An electric push rod with a refueling structure and a refueling method thereof

Abstract

The present invention discloses an electric push rod with a refueling structure and a refueling method thereof, which belongs to the field of linear transmission technology, and comprises an outer tube, an inner tube, a screw and a nut movably installed along the axial direction of the screw, the nut is installed on the screw, the screw is arranged in the inner tube, the inner tube is arranged in the outer tube, the nut is installed on the inner tube, an oil cavity is formed between the inner wall of the inner tube and the screw, an outer through hole is provided on the side wall of the outer tube, an inner through hole is provided on the side wall of the inner tube, the inner through hole and the oil cavity are connected, and the inner through hole is used to fill the oil cavity with oil. The advantage of the present invention is that the oil cavity is filled with oil through the inner through hole, so that grease can be supplemented between the screw and the nut. At the same time, the relative movement between the screw and the nut is utilized, so that the screw and the nut can drive the grease to move, so that the screw and the nut can always maintain a grease-lubricated state.

Description

[Technical field]

[0001] The invention relates to an electric push rod with a refueling structure and a refueling method thereof, belonging to the technical field of linear transmission. [Background technology]

[0002] The main working principle of an electric push rod is to drive the lead screw to rotate through a motor. A transmission nut is arranged on the lead screw, and the transmission nut is driven to reciprocate when the lead screw rotates.

[0003] Conventional electric linear actuators are greased once before being assembled and shipped out of the factory, and the grease is basically not added during the service life of the linear actuator. For linear actuators used in ordinary environments, the service life requirements can be met.

[0004] However, taking the solar push rod used outdoors as an example, its service life is required to be as long as 25 years. The grease initially added to the screw rod and the nut is not enough to enable the solar push rod to meet the 25-year service life requirement. During the use of the solar push rod within the service life range, the screw rod and the nut cannot always remain lubricated with grease. [Summary of the invention]

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an electric push rod with a refueling structure and a refueling method thereof. During the use of the electric push rod, grease can be regularly added to the electric push rod to always keep grease lubrication between the screw rod and the nut.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] An electric push rod with an oiling structure comprises an outer tube, an inner tube, a screw and a nut movably installed along the axial direction of the screw, the nut is installed on the screw, the screw is arranged in the inner tube, the inner tube is arranged in the outer tube, the nut is installed on the inner tube, an oil cavity is formed between the inner wall of the inner tube and the screw, an outer through hole is opened on the side wall of the outer tube, an inner through hole is opened on the side wall of the inner tube, the inner through hole and the oil cavity are connected, and the inner through hole is used for filling oil into the oil cavity.

[0008] When the outer through hole is connected to the inner through hole, oil is injected into the inner through hole through the outer through hole, thereby injecting oil into the oil chamber, so that grease can be replenished between the screw rod and the nut. At the same time, the relative movement between the screw rod and the nut is used to drive the grease to move, so that the screw rod and the nut can always maintain a grease lubricated state. The method of using the relative movement of the screw rod and the nut to drive the grease movement can maintain the amount of grease required for lubrication between the screw rod and the nut at a low level, while maintaining a high lubrication effect between the screw rod and the nut.

[0009] The nut of the present invention is located at one end of the oil cavity, and a closure is provided at the other end of the oil cavity. The nut and the closure respectively close the two ends of the oil cavity, and the inner through hole is located between the closure and the nut. The oil cavity has no other inlet and outlet except the inner through hole, so that the oil in the oil cavity can be preserved for a long time, and the oil in the oil cavity is reduced from flowing out of the oil cavity.

[0010] The closure member of the present invention is a limit ring, which is installed on the screw rod. The limit ring can play a hard limit role on the position of the nut when the screw rod moves in the axial direction, and the limit ring can prevent the screw rod from contacting the inner wall of the inner tube during rotation.

[0011] The screw rod of the present invention includes a smooth section and a transmission section fixed to each other, a nut is threadedly connected to the transmission section, the inner wall of the limit ring fits on the outer wall of the smooth section, and the outer wall of the limit ring and the outer wall of the nut both fit on the inner wall of the inner tube. The threaded connection between the nut and the transmission section allows the inner wall of the nut to be sealed with the outer wall of the transmission section, and the inner wall of the limit ring fits on the outer wall of the smooth section, allowing the inner wall of the limit ring to be sealed with the outer wall of the smooth section. The outer wall of the limit ring and the outer wall of the nut fit on the inner wall of the inner tube, allowing the outer wall of the limit ring to be sealed with the inner wall of the inner tube, and at the same time, allowing the outer wall of the nut to be sealed with the inner wall of the inner tube, thereby ensuring that the oil chamber has no other inlet and outlet except the inner through hole.

[0012] The refueling channel is formed between the inner side of the inner through hole and the outer side of the outer through hole of the present invention. The refueling channel is used to inject oil into the oil cavity from the outer side of the outer through hole. A sealing member is arranged in the refueling channel. The sealing member is connected to a reset member. The reset member is used to block the refueling channel. When not injecting oil, the sealing member blocks the refueling channel under the action of the reset member, and thus the oil cavity cannot be injected with oil from the outer side of the outer through hole. When injecting oil, the sealing member overcomes the action of the reset member, so that the refueling channel is unobstructed, so that the user can inject oil into the oil cavity from the outer side of the outer through hole.

[0013] The outer through hole of the present invention is provided with a refueling nozzle, which is used to inject oil into the outer through hole, and a reset member is used to make a sealing member block the mouth of the refueling nozzle. The reset member is a spring, and the sealing member is fixed on the spring. The spring and the sealing member are both located in the refueling nozzle, and the end of the spring is fixed on the inner wall of the refueling nozzle or the outer wall of the outer tube. In the non-oil injection state, the seal is blocked at the mouth of the refueling nozzle by the reset member, so that the oil is sealed in the electric push rod. When injecting oil, the seal overcomes the action of the reset member through the oil pressure, so that the mouth of the refueling nozzle and the inner through hole are connected, so that the electric push rod is injected with oil. The spring has a simple structure and a small size, and can be installed in the refueling nozzle without affecting the flow of oil. In addition, the spring and the seal located in the refueling nozzle will not affect the relative movement between the inner tube and the outer tube.

[0014] The sealing member of the present invention is arranged in the oil cavity, and the reset member is used to make the sealing member block the inner through hole. When oil is not injected, the sealing member blocks the inner through hole from the inner side of the inner through hole under the action of the reset member, so that the inner through hole cannot be filled with oil or discharged with oil. When oil is injected, the sealing member overcomes the action of the reset member and leaves the inner through hole, so that the inner through hole can be filled with oil or discharged with oil.

[0015] The outer wall of the inner tube of the present invention is provided with an oil guide groove for injecting oil into the inner through hole, the bottom of the oil guide groove is located on the outer wall of the inner tube, the bottom of the oil guide groove is connected with the inner through hole, and the outer through hole is used to inject oil into the notch of the oil guide groove. Relative movement will occur between the inner tube and the outer tube. When the outer through hole is not aligned with the oil guide groove, the outer through hole cannot accurately inject oil into the oil guide groove, and further, the inner through hole cannot be accurately injected with oil. When the inner tube and the outer tube move relative to a specific position, so that the outer through hole is aligned with the notch that penetrates the oil guide groove, the oil guide groove can be accurately injected with oil through the outer through hole, and further, the inner through hole can be accurately injected with oil.

[0016] The number of the inner through holes of the present invention is more than two, and all the inner through holes are connected to the oil guide groove. When oil is injected into one inner through hole, the air in the oil cavity is connected to the air in the oil guide groove through the remaining inner through holes, so that there is no air pressure difference between the oil cavity and the oil guide groove, making the oil injection process of the oil cavity smoother.

[0017] The inner wall of the outer tube of the present invention is used to seal the notch of the oil guide groove. When the outer through hole is not aligned with the notch of the oil guide groove, the inner wall of the outer tube completely seals the notch of the oil guide groove, so that the oil can be confined in the oil guide groove and the oil cavity. When the outer through hole is aligned with the notch of the oil guide groove and penetrates, the grease injected into the outer through hole can completely flow into the oil guide groove, and thus completely flow into the oil cavity.

[0018] There is a ventilation gap between the inner wall of the outer tube and the notch of the oil guide groove. The ventilation gap is small in size, and the air in the oil guide groove can be connected with the air in the outer tube during oil filling, so that the air pressure is kept consistent, making the oil filling process smoother, while not affecting the precise oil filling of the oil guide groove by the outer through hole.

[0019] The nut of the present invention is sealed with the inner wall of the outer tube, and the outer tube is sealed with one end adjacent to the closure member. This structure forms a relatively closed structure between the outer tube and the inner tube.

[0020] A refueling method for an electric push rod having a refueling structure, comprising the following steps:

[0021] Step ①: inject oil into the inner through hole through the outer through hole, so that the inner through hole injects oil into the oil cavity;

[0022] Step 2: When the nut and the screw rod move relative to each other along the screw rod axis, the oil in the oil chamber moves

[0023] The relative movement of the nut and the screw rod drives the movement of the oil, so that the lubrication effect between the nut and the screw rod is most uniform, and the loss of oil is also small.

[0024] When the invention is not filling oil, the seal blocks the mouth of the oiling nozzle through the elastic force of the spring; when the oiling nozzle is filled with oil, the seal leaves the mouth of the oiling nozzle under the action of oil pressure. The seal cooperates with the spring to control whether the oiling nozzle is filled with oil, and finally controls the oil inlet of the inner tube.

[0025] Other features and advantages of the present invention will be disclosed in detail in the following specific embodiments and drawings.

Brief Description of the Drawings

[0026] The present invention will be further described below in conjunction with the accompanying drawings:

[0027] Figure 1 This is a schematic diagram of the front and cross-sectional structure of an electric push rod with a refueling structure according to Embodiment 1 of the present invention;

[0028] Figure 2 It is a schematic diagram of a right side cross-sectional structure of an electric push rod with a refueling structure according to Embodiment 1 of the present invention;

[0029] Figure 3 This is a schematic diagram of the explosion structure of the electric push rod with a refueling structure according to Example 1 of the present invention. [Specific implementation method]

[0030] The technical solutions of the embodiments of the present invention are explained and described below in conjunction with the drawings of the embodiments of the present invention, but the following embodiments are only preferred embodiments of the present invention, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the protection scope of the present invention.

[0031] In the following description, terms such as "inside", "outside", "up", "down", "left", "right", etc. that indicate orientation or position relationship are based on the orientation or position relationship shown in the drawings and are only for the convenience of describing the embodiments and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0032] Example 1.

[0033] See also Figure 1-3 .

[0034] This embodiment provides an electric push rod with an oil filling structure, including a screw rod 3, a nut 4 and an inner tube 2. The nut 4 is threadedly connected to the screw rod 3 so that the nut 4 can move relatively along the axial direction of the screw rod 3. The screw rod 3 is arranged in the inner tube 2, the nut 4 is arranged on the inner tube 2, and an oil cavity is formed between the inner wall of the inner tube 2 and the screw rod 3. An inner through hole for filling the oil cavity with oil is opened on the side wall of the inner tube 2, and the inner through hole and the oil cavity are connected.

[0035] The refueling method of the electric push rod with a refueling structure in this embodiment includes the following steps: injecting oil into the oil chamber through the inner through hole, and when the nut 4 and the screw rod 3 move relative to each other along the axial direction of the screw rod 3, the oil in the oil chamber is driven to move.

[0036] In this embodiment, the oil chamber is filled with oil through the inner through hole so that grease can be replenished between the screw rod 3 and the nut 4. At the same time, since the nut 4 and the screw rod 3 can generate relative movement along the axial direction of the screw rod 3, the oil injected into the oil chamber can spread throughout the screw rod 3 as the screw rod 3 and the nut 4 move relative to each other, ensuring that the screw rod 3 and the nut 4 can always maintain a grease-lubricated state during the relative movement. In addition, in this way, the amount of grease required for lubrication between the screw rod 3 and the nut 4 can be maintained at a low level, while maintaining a good lubrication effect between the screw rod 3 and the nut 4. This embodiment makes full use of the relative movement between the screw rod 3 and the nut 4, effectively and evenly disperses the oil injected into the oil chamber, and optimizes the cost-effectiveness of the lubrication effect.

[0037] In this embodiment, the nut 4 is located at one end of the oil chamber, a sealing member is provided at the other end of the oil chamber, the oil chamber is located in the inner tube 2, and the nut 4 and the sealing member seal the two ends of the oil chamber respectively. The side of the nut 4 close to the sealing member is the left end face 41, the side of the nut 4 away from the sealing member is the right end face 42, and the inner through hole is located between the sealing member and the left end face 41.

[0038] See also Figure 1 , the nut 4 is usually fixed to one end of the inner tube 2. For example, in this embodiment, the nut 4 is fixed to the right end of the inner tube 2. At this time, the left end face 41 and the right end of the oil chamber overlap with each other, and the left end face 41 is the right end of the oil chamber. The nut 4 closes the right end of the oil chamber. After the nut 4 is installed on the screw 3, the right end of the oil chamber is completely closed. Similarly, the closure is set at the left end of the oil chamber, and the closure is located in the inner tube 2 (not limited to the end of the inner tube 2) to close the left end of the oil chamber. At this time, the entire oil chamber has no other oil inlets and outlets except the inner through hole. The nut 4 and the closure cooperate with each other, so that the oil in the oil chamber can be preserved for a long time, reducing the oil in the oil chamber from flowing in and out of the oil chamber.

[0039] In addition, since the sealing member and the nut 4 cooperate to make the oil chamber a relatively closed space, when the inner through hole is located between the sealing member and the left end face 41, the inner through hole can be filled with oil so that the oil is in the relatively closed oil chamber, ensuring that the oil can be surely distributed throughout the screw rod when the screw rod 3 and the nut 4 move relative to each other. If the inner through hole is located on the right side of the right end face 42, the oil injected through the inner through hole falls into a non-closed structure, and even if a large amount of oil is injected, it cannot be ensured that enough oil falls on the screw rod 3, which hinders the lubrication between the screw rod 3 and the nut 4.

[0040] Preferably, the closing member is a limit ring 8, which is mounted on the screw rod 3. In this embodiment, the limit ring 8 can not only close the left end of the oil chamber, but also play a hard limit role on the position of the nut 4 when the screw rod 3 moves in the axial direction. At the same time, the limit ring 8 can prevent the screw rod 3 from contacting the inner wall of the inner tube 2 during the rotation process.

[0041] In contrast to the structure of the limiting ring 8, the screw rod 3 includes a smooth section 31 and a transmission section 32 fixed to each other. The outer wall of the transmission section 32 is provided with threads so that the nut 4 is threadedly connected to the transmission section 32, thereby sealing the inner wall of the nut 4 and the outer wall of the transmission section 32. The outer wall of the smooth section 31 is smooth so that the inner wall of the limiting ring 8 fits on the outer wall of the smooth section 31, thereby sealing the inner wall of the limiting ring 8 and the outer wall of the smooth section 31. In addition, the outer wall of the limiting ring 8 and the outer wall of the nut 4 at the left end face 41 are both fitted on the inner wall of the inner tube 2, so that the outer wall of the limiting ring 8 and the inner wall of the inner tube 2 are sealed, and at the same time, the outer wall of the nut 4 and the inner wall of the inner tube 2 are sealed, which ensures that the left and right ends of the oil chamber are sealed, thereby ensuring that the oil chamber has no other inlet and outlet except the inner through hole.

[0042] Preferably, the number of the inner through holes is more than two. All the inner through holes can be evenly arranged along the circumference of the inner tube 2. When oil is injected into one or more inner through holes, it is ensured that at least one inner through hole is connected to the air outside the inner tube 2 during the oil injection process, so that there is no pressure difference between the inside of the oil chamber and the outside of the inner tube 2, thereby reducing the occurrence of the situation where oil injection cannot be performed.

[0043] In this embodiment, the number of the inner through holes is two as an example, and the two inner through holes are respectively an upper inner through hole 21 and a lower inner through hole 22, and the upper inner through hole 21 and the lower inner through hole 22 are symmetrically arranged on the inner tube 2 along the radial direction of the inner tube 2. During the refueling process of the lower inner through hole 22, the air in the oil cavity is discharged from the upper inner through hole 21 and communicates with the air at the inner through hole 22, forming a relatively flowing ventilation structure.

[0044] In addition, the electric push rod of the refueling structure in this embodiment also includes an outer tube 1, an inner tube 2 is arranged inside the outer tube 1, and a screw rod 3 is fixed to the outer tube 1. When the screw rod 3 and the nut 4 move relative to each other, the inner tube 2 and the outer tube 1 are driven to move relative to each other, and the relative movement direction of the inner tube 2 and the outer tube 1 is the axial direction of the screw rod 3.

[0045] The outer tube 1 is provided with an outer through hole 11, and a refueling channel is formed between the inner side of the lower inner through hole 22 and the outer side of the outer through hole 11. The refueling channel is used to inject oil into the oil chamber from the outer side of the outer through hole 11, and the outer through hole 11 is used to inject oil into the lower inner through hole 22. In this embodiment, when the outer through hole 11 and the lower inner through hole 22 are connected, the outer through hole 11 injects oil into the lower inner through hole 22. When one of the outer through hole 11 and the lower inner through hole 22 is blocked, or the outer through hole 11 and the lower inner through hole 22 are blocked, the outer through hole 11 cannot inject oil into the lower inner through hole 22.

[0046] In this embodiment, a pull head 10 is installed at the left end of the outer tube 1. The pull head 10 includes an inserting portion 101 inserted into the left end of the inner tube 2, and the left end of the inner tube 2 is sealed by the inserting portion 101.

[0047] Usually, there is a gap between the outer tube 1 and the inner tube 2. In order to form a relatively sealed environment between the outer tube 1 and the inner tube 2, a clamping ring 9 can be provided between the inner tube 2 and the inner wall of the outer tube 1. The clamping ring 9 is sleeved on the inner tube 2, and the outer wall of the clamping ring 9 is attached to the inner wall of the outer tube 1. The inner tube 2, the plug-in portion 101 and the clamping ring 9 cooperate to achieve the sealing of the left end of the outer tube 1.

[0048] In addition, in order to fix the nut 4 on the inner tube 2, the portion of the nut 4 close to the right end surface 42 is exposed outside the inner tube 2, so as to achieve the clamping effect between the nut 4 and the inner tube 2. A sealing ring 6 is sleeved on the outer wall of the portion of the nut 4 exposed outside the inner tube 2, and the outer wall of the sealing ring 6 is attached to the inner wall of the outer tube 1. The screw rod 3, the nut 4 and the sealing ring 6 cooperate to achieve the sealing of the right end of the outer tube 1.

[0049] In this embodiment, the left end of the outer tube 1, the limiting ring 8, the nut 4 and the right end of the outer tube 1 are arranged in sequence, so no matter how the mutual spacing between the left end of the outer tube 1, the limiting ring 8, the nut 4 and the outer tube 1 is, the left end of the outer tube 1 is the end of the outer tube 1 adjacent to the limiting ring 8.

[0050] In order to accurately inject oil into the lower inner through hole 22 through the outer through hole 11, an oil guide groove for injecting oil into the lower inner through hole 22 is provided on the outer wall of the inner tube 2. The installation form of the oil guide groove can be integrally formed with the inner tube 2 or fixedly installed on the inner tube 2. In this embodiment, the oil guide groove is fixedly installed on the inner tube 2.

[0051] Specifically, the oil guide groove is provided on a guide ring 5, and the oil guide groove is formed by the middle of the outer surface of the guide ring 5 being recessed inwardly along the radial direction of the guide ring 5, and the edge of the outer surface of the guide ring 5 becomes the groove wall 53 of the oil guide groove. In the radial direction of the guide ring 5, the inner side of the oil guide groove is the groove bottom 54 of the oil guide groove, and the outer side of the oil guide groove is the notch of the oil guide groove. The middle of the inner surface of the guide ring 5 protrudes inwardly along the radial direction of the guide ring 5 to form a convex ring 55. In addition, the groove bottom 54 is provided with an upper hole 51 and a lower hole 52.

[0052] In contrast, an annular groove 23 is provided on the inner tube 2, and the convex ring 55 matches the shape of the annular groove 23, so that after the convex ring 55 is installed in the annular groove 23, it cannot generate relative displacement with the annular groove 23 along the axial direction of the inner tube 2. At the same time, the upper hole 51 is connected with the upper inner through hole 21, and the lower hole 52 is connected with the lower inner through hole 22. After the guide ring 5 is installed in the annular groove 23, the groove bottom 54 of the oil guide groove is located on the outer wall of the inner tube 2, the outer through hole 11 is used to fill the notch of the oil guide groove with oil, and the inner wall of the outer tube 1 is used to seal the notch of the oil guide groove. At the same time, the inner wall of the outer tube 1 and the groove wall 53 fit each other, so that when the outer through hole 11 is filled with oil, the oil is confined in the oil guide groove. Relative movement will occur between the inner tube 2 and the outer tube 1. By controlling the relative position of the inner tube 2 and the outer tube 1, it is controlled whether the outer through hole 11 is connected with the notch of the oil guide groove.

[0053] When oil is not injected, when the outer through hole 11 is not connected to the notch of the oil guide groove, the inner wall of the outer tube 1 and the groove wall 53 fit each other, and the inner wall of the outer tube 1 completely seals the notch of the oil guide groove, so the outer through hole 11 cannot inject oil into the oil guide groove, and further cannot inject oil into the lower inner through hole 22, and the oil in the inner tube 2 will not leak out from the outer through hole 11. At this time, the inner wall of the outer tube 1, the oil guide groove and the oil chamber form a closed structure.

[0054] When the outer through hole 11 is connected to the slot of the oil guide groove, oil can be injected into the oil guide groove through the outer through hole 11, and then into the lower inner through hole 22. In addition, since the inner wall of the outer tube 1 and the slot wall 53 of the oil guide groove cooperate and seal with each other, the oil injected from the outer through hole 11 is limited to be injected into the lower inner through hole 22 through the oil guide groove, and will not flow into other positions between the inner tube 2 and the outer tube 1 except the oil guide groove, thereby realizing accurate oil injection into the oil cavity.

[0055] Preferably, the oil guide groove is an annular groove, and the oil guide groove is coaxially arranged with the inner tube 2. At this time, the oil guide groove penetrates the upper inner through hole 21 and the lower inner through hole 22 at the same time. Since there is a gap between the groove bottom 54 of the oil guide groove and the inner wall of the outer tube 1, the air discharged from the oil cavity when the lower inner through hole 22 is filled with oil can leave from the upper inner through hole 21, and then flow to the lower inner through hole 22 through the oil guide groove, ensuring that the air pressure in the oil cavity and the oil guide groove is the same during the oil filling process. At this time, the electric push rod of this embodiment can be used as a solar push rod for outdoor use, which is adapted to the requirements of a higher protection level.

[0056] In this embodiment, a sealing member is provided in the refueling passage, and the sealing member is connected to a reset member, and the reset member is used to block the refueling passage. When not filling oil, the sealing member blocks the refueling passage under the action of the reset member, and thus the oil cavity cannot be filled with oil from the outside of the outer through hole 11. When filling oil, the sealing member overcomes the action of the reset member, making the refueling passage unobstructed, so that the user can fill oil into the oil cavity from the outside of the outer through hole 11.

[0057] In addition, in order to facilitate the control of oil filling through the outer through hole 11 , a refueling nozzle 7 can be provided on the outer through hole 11 , and the mouth of the refueling nozzle 7 is located outside the outer through hole 11 so that the user can fill oil into the outer through hole 11 through the refueling nozzle 7 .

[0058] In this embodiment, the sealing member is arranged in the oiling nozzle 7, and the reset member is used to make the sealing member block the mouth of the oiling nozzle 7. When oil is not injected, the sealing member blocks the mouth of the oiling nozzle 7 under the action of the reset member, so that the mouth of the oiling nozzle 7 cannot discharge oil or inject oil, thereby sealing the inside of the electric push rod. When oil is injected, the sealing member overcomes the action of the reset member under the action of oil pressure and moves away from the mouth of the oiling nozzle 7 toward the inner tube 2, so that the mouth of the oiling nozzle 7 and the lower inner through hole 22 are connected to each other.

[0059] When filling oil, pay attention to controlling the oil pressure, or reasonably design the shape relationship among the nozzle of the oil filling nozzle 7, the external through hole 11 and the sealing member to ensure that the sealing member does not block the external through hole 11 when filling oil.

[0060] Preferably, the reset member is a spring and the sealing member is a steel ball. The steel ball can be fixed on one end of the spring, and the other end of the spring is fixed on the inner wall of the oiling nozzle 7 or the outer wall of the outer tube 1. The steel ball is used to block the mouth of the oiling nozzle 7, and the steel ball and the spring are both located in the oiling nozzle 7.

[0061] In the non-oiling state, the steel ball blocks the mouth of the oiling nozzle 7 under the action of the spring. When oiling, the steel ball overcomes the elastic force of the spring and leaves the mouth of the oiling nozzle 7 and moves toward the inner tube 2. At the same time, the oil pressure, the shape and size of the outer through hole 11 and the shape and size of the steel ball are controlled to ensure that the steel ball does not block the outer through hole 11. At this time, the movement space of the steel ball and the spring is always limited in the oiling nozzle 7. At this time, due to the simple structure and small size of the spring, it can be installed in the oiling nozzle 7 without affecting the flow of oil. In addition, the steel ball and the spring will not affect the relative movement between the inner tube 2 and the outer tube 1.

[0062] Example 2.

[0063] The difference between this embodiment and embodiment 1 is that there is no oil guide groove in this embodiment, and in addition, a sealing member is arranged between the inner wall of the outer tube and the outer wall of the inner tube, and the reset member is used to make the sealing member block the outer through hole.

[0064] In the non-oil injection state, the seal blocks the outer through hole under the action of the reset member, so that the outer through hole cannot discharge oil or inject oil, thereby sealing the inside of the outer tube. When injecting oil, the seal overcomes the action of the reset member under the action of oil pressure, leaves the outer through hole and moves toward the inner tube, so that the lower inner through hole and the outer through hole are interconnected, so that the outer through hole can be injected with oil. When injecting oil, pay attention to controlling the oil pressure, or reasonably design the shape relationship between the lower inner through hole and the seal to ensure that the seal does not block the lower inner through hole when injecting oil.

[0065] Preferably, the reset member is a spring and the sealing member is a steel ball. The steel ball can be fixed on one end of the spring, and the other end of the spring is fixed on the inner wall of the oil nozzle or the inner wall of the outer tube. In the non-oil injection state, the steel ball blocks the outer through hole on the inner side of the inner wall of the outer tube under the action of the spring. When oil is injected, the steel ball overcomes the elastic force of the spring and leaves the outer through hole and moves toward the inner tube. At this time, the sealing member and the reset member will not affect the relative movement of the inner tube and the outer tube.

[0066] Example 3.

[0067] The difference between this embodiment and embodiment 1 is that the sealing member is arranged in the oil chamber, and the reset member is used to make the sealing member block the lower inner through hole.

[0068] In the non-oil injection state, the seal blocks the lower inner through hole under the action of the reset member, so that the lower inner through hole cannot be filled with oil or discharged. If there is no upper inner through hole, the oil cavity is sealed at this time. When filling oil, the seal overcomes the action of the reset member under the action of oil pressure and leaves the lower inner through hole, so that the nozzle of the oil filling nozzle and the lower inner through hole are connected, so that the lower inner through hole can be filled with oil.

[0069] Preferably, the reset member is a spring and the sealing member is a steel ball. The steel ball can be fixed on one end of the spring, and the other end of the spring is fixed on the inner wall of the inner tube. In the non-oil-injected state, the steel ball blocks the lower inner through hole in the oil chamber under the action of the spring. When oil is injected, the steel ball overcomes the elastic force of the spring and moves toward the axis of the inner tube.

[0070] At this time, it is necessary to reasonably set the limit device and the position of the lower inner through hole of the electric push rod with the oiling structure so that the spring and the steel ball will not affect the relative movement of the screw rod and the nut.

[0071] Example 4.

[0072] The difference between this embodiment and embodiment 1 is that there is a ventilation gap between the inner wall of the outer tube and the notch of the oil guide groove, and the size of the ventilation gap is relatively small. When the outer through hole and the notch of the oil guide groove are relatively connected, most of the oil injected from the outer through hole can still enter the oil guide groove and then enter the oil cavity.

[0073] In this embodiment, when oil is injected, the air in the oil guide groove can be connected with the air in the outer tube to keep the air pressure consistent, so that the oil injection process can be smoother.

[0074] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the contents described in the drawings and the above specific embodiments. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims

1. An electric push rod with a refueling structure, comprising an outer tube, an inner tube, a screw rod and a nut movably installed along the axial direction of the screw rod, the nut is installed on the screw rod, the screw rod is arranged in the inner tube, the inner tube is arranged in the outer tube, and the nut is installed on the inner tube, characterized in that: An oil chamber is formed between the inner wall of the inner tube and the screw rod, an outer through hole is provided on the side wall of the outer tube, and an inner through hole is provided on the side wall of the inner tube, the inner through hole and the oil chamber are connected, and the inner through hole is used to fill the oil chamber with oil; when the nut and the screw rod move relative to each other along the axial direction of the screw rod, the oil in the oil chamber is driven to move; the nut is located at one end of the oil chamber, and a closing piece is provided at the other end of the oil chamber, the nut and the closing piece respectively close the two ends of the oil chamber, and the inner through hole is located between the closing piece and the nut; the closing piece is a limit ring, and the limit ring is installed on the screw rod; the screw rod includes a smooth section and a transmission section fixed to each other, the nut is threadedly connected to the transmission section, the inner wall of the limit ring fits on the outer wall of the smooth section, and the outer wall of the limit ring and the outer wall of the nut are both fitted on the inner wall of the inner tube; a refueling channel is formed between the inner side of the inner through hole and the outer side of the outer through hole, and the refueling channel is used to fill oil into the oil chamber from the outside of the outer through hole, a sealing member is arranged in the refueling channel, and the sealing member is connected with a reset member, and the reset member is used to make the seal block the refueling channel; a refueling nozzle is arranged on the outer through hole, and the refueling nozzle is used to fill oil into the outer through hole, and the reset member is used to make the seal block the mouth of the refueling nozzle, the reset member is a spring, and the seal is fixed on the spring, and the spring and the seal are both located in the refueling nozzle, and the end of the spring is fixed on the inner wall of the refueling nozzle or the outer wall of the outer tube; the seal is arranged in the oil chamber, and the reset member is used to make the seal block the inner through hole.

2. The electric push rod with a refueling structure according to claim 1, characterized in that: The outer wall of the inner tube is provided with an oil guide groove for injecting oil into the inner through hole. The bottom of the oil guide groove is located on the outer wall of the inner tube. The bottom of the oil guide groove is connected with the inner through hole. The outer through hole is used to inject oil into the notch of the oil guide groove.

3. The electric push rod with a refueling structure according to claim 2, characterized in that: The number of the inner through holes is more than two, and all the inner through holes are connected to the oil guide groove.

4. The electric push rod with a refueling structure according to claim 3, characterized in that: The inner wall of the outer tube is used to seal the notch of the oil guide groove, or there is a ventilation gap between the inner wall of the outer tube and the notch of the oil guide groove.

5. A refueling method for an electric push rod having a refueling structure according to any one of claims 1 to 4, characterized in that: The steps include: Step ①: inject oil into the inner through hole through the outer through hole, so that the inner through hole injects oil into the oil cavity; Step ②: When the nut and the screw rod move relative to each other along the axial direction of the screw rod, the oil in the oil chamber moves.

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