Hoist

Abstract

A hoist according to the present invention comprises: a drive sheave having, on the outer periphery thereof, a rope winding surface for winding and unwinding a rope; a brake disk attached to one side in the axial direction of the drive sheave; and a cover member disposed between the rope winding surface and the brake disk in the axial direction of the drive sheave and shielding the brake disk from the outer periphery of the drive sheave. A plurality of protrusions are formed on the outer periphery of the drive sheave at positions between the rope winding surface and the cover member in the axial direction, with each protrusion having an annular shape in the circumferential direction of the drive sheave and protruding more radially outward than the rope winding surface.

Description

hoisting machine

[0001] The present invention relates to a hoist.

[0002] Conventionally, a hoist for a elevator has been known in which an electric motor rotates a drive sheave to move a car and a brake unit stops the rotation of the drive sheave. In this type of hoist, a lubricating oil is used on the rope winding surface of the drive sheave to lubricate the rope, but the braking surface of the brake unit needs to be protected from the lubricating oil to maintain the performance of the brake unit.

[0003] As an example, Patent Document 1 proposes a structure in which a ring-shaped felt that comes into contact with the rope winding surface is attached to a cover that houses the brake disc of a hoist, and the felt absorbs lubricating oil from the drive sheave.

[0004] As another example, Patent Document 2 proposes an elevator device in which a groove is formed in an area including directly below a protective cover on the outer periphery of a traction sheave, and an exhaust member that regulates the direction of oil scattering is disposed in the groove. In Patent Document 2, oil adheres to the protective cover guided by the exhaust member in the groove, thereby suppressing adhesion of oil to the braking surface of the braking unit.

[0005] JP 2015-124063 A JP 2011-241062 A

[0006] According to the above-mentioned Patent Document 1, when applied to a hoist whose cover is structurally not removable, it is difficult to attach an oil absorbent material such as felt to the cover. Furthermore, when performing maintenance on the hoist, the felt needs to be correctly reattached to the drive sheave, which can make the maintenance assembly work complicated. Furthermore, according to the above-mentioned Patent Document 2, a discharge member with a complex shape needs to be fitted into the groove of the drive sheave, which leaves room for improvement in terms of workability during manufacturing and assembly.

[0007] The present invention has been made in consideration of the above circumstances, and provides a hoist that is easier to manufacture and assemble than conventional hoists and can prevent lubricating oil from penetrating into the braking section.

[0008] A hoist according to one embodiment includes a drive sheave having a rope winding surface on its outer periphery for winding and unwinding a rope, a brake disc attached to one axial side of the drive sheave, and a cover member disposed between the rope winding surface and the brake disc in the axial direction of the drive sheave and shielding the brake disc from the outer periphery of the drive sheave. A plurality of protrusions are formed on the outer periphery of the drive sheave at positions between the rope winding surface and the cover member in the axial direction, each of which forms an annular shape in the circumferential direction of the drive sheave and protrudes radially beyond the rope winding surface.

[0009] In the above-mentioned aspect, the cover member may extend from the rope winding surface to the protrusion, and may receive oil scattered from the protrusion due to centrifugal force caused by rotation of the drive sheave at the surface on the other axial side.

[0010] According to one aspect, it is possible to provide a hoist that is easier to manufacture and assemble than conventional hoists and that can prevent lubricating oil from entering the braking section.

[0011] It is an axial cross-sectional view showing a main part of the hoisting machine of the present embodiment. It is an enlarged partial view of Figure 1. It is a cross-sectional view of a driving sheave in a direction perpendicular to the axial direction.

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiments, in order to make the description easier to understand, structures and elements other than the main parts of the present invention will be described in a simplified or omitted manner. In addition, the same elements will be given the same reference numerals in the drawings. Note that the shapes, dimensions, etc. of each element shown in the drawings are shown schematically and do not represent the actual shapes, dimensions, etc.

[0013] In the following description, the direction parallel to the extension direction of the rotation axis Ax of the hoisting machine will be referred to as the axial direction, the circumferential direction centered on the rotation axis Ax will be simply referred to as the circumferential direction, and the radial direction centered on the rotation axis Ax will be simply referred to as the radial direction.

[0014] Fig. 1 is an axial cross-sectional view showing the main part of a hoisting machine 1 of this embodiment. Fig. 2 is a partially enlarged view of Fig. 1. Fig. 3 is a cross-sectional view of a traction sheave 2 in a direction perpendicular to the axial direction.

[0015] The hoist 1 of this embodiment is applied to, for example, an elevator hoist. The hoist 1 includes a cylindrical traction sheave 2, a shaft 3, a rotor and a stator (neither of which are shown), and a brake unit 4.

[0016] The drive sheave 2 has the function of winding or unwinding the rope 5 that connects the car and the weight. The outer periphery of the drive sheave 2 is provided with a rope winding surface 2a on which grooves corresponding to the rope 5 are engraved in the circumferential direction. The surface of the rope winding surface 2a is lubricated by lubricating oil that seeps out from the rope 5.

[0017] The shaft 3 passes through the drive sheave 2 in the axial direction and is attached concentrically to the drive sheave 2. The shaft 3 is rotatably supported at both ends by a pair of bearing pedestals (neither of which is shown) that are each fixed to a base (not shown).

[0018] One end of the shaft 3 (right side in the figure) protrudes through one of the bearing pedestals. A rotor with cylindrical magnetic poles is attached to one end of the shaft 3. A cylindrical stator is disposed on the outer periphery of this rotor, separated by an air gap. A coil is wound around the stator, and by controlling the current in the coils to sequentially switch the magnetic field of the stator, an attractive or repulsive force is generated in the stator relative to the magnetic poles of the rotor. This rotates the drive sheave 2 via the shaft 3 to which the rotor is attached.

[0019] The braking unit 4 is a braking device that stops the rotation of the traction sheave 2. The braking unit 4 is arranged on one side (the right side in the figure) of the traction sheave 2, and includes a brake disc 6, a pair of brake pads 7 that sandwich the brake disc 6, and an electromagnetic clamper (not shown) that drives the brake pads 7 in the axial direction.

[0020] The brake disc 6 has an overall annular plate shape and is fixed to the drive sheave 2 on one side thereof. The brake disc 6 extends radially so as to be perpendicular to the rope winding surface 2a of the drive sheave 2, and is attached to one side of the drive sheave 2 so that the braking surface 6a forms a flange shape. A groove 6b that functions as an oil return is formed on the inner peripheral side of the braking surface 6a of the brake disc 6. The outer peripheral surface of the groove 6b is inclined toward the inner peripheral side in the height direction of the groove. This allows the groove 6b to receive lubricating oil from the inner peripheral side and suppresses leakage of lubricating oil from within the groove 6b to the braking surface 6a.

[0021] The brake pads 7 and electromagnetic clampers of the braking unit 4 are provided in the housing 10 of the hoist 1. In the braking unit 4, the braking surface 6 a of the brake disc 6 is clamped by the brake pads 7, thereby stopping the rotation of the drive sheave 2 connected to the brake disc 6.

[0022] In addition, a circular disk-shaped cover member 11 that shields the brake disc 6 from the outer periphery of the drive sheave 2 is arranged between the braking unit 4 and the rope winding surface 2a of the drive sheave 2 in the axial direction of the hoist 1. The cover member 11 is fixed to a housing 10 of the hoist 1, and separates the space of the rope winding surface 2a from the braking unit 4 on the other side (left side in the figure) of the brake disc 6. In addition, the cover member 11 covers the other surface of the brake disc 6 with a small gap from the outer periphery of the drive sheave 2 to avoid interference with the rotating drive sheave 2.

[0023] The cover member 11 has the function of preventing lubricating oil scattered from the drive sheave 2 from adhering to the braking surface 6a and the brake pads 7. An oil recovery plate 12 is disposed on the outer periphery of the cover member 11 to return the lubricating oil adhering to the cover member 11 to an oil pan (not shown).

[0024] In addition, a plurality of protrusions 13 are formed on the outer peripheral surface of the drive sheave 2 between the rope winding surface 2a and the cover member 11 in the axial direction. As shown in Fig. 2, each of the protrusions 13 protrudes radially beyond the rope winding surface 2a and is formed in parallel with the drive sheave 2 at intervals in the axial direction. In addition, as shown in Fig. 3, each of the protrusions 13 is arranged in an annular shape along the circumferential direction of the drive sheave 2.

[0025] In this embodiment, an example is shown in which two protrusions 13 are formed in the axial direction on the outer peripheral surface of the traction sheave 2, but three or more protrusions 13 may be formed in the axial direction. Furthermore, the multiple protrusions 13 may all have the same shape, or may have shapes that are different from each other, such as radial heights and axial widths.

[0026] The multiple protrusions 13 formed on the outer periphery of the drive sheave 2 have the function of scattering lubricating oil flowing from the rope winding surface 2a to one side (towards the braking section 4) toward the outer periphery by centrifugal force.

[0027] When the hoist 1 is in operation, as shown by the dashed line in Figure 2, when the lubricating oil heading from the rope winding surface 2a toward one side reaches the protrusion 13 on the other side (the protrusion on the left side in the figure), much of it is scattered toward the outer periphery by centrifugal force as it passes over the protrusion 13 on the other side. Furthermore, when the remaining lubricating oil heading toward one side passes over the protrusion 13 on the other side, much of it is scattered toward the outer periphery by centrifugal force as it passes over the protrusion 13 on the one side when it reaches the protrusion 13 on the one side (the protrusion on the right side in the figure). Note that the lubricating oil scattered at the protrusion 13 adheres to the cover member 11 or the oil recovery plate 12 and flows back to the oil pan.

[0028] As described above, the multiple protrusions 13 formed on the outer periphery of the driving sheave 2 significantly reduce the amount of lubricating oil that flows from the rope winding surface 2a to the braking unit 4. Note that the small amount of lubricating oil that leaks through the gap between the cover member 11 and the driving sheave 2 via the multiple protrusions 13 is prevented from penetrating into the braking surface 6a by the oil return groove 6b of the brake disc 6. Therefore, according to the hoist 1 of this embodiment, it is possible to prevent a decrease in the braking performance of the braking unit 4 due to the lubricating oil from the rope winding surface 2a.

[0029] Furthermore, in the hoist 1 of this embodiment, the lubricating oil is drained by the multiple annular protrusions 13 formed on the outer peripheral surface of the drive sheave 2, so there is no need to attach a separate oil-slinger component or a component supporting said component to the drive sheave 2 or the housing 10. Therefore, with the configuration of this embodiment, it is possible to reduce the manufacturing cost of the hoist 1 and improve workability during manufacturing and assembly. Furthermore, omitting the component supporting the separate oil-slinger component also makes it easier to reduce the size of the hoist 1.

[0030] The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention. For example, the hoist 1 of the above-described embodiment is not limited to a hoist for an elevator, and may be applied to a hoist for any purpose as long as it is a hoist for winding up a rope. Note that in the hoist 1 of the above-described embodiment, the rotor and the stator may be configured to be disposed on the other side.

[0031] Furthermore, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0032] DESCRIPTION OF SYMBOLS 1... Hoist, 2... Driving sheave, 2a... Rope winding surface, 3... Shaft, 4... Braking portion, 5... Rope, 6... Brake disc, 6a... Braking surface, 6b... Groove, 7... Brake pad, 10... Housing, 11... Cover member, 12... Oil recovery plate, 13... Protrusion

Claims

1. A hoist comprising: a drive sheave having a rope winding surface on its outer periphery for winding and unwinding a rope; a brake disc attached to one axial side of the drive sheave; and a cover member arranged between the rope winding surface and the brake disc in the axial direction of the drive sheave and shielding the brake disc from the outer periphery of the drive sheave, wherein the outer periphery of the drive sheave is formed with a plurality of protrusions that are each annular in the circumferential direction of the drive sheave and protrude radially beyond the rope winding surface, at positions between the rope winding surface and the cover member in the axial direction.

2. A hoist as described in claim 1, wherein the cover member extends from the rope winding surface to the plurality of protrusions and receives oil scattered from the protrusions by centrifugal force caused by the rotation of the drive sheave on the other axial side surface.

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