Circulating roller screw structure and design method thereof

Abstract

The present invention provides a circulating roller screw structure and design method. Multiple rollers are installed within the support bar structure of a cage retainer, meshing with the screw threads. Two roller circulation control components are fixed to either side of the screw thread segment. The screw, rollers, cage retainer, and roller circulation control components are screwed into a nut as a whole, with the rollers meshing with the nut's internal threads. The present invention proposes a method for designing the contours of circulating roller screw components using circular arcs. This eliminates component collisions caused by thread misalignment when the rollers disengage and re-engage with the screw, significantly improving the problem of discontinuity during the roller reset motion.

Description

Technical Field

[0001] The invention relates to the field of structural design, in particular to a method for designing the contours of roller circulation control parts and nuts in a circulating roller screw by adopting arc curves. Background Art

[0002] A planetary roller screw is a precision mechanical transmission device that converts rotational motion into linear motion through threaded engagement. The screw and nut of a recirculating roller screw drive feature multi-start threads with the same tooth profile. While recirculating roller screws do not require a gear pair compared to standard planetary roller screws, the rollers experience axial movement and resetting relative to the nut, and the helix angles of the roller and nut threads differ. Therefore, recirculating roller screws have different meshing characteristics than standard planetary roller screws, and consideration of roller recirculation and resetting must be taken into account during structural design.

[0003] Traditional recirculating roller screws suffer from issues such as interference between the roller threads and the screw and nut threads when the rollers enter and exit meshing, resulting in discontinuous motion during the reset process. The present invention includes a roller recirculation control component with a reset mechanism and a corresponding nut, and proposes a design method that first disengages the rollers before performing the reset movement. Compared to traditional structures, this invention significantly improves the discontinuity problem during the roller reset movement. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a circulating roller screw structure and a design method thereof.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A circulating roller screw structure includes a screw 1, a nut 2, rollers 3, a cage retainer 4, and a roller circulation control component 5. Multiple rollers 3 are installed in the gaps of the support bar structure of the cage retainer 4. The rollers 3 are engaged with the threads of the screw 1. Two roller circulation control components 5 are fixed to either side of the threaded section of the screw 1. The screw 1, rollers 3, cage retainer 4, and roller circulation control component 5 are screwed into the nut 2 as a whole, and the rollers 3 are engaged with the internal threads of the nut 2.

[0007] Due to assembly requirements, the internal thread of the nut, the external thread of the screw and the annular tooth structure of the roller have the same pitch.

[0008] When the roller exits and re-enters engagement, the roller annular tooth structure 3-1 does not interfere with the nut internal thread structure 2-1 and the screw external thread structure 1-2; and during the cycle, the roller optical axis structure 3-2 does not interfere with the roller cycle control part circumferential motion upper control surface structure 5-2, circumferential motion lower control surface structure 5-3 and nut special-shaped groove structure 2-2, and nut internal thread structure 2-1.

[0009] The design steps of a circulating roller screw structure are:

[0010] Step 1: The horizontal distance corresponding to the meshing part between the roller, the lead screw and the nut in one cycle is x, and the horizontal distance corresponding to the reset movement of the roller is y. λ represents the helix angle of the helix part, and h represents the helix lift of the helix part. is the diameter of the screw, d2 is the contact circle diameter between the bottom of the roller and the roller circulation control part, h1 is the actual gap that should be left during assembly, h2 is the height of the section where the roller cannot contact, α is the central angle corresponding to the roller reset motion section, and P is the thread lead of the screw or nut;

[0011] in

[0012] (1)

[0013] (2)

[0014] (3)

[0015] (4)

[0016] (5)

[0017] The bottom of the roller is of diameter When the actual movement starts to reset, the actual contact point between roller 3 and roller circulation control part 5 is at an angle of 1 / 4 of the theoretical contact point. The phase of the contact point is advanced, and the actual contact point has an angle of The phase is delayed. To ensure that the translation process does not affect the thread engagement, the central angle α is expanded to α1, and α1 satisfies:

[0018] (6)

[0019] Step 2: Design roller cycle to control part contour;

[0020] Step 3: Design the inner profile of the nut.

[0021] The specific steps of step 2 for designing the roller cycle control part profile are:

[0022] Determine the contour shape of the roller cycle control part; the contour shape of the roller cycle control part is composed of six continuous tangent arc curves P S1 ~P S6 The arc curve is designed to be composed of four parts: roller meshing with the screw, roller gradually disengaging from the screw, roller reset and roller re-engaging with the screw. The meshing part between the roller and the screw is a section with a central angle of Arc P S1 The roller gradually disengages from the screw meshing part, which is two tangent arcs P S2 and P S3 , the arc P that is tangent to the meshing part between the roller and the screw S2 The arc P with the corresponding central angle γ and tangent to the roller reset part S3 The corresponding central angle is The roller reset part is an arc P with a central angle of α. S4 , the roller re-engages with the screw at part of the arc P S5 and P S6 Same as the roller gradually disengaging from the screw engagement part;

[0023] Determine the profile of the roller cycle control part screw side. The origin of the coordinate system O is located at the center of the screw axial section circle. The curve segment P S1 The starting point is on the X axis, where the curve segment P S1 Represents the roller return segment roller cycle control part screw side profile shape, curve segment P S1 The corresponding radius is r1, and the corresponding central angle is , P S1 The polar coordinate equation of is shown in formula (11);

[0024] Curve segment P S2 ~P S3 Represents the roller disengagement and nut engagement section of the roller cycle control part, the screw side profile shape, the corresponding center angle is , curve segment P S2 The corresponding radius is r2, the corresponding central angle is γ, and the corresponding central angle of the circle with r2 as the radius is , P S2 The polar coordinate equation of the curve segment P is shown in formula (12); S3 The corresponding radius is r3, and the corresponding central angle of the circle with r3 as radius is , P S3 The polar coordinate equation of is shown in formula (13); where, 、 、 , γ satisfies the following equation:

[0025] (7)

[0026] (8)

[0027] (9)

[0028] (10)

[0029] Curve segment P S4 Represents the roller, screw and nut meshing segment. The roller cycle controls the screw side profile of the part. Curve segment P S4 The corresponding radius is r4, P S4 The polar coordinate equation of is shown in formula (14);

[0030] Curve segment P S5 ~P S6 Represents the roller, screw and nut re-engagement section roller cycle control parts screw side profile shape, P S5 With curve segment P S3 The contour shape is the same, and the polar coordinate equation is shown in formula (15), P S6 With curve segment P S2 The contour shape is the same, and its polar coordinate equation is shown in Equation (16);

[0031] Curve segment P S1 With curve segment P S2 Tangent, curve segment P S2 With curve segment P S3 Tangent, curve segment P S3 With curve segment P S4 Tangent, curve segment P S4 With curve segment P S5 Tangent, curve segment P S5 With curve segment P S6 Tangent, curve segment P S6 With curve segment P S1 tangent;

[0032] The polar coordinate equation of the screw side curve of the roller circulation structure is:

[0033] (11)

[0034] (12)

[0035]

[0036] (13)

[0037] (14)

[0038]

[0039] (15)

[0040]

[0041] (16)

[0042] Among them, x 21 with y 21 P S6 The x and y coordinates of the arc segment corresponding to the center of the circle, x 21 with y 21 satisfy:

[0043] (17)

[0044] (18)

[0045] (19)

[0046] x 22 with y 22 P S2 The x and y coordinates of the arc segment corresponding to the center of the circle, x 21 with y 21 satisfy:

[0047] (20)

[0048] (twenty one)

[0049] (twenty two)

[0050] x 31 with y 31 P S5 The x and y coordinates of the arc segment corresponding to the center of the circle, x 31 with y 31 satisfy:

[0051] (twenty three)

[0052] (twenty four)

[0053] (25)

[0054] x 32 with y 32 P S3 The x and y coordinates of the arc segment corresponding to the center of the circle, x 32 with y 32 satisfy:

[0055] (26)

[0056] (27)

[0057] (28)

[0058] Determine the side profile of the roller cycle control part nut, the side profile of the roller cycle control part screw is composed of four arc curves P n1 ~ P n4 Composition, n represents the roller cycle control part nut side, where the curve segment P n1 Represents the roller return segment roller cycle control part nut side profile shape, curve segment P n2 Represents the roller, screw and nut re-engagement segment roller cycle control part nut side curve, curve segment P n3 Represents the roller, screw and nut meshing segment. The roller cycle controls the nut side profile of the part. The curve segment P n4 Represents the roller, screw and nut disengagement segment roller cycle control part nut side profile shape; curve segment P n2 With curve segment P n3 Tangent, curve segment P n3 With curve segment P n4 tangent;

[0059] Make sure the nut side profile coordinate system of the roller cycle control part coincides with the screw side profile coordinate system of the column cycle control part. n1 The starting point is on the X axis;

[0060] Curve segment P n1 The arc radius is r n1 , the corresponding central angle is α n , its polar coordinate equation is shown in formula (29);

[0061] Curve segment P n2 The arc radius is r n2 , and its corresponding central angle is , its polar coordinate equation is shown in formula (30);

[0062] Curve segment P n3 The arc radius is r n3 , its polar coordinate equation is shown in formula (31);

[0063] Curve segment P n4 The arc radius is r n2 , and its corresponding central angle is , its polar coordinate equation is shown in formula (32);

[0064] The polar coordinate equation of the nut side curve of the roller circulation structure is:

[0065] (29)

[0066]

[0067] (30)

[0068] (31)

[0069]

[0070] (32)

[0071] Among them, x n21 with y n21 P n4 The x and y coordinates of the arc segment corresponding to the center of the circle, x n21 with y n21 satisfy:

[0072] (33)

[0073] (34)

[0074] (35)

[0075] Among them, x n22 with y n22 P n2 The x and y coordinates of the arc segment corresponding to the center of the circle, x n22 with y n22 satisfy:

[0076] (36)

[0077] (37)

[0078] (38)

[0079] At this point, the structural design of the roller circulation control parts is completed;

[0080] The specific steps of step 3 for designing the inner profile of the nut are:

[0081] Determine the inner contour of the nut, which includes four arc curves P N1 ~P N4 ;

[0082] Make sure the inner contour coordinate system of the nut coincides with the contour shape coordinate system of the column cycle control part screw side. N1 The starting point is on the X axis;

[0083] Among them, the curve segment P N1 Represents the inner curve of the roller nut in the roller return section, with an arc radius of r N1 , the corresponding central angle is α N , its polar coordinate equation is shown in formula (39):

[0084] (39)

[0085] Curve segment P N2 ~ P N4 It consists of three continuous tangent arcs, the curve segment P N2 Represents the inner curve of the nut during the re-engagement of the roller, the screw and the nut, P N2 With P N1 Tangent, arc radius is r N2 , and its corresponding central angle is , its polar coordinate equation is shown in formula (40):

[0086]

[0087] (40)

[0088] Curve segment P N3 Represents the inner curve of the nut in the section where the roller, screw, and nut are engaged at the same time, with an arc radius of r N3 , its polar coordinate equation is shown in formula (41):

[0089] (41)

[0090] Curve segment P N4 The curve on the inside of the nut represents the disengagement of the roller from the screw and nut. The curve segment P N4 Contour shape and curve segment P N2 Same, P N4 With P N1 Tangent, arc radius is r N2 , and its corresponding central angle is , its polar coordinate equation is shown in formula (42):

[0091]

[0092] (42)

[0093] The polar coordinate equation of the curve inside the nut is:

[0094] Among them, xN21 with y N21 P N4 The x and y coordinates of the arc segment corresponding to the center of the circle, x N21 with y N21 satisfy:

[0095] (43)

[0096] (44)

[0097] (45)

[0098] Among them, x N22 with y N22 P N2 The x and y coordinates of the arc segment corresponding to the center of the circle, x N22 with y N22 satisfy:

[0099] (46)

[0100] (47)

[0101] (48)

[0102] The inner curve design of the nut is now completed.

[0103] The beneficial effect of the present invention is that the present invention proposes a method of using arc curves to design the contour of circulating roller screw parts, which solves the problem of parts collision caused by thread misalignment when the roller and the screw are disengaged and re-engaged, and greatly improves the problem of discontinuous motion in the roller resetting motion of the electromechanical actuator and the motor during movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0104] Figure 1 It is a schematic diagram of a circulating roller screw mechanism.

[0105] Figure 2 It is a schematic diagram of the cross-sectional position of the circulating roller screw mechanism.

[0106] Figure 3 It is a schematic diagram of the AA cross section of the circulating roller screw mechanism.

[0107] Figure 4 It is a schematic cross-sectional view of the circulating roller screw mechanism BB.

[0108] Figure 5 This is a flow chart for designing roller circulation control parts and nuts.

[0109] Figure 6 It is a schematic diagram of the axial displacement of the roller relative to the screw during the cycle.

[0110] Figure 7 It is a schematic diagram of the axial clearance of the nut structure.

[0111] Figure 8 It is a schematic diagram of the screw structure.

[0112] Figure 9 This is a diagram of a nut.

[0113] Figure 10 This is the structure diagram of the annular roller.

[0114] Figure 11 It is a schematic diagram of the squirrel cage retainer structure.

[0115] Figure 12 This is a schematic diagram of the roller circulation control parts structure Figure 1 .

[0116] Figure 13 This is a schematic diagram of the roller circulation control parts structure Figure 2 .

[0117] Figure 14 It is a curve diagram of the screw side of the roller circulation structure.

[0118] Figure 15 It is a schematic diagram of the nut side curve of the roller circulation structure.

[0119] Figure 16 It is a schematic diagram of the curve inside the nut.

[0120] Among them, 1 is the screw, 2 is the nut, 3 is the roller, 4 is the squirrel cage, 5 is the roller circulation control part, 1-1 is the push rod, 1-2 is the external thread, 2-1 is the internal thread of the nut, 2-2 is the special-shaped groove structure, 2-2a is the first arc segment, 2-2b is the second arc segment, 2-2c is the third arc segment, 2-3 is the roller circulation control part fixed surface structure, 2-4 is the roller circulation control part mounting surface structure, 3-1 is the annular tooth structure, 3-2 is the optical axis structure, 4-1 is the open groove structure in the annular layout, 4-2 is the annular layout External opening groove structure, 4-3 is an annular layout support strip structure, 5-1 is an axial motion control surface structure, 5-2 is a circumferential motion upper control surface structure, 5-3 is a circumferential motion lower control surface structure, 5-4 is an inner circular surface structure, 5-1a is a spiral surface structure, 5-1b is a spline surface structure, 5-2a is a circular motion upper control arc surface structure, 5-2b is a reset motion upper control arc surface structure, 5-3a is a circular motion lower control arc surface structure, 5-3b is a reset motion lower control arc surface structure, 5-5 is a roller circulation control part process groove, R d is the revolution direction of roller 3. DETAILED DESCRIPTION

[0121] The present invention will be further described below with reference to the accompanying drawings and examples.

[0122] This example is a design solution for a circulating roller screw. The roller circulating control component consists of two parts: an engagement section and a return section. The curve equation corresponding to the contour is established based on the radius and center of each section of the roller circulating control component.

[0123] 1 is the lead screw, 2 is the nut, 3 is the annular roller, 4 is the squirrel cage, and 5 is the roller circulation control component. The lead screw 1 consists of two sections, one of which is a push rod 1-1 and the other has an external thread 1-2. The nut 2 has a single-start internal thread and consists of four sections, one of which is an internal thread 2-1. This internal thread 2-1 is interrupted by a special-shaped groove 2-2. The axial cross-section of the special-shaped groove 2-2 consists of three consecutive tangential arcs: the first arc segment 2-2a, the second arc segment 2-2b, and the third arc segment 2-2c. The ends of the internal thread 2-1 are provided with the roller circulation control component fixing surface structure 2-3 and the roller circulation control component mounting surface structure 2-4, respectively. The roller 3 is also divided into three sections, with the middle section being the annular thread structure 3-1. Both ends of the annular thread structure 3-1 have smooth axis structures 3-2. The designed squirrel cage retainer 4 has a three-section structure: the front section is an annular inner open groove structure 4-1, the rear section is an annular outer open groove structure 4-2, and the middle section is an annular support bar structure 4-3. The designed squirrel cage retainer 4 has a three-section structure: the front section is an annular inner open groove structure 4-1, the rear section is an annular outer open groove structure 4-2, and the middle section is an annular support bar structure 4-3. The roller circulation control component 5 is a circular ring structure, and a special-shaped groove is opened on the side wall of the ring. The special-shaped groove includes an axial motion control surface structure 5-1, a circumferential motion upper control surface structure 5-2, a circumferential motion lower control surface structure 5-3 and an inner circle surface structure 5-4. The axial motion control surface structure 5-1 is the outer side wall of the special-shaped groove, the circumferential motion upper control surface structure 5-2 is the bottom surface of the special-shaped groove, the circumferential motion lower control surface structure 5-3 is the inner side wall of the special-shaped groove, the inner circle surface structure 5-4 is the side wall of the inner ring of the roller circulation control component 5, and the axial motion control surface structure 5-1 is a spiral The curved surface structure 5-1a is connected to the spline curved surface structure 5-1b, the upper control surface structure 5-2 for circumferential motion is connected to the upper control arc surface structure 5-2a for circular motion and the upper control arc surface structure 5-2b for reset motion, the lower control surface structure 5-3 for circumferential motion is connected to the lower control arc surface structure 5-3a for circular motion and the lower control arc surface structure 5-3b for reset motion, the spline curved surface structure 5-1b, the upper control arc surface structure 5-2b for reset motion and the lower control arc surface structure 5-3b for reset motion together constitute the roller reset motion control structure in the roller circulation control part 5.

[0124] The circulating roller screw parts of this embodiment include roller circulation control parts and nuts. The specific design process includes the following steps:

[0125] Step 1: Design the geometric non-interference conditions of the circulating roller screw, and the specific process is: for the circulating roller screw transmission mechanism, due to assembly requirements, the nut internal thread, the screw external thread and the roller annular tooth structure have the same pitch; when the roller exits and re-enters the engagement, the roller annular tooth structure 3-1 does not interfere with the nut internal thread structure 2-1 and the screw external thread structure 1-2; and the roller optical axis structure 3-2 does not interfere with the roller circulating control part circumferential motion upper control surface structure 5-2, circumferential motion lower control surface structure 5-3 and the nut special-shaped groove structure 2-2, and the nut internal thread structure 2-1 during the cycle.

[0126] The horizontal distance corresponding to the engagement between the roller and the screw and nut in one cycle is x, and the horizontal distance corresponding to the roller's reset movement is y. λ represents the helix angle of the helical portion, and h represents the helical lift of the helical portion. is the screw diameter, d2 is the contact circle diameter between the roller base and the roller circulation control component, h1 is the actual clearance required during assembly, and h2 is the height of the section where the roller cannot make contact. α is the central angle corresponding to the roller's return motion section, and P is the screw or nut thread lead.

[0127] in

[0128] (1)

[0129] (2)

[0130] (3)

[0131] (4)

[0132] (5)

[0133] In this embodiment , 10mm, , According to the calculation formula of each parameter, the value of each parameter is determined as follows:

[0134] (49)

[0135] (50)

[0136] (51)

[0137] (52)

[0138] (53)

[0139] The bottom of the roller is of diameter When the actual movement starts to reset, the actual contact point between roller 3 and roller circulation control part 5 is at an angle of 1 / 4 of the theoretical contact point. The phase of the contact point is advanced, and the actual contact point has an angle of The phase is delayed. To ensure that the translation process does not affect the thread engagement, the central angle α should be expanded to α1, and α1 satisfies:

[0140] (6)

[0141] Step 2: Design the contour of the roller circulation control part. The specific process is as follows: determine the contour shape of the roller circulation control part; the contour shape of the roller circulation control part is composed of six continuous tangent arc curves, and the arc curve is designed to be divided into four parts: the roller engages with the screw, the roller gradually disengages from the screw, the roller resets, and the roller re-engages with the screw. The roller and screw engagement part is a section with a central angle of Arc P S1 The roller gradually disengages from the screw meshing part, which is two tangent arcs P S2 and P S3 , the arc P that is tangent to the meshing part between the roller and the screw S2 The arc P with the corresponding central angle γ and tangent to the roller reset part S3 The corresponding central angle is The roller reset part is an arc P with a central angle of α. S4 , the roller re-engages with the screw at part of the arc P S5 and P S6 Same as the roller gradually disengaging from the screw engagement part;

[0142] The origin O of the coordinate system that determines the contour of the roller cycle control part is located at the center of the axial section of the screw. S1 The starting point is located on the X axis.

[0143] Among them, the curve segment P S1 Represents the roller return segment roller cycle control part screw side profile shape, curve segment P S1 The corresponding radius is r1, and the corresponding central angle is , P S1 The polar coordinate equation of is shown in formula (11);

[0144] Curve segment P S2 ~P S3 Represents the roller disengagement and nut engagement section of the roller cycle control part, the screw side profile shape, the corresponding center angle is , curve segment PS2 The corresponding radius is r2, the corresponding central angle is γ, and the corresponding central angle of the circle with r2 as the radius is , P S2 The polar coordinate equation of is shown in formula (12);

[0145] Curve segment P S3 The corresponding radius is r3, and the corresponding central angle of the circle with r3 as radius is , P S3 The polar coordinate equation of is shown in formula (13);

[0146] Curve segment P S4 Represents the roller, screw and nut meshing segment. The roller cycle controls the screw side profile of the part. Curve segment P S4 The corresponding radius is r4, P S4 The polar coordinate equation of is shown in formula (14);

[0147] Curve segment P S5 ~P S6 Represents the roller, screw and nut re-engagement section roller cycle control parts screw side profile shape, P S5 With curve segment P S3 The contour shape is the same, and its polar coordinate equation is shown in formula (15), P S6 With curve segment P S2 The contour shape is the same, and its polar coordinate equation is shown in Equation (16);

[0148] Curve segment P S1 With curve segment P S2 Tangent, curve segment P S2 With curve segment P S3 Tangent, curve segment P S3 With curve segment P S4 Tangent, curve segment P S4 With curve segment P S5 Tangent, curve segment P S5 With curve segment P S6 Tangent, curve segment P S6 With curve segment P S1 Tangent. Among them, φ1, φ2, φ3, and γ satisfy the following equations:

[0149] (7)

[0150] (8)

[0151] (9)

[0152] (10)

[0153] The polar coordinate equation of the screw side curve of the roller circulation structure is:

[0154] (11)

[0155] (12)

[0156]

[0157] (13)

[0158] (14)

[0159]

[0160] (15)

[0161]

[0162] (16)

[0163] Among them, x 21 with y 21 P S6 The x and y coordinates of the arc segment corresponding to the center of the circle, x 21 with y 21 satisfy:

[0164] (17)

[0165] (18)

[0166] (19)

[0167] x 22 with y 22 P S2 The x and y coordinates of the arc segment corresponding to the center of the circle, x 21 with y 21 satisfy:

[0168] (20)

[0169] (twenty one)

[0170] (twenty two)

[0171] x 31 with y 31 P S5 The x and y coordinates of the arc segment corresponding to the center of the circle, x 31 with y31 satisfy:

[0172] (twenty three)

[0173] (twenty four)

[0174] (25)

[0175] x 32 with y 32 P S3 The x and y coordinates of the arc segment corresponding to the center of the circle, x 32 with y 32 satisfy:

[0176] (26)

[0177] (27)

[0178] (28)

[0179] In this embodiment, , , , , , according to the parameter calculation formula, determine the value of each parameter , , , According to the calculation formula of the curve, the polar coordinate equation of the roller circulation structure screw side curve is determined as:

[0180] (54)

[0181]

[0182] (55)

[0183]

[0184] (56)

[0185] (57)

[0186]

[0187] (58)

[0188]

[0189] (59)

[0190] Determine the side profile of the roller cycle control part nut, the side profile of the roller cycle control part screw is composed of four arc curves P n1 ~ P n4 Composition, where the curve segment P n1 Represents the roller return segment roller cycle control part nut side profile shape, curve segment P n2 Represents the roller, screw and nut re-engagement segment roller cycle control part nut side curve, curve segment P n3 Represents the roller, screw and nut meshing segment. The roller cycle controls the nut side profile of the part. The curve segment P n4 Represents the roller, screw and nut disengagement segment roller cycle control part nut side profile shape; curve segment P n2 With curve segment P n3 Tangent, curve segment P n3 With curve segment P n4 tangent;

[0191] Make sure that the nut side profile coordinate system of the roller cycle control part coincides with the screw side profile coordinate system of the column cycle control part. n1 The starting point is on the X axis;

[0192] Curve segment P n1 The arc radius is r n1 , the corresponding central angle is α n , its polar coordinate equation is shown in formula (29);

[0193] Curve segment P n2 The arc radius is r n2 , and its corresponding central angle is , its polar coordinate equation is shown in formula (30);

[0194] Curve segment P n3 The arc radius is r n3 , its polar coordinate equation is shown in formula (31);

[0195] Curve segment P n4 The arc radius is r n2 , and its corresponding central angle is , its polar coordinate equation is shown in formula (32);

[0196] The polar coordinate equation of the nut side curve of the roller circulation structure is:

[0197] (29)

[0198]

[0199] (30)

[0200] (31)

[0201]

[0202] (32)

[0203] Among them, x n21 with y n21 P n4 The x and y coordinates of the arc segment corresponding to the center of the circle, x n21 with y n21 satisfy:

[0204] (33)

[0205] (34)

[0206] (35)

[0207] Among them, x n22 with y n22 P n2 The x and y coordinates of the arc segment corresponding to the center of the circle, x n22 with y n22 satisfy:

[0208] (36)

[0209] (37)

[0210] (38)

[0211] In this embodiment, , , , , According to the calculation formula of the curve, the polar coordinate equation of the roller circulation structure nut side curve is determined as:

[0212] (60)

[0213]

[0214] (61)

[0215] (62)

[0216]

[0217] (63)

[0218] At this point, the structural design of the roller circulation control parts is completed.

[0219] Step 3: Design the inner profile of the nut. The specific process is as follows:

[0220] Determine the inner contour of the nut, which is composed of four arc curves P N1 ~P N4 composition;

[0221] Make sure the inner contour coordinate system of the nut coincides with the contour shape coordinate system of the column cycle control part screw side. N1 The starting point is on the X axis;

[0222] Among them, the curve segment P N1 Represents the inner curve of the roller nut in the roller return section, with an arc radius of r N1 , the corresponding central angle is α N , its polar coordinate equation is shown in formula (39);

[0223] Curve segment P N2 ~ P N4 It consists of three continuous tangent arcs, the curve segment P N2 Represents the inner curve of the nut during the re-engagement of the roller, the screw and the nut, P N2 With P N1 Tangent, arc radius is r N2 , and its corresponding central angle is , its polar coordinate equation is shown in formula (40);

[0224] Curve segment P N3 Represents the inner curve of the nut in the section where the roller, screw, and nut are engaged at the same time, with an arc radius of r N3 , its polar coordinate equation is shown in formula (41);

[0225] Curve segment P N4 The curve on the inside of the nut represents the disengagement of the roller from the screw and nut. The curve segment P N4 Contour shape and curve segment P N2 Same, P N4 With P N1 Tangent, arc radius is r N2 , and its corresponding central angle is , and its polar coordinate equation is shown in formula (42).

[0226] The polar coordinate equation of the curve inside the nut is:

[0227] (39)

[0228]

[0229] (40)

[0230] (41)

[0231]

[0232] (42)

[0233] Among them, x N21 with y N21 P N4 The x and y coordinates of the arc segment corresponding to the center of the circle, x N21 with y N21 satisfy:

[0234] (43)

[0235] (44)

[0236] (45)

[0237] Among them, x N22 with y N22 P N2 The x and y coordinates of the arc segment corresponding to the center of the circle, x N22 with y N22 satisfy:

[0238] (46)

[0239] (47)

[0240] (48)

[0241] In this embodiment, , , , , According to the calculation formula of the curve, the polar coordinate equation of the curve inside the nut is determined as follows:

[0242] (64)

[0243]

[0244] (65)

[0245] (66)

[0246]

[0247] (67)

[0248] The inner curve design of the nut is now completed.

Claims

1. A design method for a circulating roller screw structure, the circulating roller screw structure includes a screw, a nut, a roller, a squirrel cage retainer and a roller circulation control part, a plurality of rollers are installed in the gap of the support bar structure of the squirrel cage retainer, and the rollers are meshed with the screw thread, and two roller circulation control parts are respectively fixed on both sides of the screw thread segment, and the screw, roller, squirrel cage retainer and roller circulation control part are screwed into the nut as a whole, and the rollers are meshed with the internal thread of the nut; the internal thread of the nut, the external thread of the screw and the annular tooth structure of the roller have the same pitch; when the roller exits and re-enters the meshing, the annular tooth structure of the roller does not interfere with the internal thread structure of the nut and the external thread structure of the screw; and the optical axis structure of the roller does not interfere with the circumferential motion upper control surface structure, the circumferential motion lower control surface structure and the nut special-shaped groove structure and the internal thread structure of the nut during the cycle; it is characterized in that The steps include: Step 1: The horizontal distance corresponding to the meshing portion of the roller with the screw and nut in one cycle is x, and the horizontal distance corresponding to the roller's reset motion is y. λ represents the helix angle of the helix portion, h represents the helix lift of the helix portion, d1 is the screw diameter, d2 is the contact circle diameter between the roller bottom and the roller cycle control part, h1 is the actual gap that should be left during assembly, h2 is the height of the roller's non-contact section, α is the central angle corresponding to the roller's reset motion section, and P is the thread lead of the screw or nut; in, h1=h+2h2 (4) The bottom of the roller is a circle with a diameter of d2. When the actual movement starts to reset, the actual contact point between the roller and the roller circulation control part is at an angle of The phase of the contact point is advanced, and the actual contact point has an angle of The phase is delayed. To ensure that the translation process does not affect the thread engagement, the central angle α is expanded to α1, and α1 satisfies: Step 2: Design roller cycle to control part contour; Step 3: Design the inner profile of the nut.

2. The design method of a circulating roller screw structure according to claim 1, characterized in that: The specific steps of step 2 for designing the roller cycle control part profile are: Determine the contour shape of the roller cycle control part; the contour shape of the roller cycle control part is composed of six continuous tangent arc curves P S1 ~P S6 The arc curve is designed to be composed of four parts: roller meshing with the screw, roller gradually disengaging from the screw, roller reset and roller re-engaging with the screw. The meshing part between the roller and the screw is a section with a central angle of Arc P S1 The roller gradually disengages from the screw meshing part, which is two tangent arcs P S2 and P S3 , the arc P that is tangent to the meshing part between the roller and the screw S2 The arc P with the corresponding central angle γ and tangent to the roller reset part S3 The corresponding central angle is The roller reset part is an arc P with a central angle of α S4 , the roller re-engages with the screw at part of the arc P S5 and P S6 Same as the roller gradually disengaging from the screw engagement part; Determine the profile of the roller cycle control part screw side. The origin of the coordinate system O is located at the center of the screw axial section circle. The curve segment P S1 The starting point is on the X axis, where the curve segment P S1 Represents the roller return segment roller cycle control part screw side profile shape, curve segment P S1 The corresponding radius is r1, the corresponding central angle is α1, P S1 The polar coordinate equation of is shown in formula (11); Curve segment P S2 ~P S3 Represents the roller disengagement and nut engagement section of the roller cycle control part, the screw side profile shape, the corresponding center angle is Curve segment P S2 The corresponding radius is r2, the corresponding central angle is γ, and the corresponding central angle of the circle with r2 as the radius is P S2 The polar coordinate equation of the curve segment P is shown in formula (12); S3 The corresponding radius is r3, and the corresponding central angle of the circle with r3 as radius is P S3 The polar coordinate equation of is shown in formula (13); where, γ satisfies the following equation: Curve segment P S4 Represents the roller, screw and nut meshing segment. The roller cycle controls the screw side profile of the part. Curve segment P S4 The corresponding radius is r4, P S4 The polar coordinate equation of is shown in formula (14); Curve segment P S5 ~P S6 Represents the roller, screw and nut re-engagement section roller cycle control parts screw side profile shape, P S5 With curve segment P S3 The contour shape is the same, and the polar coordinate equation is shown in formula (15), P S6 With curve segment P S2 The contour shape is the same, and its polar coordinate equation is shown in Equation (16); Curve segment P S1 With curve segment P S2 Tangent, curve segment P S2 With curve segment P S3 Tangent, curve segment P S3 With curve segment P S4 Tangent, curve segment P S4 With curve segment P S5 Tangent, curve segment P S5 With curve segment P S6 Tangent, curve segment P S6 With curve segment P S1 tangent; The polar coordinate equation of the screw side curve of the roller circulation structure is: R(θ)=r1,θ∈(0,α1) (11) Among them, x 21 with y 21 P S6 The x and y coordinates of the arc segment corresponding to the center of the circle, x 21 with y 21 satisfy: x 21 =(r1-r2)cosθ 21 (17) and 21 =(r1-r2)sinθ 21 (18) i 21 =0 (19) x 22 with y 22 P S2 The x and y coordinates of the arc segment corresponding to the center of the circle, x 21 with y 21 satisfy: x 22 =(r1-r2)cosθ 22 (20) and 22 =(r1-r2)sinθ 22 (21) i 22 =α1 (22) x 31 with y 31 P S5 The x and y coordinates of the arc segment corresponding to the center of the circle, x 31 with y 31 satisfy: x 31 =(r3+r4)cosθ 31 (23) y 31 =(r3+r4)sinθ 31 (24) x 32 with y 32 P S3 The x and y coordinates of the arc segment corresponding to the center of the circle, x 32 with y 32 satisfy: x 32 =(r3+r4)cosθ 32 (26) y 32 =(r3+r4)sinθ 32 (27) Determine the side profile of the roller cycle control part nut, the side profile of the roller cycle control part screw is composed of four arc curves P n1 ~P n4 Composition, n represents the roller cycle control part nut side, where the curve segment P n1 Represents the roller return segment roller cycle control part nut side profile shape, curve segment P n2 Represents the roller, screw and nut re-engagement segment roller cycle control part nut side curve, curve segment P n3 Represents the roller, screw and nut meshing segment. The roller cycle controls the nut side profile of the part. The curve segment P n4 Represents the roller, screw and nut disengagement segment roller cycle control part nut side profile shape; curve segment P n2 With curve segment P n3 Tangent, curve segment P n3 With curve segment P n4 tangent; Make sure the nut side profile coordinate system of the roller cycle control part coincides with the screw side profile coordinate system of the column cycle control part. n1 The starting point is on the X axis; Curve segment P n1 The arc radius is r n1 , the corresponding central angle is α n , its polar coordinate equation is shown in formula (29); Curve segment P n2 The arc radius is r n2 , and its corresponding central angle is Its polar coordinate equation is shown in formula (30); Curve segment P n3 The arc radius is r n3 , its polar coordinate equation is shown in formula (31); Curve segment P n4 The arc radius is r n2 , and its corresponding central angle is Its polar coordinate equation is shown in formula (32); The polar coordinate equation of the nut side curve of the roller circulation structure is: R(θ)=r n1 ,θ∈(0,α n ) (29) Among them, x n21 with y n21 P n4 The x and y coordinates of the arc segment corresponding to the center of the circle, x n21 with y n21 satisfy: x n21 =(r n1 -r n2 )cosθ n21 (33) y n21 =(r n1 -r n2 )sinθ n21 (34) i n21 =0 (35) Among them, x n22 with y n22 P n2 The x and y coordinates of the arc segment corresponding to the center of the circle, x n22 with y n22 satisfy: x n22 =(r n1 -r n2 )cosθ n22 (36) y n22 =(r n1 -r n2 )sinθ n22 (37) i n22 =a n (38) At this point, the structural design of the roller circulation control parts is completed.

3. The design method of a circulating roller screw structure according to claim 1, characterized in that: The specific steps of step 3 for designing the inner profile of the nut are: Determine the inner contour of the nut, which includes four arc curves P N1 ~P N4 ; Make sure the inner contour coordinate system of the nut coincides with the contour shape coordinate system of the column cycle control part screw side. N1 The starting point is on the X axis; Among them, the curve segment P N1 Represents the inner curve of the roller nut in the roller return section, with an arc radius of r N1 , the corresponding central angle is α N , its polar coordinate equation is shown in formula (39): R(θ)=r N1 ,θ∈(0,α N ) (39) Curve segment P N2 ~P N4 It consists of three continuous tangent arcs, the curve segment P N2 Represents the inner curve of the nut during the re-engagement of the roller, the screw and the nut, P N2 With P N1 Tangent, arc radius is r N2 , and its corresponding central angle is , its polar coordinate equation is shown in formula (40): Curve segment P N3 Represents the inner curve of the nut in the section where the roller, screw, and nut are engaged at the same time, with an arc radius of r N3 , its polar coordinate equation is shown in formula (41): Curve segment P N4 The curve on the inside of the nut represents the disengagement of the roller from the screw and nut. The curve segment P N4 Contour shape and curve segment P N2 Same, P N4 With P N1 Tangent, arc radius is r N2 , and its corresponding central angle is Its polar coordinate equation is shown in formula (42): The polar coordinate equation of the curve inside the nut is: Among them, x N21 with y N21 P N4 The x and y coordinates of the arc segment corresponding to the center of the circle, x N21 with y N21 satisfy: x N21 =(r N1 -r N2 )cosθ N21 (43) y N21 =(r N1 -r N2 )sinθ N21 (44) i N21 =0 (45) Among them, x N22 with y N22 P N2 The x and y coordinates of the arc segment corresponding to the center of the circle, x N22 with y N22 satisfy: x N22 =(r N1 -r N2 )cosθ N22 (46) y N22 =(r N1 -r N2 )sinθ N22 (47) i N22 =a N (48) The inner curve design of the nut is now completed.

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