circumferential surface of the shaft sealing member is prevented.
Further, the shaft sealing member can be disposed on the polished portion of the outer periphery of the bearing fitting portion of the drive gear shaft, eliminating the need for polishing the outer periphery of the long intermediate shaft.

[Example of idea]

An embodiment of this invention will be described below with reference to the drawings. In FIG. 2, 15 indicates this second shaft joint 1.
A drive gear shaft consisting of a first gear shaft with a short shaft fitted to the other end of the drive gear shaft, and one end of which is rotatably supported via a ball bearing 16 on a hollow connecting shaft 17 serving as a fourth gear shaft. The other end is rotatably supported by a bracket 19 via a ball bearing 18. 20 is a drive gear consisting of a first gear formed in the center of the drive gear shaft 15; 21 is a second gear that meshes with this drive gear 20 and decelerates the rotation of the drive gear 20; 22;
A third gear is fitted onto the second gear 21, and both ends thereof are rotatably supported by the gear box 11 and the bracket 19 via ball bearings 23 and 24. 25 meshes with the third gear 22 and the third gear 2
A fourth gear that reduces the rotation speed of the connecting shaft 17 is fitted onto the outer circumferential surface of the connecting shaft 17. In addition, gear type reduction gear 1
0 is a gear box 11, a driving gear shaft 15, a ball bearing 16,
18, 23, 24, bracket 19, drive gear 2
0, second gear 21, third gear 22, fourth gear 25
and a lubricant (not shown) sealed between the gear box 11 and the bracket 19. A winding drum 26 is connected to the connecting shaft 17 via a key 27, and a winding drum 28 has one end connected to the winding drum 26 and a middle part wound around it, suspending the hook block, and having the other end connected to the frame. Wire row connected to 9
Numerals 29 and 30 are a pair of ball bearings fitted on the inner peripheral surface of the gear box 11, and rotatably support one end of the winding drum 26, the connecting shaft 17, and the fourth gear 25. A ball bearing 31 is fitted to the inner peripheral surface of the other end of the winding drum 26, and rotatably supports the other end of the winding drum 26. 32 is a shaft sealing member made of an oil seal fitted to the inner circumferential surface of the connecting shaft 17;
The inner circumferential surface is in sliding contact with the outer circumferential surface of the drive gear shaft 15. Descriptions of other symbols are omitted as they are the same as in the conventional device.

In the configuration as described above, the shaft sealing member 32 is fitted in close proximity to the ball bearing 16, and the inner circumferential surface of the short drive gear shaft 1 does not run out during rotation.
Since the shaft sealing member 32 is in sliding contact with the outer circumferential surface of the shaft sealing member 5, abnormal wear and the like of the shaft sealing member 32 do not occur, and the shaft sealing member 32 has a long life. Further, since the polishing of the sliding contact portion of the drive gear shaft 15 with the shaft sealing member 32 is performed at the same time as the polishing of the fitting portion of the ball bearing 16, the number of machining steps does not increase at all. Further, since the shaft sealing member 32 is fitted to the outer end side of the connecting shaft 17, the replacement work of the shaft sealing member 32 becomes extremely easy.

[Effect of idea]

As described above, this invention consists of a frame that houses the winding drum and has a gear box connected to one end to drive the winding drum, a hoisting motor connected to the other end of the frame, and a rotor shaft of this motor. an elongated intermediate shaft connected by a first shaft joint to the intermediate shaft, a hollow connecting shaft housing the intermediate shaft and rotatably supported by the gear box, and having one end connected to the winding drum; a second shaft joint coupled to the end of the intermediate shaft within the shaft; a pair of bearings provided at the other end of the connecting shaft and the gear box; a second shaft joint supported by the pair of bearings; A short drive gear shaft coupled to the shaft joint, a gear transmission mechanism coupled to the drive gear of the drive gear shaft and transmitting rotational force to the other end of the coupling shaft, and one of the pair of bearings on the coupling shaft side. Since a shaft sealing member is provided close to the hoisting motor side of the bearing and sealing between the inner circumferential surface of the connecting shaft and the drive gear shaft, abnormal damage to the shaft sealing member is completely avoided. This has the effect of extending the life of the shaft seal member and making it extremely easy to polish the fitting portion of the shaft seal member.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional electric hoist, and FIG. 2 is a sectional view showing an embodiment of this invention. In the figure, 1 is a hoisting motor, 7 is a rotor shaft, 12 is a first shaft joint, 13 is an intermediate shaft, 14 is a second shaft joint, 15 is a drive gear shaft, 16 and 18 are ball bearings, 1
0 is a gear reduction gear, 20 is a drive gear, 21 is a second gear, 22 is a third gear, 23 and 24 are ball bearings,
17 is a connecting shaft, 23 and 24 are ball bearings, and 25 is a fourth
A gear, 26 a winding drum, and 32 a shaft sealing member. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A frame that houses the winding drum and has a gear box connected to one end to drive the winding drum, a hoisting electric motor connected to the other end of the frame, and a first shaft joint to the rotor shaft of the electric motor. a hollow connecting shaft that accommodates the intermediate shaft and is rotatably supported in the gear box and has one end connected to the winding drum; a second shaft joint coupled to the second shaft joint; a pair of bearings provided on the other end of the connecting shaft and the gear box; a short shaft joint supported by the pair of bearings and coupled to the second shaft joint; a driving gear shaft; a gear transmission mechanism connected to the driving gear of the driving gear shaft and transmitting rotational force to the other end of the connecting shaft;
and a shaft sealing member that is close to the hoisting motor side of the bearing on the connecting shaft side of the pair of bearings and seals between the inner circumferential surface of the connecting shaft and the drive gear shaft. Hoist.