CN113929000A

CN113929000A - Hoisting mechanism and crane

Info

Publication number: CN113929000A
Application number: CN202111142780.XA
Authority: CN
Inventors: 龙卫国; 黄春华; 曹吉兵; 何伟; 黄珍
Original assignee: Zoomlion Heavy Industry Science and Technology Co Ltd
Current assignee: Zoomlion Heavy Industry Science and Technology Co Ltd
Priority date: 2021-09-28
Filing date: 2021-09-28
Publication date: 2022-01-14

Abstract

The invention belongs to the field of engineering machinery, and discloses a hoisting type hoisting mechanism and a crane, wherein the hoisting type hoisting mechanism comprises a power motor (1), a speed change ratio reducer (2) and a winding drum assembly which are sequentially connected in a transmission manner, the power motor (1) comprises a motor rotating shaft (11), the speed change ratio reducer (2) comprises a reducer output shaft (21), and the reduction ratio of the speed change ratio reducer (2) can be adjusted, so that the reducer output shaft (21) can rotate at an adjustable rotating speed which is lower than that of the motor rotating shaft (11). Therefore, the hoisting mechanism can realize the hoisting of the hoisting maximum speed of the hoisting type hoisting mechanism, avoid the power motor from generating larger rotational inertia, thoroughly eliminate the hoisting speed fluctuation phenomenon, improve the controllability of the mechanism and improve the working efficiency of the mechanism.

Description

Hoisting mechanism and crane

Technical Field

The invention relates to the technical field of engineering machinery, in particular to a hoisting type hoisting mechanism and a crane.

Background

The hoisting type hoisting mechanism in the existing automobile crane is mostly provided with a system which is used by matching a variable motor and a constant speed ratio reducer, and if the rotating speed of a winding drum component is required to be adjusted, the rotating speed of the variable motor must be adjusted under the condition that the reduction ratio of the reducer is constant.

However, the variable motor can only adjust speed in the operation process, so that the motor can form a larger inertia moment in the variable process, and the whole system is in the form of an underdamped second-order system and has certain overshoot and response time. In addition, in the case of a small load, the performance of the speed reducer is not efficiently utilized, and the energy efficiency is excessive. During actual operation, the steel wire rope in the winding drum component has acceleration or deceleration process when the motor adjusts the speed, which can lead to poor control performance of the hoisting mechanism, and can only be adjusted by the experience of operators, if the rope speed has certain requirements, the overshoot formed during the motor speed adjustment can also cause the rope speed fluctuation, and the response time can also lead to poor operation hand feeling.

Disclosure of Invention

Aiming at least one defect or defect in the prior art, the invention provides a hoisting type hoisting mechanism and a crane, which can realize the hoisting at the maximum speed, avoid the generation of larger moment of inertia of a power motor, thoroughly eliminate the hoisting speed fluctuation phenomenon and improve the controllability of the mechanism.

In order to achieve the above object, a first aspect of the present invention provides a hoisting mechanism, where the hoisting mechanism includes a power motor, a speed-change-ratio reducer, and a drum assembly, the power motor includes a motor rotating shaft, the speed-change-ratio reducer includes a reducer output shaft, and a reduction ratio of the speed-change-ratio reducer is adjustable, so that the reducer output shaft can rotate at an adjustable rotation speed lower than that of the motor rotating shaft.

Optionally, the power motor is a constant speed motor capable of keeping a constant rotation speed during winding of the drum assembly.

Optionally, the hoisting mechanism comprises a hydraulic control system, and the constant-speed motor is a fixed-displacement motor with the rotation speed controlled by the hydraulic control system.

Optionally, the hoisting mechanism comprises a controller configured to obtain an optimal reduction ratio of the speed reducer according to a load weight of the hoisting mechanism.

Optionally, the variable-speed-ratio speed reducer comprises a first power gear, a second power gear, a transmission shaft, a plurality of transmission gears and a plurality of reduction gears, the first power gear is sleeved on the motor rotating shaft and meshed with the second power gear, the second power gear and the plurality of transmission gears are sequentially sleeved on the transmission shaft at intervals, the plurality of reduction gears are meshed with the plurality of transmission gears in a one-to-one correspondence manner, and an output shaft of the speed reducer can be selectively fixedly connected with one of the reduction gears to synchronously rotate.

Optionally, the number of the transmission gears and the number of the reduction gears are two, the output shaft of the speed reducer penetrates through gear center holes of the two reduction gears, a synchronizer located between the two reduction gears is sleeved on the output shaft of the speed reducer, and the output shaft of the speed reducer can move along the axial direction so that the synchronizer is fixedly connected with one of the reduction gears.

Optionally, the hoisting mechanism comprises a swing control rod and a shifting connector connected between the swing control rod and the reducer output shaft, and the shifting connector can drive the reducer output shaft to move to be fixedly connected with one of the reduction gears by controlling the swing of the swing control rod.

Optionally, the swing lever is arranged to swing by manual and/or automatic control.

Optionally, the hoisting mechanism comprises a power cylinder for driving the swing control rod to swing.

The invention provides a crane, which comprises the hoisting mechanism.

In the invention, because the hoisting type hoisting mechanism is provided with the speed change ratio reducer, when the rotating speed of the winding drum assembly needs to be adjusted, the rotating speed of the power motor does not need to be adjusted, and the adjustment can be realized only by adjusting the reduction ratio of the speed reducer, so that the power motor can be prevented from generating larger rotational inertia due to speed adjustment, the hoisting speed fluctuation phenomenon is thoroughly eliminated, and the controllability of the mechanism is improved. When the rotating speed of the power motor is constant, the reduction ratio is reduced through adjustment, the hoisting maximum speed can be increased, the energy efficiency of the speed reducer is fully utilized, and the overall working efficiency of the hoisting mechanism is improved.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic view of a portion of a hoist in accordance with an embodiment of the present invention;

FIG. 2 is a schematic diagram of a variable speed ratio reducer and associated motor shaft, swing lever, shift linkage and hinge mount in accordance with an embodiment of the present invention;

FIG. 3 is a schematic diagram of a fixed displacement motor and hydraulic control system in accordance with an embodiment of the present invention.

Description of reference numerals:

1 power motor 2 speed change ratio speed reducer

3 swing control rod 4 connecting piece that shifts

5 hinged seat 6 power cylinder

11 motor shaft 21 reducer output shaft

22 first power gear 23 second power gear

24 drive shaft 25 drive gear

26 reduction gear 27 synchronizer

41 first bar 42 second bar

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration and explanation only, not limitation.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In embodiments of the invention, where the context requires otherwise, the use of directional terms such as "upper, lower, top and bottom" is generally intended in the orientation shown in the drawings or the positional relationship of the various components in a vertical, vertical or gravitational orientation.

The invention will be described in detail below with reference to exemplary embodiments and with reference to the accompanying drawings.

As shown in fig. 1 to 3, a first exemplary embodiment of the present invention provides a hoisting mechanism, which includes a power motor 1, a speed reducer 2 and a drum assembly, which are connected in a transmission manner in sequence. The power motor 1 outputs a certain rotating speed, and after the rotating speed is reduced by the variable speed ratio reducer 2, the winding drum in the winding drum assembly is driven to rotate at the rotating speed which is the same as the output rotating speed of the variable speed ratio reducer 2, so that the function of lifting or lowering heavy objects of the mechanism is realized.

Specifically, the power motor 1 includes a motor rotating shaft 11, and the rotating speed of the motor rotating shaft 11 is the motor output rotating speed of the power motor 1. The speed change gear reducer 2 includes a reducer output shaft 21, and the rotational speed of the reducer output shaft 21, that is, the reducer output speed of the speed change gear reducer 2, and the motor output rotational speed provides the reducer input speed to the speed change gear reducer 2 via a rotating member such as a shaft or a gear fixed to the motor rotating shaft 11 in the speed change gear reducer 2.

The biggest difference from the existing hoisting mechanism applied to the crane is that the speed reduction ratio-adjustable speed reduction gear 2 is adopted in the present exemplary embodiment, rather than the fixed speed reduction gear. The reduction ratio is known as the ratio of the instantaneous input speed to the output speed in the reduction mechanism, and therefore in the present exemplary embodiment, the reduction ratio of the reduction gear ratio reducer 2, i.e., the ratio of the reducer input speed to the reducer output speed, is also equivalent to the ratio of the motor output rotational speed to the reducer output speed. Since the reduction ratio of the reduction gear ratio reducer 2 is adjustable, the reducer output shaft 21 can not only rotate at a lower speed than the motor rotating shaft 11, but also adjust the speed of the reducer output shaft 21 without adjusting the speed of the motor rotating shaft 11, which is one of the core differences between the present exemplary embodiment and the prior art.

As can be seen from the description of the background art, the hoisting mechanism using a variable displacement motor + a constant speed ratio reducer in the prior art has at least the following disadvantages:

firstly, the variable motor can be adjusted in speed only in the operation process, so that the motor can form a larger moment of inertia in the variable process, and the whole system is in the form of an underdamped second-order system and has certain overshoot and response time. Secondly, under a light load condition, the performance of the speed reducer is not utilized efficiently, and the energy efficiency is excessive. Thirdly, in actual operation, the steel wire rope in the winding drum component has acceleration or deceleration process when the motor adjusts the speed, which can lead to poor controllability of the hoisting mechanism, and can only be adjusted by the experience of the operator, if the rope speed has certain requirements, the overshoot formed when the motor adjusts the speed can also cause the fluctuation of the rope speed, and the response time can also lead to poor operation hand feeling.

In contrast to the exemplary embodiment, since the hoisting mechanism is provided with the speed-change-ratio reducer 2, when the rotation speed of the drum assembly needs to be adjusted, the rotation speed of the power motor 1 does not need to be adjusted, and the adjustment of the speed-reduction ratio of the reducer can be realized. The rotating speed of the motor cannot be very high due to the limitation of rotational inertia of the conventional variable motor, if the constant-speed motor is adopted for driving in the exemplary embodiment, the highest working speed of the motor is constant, the speed ratio of the speed reducer can be reduced, the maximum lifting speed can be improved, the energy efficiency of the speed reducer can be fully utilized, the overall working efficiency of the mechanism can be improved, the mechanism is not influenced by the rotational inertia of the motor, the lifting speed fluctuation phenomenon can be thoroughly eliminated, and the controllability of the mechanism can be improved.

In one embodiment, as mentioned above, the power motor 1 may be a constant speed motor, which can keep the rotation speed constant during the winding of the winding drum assembly, and when the rotation speed of the output shaft 21 of the speed reducer needs to be adjusted, only the reduction ratio needs to be adjusted. Of course, the present exemplary embodiment does not limit the choice of other motor types, such as a variable speed motor, and may also be used in combination with the speed reducer 2, so as to provide different speed regulation options for the hoisting mechanism.

Further, since the variable displacement motor used in the prior art is a hydraulic motor, a fixed displacement motor can be selected as a constant speed motor in the case of simplifying the adjustment of the control method of the conventional motor as much as possible. In this way, it means that a hydraulic control system is provided in the hoisting mechanism of the exemplary embodiment, and the rotation speed of the fixed displacement motor is controlled by the hydraulic control system, which can be referred to in particular in fig. 3. Thus, the hydraulic control system of the present exemplary embodiment may be kept consistent with the prior art, except that the variable displacement motor is replaced with a fixed displacement motor.

In one embodiment, the hoisting mechanism may comprise a controller configured to obtain an optimum reduction ratio of the reduction gear ratio reducer 2 based on a load weight of the hoisting mechanism. For example, a calculation relationship between the load weight and the maximum working torque to be output by the hoisting type hoisting mechanism and a calculation relationship between the maximum working torque and the optimal reduction ratio of the speed-change ratio reducer 2 are recorded in the controller in advance, the maximum working torque to be output by the hoisting mechanism is calculated by the controller through external input of the load weight and the multiplying power, and then the optimal reduction ratio required at the moment is calculated. As for how to adjust the reduction ratio subsequently, the adjustment can be realized through automatic control of the controller, and the adjustment can also remind an operator through modes such as control panel display and the like, and then the reduction ratio is manually adjusted by the operator.

In one embodiment, a novel internal structure of the speed reducer 2 is provided. Referring to fig. 2, the variable-ratio speed reducer 2 includes a first power gear 22, a second power gear 23, a transmission shaft 24, a plurality of transmission gears 25, and a plurality of reduction gears 26. The first power gear 22 is sleeved on the motor rotating shaft 11 and meshed with the second power gear 23, the second power gear 23 and the plurality of transmission gears 25 are sequentially sleeved on the transmission shaft 24 at intervals, the plurality of reduction gears 26 are meshed with the plurality of transmission gears 25 in a one-to-one correspondence manner, and the speed reducer output shaft 21 can be selectively fixedly connected with one of the reduction gears 26 completely by arranging a reasonable structure, so that the speed reducer output shaft 21 can synchronously rotate along with the connected reduction gears 26.

Based on the above arrangement, the motor shaft 11 can drive the first power gear 22 to rotate, so that the transmission shaft 24 and the plurality of transmission gears 25 sleeved on the transmission shaft 24 are driven to rotate by the second power gear 23 engaged with the first power gear 22, and the plurality of reduction gears 26 are engaged with the plurality of transmission gears 25 in a one-to-one correspondence manner, so that the reduction gears can rotate at a rotation speed lower than that of the motor shaft 11. The reduction gears 26 have different rotation speeds, and when the reducer output shaft 21 is fixedly connected with different reduction gears 26, the reduction gears can rotate at different rotation speeds, so that the adjustable reduction ratio of the speed-changing ratio reducer 2 is realized.

For example, two transmission gears 25 and two reduction gears 26 may be provided such that the reducer output shaft 21 passes through gear center holes of the two reduction gears 26, and an outer peripheral wall of the reducer output shaft 21 does not contact an inner peripheral wall of the gear center holes, and thus does not interfere with the reduction gears 26 when the reducer output shaft 21 is displaced in the axial direction. In addition, the output shaft 21 of the speed reducer is sleeved with the synchronizer 27 positioned between the two reduction gears 26, and when the output shaft 21 of the speed reducer is driven to move along the axial direction through a reasonably arranged structure, the synchronizer 27 can be driven to be fixedly connected with one of the reduction gears 26, so that the output shaft 21 of the speed reducer and one of the reduction gears 26 are fixed to each other and can rotate synchronously.

Further, the hoisting type hoisting mechanism can further comprise a swing control rod 3 and a gear shifting connecting piece 4 connected between the swing control rod 3 and the reducer output shaft 21, the gear shifting connecting piece 4 can be driven to move by controlling the swing of the swing control rod 3, and then the reducer output shaft 21 is driven to move to be fixedly connected with one of the reduction gears 26.

Taking fig. 2 as an example, the shaft of the swing control lever 3 can be hinged to the hinge seat 5, and the gearshift connection 4 comprises a first lever 41 and a second lever 42. One end of the first rod 41 is abutted to the outer peripheral wall of the synchronizer 27 so as to drive the reducer output shaft 21 to axially displace through the synchronizer 27 without affecting the rotation of the synchronizer 27, the other end of the first rod 41 is vertically connected to the second rod 42, and one end of the second rod 42 is hinged to the swing control rod 3. Under the structure, the swing control rod 3 is controlled to swing by taking the hinge base 5 as a rotation center, so that the second rod 42 can be pushed to translate, the synchronizer 27 is driven to move through the first rod 41, and finally the reducer output shaft 21 is driven to displace along the axial direction.

The control mode of the swing control rod 3 is not limited in the embodiment, and the swing control rod 3 can be set to swing through manual control, or swing through automatic control, or swing through manual and automatic integrated control. For example, a power cylinder 6, such as an electric cylinder, a hydraulic cylinder, or the like, may be provided in the hoisting mechanism for driving the swing control lever 3 to swing.

A second exemplary embodiment of the present invention provides a crane using the hoisting mechanism, and the type of the crane is not limited, and the crane may be, for example, an automobile crane. Obviously, the crane of the present exemplary embodiment has all the technical effects brought by the hoisting mechanism described above, and therefore, the description thereof is omitted here.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, the embodiments of the present invention are not limited to the details of the above embodiments, and various simple modifications can be made to the technical solutions of the embodiments of the present invention within the technical idea of the embodiments of the present invention, and the simple modifications all belong to the protection scope of the embodiments of the present invention.

It should be noted that, in the foregoing embodiments, various features described in the foregoing embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described in further detail in the embodiments of the present invention.

In addition, any combination of various different implementation manners of the embodiments of the present invention is also possible, and the embodiments of the present invention should be considered as disclosed in the embodiments of the present invention as long as the combination does not depart from the spirit of the embodiments of the present invention.

Claims

1. The utility model provides a hoist formula hoisting mechanism, its characterized in that, hoist formula hoisting mechanism is including power motor (1), gear ratio speed reducer (2) and the reel subassembly that transmission connects in proper order, power motor (1) includes motor shaft (11), gear ratio speed reducer (2) are including speed reducer output shaft (21), the adjustable setting of reduction ratio of gear ratio speed reducer (2) makes speed reducer output shaft (21) can be with adjustable and be less than the rotational speed of motor shaft (11) rotates.

2. Hoisting mechanism according to claim 1, characterized in that the power motor (1) is a constant speed motor capable of maintaining a constant rotational speed during hoisting of the drum assembly.

3. The hoist lift mechanism of claim 2, wherein the hoist lift mechanism includes a hydraulic control system, and the constant speed motor is a fixed displacement motor having a speed controlled by the hydraulic control system.

4. Hoisting mechanism according to claim 1, characterized in that it comprises a controller configured to obtain an optimal reduction ratio of the speed reducer (2) according to the load weight of the hoisting mechanism at the current moment.

5. The hoisting mechanism of any one of claims 1 to 4, wherein the speed reducer (2) comprises a first power gear (22), a second power gear (23), a transmission shaft (24), a plurality of transmission gears (25) and a plurality of reduction gears (26), the first power gear (22) is sleeved on the motor rotating shaft (11) and meshed with the second power gear (23), the second power gear (23) and the plurality of transmission gears (25) are sequentially sleeved on the transmission shaft (24) at intervals, the plurality of reduction gears (26) are meshed with the plurality of transmission gears (25) in a one-to-one correspondence manner, and the output shaft (21) of the speed reducer can be selectively and fixedly connected with one of the reduction gears (26) to synchronously rotate.

6. The hoisting mechanism of claim 5, wherein the transmission gear (25) and the reduction gear (26) are provided in two, the reducer output shaft (21) passes through gear center holes of the two reduction gears (26), a synchronizer (27) positioned between the two reduction gears (26) is sleeved on the reducer output shaft (21), and the reducer output shaft (21) can move along the axial direction to enable the synchronizer (27) to be fixedly connected with one of the reduction gears (26).

7. Hoisting mechanism according to claim 5, characterized in that it comprises a swing control lever (3) and a shift connection (4) connected between the swing control lever (3) and the reducer output shaft (21), the shift connection (4) being capable of driving the reducer output shaft (21) to move into fixed connection with one of the reduction gears (26) by controlling the swing of the swing control lever (3).

8. Hoisting mechanism according to claim 7, characterized in that the swing lever (3) is arranged to swing by manual and/or automatic control.

9. Hoisting mechanism according to claim 8, characterized in that the hoisting mechanism comprises a power cylinder (6) for driving the swing control rod (3) to swing.

10. A crane, characterized in that the crane comprises a hoisting mechanism according to any one of claims 1 to 9.