CN217301484U - Ball spline structure and robot - Google Patents

Abstract

The utility model discloses a ball screw spline structure and robot, this ball screw spline structure includes first axis body and second axis body, first axis body is the hollow shaft, the second axis body sets up in first axis body, one of them is the ball screw axle of first axis body and second axis body, another is the integral key shaft; the structure combines the independent ball screw shaft and the spline shaft into a coaxial structure, can realize the linear motion and the rotation of a load, and reduces the installation difficulty and the processing cost.

Description

Ball spline structure and robot

Technical Field

The utility model relates to a robot and transmission technical field, in particular to ball spline structure, a robot.

Background

The ball screw is the most commonly used transmission element on tool machinery and precision machinery, and has the main function of converting rotary motion into linear motion or converting torque into axial repeated acting force, and has the characteristics of high precision, reversibility and high efficiency. Ball screws are widely used in various industrial equipments and precision instruments due to their small frictional resistance. For example, in the existing SCARA robot (robot arm for assembly), the end of the robot uses a ball screw spline to realize two degrees of freedom of movement and rotation. The ball spline is actually a ball screw with an infinite lead.

For making the hot end of SCARA machine realize removing and two degrees of freedom of rotation, the most ball screw spline structures that adopt of current SCARA robot end structure, perhaps adopt ball screw and independent spline shaft parallel placement, realize end and remove and two degrees of freedom of rotation. However, the screw threads and the spline grooves are simultaneously machined on the outer surface of the same shaft, so that the machining difficulty is high, and the production cost is high; the ball screw and the independent spline shaft are arranged in parallel, so that the assembly difficulty is high, the requirement on workers is high, and the production cost is high.

It is seen that improvements and enhancements to the prior art are needed.

SUMMERY OF THE UTILITY MODEL

In view of the foregoing deficiencies of the prior art, it is an object of the present invention to provide a ball screw spline structure and a robot, which solve the above mentioned technical problems in the prior art.

In order to achieve the purpose, the utility model adopts the following technical proposal:

the utility model provides an aspect provides a ball spline structure, include:

the first shaft body is set as a hollow shaft;

the second shaft body is arranged in the first shaft body;

one of the first shaft body and the second shaft body is a ball screw shaft, and the other is a spline shaft.

The ball screw spline structure further comprises a connecting structure, the first shaft body and the second shaft body are connected through the connecting structure, and the connecting structure can transmit between the first shaft body and the second shaft body, so that the first shaft body and the second shaft body can be linked.

In the ball screw spline structure, the first shaft body is a ball screw shaft, the second shaft body is a ball spline shaft, the connecting structure is a spline nut, and the connecting structure is fixed at the first end of the first shaft body and connected with the second shaft body through a spline pair.

The ball screw spline structure further comprises a connecting structure, the first shaft body and the second shaft body are connected through the connecting structure, the connecting structure is arranged in the first shaft body, and the first shaft body and the second shaft body can rotate relatively and/or move linearly relatively through the connecting structure.

In the ball screw spline structure, a first through hole and a second through hole are respectively arranged in the first shaft body along the axial direction, the aperture of the first through hole is different from that of the second through hole, at least one end of the first through hole is connected with one of the second through holes, and the connecting structure is arranged in the second through hole.

In the ball screw spline structure, two ends of the first through hole are respectively communicated with one second through hole, and the aperture of each second through hole is larger than that of the corresponding first through hole;

the connecting structure comprises a third shaft body and two roller bearings, wherein the third shaft body is a hollow shaft, is arranged in the first shaft body, is sleeved on the second shaft body, and is connected with the second shaft body through a spline pair; and the two roller bearings are respectively sleeved on the third shaft body, are rotatably connected with the third shaft body and are respectively in interference fit with the two second through holes.

In the ball screw spline structure, the second shaft body is a spline shaft, the third shaft body comprises a fixed end and a free end, the outer diameter of the fixed end is larger than that of the free end, the inner diameter of the fixed end is smaller than that of the free end, spline grooves distributed along the axis of the fixed end are formed in the fixed end, the third shaft body is connected with the second shaft body through the spline grooves, and the roller bearing is connected to the same side of the fixed end.

In the ball screw spline structure, a second end of the third shaft body protrudes out of the first shaft body and the second shaft body.

In the ball screw spline structure, one end of the first through hole is communicated with the second through hole, the aperture of the second through hole is smaller than that of the first through hole, the first shaft body is a ball screw shaft, the second shaft body is a spline shaft, the connecting structure is a spline groove, the spline groove extends axially along the inner wall of the second through hole, and the first shaft body is connected with the second shaft body in a matched mode through a spline pair.

In the ball screw spline structure, one end of the first through hole is communicated with one second through hole, the aperture of the first through hole is smaller than that of the second through hole, and the connecting structure is nested on the second shaft body and is rotationally connected with the second shaft body.

In the ball screw spline structure, the first shaft body is a ball spline shaft, the second shaft body is a ball screw shaft, and the connecting structure is a screw nut.

In the ball screw spline structure, the second end of the first shaft body protrudes out of the second shaft body.

The ball screw spline structure is characterized by further comprising a connecting piece, wherein the connecting piece is sleeved on the first shaft body and can drive the first shaft body to move linearly or spirally along the second shaft body.

In the ball screw spline structure, the connecting piece is a screw nut or a spline nut.

The utility model discloses another aspect still provides a robot, include:

the robot arm is provided with a robot arm,

the ball screw spline structure of any one of the above, the ball screw spline structure being provided at a joint of the robot arm;

and the driving structure drives the ball screw spline structure to move.

Has the advantages that:

the utility model provides a ball spline structure is through setting up spline and lead screw thread on first axis body and second axis body respectively to set up the first axis body into hollow structure, cup joint on the second axis body, simplified ball spline structure's manufacturing and mounting process, reduced its processing cost and the installation degree of difficulty.

The utility model also provides a robot adopts foretell ball spline structure, can realize terminal removal and two degrees of freedom of rotation, for prior art, has not only reduced manufacturing cost, and has reduced the installation degree of difficulty.

Drawings

Fig. 1 is an axial cross-sectional view of the ball screw spline structure in one embodiment.

Fig. 2 is an axial cross-sectional view of the ball screw spline structure in another embodiment.

Fig. 3 is an axial cross-sectional view of the ball screw spline structure in yet another embodiment.

Fig. 4 is an axial cross-sectional view of the ball screw spline structure in yet another embodiment.

Fig. 5 is a schematic structural diagram of a ball screw spline structure according to an embodiment.

Fig. 6 is a schematic structural view of a ball screw spline structure according to another embodiment.

Fig. 7 is a schematic structural view of a ball screw spline structure according to yet another embodiment.

Fig. 8 is a schematic structural view of a ball screw spline structure according to still another embodiment.

FIG. 9 is an axial cross-sectional view of the first shaft in one embodiment.

Fig. 10 is an axial cross-sectional view of the first shaft body in another embodiment.

FIG. 11 is an axial cross-sectional view of the first shaft in yet another embodiment.

Fig. 12 is an axial cross-sectional view of the first shaft body in yet another embodiment.

Fig. 13 is a schematic structural diagram of the second shaft according to an embodiment.

FIG. 14 is an axial cross-sectional view of the third shaft according to an embodiment.

In the drawings: 1-a first shaft body, 11-a first end, 12-a second end, 13-a first through hole, 14-a second through hole, 2-a second shaft body, 3-a connecting structure, 31-a third shaft body, 32-a roller bearing, 311-a fixed end, 312-a free end, and 5-a connecting piece.

Detailed Description

The utility model provides a ball spline structure and robot, for making the utility model discloses a purpose, technical scheme and effect are clearer, clear and definite, and it is right that the following refers to the drawing and the embodiment of lifting is the utility model discloses further detailed description. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the 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", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and to simplify the description, but 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, "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, 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; may be mechanically, electrically or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other suitable relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Referring to fig. 1 to 8, the present invention provides a ball screw spline structure for realizing two degrees of freedom of movement and rotation of the end of the SCARA robot.

At present, in order to realize two degrees of freedom of movement and rotation of the tail end of the SCARA robot, the mode of simultaneously processing a screw thread and a spline groove on one shaft is difficult to process, and the production cost is high; and the mode that adopts ball screw axle and independent integral key shaft parallel placement, the degree of difficulty of installation is big, and is high to workman's technical requirement to make manufacturing cost also high.

The utility model discloses a this ball spline structure includes: a first shaft body 1 and a second shaft body 2; the first shaft body 1 is a hollow shaft, the second shaft body 2 is arranged in the first shaft body 1, wherein the first shaft body 1 is a ball screw shaft, and the second shaft body 2 is a spline shaft; or the first shaft body 1 is a spline shaft, and the second shaft body 2 is a ball screw shaft. The ball screw spline structure can be directly contacted with a load, and the movement or rotation of the load can be realized. This structure will be processed respectively for the first axis body 1 and the 2 coaxial coupling of second axis body of ball screw shaft and integral key shaft, has simplified the degree of difficulty of installation, and need not process spline groove and lead screw thread on same root axis, has simplified the processing degree of difficulty to manufacturing cost has been reduced.

Further, as shown in fig. 1 to 4, the first shaft body 1 and the second shaft body 2 are connected by a connection structure, the connection structure is disposed in the first shaft body 1, and the first shaft body 1 can generate a linear motion relative to the second shaft body 2. Specifically, a transmission structure is connected to the first shaft body 1, so that the first shaft body 1 linearly moves along the second shaft body 2; or the second shaft body 2 is connected with a transmission structure, so that the second shaft body 2 rotates to drive the first shaft body 1 to linearly move along the second shaft body 2. The connection between the first shaft body 1 and the transmission structure may be direct connection or indirect connection.

In some embodiments, the first shaft body 1 and the second shaft body 2 can be linked by connecting the connection structure, for example, when the second shaft body 2 is a ball spline shaft and the first shaft body 1 is a ball screw shaft, the connection structure can be a spline nut, and when the transmission structure drives the second shaft body 2 to rotate, the first shaft body 1 can generate a spiral motion. For another example, when the first shaft body 1 is a ball screw shaft, the second shaft body 2 is a ball spline shaft, and the connecting structure 3 is a spline groove arranged in the first shaft body 1 and matched with the second shaft body 2, the transmission structure drives the second shaft body 2 to rotate, and the first shaft body 1 can also generate spiral motion. For another example, when the first shaft 1 is a ball spline shaft, the second shaft 2 is a ball screw shaft, and the connection structure 3 is a screw nut, the transmission structure drives the second shaft 2 to rotate, and the first shaft 1 can move linearly along the second shaft 2.

As shown in fig. 1 and 5, in one embodiment, the first shaft 1 is a ball screw shaft, the second shaft 2 is a ball spline shaft, and the connection structure is a spline nut fixed at the first end 11 of the first shaft 1, specifically, the spline nut may be fixedly connected with the ball screw shaft by means of bolts, pins, or the like, and the connection structure is connected with the second shaft 2 by means of a spline pair.

Further, the one end that second axle body 2 and connection structure are close to protrudes first axle body 1 for can be at the protruding end installation drive unit of second axle body 2, make drive unit be connected with the driving source, drive second axle body 2 through the driving source and rotate, thereby drive first axle body 1 along 2 spiral motion of second axle body. In particular, the transmission member may be selected from gears, pulleys or other transmission means.

For making can set up the adapting unit who is connected with the second shaft body 2 in the first shaft body 1 or can form the vice spline groove of spline with the second shaft body 2, be equipped with first through-hole 13 and second through-hole 14 in the first shaft body 1, first through-hole 13 and second through-hole 14 distribute along the axial of first shaft body 1, first through-hole 13 and second through-hole 14 intercommunication, the aperture of first through-hole 13 and second through-hole 14 is different, a second through-hole 14 is connected to at least one end of first through-hole 13, connection structure 3 sets up in second through-hole 14.

When a separate connecting member is provided in the second through hole 14 as the connecting structure 3, the diameter of the second through hole 14 is larger than that of the first through hole 13 in order to ensure that interference does not occur between the inside of the first shaft body 1 and the second shaft body 2.

If the second through hole 14 is directly connected with the second shaft body 2 through the spline groove, the aperture of the second through hole 14 is smaller than that of the first through hole 13, so that the part of the second shaft body 2 located in the second through hole 14 can be matched and connected with the inner wall of the second through hole 14, and the part of the second shaft body 2 located in the first through hole 13 cannot interfere with the inside of the first shaft body 1.

Specifically, as shown in fig. 2 and 10, in one embodiment, two ends of the first through hole 13 are respectively communicated with one second through hole 14, two second through holes 14 are respectively communicated with two ends of the first shaft body 1, and the aperture of the second through hole 14 is larger than that of the first through hole 13; the connecting structure 3 includes a third shaft body 31 and two roller bearings 32, the third shaft body 31 is a hollow shaft, is disposed in the first shaft body 1, and is sleeved on the second shaft body 2, and is connected with the second shaft body 2 through a spline pair, and the first shaft body 1, the second shaft body 2 and the third shaft body 31 are coaxial.

The two roller bearings 32 are respectively sleeved on the third shaft 31, rotatably connected with the third shaft 31, and respectively in interference fit with the two second through holes 14. The first through hole 13 and the second through hole 14 form a step at the junction due to the difference in the bore diameter, one end surface of the roller bearing 32 is connected to the step surface, and the outer ring of the roller bearing 32 is in interference fit with the inside of the first shaft body 1.

In order to improve the wear resistance of the spline pair, wear-resistant materials such as copper can be added into the spline pair.

In this embodiment, the third shaft 31 is an action shaft, and is used to connect with a load and drive the load to generate linear motion, rotational motion, and spiral motion. The first shaft body 1 is connected with the third shaft body 31 through a roller bearing 32 between the first shaft body 1 and the second shaft body 2, and a driving source can independently control the linear motion or the rotary motion of the structure, so that the linear motion and the rotary motion of the structure are independent; therefore, the robot with the structure is more accurate and simple to control, and the installation difficulty is lower.

Specifically, as shown in fig. 2 and 14, the third shaft body 31 includes a fixed end 311 and a fixed end 312, the fixed end 311 and the fixed end 312 of the third shaft body 31 have different inner and outer diameters to form a stepped shaft, and a stepped hole is formed inside the stepped shaft. More specifically, the outer diameter of the fixed end 311 of the third shaft body 31 is larger than the outer diameter of the fixed end 312, the inner diameter of the fixed end 311 is smaller than the inner diameter of the fixed end 312, and spline grooves are formed on the inner wall of the fixed end 311 and axially distributed along the fixed end 311. The third shaft body 31 is connected with the second shaft body 2 through the spline groove, the roller bearings 32 are connected on the same side of the fixed end 311, namely, the fixed end 311 of the third shaft body 31 is located on the outer side of the second through hole 14, namely, the roller bearings 32 located in the two second through holes 14 are connected at the free end of the third shaft body 31, the hole diameters are consistent, and the installation difficulty and the opening difficulty of the first shaft body 1 are reduced.

A gap is reserved between the fixed end 312 of the third shaft body 31 and the second shaft body 2, so that dynamic friction is reduced; meanwhile, the fixed end 311 of the third shaft body 31 has a restraining effect on the roller bearing 32 adjacent thereto.

As shown in fig. 2, since the third shaft body 31 is connected to the load, in order to avoid the load colliding with the first shaft body 1, the free end 14 of the third shaft body 31 protrudes out of the first shaft body 1 and the second shaft body 2.

As shown in fig. 13, in the present embodiment, the second shaft 2 can be used to make the third shaft 31 rotate, a top end (an end close to the fixed end 311 of the third shaft 31) of the second shaft is an optical axis, and the optical axis can be processed for a second time to match with a gear, a belt pulley or other transmission tools, and is connected to the driving source through a transmission component, so that the second shaft 2, which is a spline shaft, is driven by the driving source to rotate, and then the third shaft 31 is driven to rotate.

In another embodiment, as shown in fig. 11, one end of the first through hole 13 communicates with a second through hole 14, the aperture of the second through hole 14 is smaller than that of the first through hole 13, the first shaft body 1 is a ball screw shaft, the second shaft body 2 is a spline shaft, no connecting component needs to be added between the first shaft body 1 and the second shaft body 2, the connecting structure 3 is a spline groove directly formed in the inner wall of the second through hole 14, the spline groove extends along the axial direction of the second through hole 14, the first shaft body 1 is connected with the second shaft body 2 in a matched manner through the spline groove, the structure reduces the use of the connecting component, simplifies the structure, and reduces the installation difficulty and the production cost to a certain extent. In order to improve the wear resistance of the spline pair, wear-resistant materials such as copper and the like can be added into the spline pair.

In another embodiment, as shown in fig. 12, one end of the first through hole 13 is communicated with a second through hole 14, the aperture of the first through hole 13 is smaller than the aperture of the second through hole 14, that is, a step is formed at the junction of the first through hole 13 and the second through hole 14, the connecting structure 3 is sleeved on the second shaft body 2, is rotatably connected with the second shaft body 2, is fixed in the second through hole 14, and is connected with the step formed at the junction of the first through hole 13 and the second through hole 14, and a certain limiting and supporting effect is generated by the connecting structure 3 through the step surface.

Specifically, the first shaft body 1 is a ball spline shaft, the second shaft body 2 is a ball screw shaft, and the connecting structure 3 is a screw nut. The screw nut can be fixedly connected with the ball spline shaft through bolts, pins and the like. The end of the ball screw shaft near the second through hole 14 protrudes out of the ball spline shaft, and the protruding end can be provided with a gear, a belt pulley or other transmission components, and the transmission components are driven to rotate by the driving source, so that the ball screw shaft is driven to rotate.

In some embodiments, the second end 12 of the first shaft body 1 is configured to be connected to a load, the load generates a steric hindrance to the second shaft body 2 located inside the first shaft body 1, and in order to avoid interference between the second shaft body 2 and the load, the second shaft body 2 cannot pass through the second end 12 of the first shaft body 1, so that the second end 12 of the first shaft body 1 protrudes out of the second shaft body 2.

Further, this ball spline structure still includes connecting piece 5, and 5 covers of connecting piece are established on first axis body 1, can drive first axis body 1 along 2 linear motion or the helical motion of second axis body.

Specifically, the connecting member 5 is a lead screw nut or a spline nut. When the connecting piece 5 is a screw nut, the first shaft body 1 is correspondingly a ball screw shaft, and at the moment, when the connecting piece 5 rotates, the first shaft body 1 moves linearly along the second shaft body 2; when the connecting member 5 is a spline nut, the first shaft body 1 is a ball spline shaft, and at this time, when the connecting member 5 rotates, the first shaft body 1 spirally moves along the second shaft body 2.

In one embodiment, as shown in fig. 1, 5 and 9, the ball screw spline structure includes a first shaft body 1, a second shaft body 2, a connecting structure 3 and a connecting member 5. The first shaft body 1 is a ball screw shaft, the second shaft body 2 is a ball spline shaft, the connecting structure 3 is a spline nut, and the connecting piece 5 is a screw nut.

The ball screw shaft is arranged to be a hollow shaft, the hollow shaft is sleeved on the ball spline shaft, a gap is reserved between the inside of the ball screw shaft and the ball spline shaft, the screw nut is fixed at the first end 11 of the ball screw shaft through a bolt, one end, close to the spline nut, of the ball spline shaft penetrates through the spline nut, the ball screw shaft protrudes out of the ball screw shaft, and the protruding end is connected with a driving source through a transmission component. The second end 12 of the ball screw shaft protrudes out of the ball spline shaft, which second end 12 is in direct contact with the load.

When the screw nut rotates, the ball screw shaft moves linearly along the ball spline shaft, and the load is driven to move linearly.

When the ball spline shaft rotates, the ball screw shaft performs a spiral motion along the ball spline shaft, and the load can be driven to perform a spiral motion along the ball spline shaft.

When the ball spline shaft and the lead screw nut rotate simultaneously, the ball lead screw shaft rotates to drive the load to rotate.

In another embodiment, as shown in fig. 2, 6, 10, 13 and 14, the ball screw spline structure includes a first shaft body 1, a second shaft body 2, a connecting structure 3 and a connecting member 5. First axis body 1 is the ball screw axle, and second axis body 2 is the integral key shaft, and connection structure 3 includes third axis body 31 and roller bearing 32, and third axis body 31 is the action axle, and roller bearing 32 includes two, and the connecting piece is lead screw nut.

The ball screw shaft and the action shaft are hollow shafts, the ball screw shaft is sleeved on the spline shaft, the action shaft is arranged between the ball screw shaft and the spline shaft, and the ball screw shaft, the spline shaft and the action shaft are coaxially arranged. The ball screw shaft is internally provided with a first through hole 13 and a second through hole 14 which extend along the axial direction of the ball screw shaft, two ends of the first through hole 13 are respectively connected with the second through hole 14, the roller bearing is arranged in the second through hole 14, and the periphery of the roller bearing is in interference fit with the second through hole 14. The operation shaft is a stepped shaft, and the outer diameter of the fixed end 311 is larger than that of the fixed end 312, and the inner diameter of the fixed end 311 is smaller than that of the fixed end 312. A roller bearing near the fixed end 311 of the operation shaft is fixed between the first through hole 13 and the fixed end 311 of the operation shaft. The fixed end 311 of the actuating shaft is internally provided with a spline groove which is connected with the spline shaft through a spline pair.

The spline shaft is provided with a ball screw shaft protruding from one end of the fixed end 311 close to the action shaft, and the protruding end is an optical axis, and can be connected with a transmission component such as a gear, a belt wheel and the like after secondary processing, and is connected with a driving source through the transmission component.

The fixed end 312 of the actuating shaft protrudes out of the ball screw shaft and the spline shaft, respectively, for connecting a load, and driving the load to generate linear motion, rotational motion, and spiral motion, and the linear motion and the rotational motion are independent of each other and can be independently controlled by a driving source.

When the spline shaft rotates under the driving of the driving source, the spline shaft drives the action shaft to rotate through the spline pair, so that the load is driven to rotate, and the movement of the ball screw shaft is not influenced.

When the screw nut rotates, the ball screw shaft performs linear motion, the roller bearings connected to the two ends of the action shaft drive the action shaft to perform linear motion along the spline pair, and therefore the load is driven to perform linear motion along the spline pair.

In still another specific example, as shown in fig. 3, 7 and 11, the ball screw spline structure includes a first shaft body 1, a second shaft body 2 and a connecting member 5. The first shaft body 1 is a ball screw shaft, the second shaft body 2 is a spline shaft, and the connecting piece is a screw nut.

The screw nut is sleeved on the ball screw shaft, the ball screw shaft is a hollow shaft, and the spline shaft is arranged inside the ball screw shaft. A first through hole 13 and a second through hole 14 which are distributed along the axial direction are arranged in the ball screw shaft, the aperture of the second through hole 14 is smaller than that of the first through hole 13, spline grooves which are distributed along the axial direction are arranged in the second through hole 14, and the ball screw shaft is connected with the spline shaft through a spline pair. Copper is added into the spline pair to improve the wear resistance of the spline pair. One end of the spline shaft near the second through hole 14 protrudes out of the ball screw shaft, and the protruding end is connected to a drive source via a transmission member such as a gear or a pulley. The end of the ball screw shaft remote from the second through hole 14 for direct contact with the load protrudes out of the spline shaft.

When the screw nut rotates, the ball screw shaft moves linearly along the spline shaft to drive the load to move linearly.

When the spline shaft rotates under the driving of the driving source, the ball screw shaft performs spiral motion along the spline shaft to drive the load to perform spiral motion.

When the spline shaft and the lead screw nut rotate simultaneously, the ball lead screw shaft rotates.

In another embodiment, as shown in fig. 4, 8 and 12, the ball screw spline structure includes a first shaft body 1, a second shaft body 2, a connection structure 3 and a connection member, the first shaft body 1 is a ball spline shaft, the second shaft body 2 is a ball screw shaft, the connection structure 3 is a screw nut, and the connection member is a spline nut.

The spline nut is sleeved on the ball spline shaft, the ball spline shaft is arranged to be a hollow shaft, a stepped hole is formed in the ball spline shaft, and the ball screw shaft is arranged in the stepped hole. The stepped hole comprises a first through hole 13 and a second through hole 14, the aperture of the second through hole 14 is larger than that of the first through hole 13, and a screw nut is fixed in the second through hole 14 through a bolt or a pin and is sleeved on a ball screw shaft. One side of the ball screw shaft close to the second through hole 14 protrudes out of the ball spline shaft, and the protruding end of the ball screw shaft is connected with a driving source through a connecting piece such as a gear, a belt wheel and the like. The end of the ball spline shaft remote from the second through hole 14 projects beyond the ball screw shaft and is connected to a load.

When the ball screw shaft is driven by the driving source to rotate, the ball spline shaft moves linearly along the spline nut to drive the load to move linearly. When the spline nut rotates, the ball spline shaft performs spiral motion along the ball screw shaft to drive the load to perform spiral motion. When the ball screw shaft and the spline nut rotate simultaneously, the ball spline shaft rotates to drive the load to rotate.

The utility model provides a ball spline structure, ball shaft and integral key shaft can process respectively and put together again after an independent root is epaxial, have reduced the installation degree of difficulty and manufacturing cost.

The utility model also provides a robot, this robot is specific for the SCARA robot, and its end structure realizes removing and rotatory through ball spline structure. The robot includes: the robot arm is provided with the ball screw spline structure, and the ball screw spline structure is arranged at a joint of the robot arm, particularly the tail end of the robot arm and can drive the robot arm to do linear motion and rotary motion; the ball spline structure is characterized by further comprising a driving structure and a transmission part, wherein the driving structure and the transmission part are used for driving the ball spline structure to move. The driving structure can be a motor, and the transmission part is connected with the ball screw spline structure and the driving structure to transmit power between the ball screw spline structure and the driving structure. Specifically, the driving structure may include a plurality of second shaft bodies 2 and connection members 5 connected to the ball spline structure through transmission members, respectively, so as to move and rotate the load of the SCARA robot.

It should be understood that the technical solutions of the present invention and the inventive concept thereof may be equally replaced or changed by those skilled in the art, and those equivalent modifications or replacements are included in the scope defined by the claims of the present application.

Claims (15)

1. A ball screw spline structure, comprising:

the first shaft body is arranged as a hollow shaft;

the second shaft body is arranged in the first shaft body;

one of the first shaft body and the second shaft body is a ball screw shaft, and the other is a spline shaft.

2. The ball screw spline structure of claim 1, further comprising a connecting structure through which the first shaft body and the second shaft body are connected, the connecting structure being capable of transmitting between the first shaft body and the second shaft body such that there is a linkage between the first shaft body and the second shaft body.

3. The ball screw spline structure of claim 2, wherein the first shaft body is a ball screw shaft, the second shaft body is a ball spline shaft, the connection structure is a spline nut, and the connection structure is fixed to the first end of the first shaft body and connected to the second shaft body through a spline pair.

4. The ball screw spline structure according to claim 1, further comprising a connecting structure through which the first shaft body and the second shaft body are connected, the connecting structure being provided in the first shaft body, the first shaft body and the second shaft body being relatively rotationally movable and/or relatively linearly movable by the connecting structure.

5. The ball screw spline structure of claim 4, wherein the first shaft body is provided with a first through hole and a second through hole along an axial direction, the first through hole and the second through hole have different diameters, at least one end of the first through hole is connected with one of the second through holes, and the connecting structure is disposed in the second through hole.

6. The ball screw spline structure according to claim 5, wherein one of the second through holes is communicated with each of both ends of the first through hole, and the aperture of the second through hole is larger than that of the first through hole;

the connecting structure comprises a third shaft body and two roller bearings, wherein the third shaft body is a hollow shaft, is arranged in the first shaft body, is sleeved on the second shaft body, and is connected with the second shaft body through a spline pair; and the two roller bearings are respectively sleeved on the third shaft body, are rotatably connected with the third shaft body and are respectively in interference fit with the two second through holes.

7. The ball screw spline structure of claim 6, wherein the second shaft is a spline shaft, the third shaft comprises a fixed end and a free end, the outer diameter of the fixed end is larger than the outer diameter of the free end, the inner diameter of the fixed end is smaller than the inner diameter of the free end, spline grooves distributed along the axis of the fixed end are formed in the fixed end, the third shaft is connected with the second shaft through the spline grooves, and the roller bearings are connected to the same side of the fixed end.

8. The ball screw spline structure of claim 6, wherein a second end of the third shaft body protrudes out of the first shaft body and the second shaft body.

9. The ball screw spline structure according to claim 5, wherein one end of the first through hole communicates with one of the second through holes, the second through hole has a smaller diameter than the first through hole, the first shaft body is a ball screw shaft, the second shaft body is a spline shaft, the connection structure is a spline groove extending axially along an inner wall of the second through hole, and the first shaft body is connected to the second shaft body by a spline pair in a fitting manner.

10. The ball screw spline structure of claim 5, wherein one end of the first through hole communicates with one of the second through holes, the first through hole has a smaller diameter than the second through hole, and the connecting structure is nested on the second shaft body and is rotatably connected with the second shaft body.

11. The ball screw spline structure of claim 10, wherein the first shaft body is a ball spline shaft, the second shaft body is a ball screw shaft, and the connection structure is a screw nut.

12. The ball screw spline structure of any one of claims 1-11, wherein the second end of the first shaft body protrudes out of the second shaft body.

13. The ball screw spline structure of claim 12, further comprising a connecting member, wherein the connecting member is sleeved on the first shaft body and can drive the first shaft body to move linearly or spirally along the second shaft body.

14. The ball screw spline structure of claim 13, wherein the connector is a screw nut or a spline nut.

15. A robot, comprising:

the robot arm is provided with a plurality of robot arms,

the ball screw spline structure of any one of claims 1-14, disposed at a joint of the robotic arm;

and the driving structure drives the ball screw spline structure to move.

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