CN215673423U - Planet wheel load balancing mechanism, gear transmission case and turbofan engine - Google Patents

Abstract

The utility model provides a planet wheel load balancing mechanism, a gear transmission case and a turbofan engine. The gear box includes an epicyclic gear train. The epicyclic gear train comprises a sun wheel, a plurality of planet wheels, a planet carrier, an inner gear ring and a planet wheel load balancing mechanism, wherein the planet wheels are connected with a planet wheel shaft through a bearing, the planet wheel shaft is fixedly connected with the planet carrier, the planet wheel load balancing mechanism comprises a planet wheel shaft, a shaft sleeve, an oil film cavity, an oil film and an oil supply channel, the shaft sleeve is arranged between the planet wheel shaft and an inner ring of the bearing and is respectively connected with the planet wheel shaft and the inner ring in a rotation-proof manner, and a radial gap is formed between the shaft sleeve and the planet wheel shaft on at least part of the length so as to form the oil film cavity; the oil supply channel is used for supplying oil to the oil film cavity to form an oil film; the shaft sleeve is flexible, and the shape of the oil film cavity changes along with the deformation of the shaft sleeve, so that an oil film is extruded. The turbofan engine comprises a gear transmission case, a sun gear is connected with a low-pressure shaft, one of a planet carrier and an inner gear ring is connected with a fan, and the other is a stator part.

Description

Planet wheel load balancing mechanism, gear transmission case and turbofan engine

Technical Field

The utility model relates to the technical field of gear transmission, in particular to a planet wheel load balancing mechanism, a gear transmission case and a turbofan engine.

Background

In the field of aviation, an engine of gtf (grounded turbofanner) configuration, that is, a low-pressure shaft of a gear-driven turbofan engine is connected to a fan through a fan-driven gear box, the fan-driven gear box has the characteristics of small size, high rotating speed, large transmission power and the like, a star-type gear transmission mode or a planetary gear transmission mode is usually adopted, the low-pressure shaft of the engine is connected to a sun gear of an epicyclic gear train, the fan is connected to one of an inner gear ring of the epicyclic gear train or a planet carrier, the other of the inner gear ring or the planet carrier serves as a stator member, and a planet wheel is supported on the planet carrier through a bearing and is respectively meshed with the sun gear and the inner gear ring. In order to reduce the load of a single planet wheel, a plurality of planet wheels are included in an epicyclic gear train for multi-path division, and although the arrangement method can disperse the load of a gearbox on the plurality of planet wheels, the load distribution among the plurality of planet wheels is not balanced due to machining errors and assembly errors, so that vibration and noise are generated in the rotation process of the gear.

One way to achieve equal loading of the planet wheels is to improve the precision of each part in the epicyclic gear train, but the implementation difficulty of this way is greater and the processing cost is also higher. The other way of realizing the planet wheel uniform load is to use a flexible planet wheel shaft or add a flexible shaft sleeve on the planet wheel shaft, and the uniform load is realized through the deformation of a flexible component, but for a fan driving gear box, the planet wheel is characterized by high speed and heavy load, if the flexibility of the planet wheel shaft or the shaft sleeve is too high, the deformation can be large, the precision of gear transmission is influenced, the collision and abrasion of a gear can be caused, and if the flexibility of the planet wheel shaft or the shaft sleeve is too low, the uniform load and the vibration reduction effect can be influenced.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a planet wheel load balancing mechanism which is used for achieving load balancing and vibration reduction of a plurality of planet wheels in an epicyclic gear train.

In order to realize the planetary wheel load balancing mechanism of the purpose, the planetary wheel is rotationally connected with a planetary wheel shaft through a bearing, the planetary wheel shaft is fixedly connected with a planetary frame, the planetary wheel load balancing mechanism comprises the planetary wheel shaft, a shaft sleeve, an oil film cavity, an oil film and an oil supply channel, wherein: the shaft sleeve is arranged between the planet wheel shaft and the inner ring of the bearing and is connected with the planet wheel shaft and the inner ring in a rotation-proof manner respectively, and a radial gap is formed between the shaft sleeve and the planet wheel shaft on at least part of the length, so that the oil film cavity is formed; the oil supply channel is used for supplying oil to the oil film cavity to form the oil film; the shaft sleeve is flexible, and the shape of the oil film cavity changes along with the deformation of the shaft sleeve, so that the oil film is extruded.

In one or more embodiments of the planet wheel load balancing mechanism, the shaft sleeve comprises a first end and a second end, the first end and the second end are respectively located on two axial sides of the shaft sleeve, the first end is in interference fit with the planet wheel shaft, and a sealing ring is arranged between the second end and the planet wheel shaft.

In one or more embodiments of the planet wheel load balancing mechanism, the shaft sleeve is a segmented structure and comprises a first shaft sleeve and a second shaft sleeve which are axially arranged at intervals, the first shaft sleeve comprises a first outer end and a first inner end which are respectively positioned at two axial sides, the second shaft sleeve comprises a second outer end and a second inner end which are respectively positioned at two axial sides, the first outer end and the second outer end are respectively in interference fit with the planet wheel shaft, the first inner end is opposite to the second inner end, and sealing rings are respectively arranged between the first inner end and the planet wheel shaft and between the second inner end and the planet wheel shaft.

In one or more embodiments of the planetary wheel load balancing mechanism, the sealing ring has elasticity and is provided with an opening in the circumferential direction.

In one or more embodiments of the planetary wheel load balancing mechanism, the planetary wheel shaft is a hollow structure and comprises a first oil chamber and a first oil hole, the first oil chamber extends along the axial direction of the planetary wheel shaft and is used for being communicated with a lubricating oil pump in a fluid mode, and the first oil hole is communicated with the first oil chamber and the oil film chamber and is used for conveying lubricating oil from the first oil chamber to the oil film chamber.

In one or more embodiments of the planet wheel load balancing mechanism, an annular groove is formed in the outer peripheral surface of the planet wheel shaft, and the first oil hole is communicated with the oil film cavity through the annular groove.

In one or more embodiments of the planet wheel load balancing mechanism, the planet wheel shaft comprises a plurality of groups of the first oil holes distributed at intervals along the axial direction, wherein the plurality of the first oil holes of each group are distributed at intervals along the circumferential direction.

In one or more embodiments of the planetary wheel load balancing mechanism, a shaft core is arranged in the planetary wheel shaft, the shaft core is of a hollow structure and comprises a second oil cavity and a second oil hole, the second oil cavity extends along the axial direction of the shaft core and is used for communicating the lubricating oil pump, the second oil hole is communicated with the second oil cavity and the first oil cavity and is used for conveying lubricating oil from the second oil cavity to the first oil cavity, and the length of the second oil cavity is smaller than that of the first oil cavity.

In one or more embodiments of the planetary wheel load balancing mechanism, the shaft core includes a plurality of sets of the second oil holes distributed at intervals in the axial direction, wherein the plurality of the second oil holes of each set are distributed at intervals in the circumferential direction.

In one or more embodiments of the planetary uniform load mechanism, the density of the axle core is lower than that of the planetary wheel axle.

In one or more embodiments of the planet wheel load balancing mechanism, the oil supply channel is at least partially arranged in the planet wheel shaft, and the oil supply channel further comprises a lubricating oil hole penetrating through the inner ring of the bearing.

In one or more embodiments of the planetary wheel load balancing mechanism, the inner ring includes multiple sets of the lubricating oil holes distributed at intervals in the axial direction, and the multiple lubricating oil holes in each set are distributed at intervals in the circumferential direction.

The planet wheel load balancing mechanism is characterized in that a flexible shaft sleeve is arranged between a planet wheel shaft and a bearing, and a radial gap is formed between the shaft sleeve and the planet wheel shaft on at least part of the length, so that an elastic supporting structure is formed, the deformation of the shaft sleeve can compensate processing errors and assembly errors, the load among planet wheels is uniformly distributed, and the vibration of a revolving gear train is reduced; an oil film cavity is arranged between the shaft sleeve and the planet wheel shaft, and lubricating oil with certain pressure is introduced into the oil film cavity to form an oil film, so that an extrusion oil film damper is formed, and the load balancing and vibration damping effects of the planet wheel load balancing mechanism can be improved; through adjusting the pressure of lubricating oil, can change the rigidity of aforementioned elastic support structure, adjust the vibration response of this elastic support structure to the even load and the damping effect of this planet wheel average load mechanism are further optimized. The planet wheel load balancing mechanism is simple in structure, easy to machine, manufacture and assemble and low in cost.

Another object of the present invention is to provide a gear transmission case whose epicyclic gear train allows a better load-equalizing and damping effect.

The planetary gears are respectively and rotatably arranged on the planet carrier and are respectively meshed with the sun gear and the inner gear ring, one of the sun gear, the planet carrier and the inner gear ring is fixed, and the other two planetary gears are respectively in transmission connection with the input shaft and the output shaft.

The epicyclic gear train of the gear transmission case can realize the uniform distribution of load between the planet wheels, reduce impact and vibration, reduce noise, improve the stability of the system and prolong the service life.

Still another object of the present invention is to provide a turbofan engine whose fan drive gearbox is capable of achieving better planet wheel load balancing and vibration damping effects.

In order to achieve the purpose, the turbofan engine comprises the gear transmission box, the sun gear is in transmission connection with a low-pressure shaft of the turbofan engine, one of the planet carrier and the inner gear ring is in transmission connection with a fan of the turbofan engine, and the other planet carrier is set as a stator component.

This turbofan engine is through setting up aforementioned planet wheel load balancing mechanism in fan drive gear box, can be through adjusting lubricating oil pressure, make the rigidity and the vibration response of this planet wheel load balancing mechanism and the high-speed heavily loaded operating mode phase-match of the planet wheel of fan drive gear box to can realize the load evenly distributed between each planet wheel effectively when guaranteeing the gear drive precision, reduce impact and vibration, the noise reduction, the stability and the life-span of improvement system.

Drawings

The above and other features, properties and advantages of the present invention will become more apparent from the following description of the embodiments with reference to the accompanying drawings, in which:

fig. 1 is a schematic cross-sectional view of a planet wheel load balancing mechanism according to an embodiment.

FIG. 2 is a schematic view of a partial flow of lubricant according to the embodiment of FIG. 1.

Fig. 3 is a partially enlarged schematic view at a in fig. 1.

Fig. 4 is a schematic cross-sectional view of a planet load balancing mechanism according to another embodiment.

FIG. 5 is a schematic view with portions removed according to the embodiment of FIG. 4.

Fig. 6 is a partially enlarged schematic view at B in fig. 4.

Fig. 7 is a partially enlarged schematic view at C in fig. 4.

FIG. 8 is a schematic view of a seal ring according to one or more embodiments.

Detailed Description

The following discloses many different embodiments or examples for implementing the subject technology described. Specific examples of components and arrangements are described below to simplify the present disclosure, but these are merely examples and do not limit the scope of the utility model. It is to be noted that the drawings are designed solely as examples and are not to scale and should not be construed as limiting the scope of the utility model as it may be practiced. Furthermore, some of the features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

A planetary gear load balancing mechanism 2 according to an exemplary embodiment of the present invention is shown in fig. 1 to 3, and the planetary gear load balancing mechanism 2 is arranged in an epicyclic gear train 1 to achieve load balancing and vibration reduction of a plurality of planetary gears 11.

The epicyclic gear train 1 comprises a sun gear (not shown), a plurality of planet wheels 11, a planet carrier 12 and an annulus gear (not shown), the plurality of planet wheels 11 being in engagement with the sun gear and the annulus gear respectively, each planet wheel 11 being rotatably connected to a planet wheel shaft 14 by a bearing 13, the planet wheel shaft 14 being fixedly connected to the planet carrier 12, for example by bolts or other connection means.

The planet wheel load balancing mechanism 2 comprises a planet wheel shaft 14, a shaft sleeve 15, an oil film cavity 16, an oil film 17 and an oil supply channel.

The sleeve 15 is disposed between the planetary wheel shaft 14 and the inner race 131 of the bearing 13. The boss 15 is provided with a first boss 151 and a second recess 152. The first boss 151 is engaged with the first recess 141 provided in the planetary gear axle 14 to limit the relative rotation between the sleeve 15 and the planetary gear axle 14. The second groove 152 is engaged with the second boss 132 disposed at one side of the inner ring 131 to limit the relative rotation between the sleeve 15 and the inner ring 131. The other side of the inner ring 131 achieves axial limitation of the bearing 13 by a retainer ring 18 mounted on the shaft sleeve 15.

Therefore, the shaft sleeve 15 is connected with the planet wheel shaft 14 and the inner ring 131 in a rotation-proof manner, so that the abrasion of parts and the unbalance loading caused by the relative rotation between the shaft sleeve 15 and the planet wheel shaft 14 or between the shaft sleeve 15 and the inner ring 131 are avoided. In other embodiments, the sleeve 15 can be connected to the planet wheel shaft 14 and the inner ring 131 in a rotationally fixed manner by welding, or by a fastening connection, or by another connection.

In the description of the present invention, it should be noted that the terms "first", "second", "third", etc. are used to define parts, which are only used for convenience of distinguishing corresponding parts, but are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated, and therefore are not to be construed as limiting the scope of the present invention.

With continued reference to fig. 1 to 3, the sleeve 15 includes a first end 153 and a second end 154, the first end 153 and the second end 154 are respectively located at two axial sides of the sleeve 15, the first end 153 is in interference fit with the planetary gear shaft 14, and a radial gap is provided between the rest of the sleeve 15 in the axial direction and the planetary gear shaft 14, so as to form the annular oil film cavity 16. A sealing ring 19 is arranged between the second end 154 and the planetary wheel shaft 14, so that the two sides of the oil film cavity 16 are respectively sealed by the interference fit part and the sealing ring 19. In other embodiments, the first end 153 may be fixedly connected to the planetary axle 14 by a fastener or other means, and a sealing ring or other means is used to block a side of the oil film cavity 16 corresponding to the first end 153.

The shaft sleeve 15 is flexible, so that an elastic supporting structure is formed, machining errors and assembly errors can be compensated through deformation of the shaft sleeve 15, loads among the planet wheels 11 are uniformly distributed, and vibration of the epicyclic gear train 1 is reduced.

The oil supply passage is used for introducing lubricating oil with a certain pressure into the oil film cavity 16 to form an oil film 17, which will be described in detail later. The shape of the oil film chamber 16 changes with the deformation of the sleeve 15, thereby constituting a squeeze film damper that squeezes the oil film 17 through the deformation of the sleeve 15, and provides damping by the squeezing and shearing action of the oil film 17 to suppress vibration due to uneven load distribution. The size of the radial gap between the shaft sleeve 15 and the planet wheel shaft 14 is determined according to the requirements of the squeeze film damper, the rigidity of the elastic supporting structure can be changed by adjusting the pressure of lubricating oil, and the vibration response of the elastic supporting structure is adjusted, so that the load balancing and vibration damping effects of the planet wheel load balancing mechanism 2 are further optimized.

Referring to fig. 1, 2 and 8, the sealing ring 19 is resilient and radially telescopes to maintain a close fit with the second end 154 and the planet shaft 14. The sealing ring 19 is circumferentially provided with an opening 191 to keep a certain amount of lubricating oil to circulate and flow, thereby taking away the heat of the lubricating oil generated by vibration, and simultaneously ensuring that the sealing ring 19 can radially contract after being pressed, thereby not affecting the deformation of the shaft sleeve 15.

Referring to fig. 1 and 2, the planetary axle 14 is a hollow structure, and includes a first oil chamber 142 and a first oil hole 143, the first oil chamber 142 extends in the axial direction of the planetary axle 14 for fluid communication with a lubricating oil pump or other equipment for supplying lubricating oil, and the first oil hole 143 communicates the first oil chamber 142 and the oil film chamber 16 for delivering the lubricating oil from the first oil chamber 142 to the oil film chamber 16.

The annular groove 145 is formed in the outer peripheral surface of the planet wheel shaft 14, the first oil hole 143 is communicated with the oil film cavity 16 through the annular groove 145, so that circumferential oil supply to the oil film cavity 16 is achieved, a buffering effect is achieved through the annular groove 145, the influence of the first oil hole 143 on the oil film 17 is reduced, and therefore when the squeezing effect is strong, the distribution of the oil film 17 cannot be damaged due to backflow and the characteristics of the squeeze oil film damper cannot be affected.

The planetary gear shaft 14 comprises a plurality of groups of first oil holes 143 which are distributed at intervals along the axial direction, so that the effective bearing length of the oil film 17 is ensured to be within a reasonable range. The plurality of first oil holes 143 of each group are circumferentially spaced apart to more uniformly supply oil to the oil film chamber 16 in the circumferential direction.

The planetary gear shaft 14 is also provided with a shaft core 20. The shaft core 20 is a hollow structure and includes a second oil chamber 201 and a second oil hole 202, the second oil chamber 201 extends in the axial direction of the shaft core 20, and the second oil hole 202 communicates the second oil chamber 201 and the first oil chamber 142. Sealing rings 21 are respectively provided between both ends of the shaft core 20 and the inner peripheral surface of the planetary gear shaft 14 to close both sides of the first oil chamber 142 and prevent the lubricating oil in the first oil chamber 142 from leaking.

The axle core 20 has one end connected to the oil pipe 22 and the other end stopped at a spigot 146 on the inside of the planet axle 14. The oil pipe 22 is in fluid communication with the second oil chamber 201 and a lubricating oil pump or other device that provides lubricating oil to supply oil to the second oil chamber 201. The mating surface of the oil pipe 22 and the shaft core 20 is provided with a seal 23 to prevent leakage of lubricating oil from that side, and the inside of the shaft core 20 is provided with a baffle plate 203 to close the other side of the second oil chamber 201.

The length of the second oil chamber 201 is set to be smaller than the length of the first oil chamber 142, for example, a baffle plate 203 is provided near the middle inside the spindle core 20 to reduce the volume of the oil chamber inside the planetary gear shaft 14, thereby reducing the amount of lubricating oil stored inside the planetary gear shaft 14 and reducing the weight of the epicyclic gear train 1. Optionally, the core 20 is made of a material with a lower density than the planetary axles 14 to further reduce the weight of the epicyclic gear train 1.

The oil pipe 22 is pressed against one end of the spindle 20 by a locking disc 24, and the locking disc 24 is fixedly connected with the planet carrier 12, for example, by a threaded connection or other connection means, so that the axial movement of the spindle 20, the oil pipe 22, the planetary wheel shaft 14, and the like is limited by the locking disc 24.

The shaft core 20 includes a plurality of sets of second oil holes 202 spaced apart in the axial direction, wherein the plurality of second oil holes 202 of each set are spaced apart in the circumferential direction, so that the oil is supplied to the first oil chamber 142 more uniformly.

Therefore, the oil supply channel is arranged in the planet wheel shaft 14 and comprises the oil pipe 22, the first oil chamber 142, the first oil hole 143, the annular groove 145, the second oil chamber 201 and the second oil hole 202, lubricating oil flows into the second oil chamber 201 from the oil pipe 22, then flows into the first oil chamber 142 through the second oil hole 202, and then supplies oil to the oil film chamber 16 through the first oil hole 143 and the annular groove 145, so that oil can be supplied to the oil film chamber 16 between the planet wheel shaft 14 and the shaft sleeve 15 through a simple structure, the space is saved, and the weight of the epicyclic gear train 1 is reduced.

In other embodiments, the oil supply passage is arranged at another position or in another form, for example, the shaft core 20 may not be arranged, one end of the planetary shaft 14 is directly connected to the oil pipe, and the other end of the planetary shaft 14 is blocked, and the like.

With continued reference to fig. 1 and 2, the oil supply passage further includes a lubricating oil hole 133 penetrating through the inner ring 131 of the bearing 13, and a lubricating oil passage 25 penetrating through the shaft sleeve 15 and the planetary gear shaft 14, and the lubricating oil hole 133 is communicated with the first oil chamber 142 through the lubricating oil passage 25, so that oil supply to the oil film chamber 16 and lubrication to the bearing 13 are simultaneously realized through the oil supply passage, thereby simplifying the structure of the planetary gear load balancing mechanism 2, saving space, reducing the weight of the epicyclic gear train 1, and ensuring full utilization of lubricating oil. The lubricating oil passage 25 and the first oil hole 143 are displaced from each other in the axial direction, thereby reducing the influence of the lubricating oil passage 25 on the oil film 17.

The inner race 131 includes a plurality of sets of lubrication holes 133 spaced apart in the axial direction, wherein the plurality of lubrication holes 133 of each set are spaced apart in the circumferential direction to more evenly lubricate the bearing 13.

The planet wheel load balancing mechanism 2 is characterized in that a flexible shaft sleeve 15 is arranged between a planet wheel shaft 14 and a bearing 13, and a radial gap is formed between the shaft sleeve 15 and the planet wheel shaft 14 on at least part of the length, so that an elastic supporting structure is formed, the deformation of the shaft sleeve 15 can compensate processing errors and assembly errors, the load among planet wheels 11 is uniformly distributed, and the vibration of the epicyclic gear train 1 is reduced; an oil film cavity 16 is arranged between the shaft sleeve 15 and the planet wheel shaft 14, and lubricating oil with certain pressure is introduced into the oil film cavity 16 to form an oil film 17, so that a squeeze oil film damper is formed, and the load balancing and vibration damping effects of the planet wheel load balancing mechanism 2 can be improved; through adjusting the pressure of lubricating oil, can change the rigidity of aforementioned elastic support structure, adjust the vibration response of this elastic support structure to the even load and the damping effect of this planet wheel average load mechanism 2 are further optimized. The planet wheel load balancing mechanism 2 is simple in structure, easy to machine, manufacture and assemble and low in cost.

A planetary load balancing mechanism 2 according to another exemplary embodiment of the present invention is described below with reference to fig. 4 to 7. The present embodiment follows the reference numerals and parts of the foregoing embodiments, wherein the same reference numerals are used to indicate the same or similar elements, and the description of the same technical contents is optionally omitted. For the description of the omitted parts, reference may be made to the foregoing embodiments, and the description of the embodiments is not repeated.

The main difference between this embodiment and the previous embodiments is that the shaft sleeve of this embodiment is a segmented structure, and includes a first shaft sleeve 26 and a second shaft sleeve 27 which are axially spaced.

The first hub 26 includes a first outer end 261 and a first inner end 262, and the first outer end 261 and the first inner end 262 are located on both axial sides of the first hub 26, respectively. The second sleeve 27 includes a second outer end 271 and a second inner end 272, and the second outer end 271 and the second inner end 272 are respectively located on both axial sides of the second sleeve 27. The first 26 and second 27 sleeves are disposed between the planet axle 14 and the inner race 131 of the bearing 13 with the first 262 and second 272 inner ends opposite one another with an axial gap 10 therebetween.

The first boss 26 is provided with a boss 263 and a recess 264. The boss 263 is engaged with the first recess 141 provided in the planetary axle 14 to limit the relative rotation between the first hub 26 and the planetary axle 14. The groove 264 is engaged with the second boss 132 of the inner ring 131 of the bearing 13 to limit the relative rotation between the first sleeve 26 and the inner ring 131. The other side of the inner ring 131 is stopped by a shoulder of the second sleeve 27 to realize the axial limit of the bearing 13.

The second shaft sleeve 27 is provided with a third boss 273, the planet carrier 12 is provided with a third groove 121, and the third boss 273 is clamped with the third groove 121 to limit the relative rotation between the second shaft sleeve 27 and the planet carrier 12.

The first outer end 261 of the first shaft sleeve 26 is in interference fit with the planetary wheel shaft 14, a radial gap is reserved between the rest part of the first shaft sleeve 26 in the axial direction and the planetary wheel shaft 14, and a sealing ring 19 is arranged between the first inner end 262 and the planetary wheel shaft 14, so that the first oil film cavity 28 is formed.

The second outer end 271 of the second sleeve 27 is in interference fit with the planetary wheel shaft 14, a radial gap is formed between the rest part of the second sleeve 27 in the axial direction and the planetary wheel shaft 14, and a sealing ring 19 is arranged between the second inner end 272 and the planetary wheel shaft 14, so that a second oil film cavity 29 is formed.

The first shaft sleeve 26 and the second shaft sleeve 27 are flexible, so that an elastic supporting structure is formed, machining errors and assembly errors can be compensated through deformation of the first shaft sleeve 26 and the second shaft sleeve 27, loads among the planet wheels 11 are uniformly distributed, and vibration of the epicyclic gear train 1 is reduced.

The oil supply passages supply oil to the first oil film chamber 28 and the second oil film chamber 29, respectively, to form a first oil film 30 and a second oil film 31 in the first oil film chamber 28 and the second oil film chamber 29, respectively. The shapes of the first oil film cavity 28 and the second oil film cavity 29 change along with the deformation of the first shaft sleeve 26 and the second shaft sleeve 27, so that a squeeze film damper is formed.

This planet wheel load balancing mechanism 2 sets up the structure that two place elastic support and squeeze film damper combine respectively in axial both sides, can make the support rigidity at the both ends of planet wheel 11 and bearing 13 be close unanimous to further reduce the unbalance loading, improve this planet wheel load balancing mechanism 2 all carry and the damping effect.

The inner ring 131 of the bearing 13 is provided with an oil drain hole 134, and the oil drain hole 134 penetrates the inner ring 131 and communicates with the axial gap 10, so that the lubricating oil flowing out from the opening 191 of the seal ring 19 enters the axial gap 10 and is discharged through the oil drain hole 134, and the discharged lubricating oil can be used for lubricating the bearing 13 continuously.

The gear transmission case according to one or more embodiments of the utility model comprises an input shaft, an output shaft and the epicyclic gear train 1, wherein one of the sun gear, the planet carrier 12 and the inner gear ring of the epicyclic gear train 1 is fixed, and the other two are in transmission connection with the input shaft and the output shaft respectively, the epicyclic gear train 1 adopts the planet wheel load balancing mechanism 2 to realize uniform load distribution among the planet wheels 11, reduce impact and vibration, reduce noise, and improve the stability and the service life of the system.

The planet wheel 11 and the bearing 13 of the epicyclic gear train 1 are integrally designed, the bearing 13 is an inverted bearing, the inner ring 131 is static, the outer ring rotates, and the planet wheel 11 is used as the outer ring of the bearing 13 and is directly contacted with the rolling body and respectively meshed with the sun wheel and the inner gear ring, so that the structure of the epicyclic gear train 1 can be simplified, the space can be saved, and the weight can be reduced. The planet wheels 11 can be moved axially to reduce the effect of input shaft deformation on the gearing.

The turbofan engine according to one or more embodiments of the present invention employs the aforementioned gear box as a fan drive gear box, a sun gear of the gear box is in driving connection with a low pressure shaft of the turbofan engine, and the carrier 12 and one of the ring gears are in driving connection with the fan of the turbofan engine, and the other is provided as a stationary member.

This turbofan engine is through setting up aforementioned planet wheel load balancing mechanism 2 in fan drive gear box, can be through adjusting lubricating oil pressure, make the rigidity and the vibration response of this planet wheel load balancing mechanism 2 and the high-speed heavily loaded operating mode phase-match of the planet wheel of fan drive gear box to can realize the load evenly distributed between each planet wheel 11 effectively when guaranteeing the gear drive precision, reduce impact and vibration, the noise reduction, the stability and the life-span of improvement system.

Although the present invention has been disclosed in terms of the preferred embodiment, it is not intended to limit the utility model, and variations and modifications may be made by one skilled in the art without departing from the spirit and scope of the utility model. Therefore, any modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope defined by the claims of the present invention, unless the technical essence of the present invention departs from the content of the present invention.

Claims (14)

1. The planet wheel load balancing mechanism is rotationally connected with a planet wheel shaft through a bearing, the planet wheel shaft is fixedly connected with a planet carrier, and the planet wheel load balancing mechanism is characterized by comprising the planet wheel shaft, a shaft sleeve, an oil film cavity, an oil film and an oil supply channel, wherein:

the shaft sleeve is arranged between the planet wheel shaft and the inner ring of the bearing and is connected with the planet wheel shaft and the inner ring in a rotation-proof manner respectively, and a radial gap is formed between the shaft sleeve and the planet wheel shaft on at least part of the length, so that the oil film cavity is formed;

the oil supply channel is used for supplying oil to the oil film cavity to form the oil film;

the shaft sleeve is flexible, and the shape of the oil film cavity changes along with the deformation of the shaft sleeve, so that the oil film is extruded.

2. The planet wheel load balancing mechanism according to claim 1, wherein the sleeve includes a first end and a second end, the first end and the second end are located on two axial sides of the sleeve respectively, the first end is in interference fit with the planet wheel shaft, and a sealing ring is arranged between the second end and the planet wheel shaft.

3. The planet wheel load balancing mechanism according to claim 1, wherein the sleeve is a segmented structure and includes a first sleeve and a second sleeve that are axially spaced, the first sleeve includes a first outer end and a first inner end that are respectively located at two axial sides, the second sleeve includes a second outer end and a second inner end that are respectively located at two axial sides, the first outer end and the second outer end are respectively in interference fit with the planet wheel shaft, the first inner end is opposite to the second inner end, and a sealing ring is respectively arranged between the first inner end and the planet wheel shaft and between the second inner end and the planet wheel shaft.

4. The planet wheel load balancing mechanism of claim 2 or 3, wherein the sealing ring is elastic and has openings in the circumferential direction.

5. The planetary equalizing load mechanism as recited in any one of claims 1 to 3, wherein the planetary shaft is a hollow structure, and includes a first oil chamber extending in the axial direction of the planetary shaft for fluid communication with a lubricating oil pump, and a first oil hole communicating the first oil chamber and the oil film chamber for delivering the lubricating oil from the first oil chamber to the oil film chamber.

6. The planet wheel load balancing mechanism according to claim 5, wherein an annular groove is formed in the outer peripheral surface of the planet wheel shaft, and the first oil hole is communicated with the oil film cavity through the annular groove.

7. The planet wheel load balancing mechanism according to claim 5, wherein the planet wheel shaft comprises a plurality of groups of the first oil holes distributed at intervals along the axial direction, and the plurality of the first oil holes of each group are distributed at intervals along the circumferential direction.

8. The planetary uniform-load mechanism of claim 5, wherein a shaft core is arranged in the planetary shaft, the shaft core is of a hollow structure and comprises a second oil chamber and a second oil hole, the second oil chamber extends in the axial direction of the shaft core and is used for communicating with the lubricating oil pump, the second oil hole is communicated with the second oil chamber and the first oil chamber and is used for conveying lubricating oil from the second oil chamber to the first oil chamber, and the length of the second oil chamber is smaller than that of the first oil chamber.

9. The planet wheel load balancing mechanism of claim 8, wherein the shaft core includes a plurality of sets of the second oil holes spaced apart in the axial direction, and wherein the plurality of the second oil holes of each set are spaced apart in the circumferential direction.

10. The planetary averaging mechanism as in claim 8, wherein the density of the axle core is lower than the density of the planetary axle.

11. The planet uniform-loading mechanism of any one of claims 1 to 3, wherein the oil supply channel is at least partially arranged in the planet wheel shaft, and the oil supply channel further comprises a lubricating oil hole penetrating through the inner ring of the bearing.

12. The planet carrier averaging mechanism as claimed in claim 11, wherein the inner ring includes a plurality of axially spaced sets of the oil holes, and wherein the oil holes of each set are circumferentially spaced.

13. A gear transmission case comprising an input shaft, an output shaft and an epicyclic gear train, the epicyclic gear train comprising a sun gear, a plurality of planet gears, a planet carrier and an annulus gear, the plurality of planet gears being rotatably mounted on the planet carrier respectively and being in engagement with the sun gear and the annulus gear respectively, one of the sun gear, the planet carrier and the annulus gear being fixed and the other two being in driving connection with the input shaft and the output shaft respectively, characterized in that the epicyclic gear train further comprises a planet gear load balancing mechanism as claimed in any one of claims 1 to 12.

14. Turbofan engine, characterized in that it comprises a gear box according to claim 13, the sun gear being in driving connection with a low pressure shaft of the turbofan engine, one of the planet carrier and the ring gear being in driving connection with a fan of the turbofan engine, the other being provided as a stationary member.

Images