Hoist and elevator

Abstract

This hoist comprises: a frame; a main shaft attached to the frame; a drum that is disposed facing the frame and has a cylindrical hole into which the main shaft is inserted; and a bearing part that rotatably supports the drum with respect to the main shaft. Oil is sealed in the bearing part.

Description

Hoists and elevators

[0001] The present invention relates to a hoist and an elevator.

[0002] Conventionally, an elevator includes a car, a counterweight, a hoist, and a main rope. An example of a conventional hoist is described in Patent Document 1.

[0003] Patent Document 1 describes a hoist including a housing, a main shaft, a brake drum, a sheave, an oil seal, a fixed part, an oil seal collar, a protrusion, an oil receiver cover, and an oil receiver. The oil seal is disposed between the brake drum and the main shaft. The fixed part is formed on an end of the brake drum facing the housing. The oil seal collar is fixed to the fixed part. The joint surface where the oil seal collar and the fixed part join is formed closer to the housing than the oil receiver cover.

[0004] Japanese Patent Application Laid-Open No. 2020-075794

[0005] However, the technology described in Patent Document 1 uses an oil-filled bearing portion, which requires oil to be supplied periodically, making inspection work very troublesome.

[0006] In consideration of the above problems, the present invention aims to provide a hoist and an elevator that allow for easy inspection work.

[0007] To solve the above problems and achieve the object, the hoist includes a frame, a main shaft attached to the frame, a drum disposed opposite the frame and having a cylindrical hole into which the main shaft is inserted, and a bearing portion that supports the drum rotatably relative to the main shaft. Oil is sealed in the bearing portion.

[0008] The elevator also includes a car that moves up and down within the hoistway, a counterweight connected to the car via a rope, and a hoist that raises and lowers the car by winding the rope around it.

[0009] According to the hoist and elevator having the above configuration, inspection work can be easily performed.

[0010] FIG. 6A is a schematic diagram showing an elevator according to an embodiment. FIG. 7B is a front view showing a hoist of an elevator according to an embodiment. FIG. 8 is a cross-sectional view showing a hoist according to an embodiment, taken along line A-A shown in FIG. 2. FIG. 9 is a cross-sectional view showing an enlarged view of a portion of a hoist according to an embodiment. FIG. 10 is a cross-sectional view showing an enlarged view of a first bearing retainer plate of a hoist according to an embodiment. FIG. 11A is a diagram showing an assembly method of a hoist according to an embodiment. FIG. 12A is a diagram showing an assembly method of a hoist according to an embodiment. FIG. 13C is a diagram showing an assembly method of a hoist according to an embodiment.

[0011] Hereinafter, embodiments of a hoist and an elevator will be described with reference to Figures 1 to 7. Note that common members in each figure are given the same reference numerals.

[0012] 1. Example of Embodiment 1-1. Example of Elevator Configuration First, the configuration of an elevator according to an example of embodiment (hereinafter referred to as "this example") will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing the configuration of an elevator.

[0013] In the elevator 1 of this example, a car 2 moves up and down in a hoistway 100 formed in a building structure. The elevator 1 of this example is a 2:1 roping type elevator. However, the elevator 1 may also be a 1:1 roping type elevator.

[0014] As shown in Figure 1, elevator 1 includes car 2 for carrying passengers and luggage, counterweight 3, hoist 4, and main rope 5. Hoist 4 is installed via a machine beam in machine room 101 provided at the top of hoistway 100. Main rope 5 is wound around sheave 13 of hoist 4 (see Figures 2 and 3).

[0015] Both ends of the main rope 5 are fixed to a machine beam installed in the machine room 101. The main rope 5 is wound around a car-side pulley 2a provided at the top of the car 2 and a weight-side pulley 3a provided at the top of the counterweight 3. When the hoisting machine 4 is driven, the car 2 and the counterweight 3 move up and down within the hoistway 100.

[0016] In this example, the machine room 101 is provided at the top of the hoistway 100, and the hoisting machine 4 is installed in this machine room 101. However, the present invention is not limited to this. For example, the machine room 101 does not have to be provided in the hoistway 100, and the hoisting machine 4 may be installed in a pit, which is the lowest part of the hoistway 100, or in the middle of the hoistway 100.

[0017] 1-2. Example of the configuration of the hoist Next, the configuration of the hoist 4 will be described with reference to Fig. 2 to Fig. 5. Fig. 2 is a front view showing the hoist 4, and Fig. 3 is a cross-sectional view taken along line A-A shown in Fig. 2. Fig. 4 is a cross-sectional view showing an enlarged portion of the hoist 4.

[0018] 2 and 3 , the hoist 4 includes a frame 11, a brake device 12, a sheave 13, a main shaft 14, an encoder 15, a drum 20, a plurality of stators 21, and a motor rotor core 22. The hoist 4 also includes a first bearing retainer plate 25 and a second bearing retainer plate 26. The hoist 4 of this example is an outer rotor type hoist in which the drum 20 is disposed radially outside the plurality of stators 21.

[0019] The main shaft 14 is formed in a cylindrical shape. A through hole 14a is formed in the radial center of the main shaft 14. The through hole 14a penetrates the main shaft 14 from one end to the other end in the axial direction. An encoder 15 is installed inside the through hole 14a of the main shaft 14.

[0020] The frame 11 is disposed on one axial end of the main shaft 14, and the drum 20 is disposed on the other axial end of the main shaft 14. The frame 11 is formed in a disk shape with an appropriate thickness. The frame 11 has a boss portion 31, an attachment portion 32, and a connecting portion 33.

[0021] Boss portion 31 is formed at the center in the radial direction of frame 11. Boss portion 31 has a fitting hole 31a formed therein, through which main shaft 14 passes. Main shaft 14 is inserted into fitting hole 31a of boss portion 31. In this way, main shaft 14 is fitted into boss portion 31.

[0022] The mounting portion 32 is a circular recess that is disposed concentrically with the fitting hole 31a of the boss portion 31. The mounting portion 32 is connected to the boss portion 31 via a disk-shaped connecting portion 33. The connecting portion 33 protrudes radially outward from the outer peripheral surface of the boss portion 31 on the radially outer side. The mounting portion 32 is formed continuously from the radially outer end of the connecting portion 33.

[0023] A plurality of stators 21 are fixed to the mounting portion 32. Each of the stators 21 is composed of an iron core and a stator coil wound around the iron core. The plurality of stators 21 are arranged in an annular shape along the circumferential direction of the mounting portion 32.

[0024] Brake devices 12 are provided at the top and bottom of the frame 11. The brake devices 12 brake the rotation of the drum 20 and the sheave 13 by coming into contact with the drum 20, which will be described later.

[0025] Next, the drum 20 and the sheave 13 will be described. The drum 20 is formed in a substantially circular ring shape. The drum 20 has a support portion 42, a drum-side boss portion 41, and a connection portion 43 that connects the support portion 42 and the drum-side boss portion 41.

[0026] The support portion 42 is provided on the radially outer side of the drum 20. The support portion 42 is formed in an annular shape and is inserted between the stator 21 fixed to the mounting portion 32 of the frame 11 and the brake device 12.

[0027] The inner wall surface of the support portion 42 faces the stator 21 provided on the frame 11. An annular motor rotor core 22 is arranged on the inner wall surface of the support portion 42 at a predetermined interval. The motor rotor core 22 is made of magnets. The north and south poles of the motor rotor core 22 are arranged alternately along the circumferential direction of the drum 20.

[0028] The outer peripheral surfaces of the upper and lower parts of the support part 42 in the vertical direction face the brake pads of the brake device 12. When braking the hoisting machine 4, the brake device 12 moves the brake pads toward the outer peripheral surface of the support part 42. As a result, the brake pads press against the outer peripheral surface of the support part 42 of the drum 20, and the drum 20 and the sheave 13 are braked.

[0029] The drum side boss 41 is provided at the radial center of the drum 20. The drum side boss 41 is cylindrical, and the sheave 13 is fitted and fixed to the outer peripheral surface of the drum side boss 41. A bearing 17 is disposed on the inner wall surface of a cylindrical hole 41a in the drum side boss 41. The main shaft 14 is inserted into the cylindrical hole 41a of the drum side boss 41. The drum 20 is rotatably supported by the main shaft 14 via the bearing 17. The detailed configuration of the bearing 17 will be described later.

[0030] An encoder shaft 16 is disposed on the end of the drum-side boss 41 opposite the frame 11, on the other axial end side of the main shaft 14. The encoder shaft 16 is formed in a substantially circular plate shape. The encoder shaft 16 closes the opening of the cylindrical hole 42a of the drum-side boss 41 on the other axial end side of the main shaft 14. The encoder shaft 16 is connected to an encoder 15 disposed in the through-hole 14a of the main shaft 14.

[0031] Next, the configuration of the hoist 4 around the bearing unit 17 will be described with reference to Figure 4. As shown in Figure 4, the bearing unit 17 has an inner ring 51, an outer ring 52, and rollers 53 interposed between the inner ring 51 and the outer ring 52. The surfaces of the inner ring 51 and the outer ring 52 that come into contact with the rollers 53 are inclined. The rollers 53 are formed in a conical shape. That is, the bearing unit 17 in this example is a conical roller bearing. The hoist 4 in this example is provided with two bearing units 17. By using a conical roller bearing as the bearing unit 17, rigidity can be increased compared to a cylindrical roller bearing.

[0032] Furthermore, the bearing portion 17 is an enclosed type bearing in which grease is enclosed in advance inside the inner ring 51, the outer ring 52, and the rollers 53. Because grease (oil) is enclosed inside the bearing portion 17, the work of supplying grease to the bearing portion 17 during inspection can be omitted, and inspection of the hoist 4 can be easily performed.

[0033] The inner ring 51 of the bearing portion 17 is attached to the outer peripheral surface 14b on the other axial end side of the main shaft 14. A step 14c is also formed on the outer peripheral surface 14b of the main shaft 14. The outer diameter of the outer peripheral surface 14b on which the inner ring 51 of the bearing portion 17 is attached is smaller than that of the step 14c on the one axial end side. The inner ring 51 of the bearing portion 17 abuts against the step 14c. This prevents the inner ring 51 of the bearing portion 17 from falling off. Furthermore, the inner ring 51 of the bearing portion 17 is positioned by pressing the inner ring 51 of the bearing portion 17 against the step 14c.

[0034] A second bearing retainer plate 26 is fixed to the other axial end of the main shaft 14. The second bearing retainer plate 26 is formed in a substantially circular plate shape. The second bearing retainer plate 26 has an opening at its radial center. The opening of the second bearing retainer plate 26 faces the through-hole 14a of the main shaft 14. The encoder shaft 16 is inserted into the opening of the second bearing retainer plate 26.

[0035] Second bearing retainer plate 26 is fixed to the end face of the other axial end of main shaft 14. A portion of second bearing retainer plate 26 protrudes radially outward from outer peripheral surface 14b of main shaft 14. Second bearing retainer plate 26 abuts against inner ring 51 of bearing portion 17 attached to main shaft 14. This prevents inner ring 51 of bearing portion 17 from falling off from the other axial end of main shaft 14.

[0036] The outer ring 52 of the bearing 17 is attached to the cylindrical hole 41a of the drum-side boss 41. A generally disk-shaped convex portion 41b is formed at the other axial end of the drum-side boss 41. The convex portion 41b protrudes from the other axial end of the drum-side boss 41 toward the center in the radial direction. The outer ring 52 of the bearing 17 abuts against this convex portion 41b. This prevents the outer ring 52 of the bearing 17 from falling off from the other axial end of the drum-side boss 41. The outer ring 52 of the bearing 17 is positioned by pressing the outer ring 52 against the convex portion 41b.

[0037] Furthermore, a first bearing retainer plate 25 is fixed to one axial end of the cylindrical hole 41a of the drum-side boss portion 41. FIG. 5 is an enlarged cross-sectional view of the first bearing retainer plate 25. As shown in FIGS. 4 and 5, the first bearing retainer plate 25 is formed in a substantially circular plate shape. The first bearing retainer plate 25 has an opening at its radial center. The first bearing retainer plate 25 is fixed to an end surface of one axial end of the cylindrical hole 41a of the drum-side boss portion 41. The first bearing retainer plate 25 protrudes toward the radial center. The main shaft 14 is inserted through the opening of the first bearing retainer plate 25.

[0038] The first bearing retainer plate 25 has an abutment portion 25a and a fall-off prevention portion 25b. The abutment portion 25a is formed on the radially outer side of the first bearing retainer plate 25, and the fall-off prevention portion 25b is formed on the radially inner side of the first bearing retainer plate 25. The abutment portion 25a is fixed to the drum-side boss portion 41, and a portion of it protrudes radially inward of the cylindrical hole 41a. The outer ring 52 of the bearing portion 17 abuts against the abutment portion 25a. This facilitates positioning of the bearing portion 17. Furthermore, the outer ring 52 of the bearing portion 17 can be prevented from falling off one axial end of the drum-side boss portion 41.

[0039] Fall-off prevention portion 25b is formed continuously from the radially inner end of abutting portion 25a. Fall-off prevention portion 25b faces inner ring 51 of bearing portion 17 attached to main shaft 14. A gap M1 is formed between the radially inner end, which is the tip of fall-off prevention portion 25b, and main shaft 14. Providing this gap M1 makes it possible to prevent interference between main shaft 14 and first bearing retainer plate 25.

[0040] By providing the fall-off prevention portion 25b, it is possible to prevent the inner ring 51, the outer ring 52, and the rollers 53 that constitute the bearing portion 17 from coming apart during the assembly work of the hoist 4, and to prevent the inner ring 51 from falling off from the drum-side boss portion 41. In this way, since it is possible to prevent the bearing portion 17 from coming apart during the assembly work, it is possible to prevent the grease sealed inside the inner ring 51, the outer ring 52, and the rollers 53 from leaking out.

[0041] Furthermore, a minute gap M2 is formed between the fall-off prevention portion 25b and the inner ring 51 of the bearing portion 17. The size of the gap M2 is set to be equal to or less than the allowable amount of misalignment between the inner ring 51 and the outer ring 52 of the bearing portion 17. Furthermore, by providing the gap M2, it is possible to prevent the inner ring 51 from contacting the first bearing retainer plate 25, and it is possible to smoothly rotate the inner ring 51 and the outer ring 52 of the bearing portion 17.

[0042] Here, an oil-sealed bearing has oil-sealing properties due to the oil seal attached to the bearing. This oil seal is fixed to the inner ring 51 and has a lip on the outer ring 52 side. If the lip deviates from the outer ring 52, the oil-sealing properties are lost, and there is a possibility that the grease previously sealed in will leak out. Therefore, the amount of deviation that prevents the lip from deviating from the outer ring 52 is referred to as the allowable deviation here. By setting this allowable deviation, the inner ring 51, rollers 53, and outer ring 52 can be prevented from separating, and the inner ring 51 and outer ring 52 can rotate smoothly.

[0043] 2. Method of Assembling the Hoist Next, a method of assembling the hoist 4 having the above-described configuration will be described with reference to Figures 6A to 7C. Figures 6A to 7C are explanatory diagrams showing the method of assembling the hoist 4.

[0044] First, as shown in Fig. 6A, a bearing support jig 71 is attached to the drum-side boss 41 of the drum 20. The bearing support jig 71 is a disk-shaped member with an opening in its radial center. The bearing support jig 71 is attached to the end face of the other axial end of the drum-side boss 41. A portion of the bearing support jig 71 protrudes into the cylindrical hole 41a of the drum-side boss 41. The drum 20 is positioned with one axial end facing upward in the vertical direction.

[0045] The two bearings 17 are held together by a bearing holding jig 74, which has two holding plates 75 and a holding bolt 76. The two bearings 17 are sandwiched between the two holding plates 75. The holding plates 75 are in contact with the inner rings 51 of the bearings 17. The two holding plates 75 are fixed in place by the holding bolts 76. In this way, the two bearings 17 are held together by the bearing holding jig 74.

[0046] The bearings 17 are conical roller bearings, and the inclination direction of the two bearings 17 widens radially outward as they approach both axial ends. Therefore, by holding the inner rings 51 of the bearings 17 with the holding plates 75 of the bearing holding jig 74, the bearings 17 can be prevented from coming apart.

[0047] The two bearings 17 held together by the bearing holding jig 74 are inserted into the cylindrical hole 41a of the drum-side boss 41. After the two bearings 17 are attached to the drum-side boss 41, the bearing holding jig 74 is removed from the two bearings 17.

[0048] A bearing support jig 71 is attached to the drum-side boss 41. The bearing support jig 71 abuts against the inner ring 51 of the bearing 17 attached to the drum-side boss 41. The outer ring 52 of the bearing 17 is supported by a protrusion 41b (see FIG. 4) provided on the drum-side boss 41. This prevents the bearing 17 from coming apart and falling off the drum-side boss 41 during assembly, and prevents the enclosed grease from leaking.

[0049] Next, the first bearing retainer plate 25 is attached to the drum-side boss 41. As a result, the outer ring 52 of the bearing 17 attached to the drum-side boss 41 comes into contact with the first bearing retainer plate 25 (see FIG. 5). Furthermore, the inner ring 51 of the bearing 17 faces the first bearing retainer plate 25 with a gap M2 between them.

[0050] Next, as shown in Figure 7A, the drum 20 is inverted so that one end in the axial direction faces downward in the vertical direction. At this time, there is a risk that the bearing 17 attached to the drum-side boss 41 may come apart. In response to this, in the hoist 4 of this example, a first bearing retainer plate 25 is attached to the drum-side boss 41. This prevents the inner ring 51, outer ring 52, and rollers 53 of the bearing 17 from coming apart and falling off the drum-side boss 41. As a result, it is possible to prevent the grease (oil) sealed in the inner ring 51, outer ring 52, and rollers 53 from leaking out.

[0051] The main shaft 14 is attached to the frame 11 in advance. The frame 11 is then positioned so that the other axial end of the main shaft 14 faces upward in the vertical direction. In this state, the drum 20 is inserted into the frame 11. That is, the bearing 17 is inserted into the outer peripheral surface 14b of the main shaft 14 attached to the frame 11, and the bearing 17 is inserted into the main shaft 14.

[0052] Next, as shown in Fig. 7B, the bearing support jig 71 is removed from the drum-side boss portion 41. Thereafter, as shown in Fig. 7C, the encoder 15 is installed on the main shaft 14, and the second bearing retainer plate 26 is attached to the main shaft 14. As a result, the inner ring 51 of the bearing portion 17 is supported by the second bearing retainer plate 26. Then, the encoder shaft 16 is connected to the encoder 15, and the opening on the other end side of the axial direction of the main shaft 14 in the cylindrical hole 42a of the drum-side boss portion 41 is closed by the encoder shaft 16. This completes the assembly work of the hoisting machine 4.

[0053] Here, with oil-lubricated bearings used in conventional hoists, during assembly work, the inner ring, outer ring, and rollers must be attached to the drum-side boss portion 41 in a separate state, and then oil (grease) must be applied. In contrast, in the hoist 4 of this example, as described above, an oil-sealed bearing in which oil is sealed in advance is used as the bearing portion 17. This allows the inner ring 51, outer ring 52, and rollers 53 to be attached to the drum-side boss portion 41 in a state where they are pre-assembled. Furthermore, because oil is sealed in advance, the oiling work can be omitted. As a result, the work of attaching the bearing portion 17 can be simplified.

[0054] The present invention is not limited to the embodiments described above and shown in the drawings, and various modifications can be made within the scope of the invention as set forth in the claims.

[0055] In this specification, the words "parallel" and "orthogonal" are used, but these do not mean only "parallel" and "orthogonal" in the strict sense, but also include "parallel" and "orthogonal" and may also mean a "substantially parallel" or "substantially orthogonal" state within a range in which the functions can be exerted.

[0056] DESCRIPTION OF SYMBOLS 1...Elevator, 2...Cab, 2a...Cab-side pulley, 3...Counterweight, 3a...Weight-side pulley, 4...Hoist, 5...Main rope, 11...Frame, 12...Brake device, 13...Sheave, 14...Main shaft, 14a...Through hole, 14b...Outer circumferential surface, 14c...Step portion, 15...Encoder, 16...Encoder shaft, 17...Bearing portion, 20...Drum, 21...Stator, 22...Motor rotor core, 25...First bearing retainer plate, 25a...Abutment portion, 25b...Fall-off prevention portion, 26...Second bearing retainer plate, 31...Boss portion, 31a...Fitting hole, 32...Mounting portion, 33...Coupling portion, 41...Drum-side boss portion, 41a...Cylinder hole, 41b...Convex portion, 42...Support portion, 42a...Cylindrical hole, 43...Connection portion, 51...Inner ring, 52...Outer ring, 53...Roller, 71...Bearing support jig, 74...Bearing holding jig, 100...Hoistway, 101...Machine room, M1...Gap, M2...Gap

Claims

1. A hoist comprising a frame, a main shaft attached to the frame, a drum disposed opposite to the frame and having a cylindrical hole into which the main shaft is inserted, and a bearing portion that rotatably supports the drum with respect to the main shaft, wherein oil is enclosed in the bearing portion.

2. The hoist according to claim 1, wherein the bearing portion includes an inner ring attached to the main shaft, an outer ring attached to the cylindrical hole of the drum, and rollers interposed between the inner ring and the outer ring, and a first bearing retainer plate having a contact portion that contacts the outer ring of the bearing portion and a dropout prevention portion that faces the inner ring is attached to the drum.

3. The hoist according to claim 2, wherein a gap equal to or less than the allowable displacement amount between the inner ring and the outer ring is formed between the dropout prevention portion of the first bearing retainer plate and the inner ring.

4. The hoist according to claim 2, wherein the first bearing retainer plate is fixed to one axial end portion of the cylindrical hole of the drum, and a second bearing retainer plate that contacts the inner ring is fixed to the other axial end portion of the main shaft.

5. The hoist according to claim 4, wherein a stepped portion that contacts the inner ring is formed on the outer peripheral surface of the main shaft, and a convex portion that contacts the outer ring is formed in the cylindrical hole of the drum.

6. The hoist according to claim 2, wherein the bearing portion is a tapered roller bearing in which the rollers are formed in a conical shape.

7. An elevator comprising a car that moves up and down in a hoistway, a counterweight connected to the car via a rope, and a hoist that raises and lowers the car by winding the rope, wherein the hoist includes a frame, a main shaft attached to the frame, a drum disposed opposite to the frame and having a cylindrical hole into which the main shaft is inserted, and a bearing portion that rotatably supports the drum with respect to the main shaft, and oil is enclosed in the bearing portion.

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