CN213017559U - Roller screw and electric steering gear with same - Google Patents

Abstract

The utility model discloses a roller screw and have its electric steering gear, roller screw include the hole for the unthreaded nut, run through the hole and have the lead screw of first external screw thread on the periphery wall, all lie in the hole and along the axially spaced two planet carriers of lead screw, a plurality of rollers and two tip backstop structures, all have on each planet carrier for the central via hole that the lead screw passes and the spaced multiple rotation hole that sets up around the central via hole; the plurality of rollers are positioned between the screw rod and the nut and positioned between the two planet carriers, each roller comprises a cylindrical part and two light shaft parts respectively positioned at the two axial ends of the cylindrical part, the light shaft parts are matched with the rotating holes one by one, and second external threads meshed with the first external threads are arranged on the outer peripheral wall of the cylindrical part; the two end stop structures are respectively fixedly connected with the nut and respectively stop at one sides of the two planet carriers far away from the roller. The roller screw of the utility model can bear large radial and axial loads, and has simple process and reliable work.

Description

Roller screw and electric steering gear with same

Technical Field

The utility model belongs to the technical field of mechanical transmission technique and specifically relates to a roller screw and have its electric steering gear is related to.

Background

In the related technology, the planetary roller screw comprises a screw rod, a roller, a nut, an inner ring gear, a retainer, a clamp spring and the like, wherein the inner ring of the nut needs to be provided with threads with the same section type as the screw rod, so that the roller is meshed with the screw rod and the nut, the threads need to be extended from two sides of the roller, and a tooth-shaped structure meshed with the inner ring gear is radially processed to enable two ends of the roller to be meshed with the inner ring gear and then axially limited through the clamp spring. Therefore, the phase problem exists in the press fitting process of the inner gear ring, the installation precision of the roller and the inner gear ring is extremely high, and if the press fitting position is inaccurate, the whole set of mechanism cannot be installed, namely, the structure of the star-shaped roller screw is limited, so that the assembling process is complex, the machining process is complicated, the product rejection rate is high, and the product cost is very high.

SUMMERY OF THE UTILITY MODEL

The utility model provides a roller screw, roller screw has the advantage that bears radially, axial load ability reinforce, simple process, assembly are easy, the reliable operation is stable.

The utility model provides an electric steering gear, electric steering gear includes as above roller screw.

The roller screw comprises a nut, a screw rod, two planet carriers, a plurality of rollers and two end stop structures, wherein an inner hole of the nut is a unthreaded hole; the screw rod penetrates through an inner hole of the nut, and a first external thread is arranged on the outer peripheral wall of the screw rod; the two planet carriers are positioned in the inner hole of the nut and are arranged at intervals along the axial direction of the screw rod, and each planet carrier is provided with a central through hole for the screw rod to pass through and a plurality of rotating holes arranged around the central through hole at intervals; the plurality of rollers are positioned between the screw rod and the nut and between the two planetary carriers, each roller comprises a cylindrical body part and two light shaft parts respectively positioned at two axial ends of the cylindrical body part, a second external thread is arranged on the outer peripheral wall of the cylindrical body part, the second external thread is matched with the first external thread and is contacted with an inner hole of the nut, and the plurality of light shaft parts on the same axial side are in one-to-one corresponding rotating fit with the plurality of rotating holes on the planetary carriers on the corresponding side, so that the plurality of rollers are arranged at intervals along the circumferential direction of the screw rod; each end stopping structure is fixedly connected with the nut, and the two end stopping structures respectively stop at one side of the planet carrier far away from the roller.

The roller screw rod provided by the embodiment of the utility model has the advantages that firstly, the roller screw rod can bear large radial load and can be applied to transmission mechanisms such as steering gears and the like which need large radial load; secondly, the inner hole is a unthreaded hole, and the unthreaded hole is in contact with the second external thread, so that the friction resistance can be reduced and the energy consumption can be saved on the basis of bearing the radial load; thirdly, the unthreaded hole does not need to be processed with a tooth groove, the process is simpler, the assembly is easy, the work is reliable and stable, and the cost is reduced.

In some embodiments of the present invention, at least one of the two end stop structures is connected to the nut assembly.

In some embodiments of the present invention, one of the two end stop structures is a first stop structure and the other is a second stop structure, the first stop structure is connected to the nut assembly, and the second stop structure is integrated with the nut.

In some embodiments of the present invention, at least one of the end stop structures is connected to the nut assembly by a plurality of fasteners, and the plurality of fasteners are spaced apart along a circumference of the lead screw.

In some embodiments of the present invention, the roller screw further comprises a first thrust bearing, each of the end stop structures and the planet carrier between which the first thrust bearing is respectively disposed.

In some embodiments of the present invention, the orientation of the planet carrier has a first annular groove around the lead screw on a side end face of the end stop structure, the orientation of the end stop structure has a second annular groove on a side end face of the planet carrier, and the first thrust bearing is an annular thrust bearing and is fitted to the first annular groove and the second annular groove.

In some embodiments of the present invention, the roller screw further comprises a second thrust bearing, and each of the rollers and the planet carrier is provided with the second thrust bearing therebetween.

In some embodiments of the present invention, the second thrust bearings are all configured as annular thrust bearings that are sleeved on the smooth shaft portion.

In some embodiments of the present invention, the rotation hole is a blind hole opened toward the roller direction.

In some embodiments of the present invention, at least one of the first external thread and the second external thread has a profile that is curved.

According to the utility model discloses electric steering gear, including motor, steering gear subassembly and as above roller screw, the motor with the lead screw links to each other in order to drive the lead screw rotates, the nut with steering gear subassembly links to each other.

According to the utility model discloses electric steering gear, through the application as above roller screw, because roller screw processing is simple, can bear great radial and axial load, stability is high, good reliability for electric steering gear can realize stably, and the reliable function that turns to, and then can promote driver and crew's security.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is an exploded view of a roller screw according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the roller screw shown in FIG. 1;

FIG. 3 is an exploded view of the nut, carrier and end stop structure shown in FIG. 2;

FIG. 4 is a schematic view of the meshing of the rollers and screw of FIG. 2;

fig. 5 is a schematic view of an electric power steering apparatus according to an embodiment of the present invention.

Reference numerals:

an electric steering gear 1000, a roller screw 100, a motor 200, a steering gear assembly 300, a sector 301,

the nut 1, the inner hole 11, the first connecting hole 12, the tooth groove 13,

the screw 2, the first external thread 21,

the planet carrier 3, the central through hole 31, the rotation hole 32, the first annular groove 33,

the roller 4, the cylindrical portion 41, the second external thread 411, the optical axis portion 42,

an end stop 5, a first stop 5a, a second stop 5b, a second annular groove 51, a second connection hole 52,

a fastener 6, a first thrust bearing 7 and a second thrust bearing 8.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

A roller screw 100 according to an embodiment of the present invention is described below with reference to the drawings.

As shown in fig. 1-2, a roller screw 100 according to an embodiment of the present invention includes a nut 1, a screw 2, two planetary carriers 3, a plurality of rollers 4, and two end stops 5.

Specifically, referring to fig. 1-2, an inner hole 11 of the nut 1 is a smooth hole, the lead screw 2 penetrates through the inner hole 11 of the nut 1, and a peripheral wall of the lead screw 2 has a first external thread 21, two planetary carriers 3 are located in the inner hole 11 of the nut 1 and are arranged at intervals in the axial direction of the lead screw 2, each planetary carrier 3 has a central through hole 31 for the lead screw 2 to pass through and a plurality of rotation holes 32 arranged around the central through hole 31 at intervals, the plurality of rollers 4 are located in the inner hole 11, and the plurality of rollers 4 are located between the lead screw 2 and the nut 1 and between the two planetary carriers 3.

As shown in fig. 1 and 2, each roller 4 includes a cylindrical portion 41 and two optical axis portions 42 respectively located at two axial ends of the cylindrical portion 41, a second external thread 411 is provided on an outer circumferential wall of the cylindrical portion 41, the second external thread 411 is matched with the first external thread 21 and contacts with the inner hole 11 of the nut 1, and the optical axis portions 42 on the same axial side are in one-to-one corresponding rotational fit with the rotational holes 32 on the planet carrier 3 on the corresponding side, so that the rollers 4 are arranged at intervals in the circumferential direction of the screw 2. Each end stop 5 is fixedly connected (including directly connected, indirectly connected, detachably connected, non-detachably connected, integrally formed, etc.) to the nut 1 so as to be relatively stationary, and the two end stops 5 respectively stop at one side of the two planetary carriers 3 away from the roller 4, that is, one side of each planetary carrier 3 away from the roller 4 is provided with the end stop 5.

It can be understood that, because the first external thread 21 and the second external thread 411 are engaged, the rotation of the screw 2 can drive the rollers 4 to rotate, the rollers 4 rotate to enable the light shaft portions 42 of the rollers 4 to rotate relative to the rotation holes 32 on the planet carrier 3, and then drive the planet carrier 3 to rotate around the screw 2, the planet carrier 3 rotates to drive the plurality of rollers 4 arranged at intervals around the central via hole 31 to revolve around the screw 2, during the revolution of the plurality of rollers 4, the rollers 4 can generate displacement along the axial direction of the screw 2, and then drive the nut 1 to generate displacement along the axial direction of the screw 2, or, during the revolution of the plurality of rollers 4, the screw 2 can generate displacement along the axial direction of the screw 2 relative to the nut 1.

Wherein, nut 1 can provide the support for lead screw 2, two planet carriers 3, a plurality of roller 4, and the hole 11 of nut 1 is the unthreaded hole can be convenient for the processing of hole 11, and second external screw thread 411 can laminate with hole 11, and first external screw thread 21 and the cooperation of second external screw thread 411 make roller 4 can rotate for lead screw 2. The planet carrier 3 can provide support for the two optical shaft parts 42 of the roller 4 and also provide power for the roller 4 to revolve around the screw rod 2, and the two planet carriers 3 are arranged at intervals along the axial direction of the screw rod 2 so as to facilitate the balance of the rotation and revolution of the roller 4. The central through hole 31 on the planet carrier 3 can facilitate the planet carrier 3 to be sleeved on the screw rod 2 in an empty way, so that the planet carrier 3 can rotate around the screw rod 2, and then the plurality of rollers 4 are driven to revolve around the screw rod 2.

The two end stop structures 5 stop at the sides of the two planetary carriers 3 far away from the rollers 4 respectively, so that the two end stop structures 5 can axially position the two planetary carriers 3 respectively, the two planetary carriers 3 can be reliably and stably installed in the nut 1, and the rollers 4 are limited from moving out of the nut 1. Moreover, the axial displacement of the roller 4 relative to the screw 2 drives the planet carrier 3 to axially displace relative to the screw 2, and then the planet carrier 3 drives the nut 1 to axially displace relative to the screw 2 through the end stop structure 5.

In the related technology, the roller of the roller screw structure is suspended from the inner ring of the nut and is not contacted, and when bearing a large radial force, the serious deformation of the mechanism parts can be generated, so that the normal operation can not be realized, and a large radial load can not be borne. Moreover, the both ends of the nut of the roller screw structure are opened, a plurality of rollers are arranged on the planet carrier at intervals along the circumferential direction of the planet carrier, one side of the planet carrier, which is far away from the rollers, adopts the rolling bearing to axially position the planet carrier, the positioning mode has low reliability and is unstable, the bearing size of the axial load has uncertainty, and the risk that the rolling bearing and the planet carrier fall off from the nut easily occurs.

The roller screw 100 according to the embodiment of the present invention has advantages that firstly, the roller screw 2 is engaged with the roller 4, and the roller 4 is attached to the inner hole 11 of the nut 1, so that a large radial load can be borne, and the roller screw 100 can be applied to a transmission mechanism such as a steering gear, which requires a large radial load; secondly, the inner hole 11 is a unthreaded hole which is in contact with the second outer thread 411, so that the frictional resistance can be reduced, and the energy consumption is saved; thirdly, tooth grooves do not need to be machined in the unthreaded holes, the process is simpler, and the cost is reduced; fourthly, through setting up two tip backstop structures 5 backstop respectively in two planet carrier 3 keep away from one side of roller 4, let two tip backstop structures 5 can be respectively to two planet carrier 3 axial spacing, this kind of spacing mode reliability is high, stability is good, can bear great axial load, can reduce the risk that planet carrier 3 breaks away from nut 1. And the roller screw 100 can ensure that the rotary motion is converted into linear motion, and the work is reliable and effective.

In addition, in the related art, the planetary roller screw comprises a screw rod, a roller, a nut, an inner ring gear, a retainer, a snap spring and the like, wherein the inner ring of the nut needs to be provided with threads with the same section type as the screw rod, so that the roller is meshed with the screw rod and the nut, the threads need to be extended from two sides of the roller, and a tooth-shaped structure meshed with the inner ring gear is radially processed, so that two ends of the roller are meshed with the inner ring gear and are axially limited through the snap spring. Therefore, the phase problem exists in the press fitting process of the inner gear ring, the installation precision of the roller and the inner gear ring is extremely high, and if the press fitting position is inaccurate, the whole set of mechanism cannot be installed, namely, the structure of the star-shaped roller screw is limited, so that the assembling process is complex, the machining process is complicated, the product rejection rate is high, and the product cost is very high.

And the utility model discloses a roller screw 100, roller 4 and the meshing of lead screw 2, not with the meshing of nut 1, laminate for not having the clearance with nut 1, the hole 11 of nut 1 is unthreaded hole, no tooth groove to the processing of nut 1 has been simplified, has avoided the radial positioning problem of roller 4, nut 1 and ring gear moreover, has simplified assembly process. And the utility model discloses a roller screw 100 has cancelled ring gear, jump ring to greatly reduced the assembly complexity, and the both ends of roller 4 are optical axis portion 42, and optical axis portion 42 directly assembles on planet carrier 3, thereby makes 4 both ends of roller need not the complex construction of processing screw thread stack profile of tooth, directly is the polished rod structure, has further reduced manufacturing procedure.

In some embodiments of the present invention, at least one of the two end stop structures 5 is assembled with the nut 1, that is, one of the two end stop structures 5 may be assembled with the nut 1, or both of them may be assembled with the nut 1. Thereby, it is possible to facilitate the assembly of the screw 2, the plurality of rollers 4 and the two planetary carriers 3 into the nut 1 and also the removal of the screw 2, the plurality of rollers 4 and the two planetary carriers 3 from the nut 1, thereby facilitating the maintainability and replaceability of the nut 1, the screw 2, the plurality of rollers 4 and the two planetary carriers 3.

In the example shown in fig. 2-3, one of the two end stops 5 is in fitting connection with the nut 1 and the other is in one piece with the nut 1. Therefore, one of the two end stop structures 5 is a first stop structure 5a, the other end stop structure is a second stop structure 5b, the first stop structure 5a is assembled and connected with the nut 1, so that the screw rod 2, the plurality of rollers 4 and the two planetary carriers 3 can be assembled into the nut 1 conveniently, the screw rod 2, the plurality of rollers 4 and the two planetary carriers 3 can be taken out of the nut 1 conveniently, and the maintenance and the replaceability of the nut 1, the screw rod 2, the plurality of rollers 4 and the two planetary carriers 3 are further facilitated. Under the prerequisite that can satisfy above-mentioned assembly convenience, second backstop structure 5b and nut 1 are integrative can be convenient for nut 1 and second backstop structure 5 b's manufacturing, save nut 1 and second backstop structure 5 b's assembly process, can practice thrift the manual work.

According to some embodiments of the present invention, as shown in fig. 1-2, at least one end stop structure 5 is assembled with the nut 1 by a plurality of fasteners 6, and the plurality of fasteners 6 are spaced apart along the circumference of the lead screw 2. Thus, the assembly of end stop 5 to nut 1 is made more reliable and stable by the plurality of fasteners 6, and the fasteners 6 may also be some removable fasteners, such as screws or the like, to facilitate the installation of end stop 5 to nut 1 and the removal of end stop 5 from nut 1. Further, the plurality of fasteners 6 being spaced apart along the circumference of the lead screw 2 may facilitate the structural placement of the fasteners 6 on the end stop 5 and the nut 1.

For example, in the specific example shown in fig. 1 to 3, the nut 1 is provided with a first connecting hole 12, the end stop 5 is provided with a second connecting hole 52, and the fastening member 6 is a screw, and is threaded with the first connecting hole 12 after passing through the second connecting hole 52, so as to connect the nut 1 and the end stop 5. Of course, the present invention is not limited to this, and the fastening member 6 may be a fastening member such as a rivet.

As shown in fig. 1-2, in some embodiments of the present invention, the roller screw 100 further comprises a first thrust bearing 7, and a first thrust bearing 7 is disposed between each end stop 5 and the planet carrier 3. From this, first thrust bearing 7 can support planet carrier 3, to planet carrier 3 axial positioning for planet carrier 3's rotation is more steady, smooth and easy, can improve planet carrier 3 pivoted reliability. Of course, the manner of improving the rotational reliability of the planet carrier 3 may not only be provided with the first thrust bearing 7, but also be provided with a plurality of balls between the end stop structure 5 and the planet carrier 3, or be provided with a plurality of wear-resistant ribs on the end stop structure 5, and the like, and the manner of improving the rotational reliability of the planet carrier 3 is not limited, and is not described herein.

According to some embodiments of the present invention, referring to fig. 2-3, the planet carrier 3 has a first annular groove 33 (see fig. 1) disposed around the screw 2 on a side end surface of the end stop 5, and the end stop 5 has a second annular groove 51 on a side end surface of the planet carrier 3, and the first thrust bearing 7 is an annular thrust bearing and is fitted to the first annular groove 33 and the second annular groove 51. Thus, the first annular groove 33 and the second annular groove 51 may support the first thrust bearing 7 and radially limit the first thrust bearing 7 such that the first thrust bearing 7 may be more reliably mounted between the end stop 5 and the planet carrier 3, the first thrust bearing 7 being an annular thrust bearing may facilitate the first thrust bearing 7 to simultaneously mate with the first annular groove 33 and the second annular groove 51. It should be noted that the structure of the first thrust bearing 7 is not limited to this, for example, the first thrust bearing 7 may further include a sub-thrust bearing and the like disposed around the lead screw 2, which is not described herein.

With reference to fig. 1-2, in some embodiments of the present invention, the roller screw 100 further comprises a second thrust bearing 8, and a second thrust bearing 8 is respectively disposed between each roller 4 and the planet carrier 3. Therefore, the second thrust bearing 8 can support the roller 4 and axially position the roller 4, so that the roller 4 rotates more stably and smoothly relative to the planet carrier 3, and the reliability of the rotation of the roller 4 can be improved. Of course, the manner of improving the rotational reliability of the roller 4 may be not only to provide the second thrust bearing 8, but also to provide a plurality of balls between the roller 4 and the planet carrier 3, or to provide a plurality of wear-resistant ribs on the planet carrier 3, and the like, and the manner of improving the rotational reliability of the roller 4 is not limited and will not be described in detail herein.

According to some embodiments of the present invention, as shown in fig. 1-2, the second thrust bearings 8 are each configured as an annular thrust bearing that is sleeved over the light shaft portion 42. Therefore, the second thrust bearing 8 is sleeved on the light shaft part 42, so that the light shaft part 42 is radially limited, and the two thrust bearings 8 can be more reliably arranged between the roller 4 and the planet carrier 3.

With reference to fig. 2, in some embodiments of the present invention, the rotation hole 32 is a blind hole opened toward the roller 4. Therefore, the supporting area of the first thrust bearing 7 and the planet carrier 3 can be increased, the operational reliability and effectiveness of the first thrust bearing 7 can be improved, and when the second thrust bearing 8 is eliminated, the bottom wall of the rotation hole 32 as a blind hole can be used for supporting the roller 4 and axially limiting the roller 4.

According to some embodiments of the present invention, at least one of the first external thread 21 and the second external thread 411 has a curved profile. That is, the profile of the first external thread 21 may be curved, or the profile of the second external thread 411 may be curved, or both the profiles of the first external thread 21 and the second external thread 411 may be curved, whereby the engagement of the first external thread 21 and the second external thread 411 is more reliable, the lead of the roller 4 with respect to the axial translation of the lead screw 2 is more accurate, and the revolution of the roller 4 with respect to the lead screw 2 is smoother and smoother.

In particular, considering that the screw 2 is axially provided with a plurality of rollers 4, if the threads of the rollers 4 and the screw 2 are both flat profiles, it is possible to cause variations in the contact point, and therefore at least one of the screw 8 and the rollers 2 is curved, which makes it easy to obtain an accurate lead. In the planetary roller screw structure in the related art, the screw and the roller are in discontinuous point contact, and the roller screw 100 of the present invention has a curved surface shape due to at least one of the first external thread 21 and the second external thread 411, so that the screw 2 and the roller 4 are in continuous point contact, i.e. line contact, and the number of contact points is more, and the bearing capacity is larger under the same condition.

For example, in the example shown in fig. 4, the screw 2 may have a triangular profile with a profile angle of 90 °, and the roller 4 may have a convex profile with a profile angle of 90 °. From this, the hole 11 of nut 1 is the smooth surface that the roughness is higher, roller 4 adopts the profile structure of the profile of 90 tooth type angles, specifically speaking, the screw thread top of roller 4 is through the mould finish grinding unanimous with the hole 11 curved surface of nut 1, guarantee can laminate with the smooth curved surface of the hole 11 of nut, bear radial force, the screw thread both sides of roller 4 adopt the curved surface that the radius is r and the point contact of the screw thread shape of lead screw 2 formation continuity, final continuity contact point links up just to become line contact, bearing capacity is big, and transmit axial force through two arc surfaces.

Next, a roller screw 100 according to an embodiment of the present invention is described.

Referring to fig. 1-3, the two ends of the roller 4 are optical axis portions 42, the optical axis portions 42 are assembled with the second thrust bearing 8, the optical axis portions 42 are assembled into the rotation holes 32 of the planet carrier 3, one end of the first thrust bearing 7 is assembled with one side of the planet carrier 3 away from the roller 4, the other end of the first thrust bearing 7 is assembled with the end stop structure 5, the first annular groove 33 is formed on the opposite surface of the planet carrier 3 to the end stop structure 5, the second annular groove 51 is formed on the opposite surface of the end stop structure 5 to the planet carrier 3, and the first annular groove 33 and the second annular groove 51 are used for assembling the first thrust bearing 7. One end stop 5 is integral with the nut 1 and, when assembled, the screw 2 is screwed into the nut 1 with the rollers 4, etc. assembled, and the other end stop 5 is then connected to the nut 1 by a plurality of fasteners 6.

The opposite surfaces of the end stop structure 5 and the nut 1 can be working surfaces of a first thrust bearing 7, and the planet carrier 3 is matched with the first thrust bearing 7 and a second thrust bearing 8 to ensure smooth rotation and revolution of the roller 4. The first thrust bearing 7 and the second thrust bearing 8 can bear axial force, and the joint of the nut 1 and the roller 4 can bear radial force. Tooth's socket structure in the hole 11 of nut 1 need not to process, and the hole 11 of nut 1 can laminate with a plurality of rollers 4, and roller 4 and lead screw 2 are the external tooth structure, can save processing man-hour, reduce product cost.

Wherein, because of lead screw 2 and roller 4 are thread engagement, the pitch of first external screw thread 21 and second external screw thread 411 equals, first external screw thread 21 can be multi-start thread structure, when lead screw 2 was rotatory, roller 4 took place the rotation, it is rotatory to drive second thrust bearing 8, second thrust bearing 8 drives planet carrier 3 rotatory, planet carrier 3 drives roller 4 and takes place along the revolution of lead screw 2 to make roller 100 can make rotary motion convert linear motion into rotary motion, perhaps make linear motion convert rotary motion into.

Furthermore, the utility model discloses a workable rack of nut 1's excircle, keyway or flange face isotructure for connect other structures, with will the utility model discloses a roller lead screw 100 applies to and needs turn into rotary motion into linear motion, perhaps turns into rotary motion's occasion with linear motion. In addition, because the hole 11 of nut 1 is smooth and the zero clearance laminating of roller 4 to hole 11 smooth surface is the screw hole that the profile angle is 180 degrees promptly, so the utility model discloses a roller screw 100's helical pitch formula is differential type PRS's system helical pitch formula.

As shown in fig. 5, the electric power steering apparatus 1000 according to the embodiment of the present invention includes the motor 200, the steering apparatus assembly 300, and the roller screw 100 as described above, the motor 200 is connected to the screw 2 to drive the screw 2 to rotate, and the nut 1 is connected to the steering apparatus assembly 300.

For example, the steering gear assembly 300 may be coupled to a steering wheel of a vehicle to drive the steering wheel for steering. Specifically, the motor 200 can drive the screw rod 2 to rotate, as described above, the screw rod 2 can drive the nut 1 to displace along the axial direction of the screw rod 2, and then the nut 1 can drive the steering gear assembly 300 to rotate, so that the steering gear assembly 300 can drive the steering wheel to steer.

According to the utility model discloses electric steering gear 1000, through the application as above roller screw 100, because roller screw 100 processing is simple, can bear great radial and axial load, stability is high, good reliability for electric steering gear 1000 can realize stably, the reliable function that turns to, and then can promote driver and crew's security.

In some embodiments of the present invention, referring to fig. 5, the steering gear assembly 300 may include the sector gear 301, the nut 1 has the tooth socket 13, and the sector gear 301 may be engaged with the tooth socket 13, and thus, the nut 1 generates displacement along the axial direction of the screw rod 2 to drive the sector gear 301 to rotate, so that the steering gear assembly 300 may rotate.

In other specific examples, the roller screw 100 can be used in other applications, not limited to the electric power steering device 1000, but the present invention is only exemplified by the electric power steering device 1000, and the roller screw 100 cannot be used in the electric power steering device 1000 as a limitation of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship indicated based on the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention. Furthermore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (11)

1. A roller screw (100), comprising:

the nut (1), the inner hole (11) of the nut (1) is a unthreaded hole;

the lead screw (2), the lead screw (2) penetrates through the inner hole (11) of the nut (1), and the outer peripheral wall of the lead screw (2) is provided with a first external thread (21);

the two planet carriers (3) are positioned in the inner hole (11) of the nut (1) and are arranged at intervals along the axial direction of the screw rod (2), and each planet carrier (3) is provided with a central through hole (31) for the screw rod (2) to pass through and a plurality of rotating holes (32) arranged around the central through hole (31) at intervals;

the rollers (4) are located between the screw rod (2) and the nut (1) and between the two planet carriers (3), each roller (4) comprises a cylindrical body portion (41) and two light shaft portions (42) respectively located at two axial ends of the cylindrical body portion (41), a second external thread (411) is arranged on the outer peripheral wall of the cylindrical body portion (41), the second external thread (411) is matched with the first external thread (21) and is in contact with an inner hole (11) of the nut (1), the light shaft portions (42) on the same axial side are in one-to-one corresponding rotating fit with the rotating holes (32) on the planet carrier (3) on the corresponding side, and therefore the rollers (4) are arranged at intervals along the circumferential direction of the screw rod (2);

the two end stopping structures (5), each end stopping structure (5) is fixedly connected with the nut (1), and the two end stopping structures (5) respectively stop at one side of the planet carrier (3) far away from the roller (4).

2. Roller screw (100) according to claim 1, characterised in that at least one of the two end stops (5) is in fitting connection with the nut (1).

3. Roller screw (100) according to claim 2, characterised in that one of the two end stops (5) is a first stop (5a) and the other is a second stop (5b), the first stop (5a) being in fitting connection with the nut (1) and the second stop (5b) being in one piece with the nut (1).

4. Roller screw (100) according to claim 2, characterised in that at least one of the end stops (5) is in fitting connection with the nut (1) by means of a plurality of fasteners (6), the plurality of fasteners (6) being arranged at intervals along the circumference of the screw (2).

5. The roller screw (100) of claim 1, further comprising:

the first thrust bearing (7) is arranged between each end stop structure (5) and the planet carrier (3).

6. Roller screw (100) according to claim 5, characterised in that the planet carrier (3) has a first annular groove (33) arranged around the screw (2) on the end face facing the end stop (5), in that the end stop (5) has a second annular groove (51) on the end face facing the planet carrier (3), in that the first thrust bearing (7) is an annular thrust bearing and is fitted to the first annular groove (33) and to the second annular groove (51).

7. The roller screw (100) of claim 1, further comprising:

and the second thrust bearing (8) is arranged between each roller (4) and the planet carrier (3).

8. Roller screw (100) according to claim 7, characterized in that the second thrust bearings (8) are each configured as an annular thrust bearing which is sleeved on the light shaft portion (42).

9. Roller screw (100) according to claim 1, characterised in that the turning hole (32) is a blind hole opening towards the roller (4).

10. Roller screw (100) according to any one of claims 1 to 9, characterised in that at least one of the first external thread (21) and the second external thread (411) is of curved profile.

11. Electric power steering (1000), characterized in that it comprises an electric motor (200), a steering assembly (300) and a roller screw (100) according to any one of claims 1 to 10, said electric motor (200) being connected to said screw (2) to drive said screw (2) in rotation, said nut (1) being connected to said steering assembly (300).

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