High-rigidity push rod linear motor

Abstract

The high-rigidity push rod linear motor comprises a guide shaft, a locking nut, a front bearing, a front end cover, a hollow shaft, a rotor, a stator, a rear bearing and a rear end cover, one end of the hollow shaft penetrates through the front bearing and then is connected with the front end cover, the other end of the hollow shaft penetrates through the rear bearing and then is connected with the rear end cover, and the rotor is installed on the outer side of the hollow shaft; the stator is installed on the outer side of the rotor, the linear motor further comprises a ball spline, and the guide shaft sequentially penetrates through the ball spline and the locking nut and then is connected with the hollow shaft. Compared with the prior art, the invention has the advantages of high rigidity, high precision and the like.

Description

Technical Field

[0001] The invention relates to a, and in particular to a high-rigidity push rod linear motor. Background Art

[0002] A linear motor, or linear motor, uses a screw and nut that mesh with each other to convert rotational motion into linear motion. After searching, Chinese Patent Publication No. CN221177456U discloses a new type of through-ball screw motor, including: a stator and a front box cover mounted on its front end, a rear end cover mounted on its rear end, a rotor mounted in the stator, a large bearing mounted on the outer side of the front end of the rotor shaft, and a small bearing mounted on the outer side of the rear end, wherein the outer ring of the large bearing is mounted in the front box cover, and the outer ring of the small bearing is mounted in the rear end cover, the front end end of the rotor shaft is fixed to the screw nut, and the ball screw passes through the front box cover, the screw nut, the rotor, and the rear end cover in sequence. The shaft of the rotor is provided with an axial through hole. The existing patent screw needs to be prevented from rotating relative to the screw nut by an external mechanism to achieve axial movement of the screw. The above-mentioned prior art has the following disadvantages:

[0003] 1) The lead screw needs to be protected from rotation by an external mechanism: the lead screw itself does not have an anti-rotation design and requires an external anti-rotation mechanism to assist in achieving linear movement;

[0004] 2) Weak axial rigidity: Due to structural limitations, the motor rear end cover bearing needs to use a smaller bearing, and the preload nut applies a certain preload force on the bearing, so it is easy to be damaged when subjected to axial push and pull forces;

[0005] 3) Weak radial rigidity: The motor screw is only connected to the nut, and its radial force bearing capacity is weak. Summary of the invention

[0006] The purpose of the present invention is to provide a high-rigidity push rod linear motor in order to overcome the defects of the above-mentioned prior art.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] According to one aspect of the present invention, a high-rigidity push rod linear motor is provided, comprising a guide shaft, a locking nut, a front bearing, a front end cover, a hollow shaft, a rotor, a stator, a rear bearing and a rear end cover, wherein one end of the hollow shaft passes through the front bearing and is connected to the front end cover, and the other end passes through the rear bearing and is connected to the rear end cover, the rotor is mounted on the outside of the hollow shaft, and the stator is mounted on the outside of the rotor. The linear motor also comprises a ball spline, and the guide shaft passes through the ball spline and the locking nut in sequence and is connected to the hollow shaft.

[0009] As a preferred technical solution, the locking nut is provided with a positioning circle and a thread, the thread is connected to the hollow shaft, and the flange surface of the locking nut is evenly fitted with the inner ring of the front bearing.

[0010] As a preferred technical solution, the guide shaft includes a push rod, a first surface of which is provided with a first raceway, and a second surface of the ball spline is provided with a second raceway. The first raceway and the second raceway cooperate with each other through balls to achieve axial movement and limit the rotation of the guide shaft.

[0011] As a preferred technical solution, the guide shaft includes a screw rod, a third surface of which is provided with a third raceway, a first reflow device and a second reflow device are provided on both sides of the screw rod, a fourth surface of the hollow shaft is provided with a fourth raceway, and the third raceway and the fourth raceway cooperate with each other through balls to convert the rotational motion of the hollow shaft into linear motion.

[0012] As a preferred technical solution, the ball spline and the front end cover are connected by screws, and the outer ring of the front bearing is locked.

[0013] As a preferred technical solution, the locking nut and the hollow shaft lock the inner ring of the front bearing.

[0014] As a preferred technical solution, two front bearings are provided, and a clearance-eliminating washer is provided between the two front bearings.

[0015] As a preferred technical solution, the front end cover is provided with a process groove, and the corresponding position of the hollow shaft is provided with a step. During assembly, the step passes through the process groove and fits with the inner ring of the front bearing.

[0016] As a preferred technical solution, the cross-sectional dimension of the process groove is larger than the cross-sectional dimension of the step.

[0017] As a preferred technical solution, the hollow shaft and the rear end cover are both provided with high-precision encoders.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1) Self-anti-rotation design: The guide shaft cooperates with the ball spline to limit the rotation of the guide shaft;

[0020] 2) High rigidity design: two front bearings and ball splines, better axial and radial rigidity;

[0021] 3) High-precision design: high rigidity and low deformation, combined with high-precision encoder, position control is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of the high-rigidity push rod linear motor of the present invention;

[0023] Figure 2 It is a schematic cross-sectional view of the high-rigidity push rod linear motor of the present invention;

[0024] Figure 3It is a schematic cross-sectional structural diagram of the guide shaft of the present invention;

[0025] Figure 4 It is a schematic diagram of the structure of the front end cover of the present invention;

[0026] Figure 5 It is a schematic cross-sectional structural diagram of the front end cover of the present invention;

[0027] Figure 6 It is a structural schematic diagram of the hollow shaft of the present invention;

[0028] Figure 7 It is a schematic diagram of the cross-sectional structure of the hollow shaft of the present invention.

[0029] Among them, 1 is the guide shaft, 2 is the ball spline, 3 is the locking nut, 4 is the front bearing, 5 is the front end cover, 6 is the hollow shaft, 7 is the rotor, 8 is the stator, 9 is the rear bearing, 10 is the rear end cover, 11 is the magnetic bead, 12 is the magnetic encoder, 1a is the push rod, 1b is the first surface, 2a is the second surface, 1c is the screw rod, 1d is the third surface, 6a is the fourth surface, 1e is the first return device, 1f is the second return device, 3a is the positioning circle, 3b is the thread, 5a is the process groove, and 6b is the step. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0031] like Figure 1 and Figure 2 As shown, a high-rigidity push rod linear motor includes a guide shaft 1, a locking nut 3, a front bearing 4, a front end cover 5, a hollow shaft 6, a rotor 7, a stator 8, a rear bearing 9 and a rear end cover 10. One end of the hollow shaft 6 passes through the front bearing 4 and is connected to the front end cover 5, and the other end passes through the rear bearing 9 and is connected to the rear end cover 10. The rotor 7 is installed on the outside of the hollow shaft 6, and the stator 8 is installed on the outside of the rotor 7. The linear motor also includes a ball spline 2. The guide shaft 1 passes through the ball spline 2 and the locking nut 3 in sequence and is connected to the hollow shaft 6. The present invention limits the rotation of the guide shaft 1 by cooperating with the ball spline 2, and has a self-rotation prevention function.

[0032] like Figure 2 As shown, the locking nut 3 is provided with a positioning circle 3a and a thread 3b, and the thread 3b is connected to the hollow shaft 6, and the flange surface of the locking nut 3 is evenly fitted with the inner ring of the front bearing 4.

[0033] like Figure 3 As shown, the guide shaft 1 includes a push rod 1a, a first surface 1b of the push rod 1a is provided with a first raceway, and a second surface 2a of the ball spline 2 is provided with a second raceway. The first raceway and the second raceway cooperate with each other through balls to achieve axial movement and limit the rotation of the guide shaft 1.

[0034] like Figure 3 As shown, the guide shaft 1 includes a screw rod 1c, a third surface 1d of the screw rod 1c is provided with a third raceway, a first return device 1e and a second return device 1f are provided on both sides of the screw rod 1c, and the balls return inside the screw rod 1c. When the hollow shaft 6 rotates, the ball spline 2 limits the rotation of the guide shaft 1. At the same time, a fourth surface 6a of the hollow shaft 6 is provided with a fourth raceway. The third raceway and the fourth raceway cooperate with each other through the balls to convert the rotational motion of the hollow shaft 6 into linear motion.

[0035] like Figure 2 As shown, the ball spline 2 and the front end cover 5 are connected by screws, and the outer ring of the front bearing 4 is locked. The locking nut 3 and the hollow shaft 6 lock the inner ring of the front bearing 4. The front bearing 4 is provided with two, and a clearance eliminating washer is provided between the two front bearings 4 to eliminate the axial clearance, thereby eliminating the axial clearance of the guide shaft 1 and improving the axial accuracy. The two front bearings and the ball spline cooperate to make the axial rigidity and radial rigidity better.

[0036] like Figure 4-Figure 7 As shown, the front end cover 5 is provided with a process groove 5a, and the hollow shaft 6 is provided with a step 6b at the corresponding position. When assembled, the step 6b passes through the process groove 5a and fits with the inner ring of the front bearing 4. The number and distribution of the process grooves 5a are the same as those of the steps 6b, and the cross-sectional size of the process grooves 5a is larger than the cross-sectional size of the steps 6b. The outer circle of the hollow shaft 6 can be designed with a larger size, and a larger bearing can be used, thereby improving the axial rigidity and radial rigidity.

[0037] like Figure 2 As shown, the hollow shaft 6 is provided with a magnetic bead 11 and a magnetic encoder 12, which, in conjunction with a closed-loop control driver, can achieve high-precision position control.

[0038] Meanwhile, the rear end cover 10 of the present invention may also be provided with other types of high-precision encoders, such as a photoelectric encoder.

[0039] Example 2

[0040] The ball spline 2 of Example 1 is replaced with an oil-containing bearing, and the fourth surface 6a of the hollow shaft 6 and the third surface of the screw rod 1c are changed to trapezoidal threads 1d, which greatly reduces the product cost while ensuring certain performance. The rest is the same as Example 1.

[0041] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A high-rigidity push rod linear motor, comprising a guide shaft (1), a locking nut (3), a front bearing (4), a front end cover (5), a hollow shaft (6), a rotor (7), a stator (8), a rear bearing (9) and a rear end cover (10), wherein one end of the hollow shaft (6) passes through the front bearing (4) and is connected to the front end cover (5), and the other end passes through the rear bearing (9) and is connected to the rear end cover (10), the rotor (7) is mounted on the outside of the hollow shaft (6), and the stator (8) is mounted on the outside of the rotor (7), characterized in that: The linear motor also includes a ball spline (2), and the guide shaft (1) passes through the ball spline (2) and the locking nut (3) in sequence and is connected to the hollow shaft (6).

2. According to claim 1, a high-rigidity push rod linear motor is characterized in that: The locking nut (3) is provided with a positioning circle (3a) and a thread (3b), the thread (3b) is connected to the hollow shaft (6), and the flange surface of the locking nut (3) is evenly fitted with the inner ring of the front bearing (4).

3. According to claim 1, a high-rigidity push rod linear motor is characterized in that: The guide shaft (1) comprises a push rod (1a), a first surface (1b) of the push rod (1a) is provided with a first raceway, and a second surface (2a) of the ball spline (2) is provided with a second raceway, the first raceway and the second raceway cooperate with each other through balls to achieve axial movement and limit the rotation of the guide shaft (1).

4. The high-rigidity push rod linear motor according to claim 1, characterized in that: The guide shaft (1) comprises a screw rod (1c), a third surface (1d) of the screw rod (1c) is provided with a third raceway, a first returner (1e) and a second returner (1f) are provided on both sides of the screw rod (1c), a fourth surface (6a) of the hollow shaft (6) is provided with a fourth raceway, and the third raceway and the fourth raceway cooperate with each other through balls to convert the rotational motion of the hollow shaft (6) into linear motion.

5. The high-rigidity push rod linear motor according to claim 1, characterized in that: The ball spline (2) and the front end cover (5) are connected by screws, and the outer ring of the front bearing (4) is locked.

6. The high-rigidity push rod linear motor according to claim 5, characterized in that: The locking nut (3) and the hollow shaft (6) lock the inner ring of the front bearing (4).

7. A high rigidity push rod linear motor according to claim 1 or 5, characterized in that: Two front bearings (4) are provided, and a clearance-eliminating washer is provided between the two front bearings (4).

8. The high-rigidity push rod linear motor according to claim 6, characterized in that: The front end cover (5) is provided with a process groove (5a), and the hollow shaft (6) is provided with a step (6b) at a corresponding position. During assembly, the step (6b) passes through the process groove (5a) and fits with the inner ring of the front bearing (4).

9. The high-rigidity push rod linear motor according to claim 8, characterized in that: The cross-sectional dimension of the process groove (5a) is greater than the cross-sectional dimension of the step (6b).

10. A high-rigidity push rod linear motor according to claim 1 or 5, characterized in that: The hollow shaft (6) and the rear end cover (10) are both provided with high-precision encoders.

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