Medical electric push rod and medical lifting equipment

Abstract

The invention provides a medical electric push rod and medical lifting equipment, the medical electric push rod comprises a rotation driving element, a transmission screw rod and a transmission nut, a transmission assembly is connected between a rotation driving assembly and the transmission nut to transmit torque to the transmission nut, and the transmission screw rod moves along the axis of the transmission nut when the transmission nut rotates; the transmission assembly comprises a worm and gear pair and a bevel gear pair, the rotation driving element, the worm and gear pair, the bevel gear pair and the transmission nut are in transmission in sequence, the transmission assembly further comprises a first shell and a second shell, a first cavity for containing the worm and gear pair is formed in the first shell, and a second cavity for containing the bevel gear pair is formed in the second shell. A first cavity for containing the worm and gear pair is arranged in the first shell, a second cavity for containing the bevel gear pair is arranged in the second shell, lubricating oil for lubricating the worm and gear pair is arranged in the first cavity, a lubricating medium for lubricating the bevel gear pair is arranged in the second cavity, and the first shell is provided with an oil seal for isolating the first cavity from the second cavity. The medical electric push rod is high in oil leakage prevention capacity, high in safety and long in service life.

Description

Technical Field

[0001] The present invention relates to the technical field of medical equipment, and in particular to a medical electric push rod and a medical lifting device. Background Art

[0002] Existing medical equipment such as medical beds usually adopt lifting structures, which can be adjusted in height to facilitate the application of medical equipment. Among them, the lifting structure mostly adopts electric push rods, which cooperate with power equipment to realize the automatic lifting of medical equipment. For example, the lifting of CT beds uses electric push rods. Electric push rods usually include motors, transmission components and screw rods. The motor drives the screw rod to rotate through the transmission components, and then the screw rod pushes the telescopic sleeve with threads to form telescopic.

[0003] For example, in the Chinese patent literature, there is a utility model patent with patent number CN2023231956317 authorized and announced on September 13, 2024, entitled "Quick Release Structure for Medical Push Rod". The application includes a casing, on which a screw and a motor are provided. The motor is provided with a worm gear for driving the screw to rotate. The motor and the worm gear are connected through a worm gear transmission. A worm gear coupling is provided in the worm gear, and the worm gear sleeve is arranged on the outer periphery of the worm gear coupling; one end of the screw is connected to the telescopic sleeve, and a screw coupling is provided on the other end of the screw, and the screw coupling is connected to the worm gear coupling in driving manner. The casing is provided with a driving worm gear coupling and the screw. The clutch mechanism for separating the coupling.

[0004] The shortcomings of the prior art are: 1. In order to prevent the electric push rod from interfering with the external area of ​​the medical equipment, the electric push rod is usually placed vertically, which limits the minimum height of the lifting bed; 2. The worm gear assembly, as the first-stage transmission assembly connected to the motor, is noisy and prone to oil leakage. In addition, the performance of the components of the medical push rod lacks monitoring, and there are defects in safety and cleanliness. Summary of the invention

[0005] In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a medical electric push rod and a medical lifting device, which have strong oil leakage prevention capability, high safety, and a long service life of the medical electric push rod.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions.

[0007] A medical electric push rod comprises a rotary drive element, a transmission screw and a transmission nut. A transmission assembly is connected between the rotary drive assembly and the transmission screw to transmit torque to the transmission nut. When the transmission nut rotates, the transmission screw moves along the axis of the transmission nut. The transmission screw is fixedly connected to a driving actuator. The transmission assembly comprises a worm gear pair and a bevel gear pair. The rotary drive element, the worm gear pair, the bevel gear pair and the transmission nut are driven in sequence. The transmission assembly also comprises a first housing and a second housing. A first chamber for accommodating the worm gear pair is provided inside the first housing, and a second chamber for accommodating the bevel gear pair is provided inside the second housing. Lubricating oil for lubricating the worm gear pair is provided in the first chamber, and a lubricating medium for lubricating the bevel gear pair is provided in the second chamber. The first housing is provided with an oil seal for isolating the first chamber and the second chamber.

[0008] The transmission assembly has two-stage transmission, namely a worm gear pair and a bevel gear pair. The worm gear is lubricated with lubricating oil. When the oil seal fails and causes the lubricating oil to leak in the first housing, the lubricating oil will not flow directly to the outside of the first housing, but will be stored in the second housing, thus providing double protection against oil leakage. Moreover, the oil seal will not be ejected due to the difference in air pressure between the first housing and the second housing. The bevel gear pair blocks the oil seal to avoid the risk of external explosion of the oil seal.

[0009] The worm gear pair is self-locking and the power is transmitted in one direction, which can prevent the transmission screw from retreating due to the pressure on the medical bed.

[0010] Preferably, the transmission nut is connected to a hollow drive shaft that rotates synchronously with the hollow drive shaft, the hollow drive shaft rotates synchronously with the driven gear of the bevel gear pair, a safety nut is limited inside the hollow drive shaft, the safety nut has the same lead as the transmission nut, the safety nut is separated from the transmission screw when the transmission nut cooperates with the transmission screw, and the safety nut cooperates with the transmission screw when the transmission nut fails, and an elastic part corresponding to the safety nut is provided in the hollow drive shaft.

[0011] When the transmission nut is crushed and fails, the transmission screw moves axially relative to the hollow drive shaft. At this time, the transmission screw cooperates with the safety nut, and the rotation of the hollow drive shaft is transmitted to the safety nut, so that the transmission screw will not fail immediately. In the process of cooperation between the transmission screw and the safety nut, the elastic part plays a role of elastic buffering, preventing the safety nut from rigidly bearing the pressure load of the transmission screw, so that the cooperation between the safety nut and the transmission screw can achieve a relatively stable transmission cooperation of the transmission screw, and at the same time prevent the safety nut from being crushed and deformed instantly, thereby playing a buffering role for the electric push rod as a whole.

[0012] Preferably, a sensor is fixedly provided on the second housing, and a sensor trigger ring cooperating with the sensor is provided on the safety nut. The sensor trigger ring follows the safety nut to cooperate with the sensor to feedback a stop signal to the rotating drive element when the safety nut is working. When the sensor cooperates with the safety nut and the transmission screw, the safety nut overcomes the elastic force of the elastic member to move axially. Since the trigger ring follows the safety nut, the trigger ring also moves axially and then cooperates with the sensor. When the sensor detects the sensor trigger ring, the sensor outputs a stop signal to the rotating drive element, and then the rotating drive element stops, so as to avoid the rotating drive element still continuously outputting power when the transmission nut fails, causing the rotating drive element to overload or the transmission screw to eject the stroke. After the rotating drive element stops, due to the self-locking effect of the worm gear pair, the transmission screw cannot reversely drive the hollow drive shaft and the safety nut, and the transmission screw is finally constrained by the action of the safety nut, which has high safety.

[0013] Preferably, the hollow drive shaft includes a connecting section extending into the second housing and a mounting section located outside the second housing, the connecting section is rotatably connected to the second housing, the hollow drive shaft is sleeved outside the transmission screw, a stepped hole is provided in the mounting section, and the elastic member, the safety nut and the transmission nut are sequentially arranged in the stepped hole in a direction away from the connecting section. The stepped hole increases in diameter in a direction away from the connecting section, so that the elastic member, the safety nut and the transmission nut can be assembled in an insert-type manner, and the installation of the elastic member and the safety nut can be completed at the same time by simply locking the transmission nut at the outermost end to fix the transmission nut and the safety section, and the installation efficiency is high.

[0014] Preferably, the safety nut and the sensor trigger ring are connected with a synchronizer, and a guide groove for the synchronizer to pass and slide is provided on the hollow drive shaft. The end of the safety nut facing the side where the second housing is located is aligned with the end of the sensor trigger ring facing the side where the second housing is located, the axial length of the sensor trigger ring is greater than the length of the guide groove, and the sensor corresponds to the radial outer side of the sensor trigger ring to monitor the axial position of the sensor trigger ring; when the transmission screw rod cooperates with the transmission nut, the end of the guide groove facing the second housing is exposed outside the sensor trigger ring; when the sensor can detect the sensor trigger ring, the sensor trigger ring blocks the end of the guide groove facing the second housing. The safety nut and the sensor trigger ring are synchronized through the synchronizer, and the guide groove provides guidance for the sliding of the synchronizer. When the safety nut is displaced, the sensor trigger ring is displaced synchronously, which can be quickly detected by the sensor and has high safety. The position setting of the guide groove allows the guide groove to be used as an external observation indicator to prevent inspection when foreign objects such as paper blocks the sensor, avoid the need to dismantle and repair the electric push rod due to false alarms of the sensor, and improve the convenience and reliability of electric push rod fault detection.

[0015] Preferably, an end cover is provided at one end of the second shell, and a mounting hole is provided in the end cover for the transmission screw to extend out, and a sliding ring groove is provided in the mounting hole, and a support nut is slidably provided in the sliding ring groove, and the support nut is threadedly engaged with the transmission screw, and the outer periphery of the support nut is a cylindrical surface so that the support nut can rotate in the sliding ring groove. The transmission nut supports one part of the transmission screw, and the support nut can support another part of the transmission screw, so as to realize multi-point support of the transmission screw, improve the transmission stability of the transmission screw, and at the same time can reduce the friction between the transmission screw and the hollow transmission shaft, and extend the service life of the transmission screw, and the support nut is slidably arranged in the mounting hole. The support nut can slide in the sliding ring groove, and its cylindrical outer peripheral structure enables it to rotate in the sliding ring groove without interfering with the movement of the transmission screw.

[0016] Preferably, a lubricating blind hole is provided on the periphery of the support nut, and a lubricating medium is filled in the lubricating blind hole. When the transmission screw is working, its thread acts on the support nut, and the rotation or sliding of the support nut in the sliding ring groove will form friction or extrusion between the outer side of the support nut and the groove wall of the sliding ring groove, which will bring out the lubricating medium in the lubricating blind hole, thereby achieving lubrication of the support nut and the sliding ring groove. At the same time, the lubricating medium in the sliding ring groove will partially fall onto the surface of the transmission screw, and then be used for lubrication of the transmission screw and the support nut, and can also serve as lubrication for the transmission screw and the transmission nut.

[0017] Preferably, a pressure sensor is provided at the end of the sliding ring groove, and the pressure sensor is arranged opposite to the axial end of the support nut to detect the axial pressure provided by the support nut. When the transmission screw is working, the support nut is pushed toward one end of the sliding ring groove, so that the support nut and the pressure sensor cooperate to form a pressure indication. When the thread of the transmission screw is excessively worn or there is a foreign object in it, the indication of the pressure sensor exceeds the normal range, thereby completing the monitoring of the state of the transmission screw and realizing the monitoring of the lubrication state of the transmission screw, facilitating the timely replacement of the support nut and extending the service life of the transmission screw.

[0018] A medical lifting device includes a lifting end, a scissor mechanism and the above-mentioned medical electric push rod, the driving actuator of the medical electric push rod is connected to the scissor mechanism and drives the scissor mechanism to extend and retract, the lifting end is connected to the scissor mechanism and rises and falls when the scissor mechanism extends and retracts, and the medical electric push rod is arranged horizontally. The lifting end is a structure such as a bed board, and the medical electric push rod is installed horizontally to effectively solve the dilemma that the medical bed body of CT MR and other medical machinery market cannot be lowered to less than 500mm.

[0019] Preferably, the first shell and the second shell are arranged up and down, and the worm gear pair includes a worm connected to the rotating drive element and a worm wheel rotatably arranged in the first shell. The first shell is rotatably connected to a worm gear shaft that rotates synchronously with the worm wheel. The worm gear shaft is perpendicular to the transmission screw, and the worm axis is parallel to the transmission screw.

[0020] The first shell and the second shell are arranged up and down. When the lubricating oil in the first shell leaks, it flows to the second shell under the action of gravity, thereby realizing secondary leakage prevention of the lubricating oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The figure is a schematic diagram of the structure of a medical electric linear actuator disclosed in one embodiment of the present invention.

[0022] Figure 2 It is a schematic structural diagram of a medical electric linear actuator disclosed in one embodiment of the present invention from a side view.

[0023] Figure 3 It is a schematic diagram of the internal structure of the first shell in the medical electric push rod disclosed in one embodiment of the present invention.

[0024] Figure 4 It is a schematic diagram of the internal structure of the second housing in the medical electric push rod disclosed in one embodiment of the present invention.

[0025] Figure 5 yes Figure 4 A magnified schematic diagram of center A.

[0026] Figure 6 It is a schematic diagram of the internal structure of the second shell in the medical electric push rod disclosed in another embodiment of the present invention.

[0027] Figure 7 yes Figure 6 A magnified schematic diagram of point B in the middle.

[0028] Figure 8 It is a schematic diagram of the structural arrangement of medical lifting equipment in the prior art.

[0029] Fig. 9 It is a schematic diagram of the structural arrangement of a medical lifting device disclosed in one embodiment of the present invention.

[0030] In the figure: transmission screw 1, transmission nut 2, boss 3, first housing 4, first chamber 41, second housing 5, second chamber 51, worm 6, worm wheel 7, worm wheel shaft 8, driving gear 9, driven gear 10, oil seal 11, hollow drive shaft 12, connecting section 13, mounting section 14, stepped hole 15, safety nut 16, elastic member 17, sensor 18, sensor trigger ring 19, synchronizer 20, guide groove 21, end cover 22, mounting hole 23, sliding ring groove 24, cover plate 25, support nut 26, lubrication blind hole 27, pressure sensor 28, lifting end 29, scissor mechanism 30, medical electric push rod 100. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention are intended to cover non-exclusive inclusions. For example, a method or product comprising a series of technical features is not necessarily limited to those technical features clearly listed, but may also include other technical features that are not clearly listed and can be included in the method or product.

[0033] In the description of the present invention, it is necessary to understand that the technical features defined by the terms "first", "second" and the like with sequential concepts are only for the purpose of clearly describing the defined technical features so that the defined technical features can be clearly distinguished from other technical features, but do not represent such naming in actual implementation, and therefore cannot be understood as a limitation of the present invention.

[0034] One embodiment of the present invention discloses a medical electric push rod, such as Figures 1 to 8 As shown, it includes a rotary drive element (not shown in the figure), a transmission screw 1 and a transmission nut 2. A transmission assembly is connected between the rotary drive assembly and the transmission screw 1 to transmit torque to the transmission nut 2. When the transmission nut 2 rotates, the transmission screw 1 moves along the axis of the transmission nut 2. The transmission screw 1 is fixedly connected to a driving actuator. The transmission assembly includes a worm gear pair and a bevel gear pair. The rotary drive element, the worm gear pair, the bevel gear pair and the transmission nut 2 are sequentially driven. The transmission assembly also includes a first housing 4 and a second housing 5. The first housing 4 is provided with a first chamber 41 for accommodating the worm gear pair. The first chamber 41 is provided with lubricating oil for lubricating the worm gear pair. The second housing 5 is provided with a second chamber 51 for accommodating the bevel gear pair. The second chamber 51 is provided with a lubricating medium for lubricating the bevel gear pair. The first housing 4 is provided with an oil seal 11 for isolating the first chamber 41 and the second chamber 51. The first housing 4 is used as a worm gear box, and the second housing 5 is used as a gear box.

[0035] The rotating drive element is a power device that provides torque, including but not limited to an electric motor, a steam turbine, etc. The lubricating medium is solid grease.

[0036] The transmission assembly has two-stage transmission, namely a worm gear pair and a bevel gear pair. The worm gear 7 and the worm 6 are lubricated with lubricating oil. When the oil seal 11 fails and causes the lubricating oil in the first housing 4 to leak, the lubricating oil will not flow directly to the outside of the first housing 4, but will be stored in the second housing 5, which plays a double role in oil leakage protection. In addition, the oil seal 11 will not be ejected due to the difference in air pressure between the first housing 4 and the second housing 5. The bevel gear pair blocks the oil seal 11, which can avoid the risk of the oil seal 11 exploding. A plurality of heat dissipation fins are provided on the outside of the first housing 4.

[0037] The worm gear pair includes a worm 6 connected to a rotating driving element and a worm wheel 7 rotatably arranged in a first housing 4. The first housing 4 is rotatably connected to a worm wheel shaft 8 that rotates synchronously with the worm wheel 7. The worm wheel shaft 8 is perpendicular to the transmission screw 1, and the axis of the worm 6 is parallel to the transmission screw 1. The bevel gear pair includes a driving gear 9 fixed to the end of the worm wheel shaft 8 and a driven gear 10 that rotates synchronously with the transmission nut 2. One end of the worm 6 is connected to the rotating driving element, and the worm wheel shaft 8 extends from the first housing 4 into the second housing 5, so that the driving gear 9 located at the outer end of the worm wheel shaft 8 can mesh with the driven gear 10 in the second housing 5. The oil seal 11 is located in the first housing 4 and contacts and fits with the worm wheel shaft 8, forming a rotating seal between the first housing 4 and the worm wheel shaft 8, thereby preventing the leakage of lubricating oil.

[0038] The worm gear pair is self-locking and the power is transmitted in one direction, so as to avoid the situation that the transmission screw 1 retreats due to the pressure on the medical bed.

[0039] As one of the embodiments of the present invention, a medical electric push rod is disclosed. Figure 1 , Figure 3 , Figure 4 and Figure 5As shown, it includes a rotary drive element, a transmission screw 1 and a transmission nut 2. A transmission assembly is connected between the rotary drive assembly and the transmission screw 1 to transmit torque to the transmission nut 2. When the transmission nut 2 rotates, the transmission screw 1 moves along the axis of the transmission nut 2. The transmission screw 1 is fixedly connected to a driving actuator. The transmission assembly includes a worm gear pair and a bevel gear pair. The rotary drive element, the worm gear pair, the bevel gear pair and the transmission nut 2 are driven in sequence. The transmission assembly also includes a first housing 4 and a second housing 5. A first chamber 41 for accommodating the worm gear pair is provided inside the first housing 4, and lubricating oil for lubricating the worm gear pair is provided in the first chamber 41. A second chamber 51 for accommodating the bevel gear pair is provided in the second housing 5, and a lubricating medium for lubricating the bevel gear pair is provided in the second chamber 51. The first housing 4 is provided with an oil seal 11 for isolating the first chamber 41 and the second chamber 51. The transmission nut 2 is connected to a hollow drive shaft 12 that rotates synchronously therewith. The hollow drive shaft 12 is connected to the driven gear 10 of the bevel gear pair and rotates synchronously. The transmission nut 2 is arranged inside the hollow drive shaft 12. The transmission nut 2 and the hollow drive shaft 12 are jointly limited by a safety nut 16. The safety nut 16 has the same lead as the transmission nut 2. When the transmission nut 2 cooperates with the transmission screw 1, the safety nut 16 is separated from the transmission screw 1. When the transmission nut 2 fails, the safety nut 16 cooperates with the transmission screw 1. An elastic member 17 corresponding to the safety nut 16 is arranged inside the hollow drive shaft 12. The elastic member 17 includes but is not limited to an elastic gasket, a wave spring, etc.

[0040] When the transmission nut 2 is crushed and fails, the transmission screw 1 moves axially relative to the hollow drive shaft 12. At this time, the transmission screw 1 cooperates with the safety nut 16, and the rotation of the hollow drive shaft 12 is transmitted to the safety nut 16, so that the transmission screw 1 will not fail immediately. In the process of cooperation between the transmission screw 1 and the safety nut 16, the elastic member 17 plays a role of elastic buffering, preventing the safety nut 16 from rigidly bearing the pressure load of the transmission screw 1, so that the safety nut 16 and the transmission screw 1 cooperate to achieve a relatively stable transmission cooperation of the transmission screw 1, and at the same time prevent the safety nut 16 from being instantly crushed and deformed, thereby playing a buffering role for the electric push rod as a whole.

[0041] In this embodiment, the hollow drive shaft 12 includes a connecting section 13 extending into the second housing 5 and a mounting section 14 located outside the second housing 5. The two ends of the connecting section 13 are rotatably connected to the second housing 5 through two rotating bearings. The hollow drive shaft 12 is sleeved outside the transmission screw 1. A stepped hole 15 is provided in the mounting section 14. The cross section of the stepped hole 15 is a rounded regular hexagon. The elastic member 17, the safety nut 16 and the transmission nut 2 are sequentially arranged in the stepped hole 15 in a direction away from the connecting section 13. The lateral dimension of the stepped hole 15 increases in a direction away from the connecting section 13. The lateral peripheral dimension of the transmission nut 2 is larger than the lateral peripheral dimension of the safety nut 16, so that the elastic member 17, the safety nut 16 and the transmission nut 2 can be assembled by insertion. It is only necessary to lock the transmission nut 2 at the outermost end to fix the transmission nut 2 and the safety section, and the installation of the elastic member 17 and the safety nut 16 is completed at the same time, and the installation efficiency is high. A boss 3 is radially extended on the outer periphery of the driving nut 2 , and the boss 3 is fixed to the end of the hollow driving shaft 12 by bolts.

[0042] Furthermore, a sensor 18 is fixedly provided on the second housing 5, and a sensor trigger ring 19 cooperating with the sensor 18 is provided on the safety nut 16. The sensor trigger ring 19 follows the safety nut 16 to cooperate with the sensor 18 to feedback a stop signal to the rotating drive element when the safety nut 16 is working. The sensor 18 adopts an infrared sensor 18, a laser sensor 18 or other inductive detection sensor 18, and the sensor 18 can detect a signal in place when the sensor trigger ring 19 is in place. When the sensor 18 cooperates with the safety nut 16 and the transmission screw 1, the safety nut 16 overcomes the elastic force of the elastic member 17 to move axially. Since the trigger ring follows the safety nut 16, the trigger ring also moves axially and then cooperates with the sensor 18. When the sensor 18 detects the sensor trigger ring 19, it outputs a stop signal to the rotating drive element, and then the rotating drive element stops, so as to avoid the rotating drive element still continuously outputting power when the transmission nut 2 fails, thereby causing the rotating drive element to be overloaded or the transmission screw 1 to be ejected. After the rotating drive element stops, due to the self-locking effect of the worm gear pair, the transmission screw 1 cannot reversely drive the hollow drive shaft 12 and the safety nut 16. The transmission screw 1 is finally constrained by the safety nut 16, which has high safety.

[0043] Specifically, the synchronous movement of the safety nut 16 and the sensor trigger ring 19 is achieved through the synchronizer 20. The safety nut 16 and the sensor trigger ring 19 are connected with the synchronizer 20, and the synchronizer 20 is a pin or a bolt, etc., and the present embodiment uses a bolt. After the sensor trigger ring 19 and the safety nut 16 are connected with the synchronizer 20, the two move together, and the hollow drive shaft 12 is provided with a guide groove 21 for the synchronizer 20 to pass through and slide. The guide groove 21 provides a guide for the sliding of the synchronizer 20 to prevent the safety nut 16 and the sensor trigger ring 19 from rotating around the axis of the hollow drive shaft 12.

[0044] The end of the safety nut 16 facing the side where the second housing 5 is located is aligned with the end of the sensor trigger ring 19 facing the side where the second housing 5 is located. The axial length of the sensor trigger ring 19 is greater than the length of the guide groove 21. The sensor 18 corresponds to the radial outer side of the sensor trigger ring 19 to monitor the axial position of the sensor trigger ring 19. In this embodiment, the sensor 18 detects the end of the sensor trigger ring 19 facing the side where the second housing 5 is located. When the transmission screw 1 and the transmission nut 2 cooperate, the end of the guide groove 21 facing the second housing 5 is exposed outside the sensor trigger ring 19; when the sensor 18 can detect the sensor trigger ring 19, the sensor trigger ring 19 blocks the end of the guide groove 21 facing the second housing 5. The safety nut 16 and the sensor trigger ring 19 are synchronized by the synchronous member 20. The guide groove 21 provides guidance for the sliding of the synchronous member 20. When the safety nut 16 moves, the sensor trigger ring 19 moves synchronously, which can be quickly detected by the sensor 18, and has high safety. The guide groove 21 is positioned so that it can be used as an external observation indicator to prevent inspection when foreign objects such as paper blocks the sensor 18, avoid the need to dismantle the electric push rod due to false alarms from the sensor 18, and improve the convenience and reliability of electric push rod fault detection.

[0045] A medical electric push rod shown as one of the embodiments of the present invention includes a rotary drive element, a transmission screw 1 and a transmission nut 2. A transmission assembly is connected between the rotary drive assembly and the transmission screw 1 to transmit torque to the transmission nut 2. When the transmission nut 2 rotates, the transmission screw 1 moves along the axis of the transmission nut 2. The transmission screw 1 is fixedly connected to a driving actuator. The transmission assembly includes a worm gear pair and a bevel gear pair. The rotary drive element, the worm gear pair, the bevel gear pair and the transmission nut 2 are driven in sequence. The transmission assembly also includes a first housing 4 and a second housing 5. A first chamber 41 for accommodating the worm gear pair is provided inside the first housing 4, and lubricating oil for lubricating the worm gear pair is provided in the first chamber 41. A second chamber 51 for accommodating the bevel gear pair is provided in the second housing 5, and a lubricating medium for lubricating the bevel gear pair is provided in the second chamber 51. The first housing 4 is provided with an oil seal 11 for isolating the first chamber 41 and the second chamber 51. The transmission nut 2 is connected to a hollow drive shaft 12 that rotates synchronously therewith. The hollow drive shaft 12 is connected to the driven gear 10 of the bevel gear pair and rotates synchronously. The transmission nut 2 is arranged inside the hollow drive shaft 12. The transmission nut 2 and the hollow drive shaft 12 are jointly limited by a safety nut 16. The safety nut 16 has the same lead as the transmission nut 2. When the transmission nut 2 cooperates with the transmission screw 1, the safety nut 16 is separated from the transmission screw 1. When the transmission nut 2 fails, the safety nut 16 cooperates with the transmission screw 1. An elastic member 17 corresponding to the safety nut 16 is arranged inside the hollow drive shaft 12. The difference from the previous embodiment is that, as Figure 6 and Figure 7As shown, an end cover 22 is provided at one end of the second housing 5 away from the mounting section 14. The end cover 22 is a self-centering structure. The end cover 22 and the end of the second housing 5 are fixed by bolts. A mounting hole 23 is provided in the end cover 22 for the transmission screw 1 to extend. The diameter of the mounting hole 23 is larger than the outer diameter of the transmission screw 1. A sliding ring groove 24 is provided in the mounting hole 23. A cover plate 25 fixed to the end cover 22 with bolts is provided at one end of the end cover 22 facing the second housing 5. A support nut 26 is slidably provided in the sliding ring groove 24. The cover plate 25 blocks the sliding ring groove 24 to form an anti-slip setting for the support nut 26. The setting of the cover plate 25 facilitates the removal and replacement of the support nut 26. The support nut 26 is threadedly engaged with the transmission screw 1. The outer periphery of the support nut 26 is a cylindrical surface so that the support nut 26 can rotate in the sliding ring groove 24. The transmission nut 2 supports one part of the transmission screw 1, and the support nut 26 can support another part of the transmission screw 1, so as to realize multi-point support of the transmission screw 1, improve the transmission stability of the transmission screw 1, and reduce the friction between the transmission screw 1 and the hollow transmission shaft, thereby extending the service life of the transmission screw 1. The support nut 26 is slidably arranged in the mounting hole 23. The support nut 26 can slide in the sliding ring groove 24, and its cylindrical outer peripheral structure enables it to rotate in the sliding ring groove 24 without interfering with the movement of the transmission screw 1. A lubricating blind hole 27 is provided on the outer periphery of the support nut 26, and a lubricating medium is filled in the lubricating blind hole 27. The shape of the lubricating blind hole 27 is spherical, and the opening diameter of the lubricating blind hole 27 is smaller than the diameter of the lubricating blind hole 27. As a simple replacement of the above scheme, the shape of the lubricating blind hole 27 is ellipsoidal, cylindrical, etc. When the transmission screw 1 is working, its thread acts on the support nut 26. The support nut 26 rotates or slides in the sliding ring groove 24, which will form friction or extrusion between the outer side of the support nut 26 and the groove wall of the sliding ring groove 24, and will bring out the lubricating medium in the lubricating blind hole 27, thereby achieving lubrication of the support nut 26 and the sliding ring groove 24. At the same time, the lubricating medium in the sliding ring groove 24 will partially fall onto the surface of the transmission screw, and then be used for lubrication of the transmission screw 1 and the support nut, and can also serve as lubrication for the transmission screw 1 and the transmission nut 2.

[0046] A pressure sensor 28 is provided at the end of the sliding ring groove 24. The pressure sensor 28 is arranged opposite to the axial end of the support nut 26 to detect the axial pressure provided by the support nut 26. Figure 7Taking the structure as an example, when the transmission screw 1 is pushed out, it slides relative to the end cover 22, driving the support nut 26 to slide to the left. When the support nut 26 reaches the left end of the sliding ring groove 24, the transmission screw 1 cannot push the support nut 26. Due to the limitation of the groove wall of the sliding ring groove 24, the transmission screw 1 and the support nut 26 are threadedly matched, and the support nut 26 rotates around the axis of the transmission screw 1. The support nut 26 gives a relatively stable pressure to the pressure sensor 28. When there is foreign matter on the surface of the transmission screw 1 or the thread on the surface of the transmission screw 1 is damaged, the thread matching of the support nut 26 and the transmission screw 1 is not smooth, and the pressure sensor 28 has a sudden large pressure indication. When the surface of the transmission screw 1 is severely worn, the matching friction between the transmission screw 1 and the support nut 26 is reduced, and the pressure of the support nut 26 on the pressure sensor 28 gradually decreases until it exceeds the normal threshold, indicating that the transmission screw 1 needs to be replaced. When the transmission screw rod 1 is retracted, the support nut 26 is driven to the right end of the sliding ring groove 24, and cooperates with the pressure sensor 28 at the right end of the sliding ring groove 24 to also play the role of abnormal condition monitoring.

[0047] One embodiment of the present invention discloses a medical lifting device, such as Fig. 9 As shown, it includes a lifting end 29, a scissor mechanism 30 and the above-mentioned medical electric push rod 100. The driving actuator of the medical electric push rod 100 is connected to the scissor mechanism 30 and drives the scissor mechanism 30 to extend and retract. The lifting end 29 is connected to the scissor mechanism 30 and rises and falls when the scissor mechanism 30 extends and retracts. The medical electric push rod 100 is arranged horizontally. Medical lifting equipment such as the medical lifting bed in the prior art, the medical electric push rod 100 is as follows Figure 8 As shown, the height of the medical lifting bed is limited. In the medical lifting bed disclosed in the present invention, the medical electric push rod 100 is installed horizontally to effectively solve the dilemma that the medical bed body of CT MR and other medical machinery market cannot be lowered to less than 500 mm.

[0048] In this embodiment, combined with Figure 2 , Figure 6 and Fig. 9 As shown, the first housing 4 and the second housing 5 are arranged up and down. When the lubricating oil in the first housing 4 leaks, it flows to the second housing 5 under the action of gravity, realizing secondary leakage prevention of the lubricating oil.

Claims

1. A medical electric push rod, comprising a rotary drive element, a transmission screw and a transmission nut, characterized in that: A transmission assembly is connected between the rotation drive assembly and the transmission nut to transmit torque to the transmission nut. When the transmission nut rotates, the transmission screw moves along the axis of the transmission nut. The transmission screw is fixedly connected to a driving actuator. The transmission assembly includes a worm gear pair and a bevel gear pair. The rotation drive element, the worm gear pair, the bevel gear pair and the transmission nut are transmitted in sequence. The transmission assembly also includes a first housing and a second housing. A first chamber for accommodating the worm gear pair is provided inside the first housing, and a second chamber for accommodating the bevel gear pair is provided inside the second housing. Lubricating oil for lubricating the worm gear pair is provided in the first chamber, and a lubricating medium for lubricating the bevel gear pair is provided in the second chamber. The first housing is provided with an oil seal for isolating the first chamber and the second chamber.

2. A medical electric linear actuator according to claim 1, characterized in that: The transmission nut is connected to a hollow driving shaft that rotates synchronously with the hollow driving shaft. The hollow driving shaft rotates synchronously with the driven gear of the bevel gear pair. A safety nut is limited in the hollow driving shaft. The safety nut has the same lead as the transmission nut. When the transmission nut cooperates with the transmission screw, the safety nut is separated from the transmission screw and when the transmission nut fails, the safety nut cooperates with the transmission screw. An elastic part corresponding to the safety nut is provided in the hollow driving shaft.

3. A medical electric linear actuator according to claim 2, characterized in that: A sensor is fixedly provided on the second housing, and the safety nut is provided with a sensor trigger ring cooperating with the sensor. The sensor trigger ring follows the safety nut to cooperate with the sensor to feed back a stop signal to the rotating drive element when the safety nut is working.

4. The medical electric linear actuator according to claim 2, characterized in that: The hollow drive shaft includes a connecting section extending into the second shell and a mounting section located outside the second shell. The connecting section is rotatably connected to the second shell. The hollow drive shaft is loosely sleeved outside the transmission screw. A stepped hole is provided in the mounting section. The elastic part, safety nut and transmission nut are arranged in sequence in the step hole away from the connecting section.

5. The medical electric linear actuator according to claim 2, characterized in that: The safety nut and the sensor trigger ring are connected with a synchronizer, and a guide groove for the synchronizer to pass and slide is provided on the hollow drive shaft. One end of the safety nut facing the side where the second shell is located is aligned with one end of the sensor trigger ring facing the side where the second shell is located, and the axial length of the sensor trigger ring is greater than the length of the guide groove. The sensor corresponds to the radial outside of the sensor trigger ring to monitor the axial position of the sensor trigger ring; when the transmission screw rod cooperates with the transmission nut, one end of the guide groove facing the second shell is exposed on the outside of the sensor trigger ring; when the sensor can detect the sensor trigger ring, the sensor trigger ring blocks the end of the guide groove facing the second shell.

6. A medical electric linear actuator according to any one of claims 1 to 5, characterized in that: An end cover is provided at one end of the second shell, and a mounting hole is provided in the end cover for the transmission screw to extend out, a sliding ring groove is provided in the mounting hole, a support nut is slidably provided in the sliding ring groove, the support nut is threadedly engaged with the transmission screw, and the outer periphery of the support nut is a cylindrical surface so that the support nut can rotate in the sliding ring groove.

7. The medical electric linear actuator according to claim 6, characterized in that: A lubricating blind hole is arranged on the outer periphery of the supporting nut, and a solid lubricating medium is filled in the lubricating blind hole.

8. The medical electric linear actuator according to claim 6, characterized in that: A pressure sensor is provided at the end of the sliding ring groove, and the pressure sensor is arranged opposite to the axial end of the support nut to detect the axial pressure provided by the support nut.

9. A medical lifting device, comprising a lifting end, a scissors-fork mechanism and the medical electric push rod as described in any one of claims 1 to 8, wherein the driving actuator of the medical electric push rod is connected to the scissors-fork mechanism and drives the scissors-fork mechanism to extend and retract, the lifting end is connected to the scissors-fork mechanism and rises and falls when the scissors-fork mechanism extends and retracts, and the medical electric push rod is arranged horizontally.

10. The medical lifting device according to claim 9, characterized in that: The first shell and the second shell are arranged up and down, and the worm gear pair includes a worm connected to the rotating drive element and a worm wheel rotatably arranged in the first shell. The first shell is rotatably connected to a worm gear shaft that rotates synchronously with the worm wheel. The worm gear shaft is perpendicular to the transmission screw, and the worm axis is parallel to the transmission screw.

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