A lightweight starting motor

Abstract

This utility model relates to the field of starter motor technology, specifically to a lightweight starter motor, including an electric motor, a planetary gear reducer mounted above the electric motor, and a transmission structure mounted above the planetary gear reducer. The electric motor has an upwardly extending output shaft, the free end of which is coaxially connected to the transmission structure via the planetary gear reducer. The transmission structure includes a splined shaft coaxially connected to the output shaft, and a drive gear mounted on the splined shaft. The drive gear can reciprocate along the axial direction of the splined shaft and rotate synchronously with it. An elastic reset member is provided between the drive gear and the splined shaft to push the drive gear axially downward. The planetary gear reducer in this utility model has a significantly smaller volume than a spur gear system while requiring the same output torque, allowing the electric motor to use a smaller stator and rotor, resulting in a significant reduction in the size and weight of the electric motor.

Description

Technical Field

[0001] This utility model relates to the field of starter motor technology, specifically to a lightweight starter motor. Background Technology

[0002] As a core component in electromechanical systems for power initialization, the starter motor's function is to provide starting torque to the driven equipment and ensure it reaches its rated operating speed within a reasonable time by converting electrical energy into mechanical energy. In existing technology, the typical structure of a mainstream starter motor usually includes a motor, a one-way clutch, a drive gear, and an electromagnetic drive mechanism. Its working principle is as follows: the motor's output shaft is directly and rigidly connected to the inner race of the one-way clutch; the outer race of the one-way clutch is linked to the electromagnetic drive mechanism via a shift fork; and the drive gear is fixedly connected to the outer race of the one-way clutch and sleeved on the output shaft via a helical spline.

[0003] However, the above-mentioned technical solutions have significant drawbacks: because the motor output shaft is directly and rigidly connected to the inner race of the one-way clutch, the motor must directly bear the peak torque load during engine startup. To meet the torque output requirements, existing designs have to adopt large-size stator, rotor, and winding structures, resulting in a significant increase in the size and weight of the motor. In addition, the larger size of the motor body further leads to an upgrade in the size of supporting components (such as the housing and heat dissipation structure), making the overall structure bulky and inconvenient to install.

[0004] Therefore, there is an urgent need to design a lightweight starter motor to solve the technical problem that existing technologies have to use large stators, rotors and winding structures to meet torque output requirements, which leads to a significant increase in the size and weight of the motor. Utility Model Content

[0005] The present invention aims to provide a lightweight starter motor to solve the technical problem that in order to meet torque output requirements, large-size stator, rotor and winding structures must be used, which leads to a significant increase in the size and weight of the motor.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] 1) A lightweight starter motor, characterized in that it includes an electric motor, a planetary gear reducer is disposed above the electric motor, a transmission structure is disposed above the planetary gear reducer, the electric motor has an upwardly extending output shaft, the free end of the output shaft is coaxially connected to the transmission structure through the planetary gear reducer, the transmission structure includes a spline shaft coaxially connected to the output shaft, a drive gear is sleeved on the spline shaft, the drive gear can reciprocate along the axial direction of the spline shaft and rotate synchronously with it, and an elastic reset member is provided between the drive gear and the spline shaft to push the drive gear axially downward.

[0008] The planetary gear reducer includes a housing, a sun gear housed within the housing, multiple planet gears, a planet carrier, and a ring gear. The sun gear is located at the center, and the planet gears are evenly distributed around the sun gear via the planet carrier, meshing with both the sun gear and the internal ring gear simultaneously. During installation, the planetary gear reducer housing is first bolted to the top of the motor housing, and the free end of the output shaft is inserted and fixed into the inner bore of the sun gear. Then, the lower end of the splined shaft is inserted and fixed into the inner bore of the planetary gear reducer. Finally, the drive gear is fitted onto the top of the splined shaft, and a spring-loaded return element is installed on the top of the splined shaft.

[0009] When the electric motor starts, the torque is transmitted to the drive gear via the output shaft, planetary gear reducer, and splined shaft. The drive gear rotates synchronously with the splined shaft. Under inertia, the drive gear moves axially upward and meshes with the engine flywheel, driving the engine flywheel to rotate. After the engine starts, if the operator promptly shuts off the electric motor, the output shaft stops rotating. Under the downward elastic potential energy of the elastic reset component, the drive gear can be pushed downward, disengaging from the engine flywheel and resetting. It is worth noting that if the operator does not promptly shut off the electric motor after the engine starts, the engine flywheel speed gradually increases, eventually exceeding the drive gear speed. At this point, the engine flywheel pushes the drive gear in the opposite direction. Under the combined effect of the engine flywheel's counter-force and the downward elastic potential energy of the elastic reset component, the drive gear can also be pushed downward, disengaging from the engine flywheel and resetting.

[0010] Planetary gear reducers are significantly smaller than spur gear systems when the same torque is required, allowing the motor to use smaller stators and rotors, resulting in a significant reduction in motor size and weight. The three-stage coaxial arrangement shortens the overall axial length, saving more space. The elastic reset component allows the drive gear to be forcibly disengaged faster when its speed is lower than that of the engine flywheel, preventing the motor from being dragged and worn.

[0011] 2) A lightweight starter motor according to 1), wherein: the elastic reset member is a compression spring; the spline shaft includes, from bottom to top, a first outer straight section, an outer helical section, and a second outer straight section; the lower end of the first outer straight section is coaxially connected to the output shaft; the inner wall of the drive gear is provided with an internal thread that meshes with the outer helical section; a retaining ring seat is fixedly sleeved on the top of the second outer straight section; the lower end of the retaining ring seat is connected to the compression spring; the compression spring is sleeved on the second outer straight section; and the lower end of the compression spring is connected to the drive gear.

[0012] In this invention, the retaining spring seat is fixed to the top of the second outer straight section by a retaining ring. When the drive gear moves upward: the internal thread rotates and rises along the outer helical section, the compression spring is compressed and stores elastic potential energy; when the drive gear resets: the compression spring releases elastic potential energy and pushes the gear to rotate and descend. With this structure, the drive gear can reciprocate along the axial direction of the spline shaft and rotate circumferentially, and the elastic reset member can push the drive gear axially downward.

[0013] The outer helical section converts the axial movement of the drive gear into rotational motion, causing the compression / release process of the compression spring to accompany the rotation of the drive gear. This converts a portion of the meshing impact energy between the drive gear and the engine flywheel into rotational kinetic energy, reducing the impact force on the gears and extending their lifespan. Simultaneously, the helical drive replaces the traditional shift fork mechanism, resulting in fewer parts, a simpler structure, and further reducing the weight of this invention.

[0014] 3) A lightweight starter motor according to 2), wherein: the diameter of the second outer straight section is smaller than the diameter of the outer spiral section, an oil-impregnated bearing that cooperates with the second outer straight section is provided in the drive gear, and the two ends of the compression spring abut against the snap ring seat and the oil-impregnated bearing respectively.

[0015] When the drive gear moves axially, the oil-impregnated bearing slides on the surface of the second outer straight section, resulting in low friction. The elastic potential energy of the compression spring is evenly applied to the drive gear through the plane of the oil-impregnated bearing, which can extend the life of the drive gear. At the same time, it can also play a role in self-lubrication and noise reduction.

[0016] 4) A lightweight starter motor according to 3), wherein: the drive gear is provided with a plurality of saw teeth evenly distributed in the circumference, the saw teeth having a forward tooth surface and a reverse tooth surface, and the upper end of the reverse tooth surface is machined with an inclined surface.

[0017] The inclined surface machined at the upper end of the reverse tooth surface of this invention can cooperate with the inclined surface at the lower end of the engine flywheel saw teeth. During the process of the drive gear meshing into the engine flywheel, the forward tooth surface guides the engine flywheel to slide into the forward gear. When the speed of the engine flywheel is greater than the speed of the drive gear, the drive gear is pushed back and gradually away from the drive engine flywheel. When the inclined surface at the lower end of the engine flywheel saw teeth comes into contact with the inclined surface machined at the upper end of the reverse tooth surface, the separation can be accelerated under the action of the inclined surface.

[0018] 5) A lightweight starter motor according to 1), wherein: the outer shell of the planetary gear reducer protrudes outward in the circumferential direction to form a mounting ring, and the upper surface of the mounting ring is provided with a plurality of mounting holes, which are arranged at uniform intervals in the circumferential direction.

[0019] The mounting ring is integrally die-cast with the planetary gear reducer housing, and this utility model has four mounting holes. Through these four mounting holes, the entire utility model can be fixed to the desired installation location with bolts, such as fixing it to a mounting plate. In this case, the motor in this utility model can be suspended, resulting in better heat dissipation.

[0020] The beneficial effects of this utility model are as follows:

[0021] When the electric motor starts, the torque is transmitted to the drive gear via the output shaft, planetary gear reducer, and splined shaft. The drive gear rotates synchronously with the splined shaft. Under inertia, the drive gear moves axially upward and meshes with the engine flywheel, driving the engine flywheel to rotate. After the engine starts, the electric motor is turned off, and the output shaft stops rotating. Under the downward elastic potential energy of the elastic reset component, the drive gear is pushed downward, disengaging from the engine flywheel and resetting. It is worth noting that if the electric motor is not turned off in time after the engine starts, the engine flywheel speed gradually increases and eventually exceeds the drive gear speed. At this time, the engine flywheel pushes the drive gear in the opposite direction. Under the combined effect of the engine flywheel's counter-force and the downward elastic potential energy of the elastic reset component, the drive gear can also be pushed downward, disengaging from the engine flywheel and resetting.

[0022] Planetary gear reducers are significantly smaller than spur gear systems when the same torque is required, allowing the motor to use smaller stators and rotors, resulting in a significant reduction in motor size and weight. The three-stage coaxial arrangement shortens the overall axial length, saving more space. The elastic reset component allows the drive gear to be forcibly disengaged faster when its speed is lower than that of the engine flywheel, preventing the motor from being dragged and worn.

[0023] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of a lightweight starter motor according to the present invention.

[0025] Figure 2 This is a cross-sectional view of a lightweight starter motor according to the present invention.

[0026] In the diagram: 1. Electric motor; 11. Output shaft; 2. Planetary gear reducer; 21. Sun gear; 22. Planet carrier; 23. Mounting ring; 231. Mounting hole; 31. Splined shaft; 32. Drive gear; 321. Forward tooth surface; 322. Reverse tooth surface; 33. Compression spring; 34. Snap ring seat; 35. Oil-impregnated bearing. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0030] In the above description of this utility model, it should be noted that the terms "one side," "the other side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0031] Furthermore, terms such as "identical" do not imply that components must be absolutely identical; minor differences are permissible. The term "perpendicular" simply means that the positional relationship between components is more perpendicular than "parallel," not that the structure must be perfectly perpendicular; a slight tilt is acceptable.

[0032] Please see Figures 1-2 This utility model discloses a lightweight starter motor, including a motor 1, a planetary gear reducer 2 disposed above the motor 1, and a transmission structure disposed above the planetary gear reducer 2. In this embodiment, the model of the motor 1 can be ZGB37RG. The motor 1 has an upwardly extending output shaft 11. The free end of the output shaft 11 is coaxially connected to the transmission structure through the planetary gear reducer 2. The transmission structure includes a spline shaft 31 coaxially connected to the output shaft 11. A drive gear 32 is sleeved on the spline shaft 31. The drive gear 32 can reciprocate along the axial direction of the spline shaft 31 and rotate synchronously with it. An elastic reset member is provided between the drive gear 32 and the spline shaft 31 to push the drive gear 32 axially downward.

[0033] The planetary gear reducer 2 includes a housing, a sun gear 21 disposed within the housing, multiple planet gears, a planet carrier 22, and a ring gear. The sun gear 21 is located at the center, and the planet gears are evenly distributed around the sun gear 21 via the planet carrier 22 and mesh with both the sun gear 21 and the internal ring gear. During installation, the housing of the planetary gear reducer 2 is first bolted to the top of the motor 1 housing, and the free end of the output shaft 11 is inserted and fixed into the inner hole of the sun gear 21. Then, the lower end of the splined shaft 31 is inserted and fixed into the inner hole of the planetary gear reducer 2. Finally, the drive gear 32 is inserted from the top of the splined shaft 31, and a resilient reset element is installed on the top of the splined shaft 31.

[0034] When motor 1 starts, the torque is transmitted to drive gear 32 via output shaft 11 → planetary gear reducer 2 → splined shaft 31. Drive gear 32 rotates synchronously with splined shaft 31. Under inertia, drive gear 32 moves axially upward and meshes with the engine flywheel, driving the engine flywheel to rotate. After the engine starts, if the operator promptly shuts off motor 1, output shaft 11 stops rotating. Under the downward elastic potential energy of the elastic reset member, drive gear 32 can be pushed downward, disengaging from the engine flywheel and resetting. It is worth noting that if the operator does not promptly shut off motor 1 after the engine starts, the engine flywheel speed gradually increases and eventually exceeds the speed of drive gear 32. At this time, the engine flywheel pushes drive gear 32 in the opposite direction. Under the combined effect of the engine flywheel's counter-thrust and the downward elastic potential energy of the elastic reset member, drive gear 32 can also be pushed downward, disengaging from the engine flywheel and resetting.

[0035] The planetary gear reducer 2 has a significantly smaller volume than the spur gear system when the same torque is required to be output. The motor 1 can use a small-sized stator and rotor, and the volume and weight of the motor 1 are significantly reduced. The three-stage structure is arranged coaxially, which can shorten the overall axial length and save more space. The elastic reset component can make the drive gear 32 disengage faster when its speed is not as fast as that of the engine flywheel, thus avoiding the motor 1 being dragged and worn.

[0036] In this embodiment: the elastic reset element is a compression spring 33. The spline shaft 31 includes a first outer straight section, an outer helical section and a second outer straight section from bottom to top. The first outer straight section, the outer helical section and the second outer straight section are coaxially fixed. The lower end of the first outer straight section is coaxially connected to the output shaft 11. The inner wall of the drive gear 32 is provided with an internal thread that meshes with the outer helical section. The top of the second outer straight section is fixedly fitted with a snap ring seat 34. The lower end of the snap ring seat 34 is connected to the compression spring 33. The compression spring 33 is fitted on the second outer straight section. The lower end of the compression spring 33 is connected to the drive gear 32.

[0037] In this embodiment, the retaining ring seat 34 is fixed to the top of the second outer straight section by a retaining ring. When the drive gear 32 moves upward: the internal thread rotates and rises along the outer helical section, the compression spring 33 is compressed and stores elastic potential energy; when the drive gear 32 returns to its original position: the compression spring 33 releases the elastic potential energy and pushes the gear to rotate downward. With this structure, the drive gear 32 can reciprocate along the axial direction of the spline shaft 31 and rotate circumferentially with it, and the elastic return member can push the drive gear 32 axially downward.

[0038] The outer helical section converts the axial movement of the drive gear 32 into rotational motion, causing the compression / release process of the compression spring 33 to accompany the rotation of the drive gear 32. This converts a portion of the meshing impact energy between the drive gear 32 and the engine flywheel into rotational kinetic energy, reducing the impact force on the gears and extending their lifespan. Simultaneously, the helical drive replaces the traditional shift fork mechanism, resulting in fewer parts, a simpler structure, and further reducing the weight of this invention.

[0039] In this embodiment: the diameter of the second outer straight section is smaller than the diameter of the outer spiral section, and an oil-impregnated bearing 35 that cooperates with the second outer straight section is provided inside the drive gear 32. The two ends of the compression spring 33 abut against the snap ring seat 34 and the oil-impregnated bearing 35 respectively.

[0040] When the drive gear 32 moves axially, the oil-impregnated bearing 35 slides on the surface of the second outer straight section, resulting in low friction. The elastic potential energy of the compression spring 33 is uniformly applied to the drive gear 32 through the plane of the oil-impregnated bearing 35, which can extend the life of the drive gear 32. At the same time, it can also play a role in self-lubrication and noise reduction.

[0041] In this embodiment, the drive gear 32 is provided with multiple saw teeth evenly distributed around its circumference. The saw teeth have a forward tooth surface 321 and a reverse tooth surface 322. The upper end of the reverse tooth surface 322 is machined with an inclined surface.

[0042] In this embodiment, the inclined surface machined on the upper end of the reverse tooth surface 322 can cooperate with the inclined surface at the lower end of the engine flywheel saw teeth. During the process of the drive gear 32 meshing into the engine flywheel, the forward tooth surface 321 guides the engine flywheel to slide into the forward gear. When the speed of the engine flywheel is greater than the speed of the drive gear 32, the drive gear 32 is pushed back to gradually move away from the drive engine flywheel. When the inclined surface at the lower end of the engine flywheel saw teeth comes into contact with the inclined surface machined on the upper end of the reverse tooth surface 322, the separation can be accelerated under the action of the inclined surface.

[0043] In this embodiment: the outer shell of the planetary gear reducer 2 protrudes outward in the circumferential direction to form a mounting ring 23. The upper surface of the mounting ring 23 is provided with a plurality of mounting holes 231, which are arranged evenly at intervals in the circumferential direction.

[0044] The mounting ring 23 is integrally die-cast with the housing of the planetary gear reducer 2. In this embodiment, there are four mounting holes 231. Through these four mounting holes 231, the entire utility model can be fixed to the desired installation location with bolts. At this time, the motor 1 in the utility model can be suspended, resulting in better heat dissipation.

[0045] The above are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A lightweight starter motor, characterized in that, The device includes an electric motor, a planetary gear reducer above the electric motor, a transmission structure above the planetary gear reducer, an upwardly extending output shaft, a free end of the output shaft coaxially connected to the transmission structure via the planetary gear reducer, and a splined shaft coaxially connected to the output shaft. A drive gear is fitted on the splined shaft, the drive gear can reciprocate along the axial direction of the splined shaft and rotate synchronously with it, and an elastic reset member is provided between the drive gear and the splined shaft to push the drive gear axially downward.

2. The lightweight starter motor according to claim 1, characterized in that: The elastic reset element is a compression spring. The spline shaft includes a first outer straight section, an outer helical section, and a second outer straight section from bottom to top. The lower end of the first outer straight section is coaxially connected to the output shaft. The inner wall of the drive gear is provided with an internal thread that meshes with the outer helical section. A retaining ring seat is fixedly sleeved on the top of the second outer straight section. The lower end of the retaining ring seat is connected to the compression spring. The compression spring is sleeved on the second outer straight section. The lower end of the compression spring is connected to the drive gear.

3. A lightweight starter motor according to claim 2, characterized in that: The diameter of the second outer straight section is smaller than the diameter of the outer spiral section. An oil-impregnated bearing that cooperates with the second outer straight section is provided inside the drive gear. The two ends of the compression spring abut against the snap ring seat and the oil-impregnated bearing, respectively.

4. A lightweight starter motor according to claim 3, characterized in that: The drive gear is provided with multiple serrations evenly distributed around its circumference. Each serration has a forward tooth surface and a reverse tooth surface, and the upper end of the reverse tooth surface is machined with an inclined surface.

5. A lightweight starter motor according to claim 1, characterized in that: The outer shell of the planetary gear reducer protrudes outward in the circumferential direction to form a mounting ring. The upper surface of the mounting ring has multiple mounting holes, which are arranged at even intervals in the circumferential direction.

Images