CN112707328B

CN112707328B - Novel pulley block

Info

Publication number: CN112707328B
Application number: CN202110068481.XA
Authority: CN
Inventors: 吴飞; 张群生
Original assignee: Chongqing Aerospace Polytechnic College
Current assignee: Chongqing Aerospace Polytechnic College
Priority date: 2021-01-19
Filing date: 2021-01-19
Publication date: 2022-08-26
Anticipated expiration: 2041-01-19
Also published as: CN112707328A

Abstract

The invention discloses a novel pulley block, which comprises a step fixed pulley and a step movable pulley, wherein the step fixed pulley and the step movable pulley are respectively composed of a plurality of pulleys formed by coaxially and fixedly connected step circles; the radius of the step circle is in an equal difference array, the circle center of the step fixed pulley and the circle center of the step movable pulley are not on the same plumb line, and an eccentricity a/2 is arranged between the step fixed pulley and the step movable pulley, so that the ropes between the two pulleys are in a vertical state and are tangent to the corresponding step circles, and the distance between the ropes is the same. This novel assembly pulley is fit for using in narrow space, and lifting capacity is stronger. The dead weight of the movable pulley is reduced, the abrasion between the rope and the pulley is greatly reduced, and the stability is better when the movable pulley is pulled.

Description

Novel pulley block

Technical Field

The utility model relates to a laborsaving mechanism specifically is a novel assembly pulley.

Background

The statements in this section merely provide background information related to the present disclosure and may constitute prior art. In the process of implementing the invention, the inventor finds that at least the following problems exist in the prior art.

The pulley block mainly comprises a fixed pulley and a movable pulley, and the purpose of saving labor is mainly realized by increasing the moving distance of the rope end. As shown in figure 5, the conventional labor-saving pulley block is provided with a fixed pulley block and a movable pulley block in the vertical direction, so that the aim of saving labor is fulfilled. However, the labor-saving multiple of the pulley block is determined by the number of rope segments wound on the movable pulley, so that corresponding fixed pulleys and movable pulleys can only be continuously added in the vertical direction if the labor-saving multiple is required to be improved. Not only occupies a large space, but also is inconvenient to install and is not suitable for being used in narrow space.

The pulley block which can save labor and can be used in a narrow space is mainly a pulley block and a differential pulley for a crane at present.

As shown in fig. 6, a plurality of fixed pulleys 1 and movable pulleys 2 with the same size are respectively formed into a fixed pulley group and a movable pulley group, and penetrate through a steel wire rope and the like, so that the aim of saving labor is fulfilled by changing the movement direction of the steel wire rope. The pulley block has the advantages that the labor-saving multiple of the whole pulley block can be improved by increasing the fixed pulleys and the movable pulleys in the axial direction, and the occupied space is small. But the space occupied by the bearing in the axial direction is increased, and the structure is more complex. And when the pulley block is replaced, the whole fixed pulley block or movable pulley block is detached, so that the maintenance and the replacement are very inconvenient.

The pulley block for the crane is divided into an opening type and a closing type according to whether the clamping plate can be opened or not. The opening pulley is convenient for installing the rope, but the safety performance is lower because the opening pulley is not sealed; the closed tackle has high safety performance, as shown in fig. 6, but is inconvenient to install the rope due to sealing.

Meanwhile, most cranes have pulleys forged from aluminum alloy. For example, in light and medium duty cranes, the sheaves are made of gray cast iron HT15-33 or nodular cast steel QT-10; for heavy-duty above-duty cranes, the sheaves are made of cast steel ZG25 or ZG 35. Although relatively light in weight to the overall sled, it is still relatively heavy in terms of its own weight and is inconvenient to transport and replace. And because the dead weight of the pulley is large, the overturning moment of the crane is increased, and the crane is easy to overturn. The cast iron pulley is heavy due to the self weight, and under the condition of poor lubrication, the cast iron pulley is very inflexible to rotate, usually, a steel wire rope runs, but the pulley is still stopped; or the steel wire rope is stopped and still rotates due to inertia, so that the steel wire rope is subjected to accelerated wear.

The differential pulley is a labor-saving hoisting machine formed by combining a wheel shaft and a movable pulley block, is called a chain block or a magic gourd, and is a pulley with a special structure commonly used in factories. The device consists of two fixed pulleys 1 and a movable pulley 2 which have the same diameter difference and are fixed together, and as shown in figure 7, the movable pulley below is connected through a rope so as to slowly hoist or move a heavy object. According to the public, the tension

(wherein R is larger than R), the smaller the difference between R and R is, the smaller the pulling force F is, so that the labor-saving effect is achieved by reducing the difference of the radiuses of the two pulleys fixed together and enabling the radiuses to be close to each other. However, the rope sleeved on the movable pulley 2 of the differential pulley is not in a vertical state, as shown in fig. 7, the stability is poor when the rope is pulled up.

The practical use of the differential pulley is a manual hoist device, which is the combination of a speed reducer with a reverse check brake and a chain pulley block. As shown in fig. 8, the wheels of radius R and R rotate together with the shaft about the horizontal axis O, and they are connected to the movable pulley on which the weight G is suspended, by a chain, which is a sprocket with teeth on the periphery. The chain is pulled by applying a pulling force F, and the weight is lifted. The hand hoist is strictly forbidden to be operated by other power except for manpower in the hoisting process, and the force is uniformly and gently applied when the hand chain is dragged no matter the heavy object rises or falls, and the force is not too strong so as to avoid the hand chain jumping or the snap ring. Once the hand pulling force is found to be greater than the normal pulling force, the use should be stopped immediately, prevent that chain pulling from being blocked by the sprocket, upper and lower lifting hook is as the board, and the ineffectiveness is warp seriously, can present the situation that can only go up can not down when using chain block to hang heavy object. Moreover, because the chain is meshed with the teeth, the chain and the teeth are abraded to a certain extent, and lubricating oil and maintenance are required frequently.

The hoisting weight of the hand hoist does not exceed 10t generally.

Disclosure of Invention

In view of the above problems, it is an object of the present invention to solve some of the problems of the prior art, or at least to alleviate them.

A novel pulley block comprises

The step fixed pulley comprises N fixed pulleys which are coaxially and fixedly connected; the fixed pulley rotating center of the step fixed pulley can be connected with the outside;

the step movable pulley comprises N movable pulleys which are coaxially and fixedly connected; the rotating center of the movable pulley of the step movable pulley can be connected with a heavy object;

wherein N is more than or equal to 1 and is a natural number;

the radiuses of the N fixed pulleys are sequentially increased, and the radiuses of the N movable pulleys are sequentially increased;

the step fixed pulley and the step movable pulley are sequentially wound through a rope.

Furthermore, the radiuses of the N fixed pulleys and the radius of the N movable pulleys form an equal difference series.

Preferably, when the radius of the first fixed pulley is a, the radius of the Nth fixed pulley is N.a, the radius of the first movable pulley is 0.5a, and the radius of the Nth movable pulley is (N-0.5) a; the distance between the rotation center of the fixed pulley and the rotation center of the movable pulley in the horizontal direction is 0.5 a.

And the fixed pulley and the movable pulley are provided with pulley grooves.

A mandrel connected with the step fixed pulley is arranged at the rotating center of the fixed pulley; the step fixed pulley is connected with the outside through a mandrel.

A mandrel connected with the step movable pulley is arranged at the rotating center of the movable pulley; the step movable pulley is connected with a heavy object through a mandrel.

The first end of the rope is fixedly connected with the rotating center of the fixed pulley and sequentially wound according to the sequence of the movable pulley and the fixed pulley.

The invention has the following beneficial effects:

1. the number of the step circles is increased axially, so that the occupied axial or vertical space is small, and compared with a common pulley block, the pulley block is more suitable for being used in a narrow space (such as an elevator) and is very convenient to install;

2. the self-weight is greatly reduced, the overturning moment of the crane is reduced when the crane is installed on the crane, the crane is not easy to overturn, the transportation and the replacement are convenient, and the abrasion of the rope and the pulley can be greatly reduced;

3. the closed clamping plate is adopted, so that the safety is ensured, the rope can be conveniently installed, and the installation difficulty is reduced;

4. the step circles of the step pulleys adopt fixed arithmetic progression, and the ropes between the fixed pulleys and the movable pulleys are in a vertical state and are tangent to the corresponding step circles, so that the step pulleys are more stable in pulling, better in stability and not easy to overturn;

5. the step circle can be axially added according to the actual situation, and the hoisting weight is theoretically unlimited; the diameters of the large step circle and the small step circle are not the same as those of a differential pulley, and the large radius R is close to the small radius R to save labor;

6. the parallel step pulleys are adopted, so that the single step fixed pulley and the step movable pulley can be designed to be smaller, and the use in a narrow space is more convenient.

Drawings

Fig. 1 is a side view of the novel pulley block of the present invention;

fig. 2 is a front view of the novel pulley block of the present invention;

FIG. 3 is a side view of the movable sheave of the present invention;

FIG. 4 is a side view of the crown block of the present invention;

FIG. 5 is a schematic view of a general pulley block;

FIG. 6 is a block diagram of a pulley block for a crane;

FIG. 7 is a schematic view of a differential pulley;

FIG. 8 is a block diagram of a hand-operated hoist;

fig. 9 is a side view of a plurality of step pulleys of the present invention side by side.

Wherein: 1-step fixed pulley; 2-step movable pulley; 3-a rope; 4-a third movable pulley; 5-a second movable pulley; 6-a first movable pulley; 7-a third fixed pulley; 8-a second fixed pulley; 9-a first fixed pulley; 10-fixed pulley rotation center; 11-center of rotation of the movable pulley.

Detailed Description

The present invention will be further described with reference to the accompanying drawings, wherein the embodiments of the present invention are provided for illustrative purpose only and not for limiting the invention, and various alternatives and modifications can be made without departing from the technical spirit of the invention, according to the common technical knowledge and conventional means in the art.

As shown in fig. 1 or 2 or 3 or 4, a novel pulley block comprises

The step fixed pulley 1 comprises N fixed pulleys which are coaxially and fixedly connected; the fixed pulley rotation center 10 of the fixed pulley 1 can be connected with the outside;

the step movable pulley 2 comprises N movable pulleys which are coaxially and fixedly connected; the rotating center 11 of the movable pulley 2 can be connected with a heavy object;

wherein N is more than or equal to 1 and is a natural number;

step fixed pulley 1 and step movable pulley 2 twine in proper order through rope 3.

The pulley block may be composed of one step fixed pulley 1 at an upper portion and one step movable pulley 2 at a lower portion, and a rope 3 wound between the two pulleys, as shown in fig. 1 or 2.

As shown in fig. 1, 3 or 4, when N is 3, the step fixed pulley 1 and the step movable pulley 2 each have a pulley formed of 3 step circles. For example, the step fixed pulley 1 is coaxially constituted by the first fixed pulley 9, the second fixed pulley 8, and the third fixed pulley 7, and the step movable pulley 2 is coaxially constituted by the first movable pulley 6, the second movable pulley 5, and the third movable pulley 4. The step circles can be fixedly connected in a welding mode and the like, and can also be integrally formed.

As shown in fig. 1 or 2, the fixed pulley rotation center 10 is provided with a mandrel connected with the step fixed pulley 1; the step fixed pulley 1 is connected with the outside through a mandrel. The mandrel can penetrate through a fixed pulley rotation center 10 of the step fixed pulley 1 and is in clearance fit with the fixed pulley on the step fixed pulley 1, so that sliding connection is realized. The two ends of the mandrel can be fixedly connected with the outside through a connecting wire or a clamping plate and the like. The mandrel can also be fixedly connected with the fixed pulley of the step fixed pulley 1 or integrally formed, and two ends can rotate on components such as a connecting line or a clamping plate.

Similarly, as shown in fig. 1 or 2, the movable pulley rotation center 11 is provided with a mandrel connected with the step movable pulley 2; the step movable pulley 2 is connected with a heavy object through a mandrel. The mandrel can be directly connected with a heavy object or connected with the heavy object through a clamping plate.

When the rope is installed, as shown in fig. 2, the first end of the rope 3 is fixedly connected with the fixed pulley rotation center 10 and sequentially wound according to the sequence of the fixed pulley and the movable pulley. If, when N equals 3, the first end of rope 3 links firmly on the lifting hook of the splint of step fixed pulley 1, walks around each step circle of two step pulleys successively again, and the order is: a first movable pulley 6, a first fixed pulley 9, a second movable pulley 5, a second fixed pulley 8, a third movable pulley 4 and a third fixed pulley 7. Finally the second end of the cord 3 extends as a free end. Of course, there are many ways of securing and wrapping.

As shown in FIG. 1 or 2, the tension at the free end of the rope 3 is G/6. The axial fixed connection mode of a plurality of pulleys is adopted, the number of step circles can be increased in the axial direction according to actual use conditions, and the lifting weight can be large theoretically. And the number of step circles is increased axially, the occupied space is small, compared with a common pulley block, the pulley block is more suitable for being used in narrow space (such as an elevator) and is very convenient to install. And because the step round radii of the two step pulleys are different, the self weight of the pulley block is greatly reduced compared with that of a pulley block for a crane. If the device is installed on a crane, the overturning moment of the device is reduced, the crane is not easy to overturn, and the device is convenient to transport and replace. Even adopt cast iron material preparation pulley can not be because of from great heavy and bulky, also can be more nimble under the lubricated bad circumstances, the wearing and tearing of rope 3 and pulley that can be fine reduce.

The utility model provides a novel assembly pulley can adopt and close mouthful splint, as shown in fig. 1, can make the coaster security higher, simultaneously because the step radius of step pulley is different, the axial space that occupies is little, even sealed also can be very convenient installation rope.

And compare with the differential pulley, the novel assembly pulley of this application utilizes the rope quantity of winding at the movable pulley to reach laborsaving purpose, on laborsaving principle and the connected mode of rope 3, is totally different with the differential pulley. First, the difference in radius between the multiple step circles need not be small to save effort. Secondly, the rope 3 does not need to be wound back to be in a closed loop state, and only the free end of the rope 3 needs to be pulled, so that the use is very convenient. Thirdly, the step circle and the rope 3 are in a non-meshing mode, a chain wheel and a chain with teeth on the periphery are not needed, even if the pulling force is uneven or the force is too strong, the rope 3 cannot be clamped by the step circle and cannot fall down, the rope is very safe, and the rope can be lifted by machinery. And the abrasion is very small, and the frequent lubrication oil feeding or maintenance is not needed.

The radiuses of the N fixed pulleys and the radius of the movable pulley form an equal difference number series. For example, when the radius of the first fixed pulley 9 is a, the radius of the Nth fixed pulley is N · a, the radius of the first movable pulley 6 is 0.5a, and the radius of the Nth movable pulley is (N-0.5) a; the distance between the fixed pulley rotation center 10 and the movable pulley rotation center 11 in the horizontal direction is 0.5 a. As shown in fig. 2,3 or 4, the radius R1 of the first fixed sheave 9 is a, the radius R2 of the second fixed sheave 8 is 2a, and the radius R3 of the third fixed sheave 7 is 3 a; the radius R ' 1 of the first movable sheave 6 is 0.5a, the radius R ' 1 of the second movable sheave 5 is 1.5a, the radius R ' 3 of the third movable sheave 4 is 2.5a, the fixed sheave rotation center 10 and the movable sheave rotation center 11 are not on the same vertical line, and an eccentricity a/2 is provided therebetween. Since the relative thickness of each step circle of the pulley is small, its thickness can be disregarded. At this moment, 6 sections of ropes between the step fixed pulley 1 and the step movable pulley 2 are all in a vertical state and tangent to corresponding step circles, and the distance between the ropes is a, so that the step fixed pulley is more stable when pulled, and the step fixed pulley is better in stability and not easy to overturn.

The working principle is as follows:

as shown in fig. 2, the fixed pulley rotation center 10 of the step fixed pulley 1 is set to 0, and the tangent points of the rope 3 and each step circle of the step fixed pulley 1 are respectively 1,2,3,4, and 5. The tangency points of the rope 3 and each step circle of the step movable pulley 2 are respectively 0 ', 1', 2 ', 3', 4 'and 5'.

When the rope is normally used, the free end of the rope is pulled, and then the fixed pulley rotates around the rotation center 0 of the fixed pulley. The instantaneous angular velocity of the pulley is set to ω, and at the same time, the movable pulley instantaneously rotates around 0' according to the knowledge in theoretical mechanics. 0' is the "instant center" of the movable pulley at that time. The speed relationship at each point on the two pulleys is as follows:

V0’＝V0＝0

V1’＝V1＝ωR1

V2’＝V2＝ωR2

V3’＝V3＝ωR3

V4’＝V4＝ωR1

V5’＝V5＝ωR2

the rope 3 is purely rolled with no relative sliding between the respective step circles. Therefore, the stress of each rope section is uniform and equal and is G/6 (wherein G is the weight of the hoisted object, and the weight of the movable pulley is not counted). The tension at the free end of the rope is also G/6.

The utility model provides a novel assembly pulley can further expand, can increase the quantity of the step circle of every pulley. For example, 6 step circles per pulley may be added. In this case, R4 ═ 4a, R5 ═ 5a, R6 ═ 6a, R ' 4 ═ 3.5a, R ' 5 ═ 4.5a, and R ' 6 ═ 5.5 a. At this time, the rope bearing the weight is 12 segments, so that the tension of the free end of the rope is G/12.

In theory, the number of step circles could also be more than 6 and is not limited. The labor-saving pulley can be used as a hoisting tool in a narrow space.

The fixed pulley and the movable pulley are provided with wheel grooves, so that the rope 3 is not easy to separate from the pulleys when pulling a heavy object.

The pulley block can be further expanded, wherein the upper part is designed into two (or more) same step fixed pulleys 1, and the lower part is designed into two (or more) same step movable pulleys 2. The step fixed pulleys 1 or the step movable pulleys 2 are coaxially and slidably connected through a mandrel. As shown in fig. 9, the pulley block is composed of two step fixed pulleys 1 located at the upper part and two step movable pulleys 2 located at the lower part, and a rope 3 wound between the two pulleys. The 2 step fixed pulleys 1 or the 2 step movable pulleys 2 can rotate independently. After the rope 3 is wound from the third fixed pulley 7 (maximum step circle) of the first step fixed pulley 1 at the upper right portion, it is continuously wound … … with the first movable pulley 6 (minimum step circle) of the second step movable pulley 2 at the lower left portion, and by such primary winding, the rope 3 finally comes out from the third fixed pulley 7 of the second step fixed pulley 1 at the upper left portion as a free end. Through test tests, the tension of the free end is approximately G/12, and the labor-saving requirement can be met.

By adopting the side-by-side step pulley, under the same labor-saving degree, compared with the combination of one step fixed pulley 1 and one step movable pulley 2, the thickness of one fixed pulley is increased only in the axial direction (in the horizontal direction), but the radial size (namely the diameter of the largest fixed pulley or movable pulley) is greatly reduced, and the use in a narrow space is facilitated.

Wherein, the axial is the length of dabber direction for show the thickness of step pulley. The radial direction is the pulley diameter, mainly the diameter of the step pulley (especially the maximum step circle).

The fixed connection which is not specified can be a connection mode such as riveting, welding, bolt connection and the like, a movable connection can be a connection mode such as hinging and the like.

Claims

1. A novel pulley block is characterized by comprising

The step fixed pulley (1) comprises N fixed pulleys which are coaxially and fixedly connected; the fixed pulley rotating center (10) of the step fixed pulley (1) can be connected with the outside;

the step movable pulley (2) comprises N movable pulleys which are coaxially and fixedly connected; the rotating center (11) of the movable pulley of the step movable pulley (2) can be connected with a heavy object;

wherein N is more than or equal to 1 and is a natural number;

the radiuses of the N fixed pulleys are sequentially increased, and the radiuses of the N movable pulleys are sequentially increased; the radiuses of the N fixed pulleys and the radius of the N movable pulleys form an equal difference number sequence; when the radius of the first fixed pulley (9) is a, the radius of the Nth fixed pulley is N.a, the radius of the first movable pulley (6) is 0.5a, and the radius of the Nth movable pulley is (N-0.5) a; the distance between the rotating center (10) of the fixed pulley and the rotating center (11) of the movable pulley in the horizontal direction is 0.5 a;

the step fixed pulley (1) and the step movable pulley (2) are sequentially wound through a rope (3);

and the fixed pulley and the movable pulley are provided with pulley grooves.

2. The new pulley block according to claim 1, characterized in that said crown block rotation centre (10) is provided with a spindle connected to said step crown block (1); the step fixed pulley (1) is connected with the outside through a mandrel.

3. -new pulley block according to claim 1, characterised in that said mobile pulley centre of rotation (11) is provided with a spindle connected to said step mobile pulley (2); the step movable pulley (2) is connected with a heavy object through a mandrel.

4. A new pulley block according to claim 1, characterised in that said first end of said rope (3) is fixedly connected to said fixed pulley rotation centre (10) and is wound in sequence according to the sequence of a first fixed pulley and a second fixed pulley.