CN207687279U - A kind of planetary roller screw - Google Patents

Abstract

The utility model provides a kind of planetary roller screw, it is related to transmission device field, the planetary roller screw includes bull lead screw, multiple planetary rollers, roller rolling retainer and accommodating nut, roller rolling retainer is set on bull lead screw, and multiple retaining holes are uniformly provided on roller rolling retainer, the extending direction of each retaining hole is consistent with the extending direction of bull lead screw, multiple planetary rollers are placed in multiple retaining holes and correspondingly around the peripheral surfaces for being located at bull lead screw, and accommodating nut is set in outside multiple planetary rollers.The inner peripheral surface of accommodating nut has annular internal thread, and there is the peripheral surface of each planetary roller annular external screw thread, annular external screw thread to be meshed with annular internal thread, so that each planetary roller is connect with accommodating nut thread.Compared to the prior art, a kind of planetary roller screw provided by the utility model, it is relatively low to the required precision of screw thread, manufacture difficulty and cost are reduced, while making transmission efficiency higher.

Description

A kind of planetary roller screw

Technical field

The utility model is related to transmission device fields, in particular to a kind of planetary roller screw.

Background technology

Planetary roller screw is earliest by Swede Carl Bruno Strandgren in nineteen forty-two utility model, but so far Still fail extensive use, that this is mainly due to its is complicated, difficulty of processing is big and cost is higher.It is mainly used at present civilian Field, such as precision machine tool, food packaging, special mechanical, test emulation；But with the development of aircraft and weaponry and Oil, chemical industry, lathe etc. need high thrust, high-precision, high frequency sound, high efficiency, the mechanical device of long-life as electromechanical start The executing agency of system, the conventional hydraulic actuating system that substitution is easy to pollute, maintenance cost is high, planetary roller screw receive extensively Concern.

Planetary roller screw can be roughly divided into three classes according to the difference of structure：Standard type, circular form, bearing are ring-like.Row Star roller screw is a kind of mechanical driving device that can mutually convert rotary motion with linear motion, uses ball as centre Transmission body replaces sliding friction, this kind of drive similar with ball-screw with rolling friction.Planetary roller screw is as a kind of Novel transmission device has the characteristics that friction is small, efficient, long lifespan, small, bearing capacity is strong.Planetary roller screw A big advantage be exactly to realize engaged transmission by threaded rollers, ensure the pure rolling in transmission process, but due to spiral liter The reason of angle, there are heeling moments on roller, if the fixation without circumferencial direction, whether roller can be in the work of heeling moment It is slided with lower generation and is even spinned, this should have certain influence for the structure design at roller both ends：If there is possible Sliding or spin, then roller both ends should be designed as the engaging structure of straight-tooth and ring gear and with the thread parameter of leading screw and roller Match to ensure pure rolling；It is only possible to slide if do not spinned, since opposite sliding will necessarily cause leading screw and rolling The axial displacement of column need not limit its rotary freedom so need to only carry out axial restraint, and be conducive to roller certainly It is adjusted by rotation to make up the error that processing installation generates；It, can not be to rolling if sliding and spin are impossible to occur Column is fixed；It slides or spins simultaneously and all have a significant impact to mesh regional, friction, lubrication.So meshing characteristic for Roller structure design has larger meaning, and the structure for being conducive to the planetary roller screw to being operated in friction speed carries out Optimization.

It investigates and finds through utility model people, the structure of current all designs is all since there is theoretically study difficulty Greatly, required precision is high in manufacture, can not produce in enormous quantities on batch etc., cause this principle not yet adequately in each work Popularization and application in industry production especially represents the integrated automobile industry of industry because of the limitation in its cost and production efficiency, even more It can not apply.Specifically, existing structure existing for current industry due to the defect in design it is undesirable in other words, cause to each The required precision of parts and assembly is very high to realize sliding Variable roll, otherwise otherwise its internal early wear out failure or Internal Planar Mechanisms clamping stagnation, some is even basic to be moved.

In view of this, designing and manufacturing a kind of high efficiency, low cost, while lower planetary roller is required to the accuracy of manufacture Leading screw is just particularly important.

Utility model content

The purpose of this utility model is to provide a kind of planetary roller screws, and transmission efficiency, manufacturing cost is low, while right Accuracy of manufacture requirement is relatively low, facilitates manufacture.

The utility model is realized using technical solution below.

A kind of planetary roller screw, including bull lead screw, multiple planetary rollers, roller rolling retainer and accommodating nut, rolling Column retainer is set on bull lead screw, and multiple retaining holes are uniformly provided on roller rolling retainer, the extension of each retaining hole Direction is consistent with the extending direction of bull lead screw, and multiple planetary rollers are placed in multiple retaining holes and more around being located at correspondingly The peripheral surface of captacula bar, accommodating nut are set in outside multiple planetary rollers.The inner peripheral surface of accommodating nut has annular internal thread, often There is the peripheral surface of a planetary roller annular external screw thread, annular external screw thread to be meshed with annular internal thread, so that each planet rolling Column is connect with accommodating nut thread.

Further, bull lead screw has threaded connection section, and the peripheral surface of threaded connection section has bull external screw thread, multiple The annular external screw thread of planetary roller is meshed with bull external screw thread.

Further, the externally threaded number of starts of bull is greater than or equal to 3.

Further, the externally threaded screw pitch of annular is equal with the annular screw pitch of internal thread.

Further, the externally threaded tooth form section of annular is triangle, and the tooth form section of annular internal thread is also triangle, And the lead angle of annular external screw thread and annular internal thread is zero.

Further, the end face flush with each other of multiple retaining holes, so that the end face flush of multiple planetary rollers.

Further, the two side of each retaining hole has curved wall, and each retaining hole and corresponding planetary roller Shape match so that planetary roller is accommodated in retaining hole.

Further, each retaining hole is interference fitted with corresponding planetary roller so that the both ends of the surface of retaining hole with it is corresponding The both ends of the surface of planetary roller abut against.

A kind of planetary roller screw, including bull lead screw, multiple planetary rollers, roller rolling retainer and accommodating nut, rolling Column retainer is set on bull lead screw, and multiple retaining holes are uniformly provided on roller rolling retainer, the extension of each retaining hole Direction is consistent with the extending direction of bull lead screw, and multiple planetary rollers are placed in multiple retaining holes and more around being located at correspondingly The peripheral surface of captacula bar, accommodating nut are set in outside multiple planetary rollers.The inner peripheral surface of accommodating nut has annular internal thread, often There is the peripheral surface of a planetary roller annular external screw thread, annular external screw thread to be meshed with annular internal thread, so that each planet rolling Column is connect with accommodating nut thread, and twice of the screw pitch that the externally threaded screw pitch of annular is annular internal thread.

Further, multiple retaining holes are interspersed, and the end face of two neighboring retaining hole is in step-like, so that multiple planets Roller is interspersed.

The utility model has the advantages that：

A kind of planetary roller screw provided by the utility model, roller rolling retainer is set on bull lead screw, will be multiple Planetary roller is placed in multiple retaining holes being opened on roller rolling retainer and correspondingly around the periphery for being located at bull lead screw Accommodating nut is set in outside multiple planetary rollers by face so that is rotatablely connected between bull lead screw and multiple planetary rollers.It is accommodating There is the inner peripheral surface of nut annular internal thread, the peripheral surface of each planetary roller to have annular external screw thread, annular external screw thread and ring Shape internal thread is meshed, so that each planetary roller is connect with accommodating nut thread.In actual use, when bull lead screw Circumferencial direction there are one rotation torque when because planetary roller on the one hand and bull lead screw be rotatablely connected, on the other hand with appearance Nut engagement is set, all there is certain frictional force on the contact point, therefore planetary roller can be driven by bull lead screw and be rotated, from And it is rolled in accommodating nut.Compared to the prior art, a kind of planetary roller screw provided by the utility model, since planet rolls Column is all made of ring screw with accommodating nut, therefore relatively low to the required precision of screw thread, reduces manufacture difficulty and cost, makes simultaneously Obtain transmission efficiency higher.

Description of the drawings

It, below will be to required use in embodiment in order to illustrate more clearly of the technical solution of the utility model embodiment Attached drawing be briefly described, it should be understood that the following drawings illustrates only some embodiments of the utility model, therefore should not be by Regard the restriction to range as, for those of ordinary skill in the art, without creative efforts, may be used also To obtain other relevant attached drawings according to these attached drawings.

Fig. 1 is the planetary roller screw overall structure diagram that the utility model first embodiment provides；

Fig. 2 is the planetary roller screw decomposition texture schematic diagram that the utility model first embodiment provides；

Fig. 3 is annular internal thread and the externally threaded engaging structure schematic diagram of annular in Fig. 2；

Fig. 4 is the structural schematic diagram of roller rolling retainer in Fig. 2；

Fig. 5 is the planetary roller screw decomposition texture schematic diagram that the utility model second embodiment provides；

Icon：100- planetary roller screws；110- bull lead screws；130- planetary rollers；131- annular external screw threads；150- is rolled Column retainer；151- retaining holes；170- houses nut；171- annular internal threads.

Specific implementation mode

It is new below in conjunction with this practicality to keep the purpose, technical scheme and advantage of the utility model embodiment clearer Attached drawing in type embodiment, the technical scheme in the utility model embodiment is clearly and completely described, it is clear that is retouched The embodiment stated is the utility model a part of the embodiment, instead of all the embodiments.Usually here described in attached drawing and The component of the utility model embodiment shown can be arranged and be designed with a variety of different configurations.

Therefore, the detailed description of the embodiments of the present invention to providing in the accompanying drawings is not intended to limit requirement below The scope of the utility model of protection, but it is merely representative of the selected embodiment of the utility model.Based in the utility model Embodiment, the every other embodiment that those of ordinary skill in the art are obtained without creative efforts, all Belong to the range of the utility model protection.

It should be noted that：Similar label and letter indicate similar terms in following attached drawing, therefore, once a certain Xiang Yi It is defined, then it further need not be defined and explained in subsequent attached drawing in a attached drawing.

In the description of the present invention, it should be noted that term "center", "upper", "vertical", "horizontal", "inner", The orientation or positional relationship of the instructions such as "outside" is to be based on the orientation or positional relationship shown in the drawings or the utility model product The orientation or positional relationship usually put when use, is merely for convenience of describing the present invention and simplifying the description, without referring to Show or imply that signified device or element must have a particular orientation, with specific azimuth configuration and operation, therefore cannot manage Solution is limitations of the present invention.In addition, term " first ", " second " etc. are only used for distinguishing description, and should not be understood as referring to Show or imply relative importance.

In the description of the present invention, it should also be noted that, unless otherwise clearly defined and limited, term " is set Set ", " connected ", " installation ", " connection " shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, Or it is integrally connected；It can be mechanical connection, can also be electrical connection；It can be directly connected, intermediary can also be passed through It is indirectly connected, can be the connection inside two elements.For the ordinary skill in the art, it can be managed with concrete condition Solve the concrete meaning of above-mentioned term in the present invention.

Below in conjunction with the accompanying drawings, it elaborates to some embodiments of the utility model.In the absence of conflict, under Feature in the embodiment stated can be combined with each other.

The utility model is to carry out Method of Spreading Design around high efficiency, inexpensive purpose.

Existing structure existing for current industry since the defect in design is undesirable in other words, cause to each parts and The required precision of assembly is very high to realize sliding Variable roll, otherwise otherwise its internal early wear out failure or inside are crossed about Beam clamping stagnation, some is even basic to be moved.Basic reason there are this phenomenon is not catch this root of sliding Variable roll This demand does not surround this point and carries out thinking innovation, but engages two points, and two around planet engagement and screw thread Point be unwilling to all loosen, and leading to accuracy requirement at all can not reduce, and also just cannot achieve high efficiency, inexpensive target.Planetary motion As a result, not being demand when being sliding Variable roll, as long as long as being rolled in the rolling even most of the time, occur once in a while Non- planetary motion is also possible.In order to realize that screw thread institute is loaded evenly, improving precision makes the more abundant of its cooperation, is one Paths, but be not exclusive path, or even if load is met the requirements, the necessity carried is also just not present, high-precision Necessity be also just not present；But in current all structures, two will ensure, and ensure simultaneously, this allows for making Make extremely difficult, the analysis of causes is as follows：First, single from the point of view of planet engagement, using row in current industry existing structure Star gear engages to ensure that planetary motion, planetary gear are engaged on field of machining and are natively not easy to realize, especially interior The processing of gear is even more the problem of industry；Secondly, from the point of view of screw thread engagement, using fine grinding spiral shell in current industry existing structure Line, to increase the engagement matching degree of screw thread, to reduce the load of each contact point, to improve fatigue life；Finally, by Must be synchronous with planet engagement in screw thread engagement, Planar Mechanisms otherwise will mutually occur, lead to clamping stagnation and its early abrasion.In fact, Screw thread carries, and not necessarily leans on so high precision, and precision is lower, if but thread hardness and rigidity reduce a bit so that tooth Type then the big deformation of stress is a bit, in the also contact for making stress small, can also be realized and be carried there are certain deformation, to Also it can improve fatigue life.But this in existing structure cannot, because of the mutual constraint of more precision so that hardness and just Degree can not possibly reduce, otherwise otherwise planet engagement goes wrong or screw thread engagement goes wrong；

When between the roller and leading screw of screw thread engagement because the accuracy of mesh is bad there is mutually sliding when, due to accommodating nut and Bull lead screw mutually pushes planetary roller, once producing relative sliding, is bound to lead to entire mechanism blockage, bull lead screw can not Linear motion.

When the planet accuracy of mesh is not high, the planetary roller of the driving relatively more captacula bar that is bound to has opposite sliding, on Face has been analyzed, once produce relative sliding, it is inevitable stuck.Therefore planet is engaged and is threadably engaged in existing structure design, It all has to meet simultaneously, and mutually assist.

To sum up, currently existing Structure on Accuracy, which requires excessively high basic reason to be several high-precision motions, to expire simultaneously Foot, and be required each other, it can not ban.

The utility model realizes following feature：

There is no planet engagement, planetary roller is allowed in structure, and there are certain slidings, but due to bull lead screw and house The driving for the frictional force that nut generates the pressure of planetary roller, planetary roller is pure rolling.Planetary roller and accommodating nut Between engagement there are the period of adjustment, even if the accuracy of manufacture it is bad due to mutual process of lapping if can gradually be mutually matched it is suitable It answers.Allow to have opposite sliding between planetary roller and bull lead screw without influencing movement.

First embodiment

In conjunction with referring to Fig. 1 and Fig. 2, a kind of planetary roller screw 100, including bull lead screw 110, multiple planetary rollers 130, Roller rolling retainer 150 and accommodating nut 170, roller rolling retainer 150 are set on bull lead screw 110, and roller rolling retainer 150 On be uniformly provided with multiple retaining holes 151, the extending direction of each retaining hole 151 is consistent with the extending direction of bull lead screw 110, Multiple planetary rollers 130 are placed in multiple retaining holes 151 and correspondingly around the peripheral surfaces for being located at bull lead screw 110, house Nut 170 is set in outside multiple planetary rollers 130.

There is the inner peripheral surface of accommodating nut 170 annular internal thread 171, the peripheral surface of each planetary roller 130 to have annular External screw thread 131, annular external screw thread 131 are meshed with annular internal thread 171, so that each planetary roller 130 and accommodating nut 170 It is threadedly coupled.

There is bull lead screw 110 threaded connection section, the peripheral surface of threaded connection section to have bull external screw thread, multiple planet rollings The annular external screw thread 131 of column 130 is meshed with bull external screw thread.Specifically, the externally threaded number of starts of bull is greater than or equal to 3 It is a.

It should be noted that in the present embodiment, the number of starts of bull lead screw 110 must be bull, else if being If single head, the planetary roller 130 that can coordinate with it cannot keep because of the relationship of helix angle in a level height, Annular external screw thread 131 either in each planetary roller 130 cannot keep in the same horizontal plane, however, accommodating nut 170 Annular internal thread 171 because being all cricoid, need the annulus in planetary roller 130 must be in approximately the same plane, this will It causes, can coordinate with bull lead screw 110, cannot necessarily coordinate with accommodating nut 170.If the thread head of bull lead screw 110 Number is bull, because in the same horizontal cross-section height, there are contact points identical with number of starts therefore to have for meeting How many a thread heads, with regard to how many identical point, as long as in this way, 130 anchor ring of planetary roller is located on identical point, that These inevitable planetary rollers 130 can coordinate with accommodating nut 170, and the status of these planetary rollers 130 is identical 's.Therefore, number of starts is preferably three heads or more, and to ensure 130 quantity of planetary roller, transmission in this way could be steady.

In the present embodiment, the externally threaded number of starts of bull is 4, is not restricted to this certainly, can also be 5 Or 6 etc., it is not specifically limited herein.

In the present embodiment, the screw pitch of annular external screw thread 131 is equal with the screw pitch of annular internal thread 171 so that planet rolls The quantity of column 130 is consistent with the externally threaded number of starts of bull.

In addition the core key feature of the utility model is in addition, accommodating nut 170, planetary roller 130, bull lead screw 110 Three's radius relationship is liberated, as long as screw pitch is equal, the lead angle of bull lead screw 110 is not too big, right The radius relationship of three requires to tell somebody what one's real intentions are, also relatively low to the required precision in the pitch diameter of thread manufacture of cooperation.In the utility model, It is to belong to contact friction to nibble in engagement because accommodating nut 170 and the internal and external threads of planetary roller 130 are all ring-shaped structures It closes, is the transmission engagement not by effect of radius, but the existing majority of current industry is all screw thread engagement, and with lead angle Screw thread engagement is substantially helical gear engagement, and this engagement pair radius and modulus etc. relevant parameter, which all has, strictly to be limited, And it is relatively high to required precision, this is the essential distinction of the utility model and existing product.

It should be noted that liberation cooperation radius benefit, to actual design production influence it is very big, will not because of by To Radius Constraint relationship, 110 diameter of bull lead screw can be made big by those skilled in the art, in this way in number of starts and In the case that screw pitch is constant, helix angle can be done smaller, and helix angle is smaller, be wanted to 130 cambered surface of planetary roller Ask lower, it might even be possible to directly apply triangular form face, manufacturing requirement in this way will substantially reduce.And the diameter of planetary roller 130 As long as meeting rolling technology either superfinishing injection molding or turning, the requirement of grinding process, that is to say, that allow bull silk The diameter that bar 110 is done is very big, and the diameter very little that planetary roller 130 is done.In addition after liberating radius, the diameter of bull lead screw 110 Can be made big, thus may be implemented bull lead screw 110 make it is hollow, and overall structure there is no especially amplification, Much this point of application fields is very crucial design demand.

The annular internal thread 171 of accommodating nut 170 and the annular external screw thread 131 of planetary roller 130 all use annulus most Big advantage is reduction of accuracy of manufacture demand, and when some planetary roller 130 because of rotation or skidding, therefore system will not just block Dead loss of function, this design capacity can greatly improve system survivability, exactly because also there is this ability, to planet In the case that the rotation of roller 130 is of less demanding, so that it may to avoid the planet engaging mechanism of manufacture timing or so in high precision, even more The synchronous of the double precision that planet is engaged with screw thread engages is avoided, therefore using annular internal thread 171 and annular external screw thread 131 Design structure is the core key of the utility model.The design being greatly lowered to the accuracy of manufacture is the planetary roller screw 100 can popularize the basic motivator of application on a large scale.

Referring to Fig. 3, the tooth form section of annular external screw thread 131 is triangle, and the tooth form section of annular internal thread 171 is also three It is angular, and annular external screw thread 131 and the lead angle of annular internal thread 171 are zero.Specifically, the tooth of annular external screw thread 131 Type section is the camber line that repairing type is done on the basis of triangle.

Significantly, since planetary roller 130 and the external screw thread of bull lead screw 110 are intermeshed, preferably to ring Shape external screw thread 131 carries out repairing type processing, and especially when 110 lead angle of bull lead screw is bigger, ratio is required to repairing type camber line It is higher.When the lead angle of bull lead screw 110 is smaller, abrasion is smaller, when fatigue life demand is not very big, also may be used Triangle is directly used with not repairing type.

It should be noted that when in 131 engagement process of screw thread and annular external screw thread of bull lead screw 110, if helix angle Bigger, the two engagement process can will pass through 131 spiral shell of annular external screw thread to planetary roller 130 there are one opposite small sliding It corrects in the type face of line so that linear contact becomes point contact, evades interference, to evade abrasion.In the present embodiment, planet rolls The lead angle of annulus on column 130 is zero, that is to say, that entirely parallel cyclic structure.As planetary roller 130 Design is to allow roller rotation or skidding in assembly, while having no effect on entire mechanism in overall structure first Operation, secondly, this annular external screw thread 131 in the cooperation of the annular internal thread 171 of accommodating nut 170, due to both being no Disconnected to repeat identical track, so there is also the relationship of break-in, such accuracy of manufacture is actually that further reduced requirement , even if there is certain dimensional accuracy, by using the period of adjustment of process, the more matching of the two also gradually, most Afterwards, the planetary roller 130 of this structure, only type face precision and screw pitch precision need to control in manufacture, compare more existing industry Structure, both without phase relation, also the external gear accuracy of manufacture not with internal gear cooperation requires, such structure, either It is all more easy to implement by rolled thread or precise injection molding, it is high efficiency, low cost manufacturing, which is beaten, has determined basis.Especially work as planet In the case that 130 diameter of roller is smaller, the advantage in manufacture is more prominent, is simply compared with extrusion process, first production effect Rate greatly improves, and machining difficulty is very big when secondly draw ratio is bigger, and uses current structure design, Ke Yiyong Thread rolling process manufactures to realize, the requirement to lathe and mold is all relatively low, and cylindrical die roll itself manufactures the bigger long axis of major diameter Screw thread just has advantage, inherently relatively more straight without the radial load that cantilever beam or cutter apply, and still more cylindrical die roll itself is again Having has the function of aligning, thus it is this without external gear on roller, it is only single nor the roller that screw thread and annulus coexist The planetary roller 130 of one circular ring structure has very big innate advantage in manufacture.The planet rolling of current line in the industry in fact Column 130 or it is screw thread and external gear integrates or is that annulus and screw thread integrate, precision of the two itself All very high, along with the two there must be certain phase relation again, especially this phase relation brings to manufacture Very big challenge, this is also that planetary roller screw 100 manufactures a bad great original to China for many years why so Cause, exactly this multi-Precision must be simultaneously achieved the drawbacks of bringing and this very perfect deceleration mechanism of theory can not A major reason that is universal and producing in enormous quantities.

Referring to Fig. 4, roller rolling retainer 150 is in cylindrical structure, the end face flush with each other of multiple retaining holes 151, so that multiple The end face flush of 130 roller of planetary roller.Specifically, the two side of each retaining hole 151 has curved wall, and each guarantor It holds hole 151 to match with the shape of corresponding planetary roller 130, so that planetary roller 130 is accommodated in retaining hole 151.

In the present embodiment, each retaining hole 151 is interference fitted with corresponding planetary roller 130, so that retaining hole 151 Both ends of the surface are abutted against with the both ends of the surface of corresponding planetary roller 130.Specifically, the interference volume of each retaining hole 151 should not be too large, It is excessive to avoid resistance in rotation process.In assembling process, it is also necessary to increase support planetary roller inside accommodating nut 170 130 accessory (not shown), accessory radial direction on support force is provided, the accessory during being threaded by bull silk Bar 110 ejects, to ensure that planetary roller 130 is not fallen off in entire assembling process.

In the present embodiment, roller rolling retainer 150 is integrally formed, and uses nylon frame, and certainly, roller is kept herein The material of frame 150 can also be plastics or other high molecular materials etc., be not specifically limited herein.

In conclusion present embodiments providing a kind of planetary roller screw 100, planetary roller 130 is evenly distributed on bull The surrounding of lead screw 110, and the quantity of planetary roller 130 is equal with the number of starts of leading screw, when bull lead screw 110 is in circumferencial direction There are one rotation torque when, due in planetary roller 130 131 one side of annular external screw thread in the annular of accommodating nut 170 Screw thread 171 engages, and is on the other hand engaged with the bull external screw thread of bull lead screw 110, all there is certain friction on the contact point Power, therefore planetary roller 130 can be driven by bull lead screw 110 and be rotated, so that planetary roller 130 is in accommodating nut 170 Middle rolling.Since all planetary rollers 130 roll under the driving of bull lead screw 110 and generate rotation and revolution motion, and Annular internal thread 171 and the lead angle of annular external screw thread 131 are zero, so housing between nut 170 and planetary roller not There are axial displacements.Compared to the prior art, a kind of planetary roller screw 100 provided in this embodiment, the precision of screw thread It asks relatively low, reduces manufacture difficulty and cost, while making transmission efficiency higher.

Second embodiment

Present embodiments provide a kind of planetary roller screw 100, basic structure and principle and the technique effect of generation and First embodiment is identical, and to briefly describe, the present embodiment part does not refer to place, can refer to corresponding contents in first embodiment.

The planetary roller screw 100 includes bull lead screw 110, multiple planetary rollers 130, roller rolling retainer 150 and holds Nut 170 is set, roller rolling retainer 150 is set on bull lead screw 110, and multiple guarantors are uniformly provided on roller rolling retainer 150 Hole 151 is held, the extending direction of each retaining hole 151 is consistent with the extending direction of bull lead screw 110, multiple planetary rollers 130 1 One is accordingly placed in multiple retaining holes 151 and around the peripheral surface for being located at bull lead screw 110, accommodating nut 170 is set in multiple Outside planetary roller 130.The inner peripheral surface of accommodating nut 170 has annular internal thread 171, the periphery mask of each planetary roller 130 Have an annular external screw thread 131, annular external screw thread 131 is meshed with annular internal thread 171 so that each planetary roller 130 with it is accommodating Nut 170 is threadedly coupled.

In the present embodiment, the screw pitch of annular external screw thread 131 is twice of the screw pitch of annular internal thread 171 so that planet rolls The quantity of column 130 is twice of the externally threaded number of starts of bull.In the case of in this way, planetary roller 130 in the first embodiment The cooperation upper limit in the case of, the planetary roller 130 of quantity such as can be spaced apart again, and the whole phases of these planetary rollers 130 For the screw pitch of the upward wrong annular internal thread 171 of the planetary roller 130 arranged originally, the upper mistake of such planetary roller 130 Just the spiral lift of bull lead screw 110 has been catered to.It is so achieved that and increases planetary roller 130, and be into multiplication Add 130 quantity of planetary roller, makes full use of the purpose of circuferential spacing.Specifically, in the case where number of starts is 4, planet rolling The quantity of column 130 is 8.

It is worth noting that, the screw pitch of annular external screw thread 131 is not restricted to as the screw pitch of annular internal thread 171 herein Twice, can also be other integral multiples such as three times or four times, be not specifically limited herein.

In the present embodiment, multiple retaining holes 151 are interspersed, the end face of two neighboring retaining hole 151 in step-like, with Multiple planetary rollers 130 are made to be interspersed.

A kind of planetary roller screw 100 provided in this embodiment, increases the quantity of planetary roller 130 so that transmission is more Add steady.

The above descriptions are merely preferred embodiments of the present invention, is not intended to limit the utility model, for this For the technical staff in field, various modifications and changes may be made to the present invention.It is all in the spirit and principles of the utility model Within, any modification, equivalent replacement, improvement and so on should be included within the scope of protection of this utility model.

Claims (10)

1. a kind of planetary roller screw, which is characterized in that including bull lead screw, multiple planetary rollers, roller rolling retainer and appearance Nut is set, the roller rolling retainer is set on the bull lead screw, and multiple guarantors are uniformly provided on the roller rolling retainer Hole is held, the extending direction of each retaining hole is consistent with the extending direction of bull lead screw, multiple planetary rollers one One is accordingly placed in multiple retaining holes and around the peripheral surface for being located at the bull lead screw, the accommodating nut is set in more Outside a planetary roller；

There is the inner peripheral surface of the accommodating nut annular internal thread, the peripheral surface of each planetary roller to have the outer spiral shell of annular Line, the annular external screw thread are meshed with the annular internal thread, so that each planetary roller and the accommodating nut spiral shell Line connects.

2. planetary roller screw according to claim 1, which is characterized in that the bull lead screw has threaded connection section, The peripheral surface of the threaded connection section has a bull external screw thread, the annular external screw thread of multiple planetary rollers with it is described more Head external screw thread is meshed.

3. planetary roller screw according to claim 2, which is characterized in that the externally threaded number of starts of bull is more than Or it is equal to 3.

4. planetary roller screw according to claim 1, which is characterized in that the externally threaded screw pitch of annular and the ring The screw pitch of shape internal thread is equal.

5. planetary roller screw according to claim 4, which is characterized in that the externally threaded tooth form section of annular is three Angular, the tooth form section of the annular internal thread is also triangle, and the spiral shell of the annular external screw thread and the annular internal thread Line lift angle is zero.

6. planetary roller screw according to claim 4, which is characterized in that the end face of multiple retaining holes is mutually flat Together, so that the end face flush of multiple planetary rollers.

7. planetary roller screw according to claim 6, which is characterized in that the two side of each retaining hole has arc Shape wall surface, and each retaining hole is matched with the shape of the corresponding planetary roller, so that the planetary roller is accommodating In the retaining hole.

8. planetary roller screw according to claim 6, which is characterized in that each retaining hole and the corresponding row Star roller is interference fitted, so that the both ends of the surface of the retaining hole are abutted against with the both ends of the surface of the corresponding planetary roller.

9. a kind of planetary roller screw, which is characterized in that including bull lead screw, multiple planetary rollers, roller rolling retainer and appearance Nut is set, the roller rolling retainer is set on the bull lead screw, and multiple guarantors are uniformly provided on the roller rolling retainer Hole is held, the extending direction of each retaining hole is consistent with the extending direction of bull lead screw, multiple planetary rollers one One is accordingly placed in multiple retaining holes and around the peripheral surface for being located at the bull lead screw, the accommodating nut is set in more Outside a planetary roller；

There is the inner peripheral surface of the accommodating nut annular internal thread, the peripheral surface of each planetary roller to have the outer spiral shell of annular Line, the annular external screw thread are meshed with the annular internal thread, so that each planetary roller and the accommodating nut spiral shell Line connects, and twice of the screw pitch that the externally threaded screw pitch of annular is the annular internal thread.

10. planetary roller screw according to claim 9, which is characterized in that multiple retaining holes are interspersed, adjacent The end face of two retaining holes is in step-like, so that multiple planetary rollers are interspersed.