Linear telescopic structure for preventing lead screw from rotating, electric motor and electric pump

Abstract

The utility model relates to the technical field of electric motors, in particular to a linear telescopic structure for preventing a lead screw from rotating, which comprises a nut capable of rotating in a limited space, the lead screw driven by the rotating nut to move linearly, a rolling body and a guide groove, the rolling body can roll in the guide groove, and the guide groove is axially parallel to the lead screw. One of the rolling body and the guide groove is installed on the lead screw, and the other one is fixedly installed relative to the machine shell. The electric motor comprises a machine shell, a stator fixed in the machine shell, a rotor rotationally connected in the machine shell and a linear telescopic structure for preventing the lead screw from rotating, and the nut and the rotor rotate synchronously. The electric pump comprises the electric motor and a pump body driven by the electric motor. The scheme is used for solving the problem that a guide structure is easy to wear during reciprocating linear movement of a lead screw in an electric motor in the prior art.

Description

Technical Field

[0001] The utility model relates to the technical field of electric motors, in particular to a linear telescopic structure for preventing screw rotation, an electric motor and an electric pump. Background Art

[0002] In electric motors, using a lead screw as a linear output is one of the more common methods. In such electric motors, the lead screw is often driven to rotate back and forth in a fixed position to achieve reciprocating telescopic structure. For example, the utility model patent CN218771607U "An adjustable anti-rotation linear telescopic servo mechanism" authorized in 2023, in this anti-rotation linear telescopic servo mechanism, a guide block is fixed on the lead screw, so that the lead screw moves back and forth through the guide block in a fixed guide bar, thereby ensuring that the lead screw will not rotate with the rotation of the nut, thereby ensuring the accuracy of linear movement.

[0003] However, this type of design to prevent the screw from rotating has basically no problem when the screw moves at low speed and bears small torque. It only needs to be lubricated regularly inside the guide block and guide strip. However, in situations where a large torque needs to be borne, or when the screw moves back and forth at an extremely fast speed, the guide block and guide strip are used in a sliding friction manner, which is very prone to wear and tear that affects the guiding function. Utility Model Content

[0004] The utility model aims to provide a linear telescopic structure for preventing a lead screw from rotating, so as to solve the problem that the guide structure of the lead screw in the electric motor of the prior art is easily worn during the reciprocating linear movement.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A linear telescopic structure for preventing a screw from rotating includes a nut that can rotate within a limited space, a screw that is driven by the rotating nut to move linearly, and a rolling body and a guide groove. The rolling body can roll in the guide groove, and the guide groove is parallel to the axis of the screw. One of the rolling body and the guide groove is installed on the screw, and the other is fixedly installed relative to the casing.

[0007] The principles and advantages of this solution are: the linear telescopic structure of this solution is equipped with rolling bodies and guide grooves. The cooperation between the rolling bodies and the guide grooves can guide the axial movement of the screw, ensuring the stability and accuracy of the linear movement. The cooperation between the guide grooves and the rolling bodies can convert the sliding friction of the existing technology into rolling friction during the guiding process, thereby greatly reducing the wear rate.

[0008] Preferably, as an improvement, it also includes a guide seat fixedly installed relative to the casing, the guide groove is arranged on the guide seat, the central axis of the rolling body is fixed on the screw, and the outer ring of the rolling body is used to roll in the guide groove, so as to take into account both the guiding performance and the cost.

[0009] Preferably, as an improvement, an adapter sleeve is fixed on the screw, and the adapter sleeve is matched with the screw in a concave-convex manner, and the center axis of the rolling body passes through the radial hole provided on the adapter sleeve and is fixedly connected to the screw, and the center axis and the radial hole are gap-matched.

[0010] Beneficial effects: When this solution is adopted, since the electric motor needs to withstand a large torque during the pressure-holding pause stage, the torque will be transmitted to the screw, and the rolling elements installed on the screw will also withstand the torque. The farther away from the center of the screw, the greater the force, and the greater the force acts on the adapter sleeve. On the one hand, even if the radial hole port of the adapter sleeve is worn due to long-term torque, the conversion sleeve can be directly replaced to reduce replacement costs. On the other hand, due to the concave-convex fit between the adapter sleeve and the screw, the large torque borne by the adapter sleeve can be quickly transmitted to the thicker part of the screw structure through the fixed connection between the adapter sleeve and the screw, avoiding the problem of excessive force in the weak area of the screw in a short period of time and increasing the risk of damage.

[0011] Preferably, as an improvement, there are multiple rolling bodies, and the multiple rolling bodies are located in the circumference of the screw to ensure that the screw can have a stable and high-precision linear output even when it is subjected to torque.

[0012] Preferably, as an improvement, the plurality of rolling elements are symmetrically arranged about the center of the screw, so that the screw maintains good centering during linear motion, reduces deviation during motion, and improves accuracy.

[0013] Preferably, as an improvement, an oil adding channel is provided on the guide seat, and the oil adding channel can face the oil filling hole provided on the nut, so as to facilitate the addition of lubricating oil to the matching position of the nut and the lead screw through the oil adding channel.

[0014] Preferably, as an improvement, the nut is limited by a limiting structure that rotates synchronously with the nut, and an oil passage is provided on the limiting structure. An annular groove is provided on at least one end face of the limiting structure opposite to the nut, and the annular groove is connected to the oil passage and the oil filling hole. One end of the oil passage can face the oil filling channel to make the addition of lubricating oil simple and convenient.

[0015] The utility model also provides an electric motor, comprising a casing, a stator fixed in the casing and a rotor rotatably connected in the casing, characterized in that it also comprises the linear telescopic structure for preventing the screw from rotating, and the nut rotates synchronously with the rotor.

[0016] Preferably, as an improvement, a brake is further included, which is mounted on the casing and is used to brake the rotor. The brake added in this solution can not only provide safety protection for the electric motor under conventional applications and achieve braking in emergency situations, but also can be used in the electric motor startup-working-pressure-holding cycle mode (the pressure-holding state in this article is a state in which the electric motor has energy input but no motion output, and in this state the electric motor is subjected to torque). In the pressure-holding state, the brake can be activated after the rotor of the electric motor basically stops rotating, and the rotor can be locked by the brake, thereby avoiding the electric motor from heating up quickly due to the need to overcome torque due to pressure holding, thereby extending its service life.

[0017] Preferably, as an improvement, a brake adapter disc is fixedly connected to the rotor, and the brake can engage or release the adapter disc. By setting the brake adapter disc, the present solution enables the brake to engage and release more effectively, providing a greater braking torque.

[0018] The utility model also provides an electric pump, comprising the electric motor and a pump body driven by the electric motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the three-dimensional structure of the electric motor according to the first embodiment of the present invention.

[0020] Figure 2 for Figure 1 Axial section view of .

[0021] Figure 3 This is a schematic diagram of the three-dimensional structure of the linear telescopic structure for preventing the screw from rotating in the first embodiment of the present invention.

[0022] Figure 4 for Figure 3 The main view in .

[0023] Figure 5 for Figure 4 AA rotated section view in.

[0024] Figure 6 for Figure 3 Exploded diagram of the lead screw, guide seat, and adapter sleeve.

[0025] Figure 7 for Figure 6 Schematic diagram of the three-dimensional structure after rotating 90°.

[0026] Figure 8 This is a schematic front view of the electric pump according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0027] The following is further described in detail through specific implementation methods:

[0028] The figure marks in the drawings of the specification include: electric motor 10, lower pump body 20, casing 11, stator 12, rotor 101, limit sleeve 102, oil passage 1021, annular groove 1022, ball nut 13, oil filling hole 131, screw 14, guide seat 15, guide groove 151, oil filling passage 152, rolling body 16, adapter sleeve 17, brake 18, brake disc 181, brake adapter disc 182, encoder 19.

[0029] Implementation example Figures 1 to 8 shown.

[0030] Example 1

[0031] Combine Figure 1 and Figure 2 An electric motor 10 includes a housing 11, a stator 12 fixed to the housing 11, a rotor 101 rotatably connected to the housing 11, and a linear telescopic structure that prevents the screw from rotating. The linear telescopic structure includes a ball nut 13 and an axially movable screw 14 enclosed within the ball nut 13. When the electric motor 10 energizes the stator winding, the rotor 101 rotates, thereby driving the nut 13 to rotate synchronously, allowing the screw 14 to achieve linear output. In this embodiment, one axial end of the nut 13 is restrained by a step machined into the rotor 101, and the other axial end of the nut 13 is restrained by an annular limit sleeve 102 fixed to the rotor 101.

[0032] Combine Figures 3 to 7 The linear telescopic structure for preventing the screw from rotating also includes a guide seat 15 fixedly mounted on the housing 11, and a rolling body 16 axially slidably connected to the guide seat 15. The center axis of the rolling body 16 is fixedly connected to the screw 14, and the center axis of the rolling body 16 is radially of the screw 14. There are multiple rolling bodies 16, and the multiple rolling bodies 16 are symmetrically arranged about the center of the screw 14. A guide groove 151 is opened in the guide seat 15. When the screw 14 moves, the outer ring of the rolling body 16 can roll along the guide groove 151. The rolling body 16 in this embodiment is a bearing.

[0033] An adapter sleeve 17 is fixed on the screw 14, and the adapter sleeve 17 and the screw 14 are matched in a concave-convex manner. A radial hole is provided in the radial direction of the adapter sleeve 17. The central axis of the rolling body 16 passes through the radial hole on the adapter sleeve 17 and is fixedly connected to the screw 14. The central axis and the radial hole are clearance-matched. A section of the central axis that is clearance-matched with the radial hole is a smooth section, which facilitates the installation of the rolling body 16 and facilitates the transmission of the torque borne by the rolling body 16 to the adapter sleeve 17 through the smooth section.

[0034] To facilitate the addition of lubricating oil to the oiling hole 131 on the ball nut 13 (the oiling hole 131 is connected to the mating position of the lead screw 14 and the nut 13), an oiling channel 152 is provided at the root of the guide seat 15, which is close to the housing 11. The oiling channel 152 can be an oiling hole, an oiling notch, or an oiling groove. The nut 13 is restrained by a limiting structure on the electric motor that rotates synchronously with the nut 13. In this embodiment, the limiting structure is the limiting sleeve 102. The limiting sleeve 102 is machined with an axially extending oil passage 1021. The end surface of the limiting sleeve 102 opposite the nut 13 is machined with an annular groove 1022. The annular groove 1022 connects the oiling channel 1021 and the oiling hole. The end of the oiling channel 1021 away from the nut 13 can directly face the oiling channel 152. The lubricating oil is extended from the oil adding channel 152 to one end of the oil passage 1021, and then under the extrusion pressure, the lubricating oil passes through the oil channel 1021 into the annular groove 1022, and finally enters the oil filling hole 131 on the nut 13, completing the addition of lubricating oil to the matching structure of the nut 13 and the screw 14.

[0035] This embodiment designs a linear telescopic structure that prevents the screw 14 from rotating and has a rolling body 16, a guide seat 15, and an adapter sleeve 17. This allows the rolling body 16 to guide the screw 14 along the guide groove 151 during its linear movement, and the guiding process converts the sliding friction of the prior art into rolling friction, thereby greatly reducing the wear rate of the screw 14 under high reciprocating frequency or torque, which helps to extend the service life of the linear telescopic structure.

[0036] Combine Figure 2 A brake 18 is also installed in the housing 11 of the electric motor 10. One end of the brake 18 is fixed in the housing 11, and a brake disc 181 (such as the armature of the disc electromagnetic brake 18) at the other end of the brake 18 is fixed on the brake adapter disc 182. The brake adapter disc 182 is fixedly connected to the rotor 101 by screws, so that the brake disc 181 brakes the rotor 101 through the brake adapter disc 182 during braking.

[0037] An encoder 19 is also mounted on the housing 11 , and the encoder 19 is used to monitor the rotational speed of the rotor 101 . In this embodiment, the encoder 19 and the brake 18 are both fixed on the top cover plate of the housing 11 .

[0038] The brake 18 added in this embodiment can not only provide safety protection for the electric motor 10 in conventional applications and achieve emergency braking, but also break the conventional scheme of using only the electric motor 10 excitation braking to withstand torque when the electric motor 10 needs to withstand torque without motion output under pressure. Instead, the brake 18 is activated after the rotor 101 of the electric motor 10 basically stops rotating. The brake 18 is used to lock the rotor 101 for a longer period of time, thereby reducing the time the electric motor 10 is in a state with input but no output and extending its service life.

[0039] This situation where the electric pump needs to withstand torque but has intermittent no output occurs when it is pumping rubber. Using it in a continuous cycle of working-holding pressure and pausing can greatly reduce the temperature rise of the electric pump in the working mode and extend the service life of the electric motor 10.

[0040] Example 2

[0041] Combine Figure 8 The second embodiment provides an electric pump, including the electric motor 10 of the first embodiment and a lower pump body 20 driven by the electric motor 10. The lower pump body 20 of this embodiment adopts a plunger pump, such as the plunger pump structure as shown in the high-pressure plunger pump of patent announcement number CN218266205U. The screw 14 is fixedly connected to the drive rod 201 of the plunger pump 20, so that the reciprocating movement of the screw 14 drives the reciprocating movement of the drive rod 201 to realize continuous pumping of the fluid.

[0042] The above description is merely an embodiment of the present invention, and the commonly known specific technical solutions and / or features of the solution are not described in detail here. It should be noted that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be considered as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection claimed in this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A linear telescopic structure for preventing screw rotation, comprising a nut capable of rotating within a confined space and a screw driven by the rotating nut to move linearly, characterized in that: It also includes a rolling body and a guide groove. The rolling body can roll in the guide groove. The guide groove is parallel to the axis of the screw. One of the rolling body and the guide groove is installed on the screw, and the other is fixed relative to the casing.

2. The linear telescopic structure for preventing screw rotation according to claim 1, characterized in that: It also includes a guide seat fixedly installed relative to the casing, a guide groove is set on the guide seat, the central axis of the rolling body is fixed on the screw, and the outer ring of the rolling body is used to roll in the guide groove.

3. The linear telescopic structure for preventing screw rotation according to claim 2, characterized in that: The screw is fixed with an adapter sleeve, which is matched with the screw in a concave-convex manner. The central axis of the rolling body passes through a radial hole provided on the adapter sleeve and is fixedly connected to the screw. The central axis and the radial hole are matched with each other in a clearance.

4. The linear telescopic structure for preventing screw rotation according to claim 2, characterized in that: There are multiple rolling bodies, and the multiple rolling bodies are located in the circumference of the screw.

5. The linear telescopic structure for preventing screw rotation according to claim 2, characterized in that: An oil adding channel is provided on the guide seat, and the oil adding channel can face the oil filling hole provided on the nut.

6. The linear telescopic structure for preventing screw rotation according to claim 5, characterized in that: The nut is limited by a limiting structure that rotates synchronously with it. The limiting structure is provided with an oil passage. At least one end face of the limiting structure opposite to the nut is provided with an annular groove. The annular groove connects the oil passage and the oil filling hole. One end of the oil passage can face the oil filling channel.

7. An electric motor comprising a housing, a stator fixed in the housing, and a rotor rotatably connected in the housing, characterized in that: It also includes a linear telescopic structure for preventing the screw from rotating as described in any one of claims 1 to 6, and the nut rotates synchronously with the rotor.

8. The electric motor according to claim 7, characterized in that: The machine also includes a brake, which is mounted on the housing and is used to brake the rotor.

9. The electric motor according to claim 8, characterized in that: A brake adapter disc is fixedly connected to the rotor, and the brake can engage or release the adapter disc.

10. An electric pump comprising an electric motor and a pump body driven by the electric motor, characterized in that: The electric motor is as shown in claim 7.

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