CN212377114U

CN212377114U - Linear retainer and ball spline device

Info

Publication number: CN212377114U
Application number: CN202020575272.5U
Authority: CN
Inventors: 杨升; 吴永利
Original assignee: Shanghai Laien Machine Tool Parts Corp
Current assignee: Shanghai Laien Machine Tool Parts Corp
Priority date: 2020-04-17
Filing date: 2020-04-17
Publication date: 2021-01-19
Anticipated expiration: 2030-04-17

Abstract

The utility model provides a linear retainer and a ball spline device, wherein the linear retainer comprises a tubular main body, and the outer wall of the tubular main body comprises a plurality of ball circulation tracks; each ball circulating track comprises a linear channel section, two climbing platform sections and two arc-shaped rotary sections; the at least one climbing step section comprises a first transition section connected with the second end of the arc-shaped turning section, a second transition section connected with the linear channel section and an inclined section positioned between the first transition section and the second transition section, and the impact of the ball when moving between the inclined section and the arc-shaped turning section is reduced through the first transition section, and the impact of the ball when moving between the inclined section and the linear channel section is reduced through the second transition section. The embodiment of the utility model provides a can make the circulation operation process of ball become gentle, promote the smooth and easy nature of ball operation in ball circulation track.

Description

Linear retainer and ball spline device

Technical Field

The embodiment of the utility model provides a ball and ball spline field are related to, more specifically say, relate to a straight line keeps ware and ball spline device.

Background

The linear motion device is widely applied to the industrial automation industry, and the ball spline pair gradually forms common application along with the improvement of requirements on equipment precision, operation efficiency, silence, service life and the like. The ball spline can simultaneously perform smooth linear motion and rotational torque transmission by means of the balls and the precisely ground rolling grooves. Due to the adoption of the contact angle design, the ball spline can greatly improve the load performance besides high sensitivity, and is suitable for occasions with large vibration impact, high positioning precision requirement, high-speed movement performance requirement and low noise. By adjusting the prepressing in the application, the ball spline can meet the characteristics of zero clearance, higher torsional rigidity and moment rigidity.

Currently, the ball spline pair has a plurality of circulation structure types such as a slider type, an end cap type, a retainer type, and the like. As shown in fig. 1, is a schematic structural view of a linear retainer of a conventional ball spline device. The ball circulation track on the tubular body 1 of the linear cage consists of a linear channel section 12,

climbing platform sections

13, 16, arc-

shaped turning sections

14, 17, and a linear channel section 15. As shown in fig. 2, the

climbing stages

13 and 16 are respectively used for connecting the linear channel section 12 and the arc-shaped

revolving sections

14 and 17, and the transition at the joint is sharp and cannot be attached to the balls, so that the smoothness of the passing balls is affected, the instantaneous impact effect is generated in the running process of the balls, and the early wear is caused in the high-speed reciprocating running process.

Also, in the linear holder described above, the height Δ h1 of the

climbing stage phases

13, 16 is fixed, with both ends of the arcuate turnaround sections 14, 17 (e.g., where the arcuate turnaround section 14 joins the climbing stage phase 13, and where the arcuate turnaround section 14 joins the linear channel section 15) at the same radial height. The step height that the ball needs to climb in climbing platform stage 13 department, the resistance that meets is big, and the atress of local position is big, reflects on the complete machine is pre-pressed, and the average value of straight line frictional force is bigger. Not only influences the smoothness of ball operation, influences straight line operation feel and whole quick-witted noise decibel value promptly, and calorific capacity is higher when high-speed operation moreover, can cause plastic material to soften and lose efficacy under the extreme condition.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides a to above-mentioned ball spline device because of the ball circulation track of sharp retainer highly big because of climbing at the platform stage, influence ball moving smoothness nature, the higher problem of calorific capacity, provide a sharp retainer and ball spline device.

The technical solution of the present invention to solve the above technical problems is to provide a linear retainer, which comprises a tubular main body, wherein the outer wall of the tubular main body comprises a plurality of ball circulation tracks; each ball circulation track comprises a linear channel section, two climbing platform stages and two arc-shaped rotary sections, wherein the linear channel section and the linear channel section are respectively arranged along the axial direction of the tubular main body, two ends of the linear channel section are respectively connected with first ends of the two arc-shaped rotary sections, and two ends of the linear channel section are respectively connected with second ends of the two arc-shaped rotary sections through the climbing platform stages;

at least one of the climbing step sections comprises a first transition section connected with the second end of the arc-shaped turning section, a second transition section connected with the linear channel section and an inclined section positioned between the first transition section and the second transition section, and the impact of the ball when moving between the inclined section and the arc-shaped turning section is reduced through the first transition section, and the impact of the ball when moving between the inclined section and the linear channel section is reduced through the second transition section.

Preferably, the central line of the climbing stage is located on the longitudinal section of the tubular main body, the central line of the first transition section is a convex arc line, and the central line of the second transition section is a concave arc line.

Preferably, the included angle between the center line of the inclined section and the center line of the arc-shaped revolving section is 135-160 degrees, and the transition radius of the convex arc is 0.4-0.8 times of the radius of the ball.

Preferably, the included angle between the center line of the inclined section and the center line of the arc-shaped revolving section is 135-160 degrees, and the transition radius of the concave arc line is 1.2-2 times of the radius of the ball.

Preferably, the center line of the climbing stage is located on the longitudinal section of the tubular main body, the center lines of the first transition section and the second transition section are respectively straight lines, and the included angles between the center lines of the first transition section and the second transition section and the central axis of the tubular main body are respectively smaller than the included angles between the center line of the inclined section and the central axis of the tubular main body.

Preferably, the height difference between the centerline of the arcuate return segment and the central axis of the tubular body decreases progressively from the first end to the second end; the height difference between the second end of the arc-shaped rotary section and the linear channel section is 0.7-1 times of the height difference between the linear channel section and the linear channel section.

Preferably, the central line of the arc-shaped revolving section is an arc with a central angle equal to 180 degrees;

or the central lines of the arc-shaped rotating sections are respectively formed by connecting a plurality of arcs with central angles smaller than 180 degrees.

The embodiment of the utility model provides a ball spline device is still provided, including integral key shaft, spline nut, ball and the straight line holder as above; the ball is located in the ball circulation track of the tubular main body, the spline nut is sleeved outside the tubular main body, the spline shaft is inserted in the tubular main body, and the spline shaft groove on the spline shaft corresponds to the linear channel section of the tubular main body in position.

Preferably, the spline nut is provided with an arc transition structure at a position corresponding to the first transition section, and the radius of a transition arc of the arc transition structure is 1.1-1.9 times of the radius of the ball.

Preferably, the clearance between the inner wall of the tubular main body of the linear retainer and the outer wall of the spline shaft is 0.1-0.3 mm.

The utility model discloses a straight line keeps ware and ball spline device increases first changeover portion and second changeover portion respectively through the both ends at orbital platform stage that climbs of ball circulation for ball circulation process becomes mild, can not cause the striking contact, and the noise reduction reduces the running resistance, promotes the smooth and easy nature of ball operation in ball circulation track. The embodiment of the utility model provides a still through reducing the difference in height at the platform stage that climbs for ball circulation process is gentler, reduces the frictional force at the platform stage that climbs, effectively reduces local calorific capacity, avoids the straight line to keep ware at the high-speed reciprocal operation in-process softening deformation of ball, reduces the probability of inefficacy.

Drawings

FIG. 1 is a schematic view of a linear retainer in a prior art ball spline apparatus;

FIG. 2 is a schematic cross-sectional view of the linear retainer of FIG. 1;

fig. 3 is a schematic view of a linear retainer provided by an embodiment of the present invention;

fig. 4 is a schematic axial sectional structure view of a linear retainer provided in an embodiment of the present invention;

fig. 5 is a schematic view of a radial cross-section structure of a linear retainer according to an embodiment of the present invention;

fig. 6 is a schematic view of a linear retainer provided in accordance with another embodiment of the present invention;

fig. 7 is a schematic structural diagram of a ball spline device according to an embodiment of the present invention;

fig. 8 is a schematic sectional view of a ball spline device according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in fig. 3 and 4, the present invention provides a structural schematic diagram of a linear retainer, which can be applied to a ball spline device and provides a circulating raceway for balls. The linear retainer of this embodiment comprises a tubular body 3, the tubular body 3 comprising a cylindrical surface and a splined shaft bore enclosed by the cylindrical surface. The outer wall of the tubular body 3 (i.e. the outer wall of the cylindrical surface) comprises a plurality of ball circulation tracks, and each ball circulation track comprises a linear channel section 302, a linear channel section 307, two climbing stage sections and two arc-

shaped turning sections

306, 311.

The linear channel section 302 and the linear channel section 307 are respectively arranged along the axial direction of the tubular main body 3, and two ends of the linear channel section 307 are respectively connected with first ends of the two arc-shaped

revolving sections

306 and 311. The bottom of the straight channel section 302 has a straight hole (arranged in the axial direction of the tubular body 3) communicating with the spline shaft hole so that when the balls run into the straight channel section 302, at least a part of the balls are embedded in the straight hole and protrude into the spline shaft hole. The two ends of the linear channel section 302 are respectively connected with the second ends of the two arc-shaped

revolving sections

306 and 311 through the climbing stage, that is, in each ball circulating track, the linear channel section 302, the linear channel section 307, the two climbing stage and the two arc-shaped

revolving sections

306 and 311 are connected to form a closed annular channel, so that the balls can circularly roll in the ball circulating track.

In the present embodiment, the centerline of the climbing stage between the linear channel section 302 and the arc-shaped turning section 306 is located on a longitudinal section (i.e. a section containing the central axis of the tubular body 3) of the tubular body 3, the climbing stage includes a first transition section 305, a second transition section 303 and an inclined section 304, the climbing stage is connected to the second end of the arc-shaped turning section 306 through the first transition section 305, and is connected to the linear channel section 302 through the second transition section 303, and the inclined section 304 is located between the first transition section 305 and the second transition section 303 and is connected to the first transition section 305 and the second transition section 303 respectively. The first transition section 305 reduces the impact of the ball as it travels between the sloped section 304 and the arcuate turnaround section 306, and the second transition section 303 reduces the impact of the ball as it travels between the sloped section 304 and the linear channel section 302.

Similarly, the climbing stage between the linear channel section 302 and the arc-shaped turning section 311 includes a first transition section 310, a second transition section 308 and an inclined section 309, the climbing stage is connected to the second end of the arc-shaped turning section 311 through the first transition section 310 and connected to the linear channel section 302 through the second transition section 308, and the inclined section 309 is located between the first transition section 310 and the second transition section 308 and connected to the first transition section 310 and the second transition section 308 respectively. The first transition section 310 reduces the impact of the balls as they move between the incline section 309 and the arcuate return section 311, and the second transition section 308 reduces the impact of the balls as they move between the incline section 309 and the linear channel section 302.

In practice, only one of the two climbing stage stages may have the first transition section and the second transition section (the other climbing stage may adopt the existing structure), so as to reduce the impact of the ball when running at the transition. Of course, for smooth running of the balls in the entire ball circulation track, it is preferable that the two climbing steps include a first transition section and a second transition section, respectively.

The linear retainer is optimally designed through the ball circulating track, so that the circulating track curve of the balls is changed under the condition of not changing the overall dimension, the impact of the balls in the operation process is reduced, the linear friction force after pre-pressing is reduced, the heat productivity in the high-speed reciprocating operation process is reduced, and the durability and the linear smoothness of the retainer are improved. Specifically, this straight line keeps ware through increasing first changeover portion and second changeover portion respectively at the orbital both ends of at least one platform stage of climbing of ball circulation for ball circulation operation process becomes gentle, can not cause the striking contact, and the noise reduction reduces the running resistance, promotes the smooth and easy nature of ball operation in ball circulation track.

The stage of climbing between the linear channel section 302 and the arc-shaped turning section 306 may have the same structure as the stage of climbing between the linear channel section 302 and the arc-shaped turning section 311. Two ramp-up stages are described below, taking the ramp-up stage between the linear channel segment 302 and the arcuate turnaround segment 306 as an example.

In an embodiment of the present invention, the center line of the first transition section 305 (the center line is the path of the center of the ball at the first transition section 305) is a convex arc (i.e. convex toward the direction away from the central axis of the tubular main body 3), the center line of the second transition section 303 (the center line is the path of the center of the ball at the second transition section 303) is a concave arc (i.e. concave toward the direction of the central axis of the tubular main body 3), and the center line of the inclined section 304 (the center line is the path of the center of the ball at the inclined section 304) is a straight line. Compared with the traditional structure, the two sides of the inclined section 304 are respectively in arc transition, so that the balls can roll along the arc surface all the time, and impact contact cannot be caused.

To further improve the smoothness of the ball operation, the angle β between the center line of the inclined section 304 and the central axis of the tubular body 3 is 135-160 °, and accordingly, the transition radius of the convex arc (i.e. the center line of the first transition section 305) is 0.4-0.8 times the radius of the ball. Similarly, the transition radius of the concave arc line (i.e. the central line of the second transition section 303) is 1.2-2 times the radius of the ball. Through the structure, the contact area of the ball in the stage of passing through the climbing platform is greatly increased, so that the rolling is smoother.

In addition, the center lines of the first transition section 305 and the second transition section 303 may also be straight lines, and the included angles between the center lines of the first transition section 305 and the second transition section 303 and the central axis of the tubular main body 3 are smaller than the included angles between the center line of the inclined section 304 and the central axis of the tubular main body 3. The structure equivalently extends the length of the stage of the climbing platform, slows down the impact action on the local part of the step when the ball runs, and improves the durability of the linear retainer.

As shown in connection with fig. 5, in order to reduce the height of the climbing stage, i.e. the height difference (i.e. the distance difference from the central axis of the tubular body 3) between the top of the climbing stage (i.e. the junction of the first transition section 305 with the arc-shaped turnaround section 306) and the bottom of the climbing stage (i.e. the junction of the second transition section 303 with the straight channel section 302), the distance between the centerline of the arc-shaped turning segment 306 and the central axis of the tubular body 3 can be made to gradually decrease from the first end b (i.e. the first end of the arc-shaped turning segment 306) to the second end a (i.e. the second end of the arc-shaped turning segment 306), so as to divide the height difference h between the straight channel section 302 and the straight channel section 307 (which is the difference between the distances from the central axes of the two and the tubular body 3 respectively) into two parts, i.e. the height difference ah 1 between the second end a of the arcuate turnaround section 306 and the straight channel section 302, and a height difference Δ h2 between the first end b and the second end a of the arcuate turnaround section 306. Specifically, to avoid too thin a wall thickness of the linear retainer, the height difference Δ h1 between the second end of the arcuate turn section 306 and the linear channel section 302 is 0.7-1 times the height difference h between the linear channel section 302 and the linear channel section 307, and to avoid the height difference Δ h2 between the first end b and the second end a of the arcuate turn section 306 being too large, which affects the structural strength of the outer sidewall portion of the arcuate turn section 306 (i.e., the portion corresponding to the cross-hatched area C in fig. 4).

In the above-described linear holder, the center lines of the arc-shaped

turning sections

306, 311 are arcs having a central angle equal to 180 ° for the convenience of processing and the structural strength.

In addition, as shown in fig. 6, in another embodiment of the present invention, when the outer diameter of the ball spline device is large, the center line of the arc-shaped turning section 306 can be formed by connecting a plurality of

arcs

3061, 3062, and 3063 with central angles smaller than 180 degrees, respectively. Of course, the arcuate turnaround section 311 may also be of the same construction.

Fig. 7-8 are schematic diagrams of a ball spline device according to an embodiment of the present invention, which can be engaged with a ball screw shaft to realize linear driving. The ball spline device of the present embodiment includes the spline shaft 7, the spline nut 6, the balls 8, and the linear retainer as described above. In the ball spline device, the balls 8 are located in the ball circulation path of the tubular body 3 of the linear retainer, the spline nut 6 has the same axial dimension as the tubular body 3, the spline nut 6 is fitted over the tubular body 3, and both ends are sealed with the linear portion seal ring 62 and the hole with the elastic seal ring 63. The spline shaft 7 has a spline shaft groove 71 thereon, and the spline shaft groove 71 corresponds to the position of the linear channel section 32 of the tubular body 3 when the spline shaft 7 is inserted into the tubular body 3. The ball screw shaft 9 is inserted into the spline shaft 7, and the end is sealed by a screw seal 74.

The spline nut 6 has an arc transition structure at a position (i.e., position c in fig. 8) corresponding to the

first transition sections

305 and 310, and the radius of the transition arc of the arc transition structure is 1.1 to 1.9 times of the radius of the ball, and the arc transition structure can be matched with the

first transition sections

305 and 310 on the tubular main body 3, so that the contact area with the ball 8 is increased, and the smooth passing of the ball is ensured.

Further, in the above ball spline device, the inner diameter of the tubular body 3 of the linear retainer is as small as possible while satisfying structural and process requirements, and specifically, the clearance between the inner wall of the tubular body 3 and the outer wall of the spline shaft 7 may be 0.1 to 0.3 mm.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A linear retainer comprising a tubular body and an outer wall of the tubular body comprising a plurality of ball circulation tracks; each ball circulation track comprises a linear channel section, two climbing platform stages and two arc-shaped rotary sections, wherein the linear channel section and the linear channel section are respectively arranged along the axial direction of the tubular main body, two ends of the linear channel section are respectively connected with first ends of the two arc-shaped rotary sections, and two ends of the linear channel section are respectively connected with second ends of the two arc-shaped rotary sections through the climbing platform stages;

2. The linear retainer of claim 1, wherein a centerline of the stage of climbing is located in a longitudinal cross-section of the tubular body, the centerline of the first transition segment being a convex arc and the centerline of the second transition segment being a concave arc.

3. The linear retainer of claim 2, wherein the angle between the centerline of the inclined segment and the centerline of the arc-shaped turning segment is 135-160 °, and the radius of the transition of the convex arc is 0.4-0.8 times the radius of the ball.

4. The linear retainer of claim 2, wherein the included angle between the centerline of the inclined section and the centerline of the arc-shaped revolving section is 135-160 °, and the transition radius of the concave arc line is 1.2-2 times the radius of the ball.

5. The linear retainer of claim 1, wherein a centerline of the climbing stage is located in a longitudinal section of the tubular body, the centerlines of the first transition section and the second transition section are each linear, and an included angle between the centerlines of the first transition section and the second transition section and a central axis of the tubular body is respectively smaller than an included angle between the centerline of the inclined section and the central axis of the tubular body.

6. The linear retainer of any one of claims 1-5, wherein a height difference between a centerline of the arcuate turnaround section and a central axis of the tubular body decreases from the first end to the second end; the height difference between the second end of the arc-shaped rotary section and the linear channel section is 0.7-1 times of the height difference between the linear channel section and the linear channel section.

7. The linear retainer of claim 6, wherein the centerline of the arcuate turnaround section is an arc having a central angle equal to 180 °;

8. A ball spline device comprising a spline shaft, a spline nut, balls, and the linear retainer of any one of claims 1 to 7; the ball is located in the ball circulation track of the tubular main body, the spline nut is sleeved outside the tubular main body, the spline shaft is inserted in the tubular main body, and the spline shaft groove on the spline shaft corresponds to the linear channel section of the tubular main body in position.

9. The ball spline device according to claim 8, wherein a circular arc transition structure is arranged on the spline nut at a position corresponding to the first transition section, and the radius of a transition circular arc of the circular arc transition structure is 1.1-1.9 times of the radius of the ball.

10. The ball spline device of claim 8, wherein the clearance between the inner wall of the tubular body of the linear retainer and the outer wall of the spline shaft is 0.1-0.3 mm.