Small-tooth-difference large-speed-ratio speed reducer for lifting mechanism

Abstract

The utility model discloses a speed reducer with small tooth difference and large speed ratio for a lifting mechanism, which belongs to the technical field of speed reducers and comprises an eccentric shaft, a duplex external gear is arranged on the eccentric shaft, one end of the duplex external gear is arranged in a fixed internal gear and meshed with the fixed internal gear, and the other end of the duplex external gear is meshed with the fixed internal gear. The other end of the duplex outer gear is arranged outside the fixed inner gear and meshed with the output inner gear, the duplex outer gear drives the output inner gear to rotate, a drum wheel is arranged on the circumferential outer wall of the output inner gear, a spiral line groove used for winding a steel cable is formed in the drum wheel, and the length direction of the spiral line groove is the same as the length direction of the drum wheel; the speed reducer adopts internal meshing planetary transmission, has the characteristics of compact structure, large transmission ratio range, small volume, reliable braking and the like, and can well meet the actual requirements of hanging equipment.

Description

Technical Field

[0001] The utility model relates to the technical field of speed reducers, in particular to a planetary gear speed reducer with small tooth difference and large speed ratio for a lifting mechanism. Background Art

[0002] A suspension is a tool for lifting heavy loads. Generally, it is required to be able to "brake" and stay at any position during the process of lifting heavy loads. Therefore, most of them adopt the structural form of motor + speed reducer + brake device to achieve lifting. The speed reducers commonly used for suspension are gear speed reducers, worm speed reducers, and planetary gear speed reducers. The disadvantages of gear speed reducers are: the transmission ratio that can be achieved by a single stage is low, the volume is large, the structure is complex, and an additional brake mechanism is required for braking. Generally, it is used for lifting suspensions with a transmission ratio not greater than 100. The disadvantages of worm speed reducers are: the volume of the worm and worm gear transmission mechanism is large, the weight is heavy, the efficiency is low, and an additional brake mechanism is required for braking. Generally, it is used for large-scale lifting suspensions. The disadvantages of planetary gear speed reducers are: braking is achieved by multiple stages and large reduction ratios, the structure is complex, and due to the large number of stages, extremely high requirements are imposed on machining, assembly accuracy, etc., and an additional brake mechanism is required for braking. Content of the Utility Model

[0003] In view of the above deficiencies of the prior art, the utility model provides a planetary gear speed reducer with small tooth difference and large speed ratio for a lifting mechanism, solves the problems existing in speed reducers of other technical routes, and achieves the purpose of small volume, light weight, and reliable braking.

[0004] In order to achieve the above utility model purpose, the technical solution adopted by the utility model is as follows:

[0005] There is provided a planetary gear speed reducer with small tooth difference and large speed ratio for a lifting mechanism, which includes an eccentric shaft. A double external gear is arranged on the eccentric shaft. One end of the double external gear is arranged inside a fixed internal gear and meshes with the fixed internal gear. The other end of the double external gear is arranged outside the fixed internal gear and meshes with an output internal gear. The eccentric shaft drives the double external gear to revolve around the axes of the fixed internal gear and the output internal gear. When the double external gear revolves around the fixed internal gear and the output internal gear, the double external gear rotates around its own axis;

[0006] A drum is arranged on the circumferential outer wall of the output internal gear. A spiral wire groove for winding a steel cable is arranged on the drum. The length direction of the spiral wire groove is the same as the length direction of the drum.

[0007] The basic principle of a planetary gear reducer with a small tooth difference and a large speed ratio for a lifting mechanism is as follows: The rotational speed and torque are input from an eccentric shaft. The double external gears mounted on the eccentric shaft are respectively meshed with a fixed internal gear and an output internal gear. Among them, the fixed internal gear does not rotate. When the double external gears revolve around the fixed internal gear and the output internal gear, the double external gears rotate around their own axes. During the process of the double external gears revolving around the output internal gear, the rotational speed and torque are transmitted to the output internal gear, causing the output internal gear to rotate around its own axis, realizing the deceleration motion. The rotating output internal gear drives the drum to rotate together, and the rotating drum drives the steel cable wound in the spiral groove to complete the lifting and lowering operations of the heavy object.

[0008] Further, a fixed bracket is arranged on the outer side of one side of the fixed internal gear, and the fixed internal gear is fixedly connected with the fixed bracket to ensure that the fixed internal gear does not rotate together with the double external gears.

[0009] Further, the fixed internal gear is located inside the drum, and a needle roller bearing is arranged between the drum and the fixed internal gear. The needle roller bearing is installed between the fixed internal gear and the drum to provide rigid support for the drum and the vibration transmitted from the eccentric shaft.

[0010] Further, the eccentric shaft is of a hollow structure, and internal splines are arranged on the inner circumferential wall at one end of the eccentric shaft. The arrangement of the internal splines facilitates the transmission of rotational speed and torque between the eccentric shaft and the power element.

[0011] Further, a retaining sleeve is arranged on one side of the needle roller bearing and one side of the step of the eccentric shaft. Since there is a spiral groove on the drum, the reducer will be pushed by the axial force during the operation of lifting heavy objects. The retaining sleeve is used to ensure that the eccentric shaft and the double external gears will not move axially during lifting.

[0012] Further, the double external gears are rotatably connected to the eccentric shaft through bearings.

[0013] Further, two eccentric connecting blocks are symmetrically arranged on the eccentric shaft. The eccentric shaft is rotatably connected to the double external gears through bearings arranged on the two eccentric blocks. The arrangement of the two eccentric connecting blocks balances the overall weight of the eccentric shaft, making its weight evenly distributed on both sides of the eccentric shaft to reduce the periodic vibration during the rotation of the eccentric shaft.

[0014] Further, the reduction ratio between the eccentric shaft and the output internal gear is 183, and the efficiency coefficient of the internal tooth meshing pair of the double external gears is 0.97 - 0.98. When the efficiency coefficient of the internal tooth meshing pair of the reducer = 0.97 and the reduction ratio ≥ 33, the speed increase self-locking of the reducer is realized. When the efficiency coefficient of the internal tooth meshing pair of the reducer = 0.97 and the reduction ratio ≥ 49, the deceleration self-locking of the reducer is realized. The above settings enable the planetary gear reducer with a small tooth difference and a large speed ratio for the lifting mechanism of the present invention to meet the requirements of the lifting mechanism.

[0015] The beneficial effects of the present utility model are as follows:

[0016] 1. The planetary drive with few teeth difference and large speed ratio in the present utility model adopts internal meshing planetary drive, and has the characteristics of compact structure, large speed ratio range, small volume, reliable "braking", etc., which can well meet the actual needs of hanging equipment.

[0017] 2. In the planetary drive with few teeth difference and large speed ratio of the present utility model, by arranging a needle roller bearing between the fixed internal gear and the drum, rigid support is provided for the drum and the vibration transmitted from the eccentric shaft, so that the drum works smoothly and the probability of failure is reduced. Description of the Drawings

[0018] Figure 1 It is a schematic diagram of the internal sectional structure of a planetary drive with few teeth difference and large speed ratio for a lifting mechanism.

[0019] Among them, 1. Eccentric shaft; 2. Double external gear; 3. Fixed internal gear; 4. Output internal gear; 5. Drum; 6. Spiral groove; 7. Fixed bracket; 8. Needle roller bearing; 9. Internal spline; 10. Retaining sleeve; 11. Bearing; 12. Eccentric connecting block. Specific Embodiments

[0020] The specific embodiments of the present utility model will be described below to facilitate those skilled in the art of the present technology to understand the present utility model. However, it should be clear that the present utility model is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of the present technology, as long as various changes are within the spirit and scope of the present utility model defined and determined by the appended claims, these changes are obvious, and all inventions and creations using the concept of the present utility model are within the scope of protection.

[0021] As Figure 1 shown, the present utility model provides a planetary drive with few teeth difference and large speed ratio for a lifting mechanism, which includes an eccentric shaft 1. A double external gear 2 is arranged on the eccentric shaft 1. One end of the double external gear 2 is arranged inside the fixed internal gear 3 and meshes with the fixed internal gear 3, and the other end of the double external gear 2 is arranged outside the fixed internal gear 3 and meshes with the output internal gear 4. The eccentric shaft 1 drives the double external gear 2 to revolve around the axes of the fixed internal gear 3 and the output internal gear 4. When the double external gear 2 revolves around the fixed internal gear 3 and the output internal gear 4, the double external gear 2 rotates around its own axis

[0022] A drum 5 is arranged on the circumferential outer wall of the output internal gear 4. A spiral groove 6 for winding a steel cable is arranged on the drum 5, and the length direction of the spiral groove 6 is the same as the length direction of the drum 5.

[0023] The basic principle of a planetary reducer with few teeth difference and large speed ratio for a lifting mechanism is as follows: The speed and torque are input from the eccentric shaft 1. The double external gears 2 mounted on the eccentric shaft 1 are respectively meshed with the fixed internal gear 3 and the output internal gear 4. Among them, the fixed internal gear 3 does not rotate. When the double external gears 2 revolve around the fixed internal gear 3 and the output internal gear 4, the double external gears 2 rotate around their own axes. During the process of the double external gears 2 revolving around the output internal gear 4, the speed and torque are transmitted to the output internal gear 4, causing the output internal gear 4 to rotate around its own axis, realizing the deceleration movement. The rotating output internal gear 4 drives the drum 5 to rotate together, and the rotating drum 5 drives the steel cable wound in the spiral wire groove 6 to complete the hoisting and lowering operations of heavy objects.

[0024] Since the planetary reducer with few teeth difference and large speed ratio adopts internal meshing planetary transmission, it has the characteristics of compact structure, large transmission ratio range, small volume, reliable "braking", etc., and can well meet the actual needs of hanging equipment.

[0025] Specifically, a fixed bracket 7 is arranged on the outer side of one side of the fixed internal gear 3, and the fixed internal gear 3 is fixedly connected with the fixed bracket 7 to ensure that the fixed internal gear 3 does not rotate together with the double external gears 2.

[0026] Preferably but not limitedly, the fixed internal gear 3 is located inside the drum 5, and a needle roller bearing 8 is arranged between the drum 5 and the fixed internal gear 3. The needle roller bearing 8 is installed between the fixed internal gear 3 and the drum 5 to provide rigid support for the drum 5 and the vibration transmitted from the eccentric shaft 1.

[0027] Specifically, the eccentric shaft 1 is of a hollow structure, and internal splines 9 are arranged on the inner wall of the circumference at one end of the eccentric shaft 1. The setting of the internal splines 9 facilitates the transmission of speed and torque between the eccentric shaft 1 and the power element. The power element can be a motor.

[0028] Preferably but not limitedly, a retaining sleeve 10 is arranged on one side of the needle roller bearing 8 and one side of the step of the eccentric shaft 1. Since there is a spiral wire groove 6 on the drum 5, the reducer will be pushed by the axial force during the operation of lifting heavy objects. The retaining sleeve 10 is used to ensure that the eccentric shaft 1 and the double external gears 2 will not move axially during hoisting.

[0029] The double external gears 2 are rotatably connected to the eccentric shaft 1 through bearings 11. Two eccentric connecting blocks 12 are symmetrically arranged on the eccentric shaft 1. The eccentric shaft 1 is rotatably connected to the double external gears 2 through bearings 11 arranged on the two eccentric blocks. The setting of the two eccentric connecting blocks 12 balances the overall weight of the eccentric shaft 1, making its weight evenly distributed on both sides of the eccentric shaft 1 to reduce the periodic vibration during the rotation of the eccentric shaft 1.

[0030] Further, the reduction ratio between the eccentric shaft 1 and the output internal gear 4 is 183, and the efficiency coefficient of the internal tooth meshing pair of the double external gears 2 is 0.97 - 0.98. When the efficiency coefficient of the internal tooth meshing pair of the speed reducer = 0.97 and the reduction ratio ≥ 33, the speed increase self-locking of the speed reducer is achieved. When the efficiency coefficient of the internal tooth meshing pair of the speed reducer = 0.97 and the reduction ratio ≥ 49, the speed reduction self-locking of the speed reducer is achieved. The above settings enable the planetary gear speed reducer with few teeth difference and large speed ratio for the lifting mechanism of the present invention to meet the requirements of the lifting mechanism.

Claims

1. A planetary gear reducer with a small tooth difference and a large speed ratio for a lifting mechanism, characterized in that, It includes an eccentric shaft, on which a double external gear is provided. One end of the double external gear is arranged inside a fixed internal gear and meshes with the fixed internal gear, and the other end of the double external gear is arranged outside the fixed internal gear and meshes with an output internal gear. The eccentric shaft drives the double external gear to revolve around the axes of the fixed internal gear and the output internal gear. When the double external gear revolves around the fixed internal gear and the output internal gear, the double external gear rotates around its own axis. A drum is provided on the circumferential outer wall of the output internal gear. A spiral wire groove for winding a steel cable is provided on the drum, and the length direction of the spiral wire groove is the same as the length direction of the drum.

2. The planetary gear reducer with small tooth difference and large speed ratio for the lifting mechanism according to claim 1, characterized in that, A fixed bracket is provided outside one side of the fixed internal gear.

3. The planetary gear reducer with few teeth difference and large speed ratio for the lifting mechanism according to claim 2, characterized in that, The fixed internal gear is located inside the drum, and a needle bearing is provided between the drum and the fixed internal gear.

4. The planetary gear reducer with few teeth difference and large speed ratio for the lifting mechanism according to claim 3, characterized in that, The eccentric shaft is of a hollow structure, and internal splines are provided on the circumferential inner wall at one end of the eccentric shaft.

5. The planetary gear reducer with small tooth difference and large speed ratio for the lifting mechanism according to claim 4, characterized in that, A retaining sleeve is provided on one side of the needle bearing and one side of the step of the eccentric shaft.

6. The planetary gear reducer with few teeth difference and large speed ratio for the lifting mechanism according to claim 4, characterized in that, The double external gear is rotationally connected to the eccentric shaft through a bearing.

7. The planetary gear reducer with small tooth difference and large speed ratio for the lifting mechanism according to claim 6, characterized in that, Two eccentric connection blocks are symmetrically arranged on the eccentric shaft, and the eccentric shaft is rotationally connected to the double external gear through bearings provided on the two eccentric connection blocks.

8. The planetary gear reducer with small tooth difference and large speed ratio for the lifting mechanism according to claim 1, characterized in that The reduction ratio between the eccentric shaft and the output internal gear is 183, and the efficiency coefficient of the internal tooth meshing pair of the double external gear is 0.97 - 0.98.

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