CN115126828A - Variable pitch gap-eliminating planetary speed regulator - Google Patents

Abstract

A variable-pitch clearance-eliminating planetary speed regulator is characterized by that it utilizes the divisible characteristic of central distance of involute gear and utilizes the variable-central-distance structure to eliminate side gap, and uses the four characteristics of locking, moving, elasticity and rigidity of force-applying component as variables to provide three basic working modes of variable-pitch mechanism, i.e. after the side gap is regulated, the force-applying component is locked in fixed position to provide rigid support for planetary wheel, and its radial position is not actively changed, or after the force-applying component is locked in fixed position, it still can actively apply elastic pressure to planetary wheel to make its radial position self-adaptive dynamic change, or the force-applying component is not locked all the time and can actively apply elastic pressure to planetary wheel to make its radial position self-adaptive dynamic change. In addition, synchronous optimization is carried out on a plurality of associated details, and the competitiveness of the involute gear system in the precision application field is improved cooperatively.

Description

Variable pitch gap-eliminating planetary speed regulator

Technical Field

The invention relates to a speed reducer, in particular to a high-precision involute gear planetary speed reducer.

Background

The gear reducer is widely applied to the output end of power equipment, plays a role in changing the rotating speed, the torque or the inertia, and is an indispensable transmission device in the field of power machinery. Backlash is an important indicator of precision reducers, and is mainly caused by material deformation and clearances between moving components, which are mainly gear backlash. Involute gears have the advantages of center distance separability, constant torque and speed ratio, large load, convenience in machining, low cost and the like, are tooth transmission technologies with the widest popularization range, but unfortunately are difficult to apply in the precision field due to large backlash, and the industry cannot pay higher cost price for using alternative technologies and accept other regressions. The backlash problem becomes a hard damage of the involute gear, and the main reason is that the backlash can contain an oil film, so that the influence of thermal expansion and machining error is absorbed, and a certain backlash needs to be reserved in normal transmission; machining errors and bearing clearances are inevitable; the use of longer drive chains to achieve larger ratios increases the amount of backlash accumulation; the center distance of the transmission pair is often fixed, or the transmission wheels are in bilateral transmission, so that the side gap is reduced by adopting a method of reducing the center distance. In order to eliminate backlash, people think of a plurality of methods, but the problems are often solved and increased and are more difficult to accept, for example, the number, the weight and the volume of gears can be increased in multiples by adopting a double-piece circumferentially staggered combined zero backlash gear, and for example, a gear pair adopts zero backlash standard design and standard installation, so that the transmission resistance can be increased, the high rotating speed is easy to generate heat and block, and the precision life is short. The pin wheel cycloid speed reducer, the RV speed reducer and the harmonic speed reducer are generally adopted in the field of precision application at present, have relatively small side clearances, but have limitations that the pin wheel and the cycloid wheel have high manufacturing and mounting precision requirements, low strength and inseparable center distance, and the precision cannot be kept by changing the center distance after being worn; the primary reduction gear pair of the RV reducer arranged in front of the pin wheel and the cycloid wheel usually adopts an involute gear, and the problem of the backlash also exists; the flexible gear material performance and the process requirement of the harmonic reducer are high, and the bearing capacity is limited; the gear reducer adopts a small tooth difference speed reduction principle, the size of the transmission ratio is determined by the tooth number difference and the tooth number of a large gear, and the situation that the large gear is not large enough and the tooth number difference is not small enough can be met when the large transmission ratio is needed. If the involute gear system can effectively solve the problem of backlash, the involute gear system has great significance in the field of precision application.

Disclosure of Invention

The invention aims to improve the precision of an involute gear reducer, firstly, the characteristic that the center distance of an involute gear can be divided is utilized, the backlash is eliminated through a variable center distance structure, four characteristics of locking, activity, elasticity and rigidity of a force application assembly are taken as variables, three basic working modes of a distance changing mechanism are provided, and synchronous optimization is carried out on a plurality of associated details, so that the competitiveness of an involute gear system in the precision application field is cooperatively improved.

The invention is provided with a distance-changing mechanism, the radial position of the planet wheel can be adjusted to change the center distance between the planet wheel and the center wheel, thereby changing the backlash; the distance changing mechanism is provided with an elastic or rigid force application component for changing the center distance of the transmission wheel set; the working mode of the variable-pitch mechanism is that the force application component is always unlocked and actively applies elastic force to the planet wheel to enable the radial position of the planet wheel to be self-adaptive and dynamically changed, or the force application component is locked and fixed after the backlash is adjusted, and still actively applies elastic acting force to the planet wheel to enable the radial position of the planet wheel to be self-adaptive and dynamically changed, or the force application component is locked and fixed after the backlash is adjusted to provide rigid acting force for the planet wheel, and the radial position of the planet wheel is not actively changed; the planet wheel is of a single-layer structure or a stepped structure, and the central wheel is external teeth or internal teeth.

The force application assembly and the planet wheels are in a one-to-one relationship, or one force application assembly acts on a plurality of planet wheels simultaneously, and different planet wheels are constrained with each other through the force application assembly.

The force application assembly, the planet wheels or the shaft sleeve between the planet wheels are provided with inclined planes, the radial positions of the planet wheels can be changed by moving the planet wheels relative to each other in the axial direction, and the distance changing mechanism is provided with an axial displacement device for changing the axial position of the force application assembly.

The axial displacement device is a manual device, or an automatic elastic device, or a magnetic, electric, hydraulic or pneumatic intelligent servo device.

The invention is provided with an acting force automatic adjusting device, which is a centrifugal type or magnetic, electric, hydraulic or pneumatic intelligent servo device, and is used for changing the acting force of a force application component on a planet wheel, thereby avoiding unnecessary tooth surface abrasion or blockage caused by insufficient acting force and then withdrawing the planet wheel during transmission or excessive acting force.

The force application component of the invention has elasticity and can be used as a planet carrier or a hollow transmission shaft.

The side face of the planet wheel and the side face of the central wheel of the invention are provided with the limited-clearance wheel which is matched with the force application component to keep the minimum side clearance, or are provided with the oil control ring to control the lubricant, or are provided with the ring rail to replace the function of the planet carrier, or at least two of the limited-clearance wheel, the oil control ring and the ring rail are the same component.

The invention is provided with a central shaft, and a variable pitch mechanism is connected with an external or system self-provided control device through a hole or a groove of the central shaft.

The interior of the central shaft or the planetary wheel shaft is provided with an oil liquid channel, and lubricating oil or cooling liquid is driven to move by centrifugal action and negative pressure suction force generated by autorotation.

The contact surfaces of the rotating connecting component of the invention are provided with axial conicity or are connected with each other through a bushing with conicity, the radial clearance can be adjusted by changing the relative axial position between the connecting pieces, or the mounting hole of the planet wheel is provided with a square shaft sleeve to increase the contact area, and the contact area is in surface contact with the side wall of the mounting hole or the force application component.

Drawings

FIG. 1 is a radial view of a pitch mechanism;

FIG. 2 is an axial view of the pitch mechanism;

FIG. 3 is an axial displacement device of the pitch change mechanism;

FIG. 4 is a pressure regulating device of the pitch mechanism;

FIG. 5 is a force applying assembly that also acts as a planet carrier in itself;

FIG. 6 is a drive wheel with a limited play ring;

fig. 7 shows a connection mode of the force application member controlled from the outside.

Detailed Description

The invention is provided with a distance-changing mechanism, the radial position of the planet wheel can be adjusted to change the center distance between the planet wheel and the center wheel, thereby changing the backlash; the distance changing mechanism is provided with an elastic or rigid force application component for changing the center distance of the transmission wheel set; the working mode of the variable-pitch mechanism is that the force application component is always unlocked and actively applies elastic force to the planet wheel to enable the radial position of the planet wheel to be self-adaptive and dynamically changed, or the force application component is locked and fixed after the backlash is adjusted, and still actively applies elastic acting force to the planet wheel to enable the radial position of the planet wheel to be self-adaptive and dynamically changed, or the force application component is locked and fixed after the backlash is adjusted to provide rigid acting force for the planet wheel, and the radial position of the planet wheel is not actively changed; the planet wheel is of a single-layer structure or a stepped structure, and the central wheel is external teeth or internal teeth. Referring to fig. 1 and 2, the rotating arm 7 is fixed on the central shaft 8, the shaft 4 of the planet wheel 2 is rotatably connected with the shaft sleeve 3, the shaft sleeve 3 is arranged on the planet carrier 6 and is limited in the circumferential direction and can move in the radial direction, the inner gear 1 rotates in a fixed shaft mode, the pressing ring 5 serves as a force application component of the variable-pitch mechanism, radial pressure is applied to the shaft sleeve 3 to enable the planet wheel 2 to move to change the center distance between the planet wheel 2 and the inner gear 1, and therefore backlash of the planet wheel 2 and the inner gear 1 is adjusted. The compression ring 5 is provided with elasticity or elastic force as a drive, so that the planet wheel 2 and the internal tooth 1 can self-adaptively and dynamically maintain the circumferential zero backlash in the transmission, or maintain the minimum backlash larger than zero in the cooperation of a backlash limiting device. The working mode of the variable-pitch mechanism can also be that the pressure ring 5 is an elastic part and is locked at a fixed position after the backlash is adjusted, elastic pressure is still actively applied to the planet wheel, so that the radial position of the planet wheel is self-adaptive and dynamically changed, or the pressure ring 5 is a rigid part and is locked at the fixed position after the backlash is adjusted, so that rigid support is provided for the planet wheel, and the radial position of the planet wheel is not actively changed any more. The drive train may be any type of "sun-pinion" combination, where the pinions are single-pinion, and combine with the sun into a single pinion train, including but not limited to WG, NG, NGW, and 2K-H configurations, or where the pinions are stepped, and combine with the sun into an in-line differential pinion train, including but not limited to WGGW, NGGW, NGGN, or an in-line differential pinion train with a primary reduction gear, where N represents internal teeth, G represents pinions, and W represents external teeth. In an embodiment in which the distance between the external toothing and the centre of the planet is to be varied, the pressure ring 5 is replaced by a pull ring acting simultaneously on a plurality of planet wheels. The force application component and the planet wheel can also be in one-to-one relation in number. The tooth form of the driving wheel adopts an involute tooth form or other tooth forms with center distance separability.

As shown in fig. 2, the compression ring 5 acts on the shaft sleeves 3 of the plurality of planet wheels 2 simultaneously, so that different planet wheels 2 are opposite and constrained with each other, the structure can be simplified, and different action points are stressed uniformly, so that different transmission sets are easy to keep the same backlash.

In fig. 3, a sleeve 12 is arranged outside the planet wheel 11 to bear the pressure of a pressure ring 13; the contact surface of the pressure ring 13 and the shaft sleeve 12 is an inclined surface, and the radial position of the planet wheel can be changed by relative movement in the axial direction; a screw 15 is screwed to the carrier 14 for adjusting the axial position of the pressure ring 13. The screw 15 may be replaced by another type of moving mechanism.

As shown in fig. 3, the axial displacement device is a screw 15 that can be manually operated, or can be an automatic biasing device that always maintains pressure, or can be a magnetic, electric, hydraulic, or pneumatic intelligent servo device with a sensor, a processor, and a controller, and can automatically adjust the axial position of the pressing ring 13 according to the detected data such as pressure, relative position, or distance, so as to change the radial position of the planet wheel 11 to obtain the desired backlash.

In the embodiment that the elastic material is used as the force application component, the automatic pressure adjustment device is arranged to change the elastic force of the force application component, so as to prevent the planet wheel from withdrawing due to insufficient supporting force during transmission, or avoid unnecessary tooth surface abrasion or being stuck due to excessive supporting force, as shown in fig. 4, the centrifugal block 18 can move radially on the groove of the planet carrier 16, and is movably connected with the elastic pressure ring 17 through the inclined groove; the centrifugal block 18 automatically adjusts the radial position under the combined action of the centrifugal force of the centrifugal block and the return spring 19, so that the axial position of the pressure ring 17 is changed, and the deformation degree of the pressure ring 17 is related to the rotating speed of the planet carrier 16; when the load changes, or the rotational speed of the planet carrier 16 changes so that the pressure between the planet wheels and the central wheel changes with inertia, the pressure ring 17 also reacts to adjust the pressure applied to the planet wheels. The automatic pressure regulating device can also be a magnetic, electric, hydraulic or pneumatic intelligent servo device.

Fig. 5 is a planetary gear train composed of internal teeth 21, planetary gears 22 and external teeth 24, the ring body of the pressing ring 23 has bending elasticity, and has potential energy shrinking towards the center or expanding outwards under the constraint of the central gear, and the whole is a part or is formed by elastically hinging a plurality of parts; the planet wheels 22 are rotatably arranged on the compression ring 23, and the elasticity of the ring body is utilized to compress the planet wheels 22 to one side to reduce the side gap; the compression ring 23 itself also serves as a planet carrier, floating in the air together with the planet wheels 22 as intermediate wheels, or also as a hollow drive shaft with elasticity, which can be used for power input or output.

In fig. 6, the inner teeth 41 and the planet wheels 44 are fixedly connected with a first gap limiting wheel 42 and a second gap limiting wheel 43 on the side surfaces respectively, and are annular components coaxial with the gears; when the planet wheel 44 is pressed outwards by the pressing ring 47, the first clearance limiting wheel 42 and the second clearance limiting wheel 43 contact with each other firstly, so that a minimum side clearance larger than zero exists between the inner tooth 41 and the planet wheel 44; the first gap limiting wheel 42 and the second gap limiting wheel 43 are kept in rolling contact in the transmission process, so that the internal teeth 41 and the planet wheels 44 always keep minimum backlash. The first and second gap limiting wheels 42 and 43 are respectively provided with a groove-shaped structure on both sides of the internal teeth 41 and the planet wheels 44, so that the agent on the lubricating tooth surface is easy to be retained on the inner wall of the groove to reduce loss, and a pressure relief gap is arranged to avoid the gear from being deadlocked. When the outer diameter of the first gap limiting wheel 42 or the second gap limiting wheel 43 is larger than the root circle diameter of the inner tooth 41 or the planet wheel 44, the first gap limiting wheel or the second gap limiting wheel can be used as a motion track to prevent the two parts of the transmission wheel set from moving relatively in the axial direction, the degree of freedom of the planet wheel 44 is limited by matching with the outer tooth 48 or the press ring 47, and the function of a planet carrier can be replaced. The pressure ring 47 has one or two or more functions as a force application member, an oil control groove, and a ring rail.

In fig. 7, the force application component is an elastic rod 35 with a V-shaped structure in the middle, the V-shaped structure is arranged in a cavity or a groove of a central shaft 37, two ends of the V-shaped structure extend out to respectively apply elastic pressure to different planet wheels 32, a pull rod 38 is arranged in the cavity or the groove of the central shaft 37, when the tip of the V-shaped structure of the elastic rod 35 is pulled upwards, the open end of the V-shaped structure is contracted by the central shaft 37, and when the pull force is released, the V-shaped structure can rebound and reset, so that the position or the pressure on the planet wheels 32 is changed. The pull rod 38 is driven by a control device either on board the system or external.

In fig. 1, in order to increase the lubricating system or the cooling system without making the whole structure too complicated, an oil passage is arranged inside the middle shaft 7 or the shaft 4, which comprises a central passage and a radiation passage leading to the periphery, when the central shaft rotates, lubricating oil or cooling liquid in the center of the inner part is thrown to the periphery through the radiation passage under the centrifugal action, and meanwhile, the central passage generates negative pressure to suck the oil.

In fig. 1 and 2, the mechanical connection clearance or abrasion is reduced by adopting the following measures that an axial taper is arranged on the rotary connection surface of a central shaft 7 or a shaft 4, or the central shaft 7 or the rotary connection surface of the shaft 4 are connected through a tapered bush, an automatic or manual adjusting device is used for changing the relative axial displacement between the connecting pieces so as to adjust the radial clearance, or a square shaft sleeve 3 made of wear-resistant and wear-reducing high-strength materials is movably connected between a planet carrier 6 and the shaft 4 in a surface contact mode, the contact area is increased to reduce the pressure, and the square shaft sleeve is in surface contact with the side wall of a mounting hole or a pressure ring 5 so as to avoid the phenomenon that the contact surface is sunken or excessively abraded to increase the side clearance.

Claims (10)

1. The variable-pitch anti-backlash planetary speed regulator is provided with a rack, a central wheel and a planetary wheel, and is characterized in that: the variable pitch mechanism is arranged, the radial position of the planet wheel can be adjusted to change the center distance between the planet wheel and the center wheel, so that the backlash is changed; the distance changing mechanism is provided with an elastic or rigid force application component for changing the center distance of the transmission wheel set; the working mode of the variable-pitch mechanism is that the force application component is always unlocked and actively applies elastic force to the planet wheel to enable the radial position of the planet wheel to be self-adaptive and dynamically changed, or the force application component is locked and fixed after the backlash is adjusted, and still actively applies elastic acting force to the planet wheel to enable the radial position of the planet wheel to be self-adaptive and dynamically changed, or the force application component is locked and fixed after the backlash is adjusted to provide rigid acting force for the planet wheel, and the radial position of the planet wheel is not actively changed; the planet wheel is of a single-layer structure or a stepped structure, and the central wheel is external teeth or internal teeth.

2. The pitch-changing backlash-eliminating planetary speed regulator according to claim 1, wherein: the force application component and the planet wheels are in a one-to-one relation, or one force application component acts on the plurality of planet wheels simultaneously, and different planet wheels are constrained with each other through the force application component.

3. The pitch-variable backlash-eliminating planetary speed regulator according to claim 2, wherein: the force application assembly, the planet wheels or a shaft sleeve between the force application assembly and the planet wheels are provided with inclined planes, the radial positions of the planet wheels can be changed by moving the planet wheels relative to each other in the axial direction, and the distance changing mechanism is provided with an axial displacement device for changing the axial position of the force application assembly.

4. The pitch-variable backlash-eliminating planetary speed regulator according to claim 3, wherein: the axial displacement device is a manual device, or an automatic elastic device, or a magnetic, electric, hydraulic or pneumatic intelligent servo device.

5. The pitch-variable backlash-eliminating planetary governor according to claim 1, 2, 3, or 4, wherein: the automatic adjusting device is provided with an acting force automatic adjusting device, the type of the automatic adjusting device is centrifugal, or a magnetic, electric, hydraulic or pneumatic intelligent servo device, and the automatic adjusting device is used for changing the acting force of the force application assembly on the planet wheel, so that the problem that the planet wheel is removed after the acting force is not large enough in transmission, or the acting force is too large to cause unnecessary tooth surface abrasion or deadlocking is avoided.

6. The pitch-variable backlash-eliminating planetary governor according to claim 1, 2, 3, or 4, wherein: the force application component has elasticity and also serves as a planet carrier or a hollow transmission shaft.

7. The pitch-variable backlash-eliminating planetary governor according to claim 1, 2, 3, or 4, wherein: the side of the planet wheel and the central wheel is provided with a clearance limiting wheel which is matched with a force application component to keep the minimum clearance, or an oil control ring is used for controlling the lubricant, or the side of the planet wheel and the central wheel is provided with a ring rail to replace the function of the planet carrier, or at least two of the clearance limiting wheel, the oil control ring and the ring rail are the same component.

8. The pitch-variable backlash-eliminating planetary governor according to claim 1, 2, 3, or 4, wherein: the pitch-variable mechanism is connected with an external or system-owned control device through a hole or a groove of the central shaft.

9. The pitch-variable backlash-eliminating planetary governor according to claim 1, 2, 3, or 4, wherein: an oil channel is arranged in the middle shaft or the planet wheel shaft, and lubricating oil or cooling liquid is driven to move under the centrifugal action and negative pressure suction force generated by autorotation.

10. The pitch-variable backlash-eliminating planetary governor according to claim 1, 2, 3, or 4, wherein: the contact surfaces of the rotating connecting components are provided with axial conicity or are connected with each other through tapered bushings, the radial clearance can be adjusted by changing the relative axial position between the connecting components, or the mounting hole of the planet wheel is provided with a square shaft sleeve to increase the contact area, and the contact area is in surface contact with the side wall of the mounting hole or the force application component.

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