Coreless deceleration push rod motor for injection

Abstract

The utility model discloses a hollow cup deceleration push rod motor for injection, which comprises a motor, a shell, an integrated screw rod shaft and an inner gear ring, a planetary gear is arranged in the inner gear ring, one end of the integrated screw rod shaft is provided with a planetary gear, the planetary gear is accommodated in the inner gear ring and is in meshing transmission with inner teeth on the inner side wall of the inner gear ring, and the integrated screw rod shaft is provided with a screw rod section and a shaft section. A push cylinder is arranged in the shell, one end of the push cylinder is arranged on the lead screw nut in a sleeving mode, the other end of the push cylinder extends out of the shell, and when the integrated lead screw shaft rotates, the lead screw nut pushes the push cylinder to stretch out and draw back in the shell. The service life of the push rod motor is prolonged through structure optimization, and noise is reduced. The integration degree of the planetary reduction gearbox and the push rod is improved, the axial size is reduced, and meanwhile the influence of gear clearance on precision is eliminated. The integrated lead screw shaft and the output shaft of the reduction gearbox are integrally designed, accumulation of axial errors caused by split connection of the lead screw and the reduction gearbox is avoided, and the occupied space of a coupler and a mounting flange is saved.

Description

Technical Field

[0001] This utility model relates to the field of medical device drive technology, and in particular to a deceleration push rod motor for a hollow cup used in injection. Background Technology

[0002] Traditional brushed motors on the market have problems such as rapid brush wear and short lifespan in medical actuator applications. In particular, carbon brushes are prone to generating dust in high-frequency start-stop scenarios, which affects the cleanliness of medical equipment.

[0003] The planetary gearbox and push rod have insufficient integration design, resulting in excessive axial length and gear backlash affecting the push rod positioning accuracy (e.g., return error ≥ 0.2mm). Summary of the Invention

[0004] To overcome the shortcomings and deficiencies of existing technologies, the purpose of this utility model is to provide a hollow cup reduction actuator motor for injection. It is suitable for medical devices requiring small size, low noise, and long lifespan, such as insulin pens and micro-infusion pumps.

[0005] The objective of this utility model is achieved through the following technical solution: a reduction actuator motor for a hollow injection cup, comprising a motor, a housing, an integrated lead screw shaft, and an internal gear ring. One end of the integrated lead screw shaft is equipped with a planetary gear, which is housed within the internal gear ring and meshes with internal teeth on the inner sidewall of the internal gear ring. The integrated lead screw shaft has a lead screw section and a shaft section, with a lead screw nut screwed onto the lead screw section. A push cylinder is provided inside the housing, with one end of the push cylinder sleeved on the lead screw nut and the other end extending out of the housing. When the integrated lead screw shaft rotates, the lead screw nut pushes the push cylinder to extend and retract within the housing. The integrated design of the lead screw shaft and the gearbox output shaft avoids the accumulation of axial errors caused by separate connections of the lead screw and the gearbox, and saves space occupied by couplings and mounting flanges.

[0006] As an improvement of the present invention, the screw nut is provided with a connecting sleeve at one end, and multiple induction magnet mounting parts are provided at intervals along the edge of the screw nut, with an induction magnet provided on each of the induction magnet mounting parts.

[0007] As an improvement of the injection hollow cup reduction push rod motor of this utility model, the push cylinder has a cavity, the cavity opening of the push cylinder is provided with a step, the step is sleeved on the connecting sleeve, and the lead screw section of the integral lead screw shaft extends into the cavity.

[0008] As an improvement to the injection-graded push rod motor for hollow cups of this utility model, a limit control plate is provided on the cavity sidewall of the outer shell. The limit control plate is equipped with an initial position sensor and an extreme position sensor. The sensing magnet can sense the initial position sensor or the extreme position sensor; both the initial position sensor and the extreme position sensor are Hall effect sensors. The limit control plate can precisely control the push cylinder to reach the set stroke and position.

[0009] When the sensing magnet senses the initial position sensor or the limit position sensor, the motor stops controlling the rotation of the integrated lead screw shaft.

[0010] As an improvement to the injection-type hollow cup reducer push rod motor of this utility model, the cavity of the internal gear ring is filled with grease. This reduces the meshing friction between the planetary gear and the internal gear ring.

[0011] As an improvement of the injection hollow cup reduction push rod motor of this utility model, one end of the internal gear ring is fixed to the output end of the motor, the outer shell covers the other end of the internal gear ring and is fixed by fixing screws, a shaft extension hole is provided in the middle of the end of the internal gear ring connected to the outer shell, two bearing mounting grooves are provided on the inner side wall of the shaft extension hole, and ball bearings are provided in both bearing mounting grooves, and the ball bearings are sleeved on the shaft section of the integrated lead screw shaft.

[0012] As an improvement to the injection-type hollow cup reducer push rod motor of this utility model, the end of the integrated lead screw shaft is provided with a planetary gear mounting part. The planetary gears are installed at intervals on the edge of the planetary gear mounting part. The output shaft of the motor is provided with a sun gear, which meshes with the planetary gears. The planetary gearbox uses a single-stage reduction gear set and adopts involute planetary gear transmission, which has the advantages of high load capacity, high precision, and high efficiency.

[0013] As an improvement of the injection hollow cup reduction push rod motor of this utility model, the edge of the inner gear ring connected to the outer shell is provided with a plurality of screw holes at intervals, and the edge of the outer shell is provided with a screw through hole corresponding to the position of each screw hole. The fixing screw passes through the screw through hole and is screwed to the screw hole.

[0014] The beneficial effects of this utility model are as follows: It extends the lifespan of the push rod motor and reduces noise through structural optimization. It improves the integration of the planetary gearbox and the push rod, reduces the axial dimension, and eliminates the impact of gear backlash on accuracy. The integrated design of the lead screw shaft and the gearbox output shaft avoids the accumulation of axial errors caused by separate connections of the lead screw and gearbox, and saves space occupied by couplings and mounting flanges. Attached Figure Description

[0015] Figure 1This is a perspective view of the present invention;

[0016] Figure 2 This is a cross-sectional view of the present invention;

[0017] Figure 3 This is a sectional view of the integrated lead screw shaft of this utility model;

[0018] Figure 4 This is a perspective view of the lead screw nut of this utility model;

[0019] The attached figures are labeled as follows: 1. Motor, 2. Housing, 3. Integrated lead screw shaft, 4. Internal gear ring, 5. Planetary gear, 6. Lead screw nut, 7. Push cylinder, 8. Limit control plate, 9. Fixing screw, 10. Ball bearing, 11. Screw hole, 31. Lead screw section, 32. Shaft section, 33. Planetary gear mounting part, 41. Screw hole, 61. Connecting sleeve, 62. Induction magnet mounting part, 63. Induction magnet, 71. Cavity, 72. Step. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0021] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0022] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0023] like Figures 1-4As shown, a hollow cup injection reducer push rod motor includes a motor 1, a housing 2, an integrated lead screw shaft 3, and an internal gear ring 4. One end of the integrated lead screw shaft 3 is equipped with a planetary gear 5, which is housed within the internal gear ring 4 and meshes with the internal teeth on the inner sidewall of the internal gear ring 4 for transmission. The integrated lead screw shaft 3 has a lead screw section 31 and a shaft section 32. A lead screw nut 6 is screwed onto the lead screw section 31. A push cylinder 7 is provided inside the housing 2, with one end of the push cylinder 7 fitted onto the lead screw nut 6 and the other end extending out of the housing 2. When the integrated lead screw shaft 3 rotates, the lead screw nut 6 pushes the push cylinder 7 to extend and retract within the housing 2. The integrated lead screw shaft 3 and the reducer output shaft are designed as a single unit, avoiding the accumulation of axial errors caused by separate connections of the lead screw and the reducer, and saving space occupied by couplings and mounting flanges.

[0024] Preferably, one end of the lead screw nut 6 is provided with a connecting sleeve 61, and the edge of the lead screw nut 6 is provided with a plurality of induction magnet mounting parts 62 at intervals, and each induction magnet mounting part 62 is provided with an induction magnet 63.

[0025] Preferably, the pusher 7 has a cavity 71, and the cavity opening of the pusher 7 is provided with a step 72. The step 72 is sleeved on the connecting sleeve 61, and the lead screw section 31 of the integral lead screw shaft 3 extends into the cavity 71.

[0026] Preferably, a limit control plate 8 is provided on the cavity sidewall of the outer shell 2. The limit control plate 8 is equipped with an initial position sensor and an extreme position sensor (not shown in the figure). The sensing magnet 63 can sense the initial position sensor or the extreme position sensor; both the initial position sensor and the extreme position sensor are Hall sensors. The limit control plate can accurately control the push cylinder to reach the set stroke and position.

[0027] When the sensing magnet senses the initial position sensor or the limit position sensor, the motor 1 stops controlling the rotation of the integrated lead screw shaft 3.

[0028] Preferably, the cavity of the internal gear ring 4 is filled with grease to reduce the meshing friction between the planetary gear and the internal gear ring.

[0029] Preferably, one end of the internal gear ring 4 is fixed to the output end of the motor 1, and the outer casing 2 covers the other end of the internal gear ring 4 and is fixed by the fixing screw 9. The middle part of the end where the internal gear ring 4 is connected to the outer casing 2 is provided with a shaft extension hole. Two bearing mounting grooves are provided on the inner side wall of the shaft extension hole. Ball bearings 10 are provided in both bearing mounting grooves. The ball bearings 10 are sleeved on the shaft section 32 of the integral lead screw shaft 3.

[0030] Preferably, the end of the shaft segment 32 of the integrated lead screw shaft 3 is provided with a planetary gear mounting part 33, and the planetary gears 5 are installed at intervals on the edge of the planetary gear mounting part 33. The output shaft of the motor 1 is provided with a sun gear (not shown in the figure), which meshes with the planetary gears 5. The planetary gearbox uses a single-stage reduction gear set and adopts involute planetary gear transmission, which has the advantages of high load capacity, high precision, and high efficiency.

[0031] Preferably, the inner gear ring 4 is provided with a plurality of screw holes 41 at intervals on one end edge where it is connected to the outer shell 2, and a screw through hole 11 is provided on one end edge of the outer shell 2 corresponding to the position of each screw hole 41. The fixing screw 9 is inserted through the screw through hole 11 and screwed into the screw hole 41.

[0032] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and structure of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hollow cup deceleration push rod motor for injection, characterized in that, The device includes a motor, a housing, an integrated lead screw shaft, and an internal gear ring. One end of the integrated lead screw shaft is equipped with a planetary gear, which is housed within the internal gear ring and meshes with internal teeth on the inner sidewall of the internal gear ring for transmission. The integrated lead screw shaft has a lead screw section and a shaft section. A lead screw nut is screwed onto the lead screw section. A push cylinder is provided inside the housing. One end of the push cylinder is sleeved on the lead screw nut, and the other end extends out of the housing. When the integrated lead screw shaft rotates, the lead screw nut pushes the push cylinder to extend and retract within the housing.

2. The injection hollow cup reduction push rod motor according to claim 1, characterized in that, One end of the lead screw nut is provided with a connecting sleeve, and the edge of the lead screw nut is provided with a plurality of induction magnet mounting parts at intervals, and each of the induction magnet mounting parts is provided with an induction magnet.

3. The injection hollow cup reduction push rod motor according to claim 2, characterized in that, The pusher has a cavity, and the cavity opening of the pusher has a step. The step is fitted onto the connecting sleeve, and the lead screw section of the integral lead screw shaft extends into the cavity.

4. The injection hollow cup reduction push rod motor according to claim 2, characterized in that, The cavity sidewall of the outer shell is provided with a limit control plate, and the limit control plate is provided with an initial position sensor and an extreme position sensor. The sensing magnet can sense the initial position sensor or the extreme position sensor. When the sensing magnet senses the initial position sensor or the limit position sensor, the motor stops controlling the rotation of the integrated lead screw shaft.

5. The injection hollow cup reduction push rod motor according to claim 1, characterized in that, The cavity of the internal gear ring is filled with grease.

6. The injection hollow cup reduction push rod motor according to claim 1, characterized in that, One end of the internal gear ring is fixed to the output end of the motor, and the outer casing covers the other end of the internal gear ring and is fixed by fixing screws. The middle part of the end of the internal gear ring connected to the outer casing is provided with a shaft protrusion hole. Two bearing mounting grooves are provided on the inner side wall of the shaft protrusion hole. Ball bearings are provided in both bearing mounting grooves. The ball bearings are sleeved on the shaft section of the integrated lead screw shaft.

7. The injection hollow cup reduction push rod motor according to claim 1, characterized in that, The end of the integral lead screw shaft is provided with a planetary gear mounting part, and the planetary gears are installed at intervals on the edge of the planetary gear mounting part. The output shaft of the motor is provided with a sun gear, and the sun gear meshes with the planetary gears.

8. The injection hollow cup reduction push rod motor according to claim 6, characterized in that, The inner gear ring is provided with a plurality of screw holes at intervals on one end edge where it is connected to the outer shell. The outer shell is provided with a screw through hole corresponding to the position of each screw hole on one end edge. The fixing screw passes through the screw through hole and is screwed into the screw hole.

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