Electric balance shaft device and engine system

Abstract

The utility model provides an electric balance shaft device and an engine system. The electric balance shaft device comprises a motor shell assembly, a first balance shaft shell, a second balance shaft shell and a motor rotor assembly. The motor rotor assembly comprises a rotor and a rotating shaft, and the rotor is located in the motor shell assembly; the motor shell assembly is detachably and fixedly connected with the first balance shaft shell, and the motor shell assembly is detachably and fixedly connected with the second balance shaft shell; the rotating shaft comprises a first shaft part and a second shaft part which extend out of the motor shell assembly in the axial direction, the electric balance shaft device further comprises two sets of balance blocks, the first shaft part and one set of balance blocks are located in a first balance shaft shell, and the second shaft part and the other set of balance blocks are located in a second balance shaft shell; and the balance block performs axial limiting and circumferential limiting. The electric balance shaft device does not contain structures such as gears and chains, the noise problem is solved, and the comfort of the whole vehicle is improved.

Description

Technical Field

[0001] The present application relates to the technical field of automobile engines, and in particular to an electric balance shaft device and an engine system. Background Art

[0002] Please refer to Figure 1 and Figure 2 , Figure 1 A schematic diagram of the structure of a single-axis balance shaft system for balancing the first-order reciprocating inertia moment of a three-cylinder engine; Figure 2 Schematic diagram of the structure of a dual-shaft balance shaft system that balances the second-order reciprocating inertia force of a four-cylinder engine.

[0003] When the engine is working, a balance shaft system is installed to balance the engine vibration and improve user comfort. Figure 1 The illustrated balance shaft system is gear-driven and includes a balance shaft 4' and balance weights 3' arranged at 180° angles at either end of the balance shaft. A gear 2' is provided at one end of the balance shaft 4'. Gear 2' meshes with a gear on the engine's crankshaft 1', driving the balance shaft 4' to rotate. This rotation of the balance weights 3' generates a certain torque at the same speed as the engine, but in the opposite direction, thereby balancing the engine's first-order reciprocating moment of inertia.

[0004] Figure 2 and Figure 1 The principle is the same as the balancing system, but it uses two balancing shafts 4'. These two balancing shafts 4' rotate at the same speed but in opposite directions. The balancing weights 3' on each balancing shaft 4' have the same imbalance and rotate at twice the engine speed. The crankshaft drives the balancing shafts 4' to rotate, generating centrifugal force. Because the balancing weights on each balancing shaft 4' have the same imbalance, rotate at the same speed, and rotate in opposite directions, the balancing shaft system only generates vertical upward or vertical downward force during rotation, thereby achieving the purpose of balancing the second-order reciprocating inertia force of the engine.

[0005] The balance shaft system mentioned above is driven by gears, and there is also a chain drive method. However, no matter which drive method is used, the transmission is carried out through hardware contact, which will bring additional noise and even abnormal noise problems such as chain system whining, gear knocking, and gear whining, affecting the comfort of the entire vehicle. Utility Model Content

[0006] The purpose of this application is to provide an electric balancing shaft device and an engine system. The electric balancing shaft device does not contain structures such as gear chains, and can improve the noise problem.

[0007] To solve the above technical problems, the present application provides an electric balancing shaft device, comprising a motor housing assembly, a first balancing shaft housing, a second balancing shaft housing, and a motor rotor assembly; the motor rotor assembly comprises a rotor and a rotating shaft, and the rotor is located in the motor housing assembly; the motor housing assembly and the first balancing shaft housing, as well as the motor housing assembly and the second balancing shaft housing, are detachably fixedly connected;

[0008] The rotating shaft includes a first shaft portion and a second shaft portion extending axially from the motor housing assembly. The electric balancing shaft device further includes two sets of balancing weights. The first shaft portion and one set of balancing weights are located in the first balancing shaft housing, and the second shaft portion and the other set of balancing weights are located in the second balancing shaft housing.

[0009] The first shaft portion and the second shaft portion are both connected to a set of balancing blocks, and the balancing blocks are provided with connecting holes, and the ends of the first shaft portion and the second shaft portion are inserted into the corresponding connecting holes and are circumferentially limited with the connecting holes;

[0010] The electric balancing shaft device further includes connecting bolts, and the first shaft portion and the corresponding balancing weight, as well as the second shaft portion and the corresponding balancing weight, are all connected via the corresponding connecting bolts.

[0011] Optionally, the hole wall of the connecting hole includes a first curved wall and a first straight wall connected to each other, the first shaft portion and the second shaft portion respectively include a first plug connector and a second plug connector, and the outer peripheral walls of the first plug connector and the second plug connector include a second curved wall adapted to the first curved wall and a second straight wall adapted to the first straight wall.

[0012] Optionally, the balancing weight includes a sector-shaped balancing weight body and a mounting portion, wherein the mounting portion protrudes from an inner end of the balancing weight body along a radial direction of the balancing weight body.

[0013] Optionally, the electric balancing shaft device further includes a first ball bearing and a first bearing retaining ring, and a second ball bearing and a second bearing retaining ring, wherein the first ball bearing is arranged between the first balancing shaft housing and the first shaft portion, and the second ball bearing is arranged between the second balancing shaft housing and the second shaft portion;

[0014] The first balancing shaft housing and the second balancing shaft housing both include bearing mounting grooves, the groove side walls of the bearing mounting grooves have retaining ring grooves, the first ball bearing and the second ball bearing are installed in the corresponding bearing mounting grooves, and the first bearing retaining ring and the second bearing retaining ring are installed in the corresponding retaining ring grooves.

[0015] Optionally, the ends of the first shaft portion and the second shaft portion are respectively provided with a first stepped shaft and a second stepped shaft, the first stepped shaft having a first stepped surface, and the second stepped shaft having a second stepped surface;

[0016] One axial end of the inner ring of the first ball bearing is in clearance fit with a group of the balancing blocks, the other axial end of the inner ring of the first ball bearing is in clearance fit with the first step surface, and the axial end surface of the first step shaft is in axial contact with the group of the balancing blocks;

[0017] One axial end of the inner ring of the second ball bearing abuts axially with another set of balancing blocks, the other axial end of the inner ring of the second ball bearing abuts with the second step surface, and the axial end surface of the second step shaft is clearance-fitted with another set of balancing blocks.

[0018] Optionally, the length of the first step axis is greater than the length of the second step axis.

[0019] Optionally, the electric balancing shaft device also includes a signal disk, a signal disk mounting hole is provided in the middle of the signal disk, and a signal disk positioning surface is provided on one side of the axial direction of the signal disk; a signal disk positioning step is provided on the rotating shaft; the signal disk is sleeved on the rotating shaft, and the signal disk positioning surface and the signal disk positioning step are axially abutted, and the other side of the signal disk along the axial direction is axially abutted against the first balancing shaft housing.

[0020] Optionally, the signal disk includes a signal disk main body and a toothed structure arranged on an outer edge of the signal disk main body, wherein the toothed structure has a tooth-missing portion;

[0021] The motor housing assembly further includes a rotational speed signal sensor and a motor control module. The rotational speed signal sensor and the motor control module are arranged outside the motor housing assembly, and the rotational speed signal sensor cooperates with the signal disk.

[0022] Optionally, the motor housing assembly has a first end face and a second end face that are respectively annular in the axial direction, and a plurality of threaded holes uniformly distributed along the circumferential direction are respectively provided on the first end face and the second end face; the first end face and the second end face are provided with at least one positioning pin hole, the positioning pin hole and one of the threaded holes are coaxially connected to form a stepped hole, and the aperture of the positioning pin hole is larger than the aperture of the threaded hole;

[0023] The first balancing shaft housing and the second balancing shaft housing further include mounting end surfaces, each of the mounting end surfaces having a fixing hole corresponding to the threaded hole and a pin hole corresponding to the positioning pin hole;

[0024] It also includes a hollow positioning pin and a connecting bolt, wherein the hollow positioning pin is inserted into the positioning pin hole and the pin hole; and the connecting bolt is inserted into a corresponding set of fixing holes and the threaded hole.

[0025] Optionally, both the first end surface and the second end surface are provided with an even number of positioning pin holes, and the even number of positioning pin holes are symmetrically distributed along the radial direction.

[0026] Optionally, a mounting base is provided on the outside of the motor housing assembly, the first balance shaft housing and the second balance shaft housing, and a plurality of threaded holes are provided on the mounting base for connection with the outside of the engine.

[0027] Optionally, the centers of mass of one group of balancing weights and the centers of mass of another group of balancing weights are arranged in the same direction or in opposite directions.

[0028] Optionally, the electric balance shaft device is installed outside the engine.

[0029] Optionally, the engine is a three-cylinder engine, and a set of the electric balance shaft devices is installed on the outside of the engine; or, the engine is a four-cylinder engine, and two sets of the electric balance shaft devices are installed on the outside of the engine.

[0030] In this application, the electric balance shaft device includes a motor housing assembly and a motor rotor assembly. The use of a motor drive eliminates the noise issues associated with conventional gear or chain drives. Furthermore, the electric balance shaft device in this embodiment includes a balancing weight, which features both circumferential and axial position limits, providing more stable fixation and improving the reliability of the electric balance shaft device's adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of the structure of a single-axis balance shaft system for balancing the first-order reciprocating inertia moment of a three-cylinder engine;

[0032] Figure 2 A schematic diagram of the structure of a dual-shaft balance shaft system that balances the second-order reciprocating inertia force of a four-cylinder engine;

[0033] Figure 3 An exploded view of the electric balance shaft device in an embodiment of the present application;

[0034] Figure 4 for Figure 3 A cross-sectional view of the electric balance shaft device in the assembled state;

[0035] Figure 5 for Figure 3 A top view of the electric balance shaft device;

[0036] Figure 6 It is a structural schematic diagram of the motor housing assembly viewed rightward along a first direction;

[0037] Figure 7 It is a structural schematic diagram of the motor housing assembly viewed leftward along a first direction;

[0038] Figure 8 It is a structural schematic diagram of the motor rotor assembly viewed rightward along a first direction;

[0039] Figure 9 It is a structural schematic diagram of the motor rotor assembly viewed leftward along a first direction;

[0040] Figure 10 It is a structural diagram of the balancing weight when viewed from the mounting portion toward the balancing weight body;

[0041] Figure 11 This is a structural diagram of the balancing weight when viewed from the balancing weight body toward the mounting portion;

[0042] Figure 12 This is a schematic diagram of the structure of the balance shaft housing viewed from the bearing mounting groove to the mounting end face;

[0043] Figure 13 This is a structural diagram of the balance shaft housing viewed from the mounting end toward the bearing mounting groove;

[0044] Figure 14 for Figure 4 An enlarged view of the assembly on one side of the first step shaft;

[0045] Figure 15 for Figure 4 An enlarged view of the assembly on one side of the second step shaft;

[0046] Figure 16 for Figure 3 Schematic diagram of the structure of the middle signal panel;

[0047] Figure 17 It is a structural diagram of the hollow locating pin.

[0048] The following are the descriptions of the reference numerals:

[0049] 1'-crankshaft;

[0050] 2'-gear;

[0051] 3'-balance block;

[0052] 4'-balance shaft;

[0053] 10 - Motor housing assembly; 101 - Motor stator; 102 - Motor housing; 103 - Motor control module; 104 - Speed ​​signal sensor; 105 - First end surface; 105a - First threaded hole; 105b - First positioning pin hole; 106 - Mounting base; 106a - Threaded hole; 107 - Second end surface; 107a - Second threaded hole; 107b - Second positioning pin hole;

[0054] 20 - Motor rotor assembly; 201 - Rotor; 202 - Rotating shaft; 2021 - First shaft; 20211 - First stepped shaft; 202111 - First stepped surface; 20212 - First plug connector; 20212a - Threaded hole; 20213 - Signal disk positioning step; 2022 - Second shaft; 20221 - Second stepped shaft; 202211 - Second stepped surface; 20222 - Second plug connector; 20222a - Threaded hole;

[0055] 30 - first balance shaft housing; 30a - housing cavity; 301 - bearing mounting slot; 302 - retaining ring slot; 303 - mounting end surface; 303a - fixing hole; 303b - pin hole; 304 - first mounting base; 304a - first threaded hole;

[0056] 40 - second balance shaft housing; 40a - housing cavity; 401 - bearing mounting slot; 402 - retaining ring slot; 403 - mounting end face; 403a - fixing hole; 403b - pin hole; 404 - second mounting base; 404a - second threaded hole;

[0057] 50-balance block; 50a-connection hole; 50b-threaded hole; 501-balance block body; 502-mounting portion;

[0058] 60-Signal disk; 601-Signal disk main body; 601a-Signal disk mounting hole; 6011-Signal disk surface; 6012-Signal disk positioning surface; 602-Tooth structure; 602a-Missing tooth portion;

[0059] 70-second ball bearing;

[0060] 80-second bearing retaining ring;

[0061] 90-first connecting bolt;

[0062] 100-stifled cover;

[0063] 110-Hollow locating pin

[0064] 120-second connecting bolt;

[0065] 130-first ball bearing;

[0066] 140-First bearing retaining ring. DETAILED DESCRIPTION

[0067] In order to enable those skilled in the art to better understand the technical solution of the present application, the present application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0068] In the embodiments of the present application, the terms "first" and "second" are mainly used to distinguish the same or similar features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0069] Please refer to Figures 3 to 9 , Figure 3 An exploded view of the electric balance shaft device in an embodiment of the present application; Figure 4 for Figure 3 Cross-sectional view of the electric balance shaft device in the assembled state; Figure 5 for Figure 3 A top view of the electric balance shaft device; Figure 6 is a structural schematic diagram of the motor housing assembly 10 viewed rightward along a first direction; Figure 7 is a structural schematic diagram of the motor housing assembly 10 viewed leftward along a first direction; Figure 8 It is a structural schematic diagram of the motor rotor assembly 20 viewed rightward along a first direction; Figure 9 It is a structural schematic diagram of the motor rotor assembly 20 when viewed leftward along a first direction.

[0070] The electric balance shaft device in this embodiment, such as Figure 3 As shown, the motor housing assembly 10, the first balance shaft housing 30, the second balance shaft housing 40 and the motor rotor assembly 20. The motor rotor assembly 20 includes a rotor 201 and a rotating shaft 202 (shown in FIG. Figure 4 、 8 ), the rotor 201 is located inside the motor housing assembly 10. In detail, the motor housing assembly 10 includes a motor stator 101 and a motor housing 102 (shown in FIG. Figure 4 、 6 ), the motor stator 101 is wrapped inside the motor housing 102, and the rotor 201 can be installed in the motor stator 101.

[0071] As mentioned above, the rotor 201 is located inside the motor housing assembly 10. The rotating shaft 202 includes a first shaft portion 2021 and a second shaft portion 2022 extending axially from the motor housing assembly 10, and another portion is fixed in the rotor 201. The electric balancing shaft device in this embodiment also includes two sets of balancing weights 50, such as Figure 4As shown, it can be seen that the first shaft portion 2021 and one set of balancing weights 50 are located inside the first balancing shaft housing 30, while the second shaft portion 2022 and another set of balancing weights 50 are located inside the second balancing shaft housing 40. By adding the balancing weights 50, the electric balancing shaft device can balance unbalanced forces or moments. Placing the balancing weights 50 inside the first balancing shaft housing 30 and the second balancing shaft housing 40 can reduce wear and tear on the balancing weights 50 and protect them.

[0072] Among them, the first balancing shaft housing 30 and the second balancing shaft housing 40 are detachably fixedly connected to the motor housing 102. Specifically, the first balancing shaft housing 30, the motor housing 102, and the second balancing shaft housing 40 are distributed and docked in sequence along the axial direction to form a relatively complete overall housing, which serves as the outer shell of the electric balancing device, and the motor rotor assembly 20 and the balancing block 50 are both arranged inside the outer shell.

[0073] With this arrangement, the rotation of the balancing weight 50 in the electric balance shaft device no longer relies on being driven by the engine's crankshaft via gears or chains, but is instead driven by a motor, thereby improving the noise issues previously associated with gear or chain drives. By adopting a motor-driven approach, information such as the motor's speed and phase can be controlled by the motor control module 103, providing a more stable power source for the rotating shaft 202. Furthermore, the rotor 201 and the rotating shaft 202 are both enclosed within the housing, and the motor housing 102 and the first balance shaft housing 30, as well as the motor housing 102 and the second balance shaft housing 40, are detachably fixedly connected, protecting the rotor 201 and the rotating shaft 202 while facilitating assembly and disassembly.

[0074] like Figure 4 As shown, the first shaft portion 2021 and the second shaft portion 2022 are both connected to a set of balancing blocks 50, and the balancing blocks 50 are provided with connecting holes 50a (shown in FIG. Figure 10 ), the ends of the first shaft portion 2021 and the second shaft portion 2022 are respectively inserted into the corresponding connecting holes 50a, so that circumferential limitation can be achieved; in addition, the electric balancing shaft device in this embodiment also includes a first connecting bolt 90, and the first shaft portion 2021 and its corresponding set of balancing blocks 50, and the second shaft portion 2022 and its corresponding another set of balancing blocks 50 are all connected by the first connecting bolt 90, so that axial limitation can be achieved.

[0075] Specifically, the rotating shaft 202 is driven by a motor. To achieve the function of balancing unbalanced forces or torques in the electric balancing shaft device, the balancing weight 50 must rotate in phase with the rotating shaft 202, that is, the balancing weight 50 must not move relative to the rotating shaft 202. Therefore, the balancing weight 50 must be circumferentially fixed to the rotating shaft 202. Obviously, the balancing weight 50 and the rotating shaft 202 must be constrained not only circumferentially but also axially to prevent the balancing weight 50 from moving outward relative to the ends of the rotating shaft 202 and dislodging from the ends of the first shaft portion 2021 and the second shaft portion 2022 when the rotating shaft 202 rotates at high speeds. Here, the balancing weight 50 is connected to the first shaft portion 2021 and the second shaft portion 2022, respectively, by means of first connecting bolts 90. This provides axial restraint and ensures that the balancing weight 50 does not disengage from the rotating shaft 202 during movement, thereby effectively performing the balancing weight 50's torque balancing function. The circumferential limiting and axial threaded connection methods make it easy to connect the balancing weight 50 and the rotating shaft 202 and facilitate disassembly.

[0076] Please continue to refer to Figures 10 and 11 , Figure 10 It is a structural schematic diagram of the balancing weight 50 when viewed from the mounting portion 502 toward the balancing weight body 501; Figure 11 Schematic diagram of the structure of the balancing weight 50 when viewed from the balancing weight body 501 toward the mounting portion 502 .

[0077] As mentioned above, it can be combined with Figure 10 It is understood that the hole wall of the connecting hole 50a includes a first arc-shaped wall and a first straight wall connected to each other, that is, the hole wall is substantially a D-shaped hole wall, and the connecting hole 50a is substantially a D-shaped hole. Figure 8 、 9 As shown, the first shaft portion 2021 and the second shaft portion 2022 include a first plug connector 20212 and a second plug connector 20222, respectively. The outer peripheral walls of the first plug connector 20212 and the second plug connector 20222 include a second curved wall that mates with the first curved wall of the connecting hole 50a, and a second straight wall that mates with the first straight wall of the connecting hole 50a. In other words, the plug connectors can also be D-shaped. In other words, both the balancing weight 50 and the corresponding plug connectors are provided with at least one straight wall to ensure that the balancing weight 50 cannot freely rotate relative to the first shaft portion 2021 or the second shaft portion 2022.

[0078] In this embodiment, the connecting hole 50a is configured as a D-shaped hole, and the first plug connector 20212 and the second plug connector 20222 are configured as D-shaped heads. This plugging arrangement ensures more stable positioning of the balancing weight 50. Of course, configuring the connecting hole 50a as a D-shaped hole is only one configuration. Other shapes are also possible, as long as the balancing weight 50 is prevented from rotating relative to the rotating shaft 202. For example, both the connecting hole and the plug connector may be square structures.

[0079] In addition, as mentioned above, the balancing weight 50 and the rotating shaft 202 are connected by the first connecting bolt 90, and a threaded hole 20212a and a threaded hole 20222a (shown in FIG. 20 ) can be provided in the middle of the first plug connector 20212 and the second plug connector 20222 along the axis. Figure 8 、 9 ). For this setting, please refer to Figure 4 The first connecting bolt 90 can be inserted into the balancing block 50 and inserted into the threaded hole 20212a or the threaded hole 20222a, thereby achieving axial limitation of the balancing block 50.

[0080] Figure 4 In the embodiment, a portion of the first connecting bolt 90 is located in the balancing weight 50, and a portion is located in the threaded hole 20212a or the threaded hole 20222a of the plug connector in the connecting hole 50a. Figure 10 、 11 It is understood that the balancing weight 50 can be provided with a through-hole portion extending axially through the rotating shaft 202. The through-hole portion is axially divided into two sections, one section being a connecting hole 50a and the other section being a plug hole 50b. The diameter of the plug hole 50b is smaller than that of the connecting hole 50a. That is, the through-hole portion provided on the balancing weight 50 is a stepped hole. The plug hole 50b can be a plain hole or a threaded hole. After the first connecting bolt 90 passes through the plug hole 50b, it is threaded into the threaded hole 20212a or the threaded hole 20222a of the plug connector located in the connecting hole 50a. It can be seen that the entire through-hole portion of the balancing weight 50 can also be the connecting hole 50a, but the stepped hole can serve as an axial limit for the plug connector of the rotating shaft 202.

[0081] like Figure 10 and Figure 11 As shown, the balancing weight 50 includes a sector-shaped balancing weight body 501 and a mounting portion 502. The mounting portion 502 protrudes radially from the inner end of the balancing weight body 501, and the balancing weight body 501 and the mounting portion 502 are integrally formed. In this embodiment, the inner end refers to the position where the circumference of the sector-shaped balancing weight body 501 is shorter. As previously mentioned, the axial thickness of the mounting portion 502 can be greater than the thickness of the balancing weight body 501 to allow for the desired lengths of the connecting hole 50a and the insertion hole 50b. The radius of the balancing weight 50 is the radius of the balancing weight body 501, and the thickness is the thickness of the balancing weight body 501. The radius and thickness can be determined according to specific needs. Providing the balancing weight 50 in this shape not only saves space, but also ensures greater stability when the balancing weight is fixed, and reduces the force acting on the first shaft portion 2021, the second shaft portion 2022, and the first connecting bolt 90.

[0082] Please refer to Figures 12 to 13 , Figure 12Schematic diagram of the structure of the first balancing shaft housing 30 or the second balancing shaft housing 40 viewed from the bearing mounting groove 301 or the bearing mounting groove 401 toward the mounting end surface 303 or the mounting end surface 403. Figure 13 It is a structural schematic diagram of the first balancing shaft housing 30 or the second balancing shaft housing 40 when viewed from the mounting end surface 303 or the mounting end surface 403 toward the bearing mounting groove 301 or the bearing mounting groove 401 .

[0083] Depend on Figure 3 As can be seen, the electric balancing shaft device in this embodiment includes a first ball bearing 130 and a first bearing retaining ring 140, as well as a second ball bearing 70 and a second bearing retaining ring 80. The first ball bearing 130 is disposed between the first balancing shaft housing 30 and the first shaft portion 2021, while the second ball bearing 70 is disposed between the second balancing shaft housing 40 and the second shaft portion 2022. Specifically, the first and second balancing shaft housings 30 and 40 are provided with bearing mounting grooves 301 and 401, respectively. The sidewalls of the bearing mounting grooves 301 and 401 have retaining ring retaining grooves 302 and 402, respectively. The first ball bearing 130 is mounted in the bearing mounting groove 301, and the first bearing retaining ring 140 is mounted in the retaining ring retaining groove 302. Correspondingly, the second ball bearing 70 is mounted in the bearing mounting groove 401, and the second bearing retaining ring 80 is mounted in the retaining ring retaining groove 402. The first ball bearing 130 and the second ball bearing 70 connect the motor housing 102 to the rotating shaft 202, ensuring that the motor rotor assembly 20 can rotate freely relative to the motor stator 101 fixed in the motor housing 102. Of course, in addition to ball bearings, other types of bearings such as roller bearings can also achieve this purpose. The use of ball bearings can make the rotation smoother. The first bearing retaining ring 140 and the second bearing retaining ring 80 can limit the first ball bearing 130 and the second ball bearing 70. At the same time, arranging the first ball bearing 130 and the second ball bearing 70 inside the first balance shaft housing 30 and the second balance shaft housing 40 can play a protective and limiting role.

[0084] Please refer to Figures 14 and 15 , Figure 14 This is an enlarged assembly view of one side of the first step shaft 20211. Figure 15 This is an enlarged assembly view of one side of the second step shaft 20221.

[0085] like Figure 8 and Figure 9As shown, the ends of the first shaft portion 2021 and the second shaft portion 2022 are respectively provided with a first stepped shaft 20211 and a second stepped shaft 20221, the first stepped shaft 20211 having a first stepped surface 202111, and the second stepped shaft 20221 having a second stepped surface 202211. As mentioned above, the first ball bearing 130 is provided between the first balancing shaft housing 30 and the first shaft portion 2021, and the second ball bearing 70 is provided between the second balancing shaft housing 40 and the second shaft portion 2022. In detail, Figure 14 It can be seen that the axial end of the inner ring of the first ball bearing 130 ( Figure 14 The left end of the shaft) and a set of balancing blocks 50 are clearance-fitted, and the other end and the first step surface 202111 are clearance-fitted, and the axial end surface of the first step shaft 20211 and a set of balancing blocks 50 are axially abutted; Figure 15 It can be seen that the axial end of the inner ring of the second ball bearing 70 ( Figure 15 The right end of the middle) and another set of balance blocks 50 are in axial contact, and the other end ( Figure 15 The first and second stepped shafts 20211 and 20221 are in contact with each other (left end in FIG). The axial end face of the second stepped shaft 20221 is in clearance with the other set of balancing weights 50. The purpose of providing the first and second stepped shafts 20211 and 20221 is to mount the first and second ball bearings 70 and 130. Subsequently, the rotating shaft 202 needs to be axially positioned. Both the first and second ball bearings 130 and 70 can perform axial positioning. If both serve as axial positioning components, the rotating shaft 202 is prone to over-positioning. Therefore, it is not suitable for both to serve as positioning components.

[0086] In this embodiment, a second ball bearing 70 is selected as the positioning component for the rotating shaft 202. On one side of the second ball bearing 70, the first connecting bolt 90, the balancing weight 50, the second shaft portion 2022, and the inner ring of the second ball bearing 70 are pressed together to form a single unit, meaning all components of this unit move synchronously. To achieve positioning, the inner ring of the second ball bearing 70 must be in contact with the balancing weight 50 and the second stepped shaft 20221. Accordingly, to account for manufacturing tolerances, a gap should exist between the ends of the balancing weight 50 and the second stepped shaft 20221, achieving a clearance fit between the two to avoid interference with the contact between the balancing weight 50 and the inner ring of the second ball bearing 70.

[0087] In addition, the inner and outer rings of the bearing can have a certain amount of axial play. Taking the second ball bearing 70 as an example, the ball bearing includes balls. The balls can move within a certain limit in the ball groove of the second ball bearing 70. The outer and inner rings of the second ball bearing 70 will not be strictly aligned, but will produce an axial gap, which is the axial play. The outer ring of the second ball bearing 70 and the motor housing 102 are in a relatively fixed relationship. If, during assembly, the inner ring of the second ball bearing 70 has an axial play relative to the outer ring, and whether the axial play is to the left or to the right is uncertain, then if the first ball bearing 130 and the rotating shaft 202 and the balancing block 50 are axially fitted and abutted, then over-positioning will be formed. Therefore, the inner ring of the first ball bearing 130 does not need to fit the surface of the first step shaft 20211 and the balancing block 50, but a certain gap is left to achieve a clearance fit, such as Figure 14 At this time, the first connecting bolt 90 makes the balancing weight 50 close to the end surface of the first stepped shaft 20211, achieving surface contact and ensuring that the balancing weight 50 and the first shaft portion 2021 rotate synchronously.

[0088] In this embodiment, the length of the first stepped shaft 20211 can be set to be greater than the length of the second stepped shaft 20221. The two sets of balancing weights 50 connected to the first and second stepped shafts 20211 and 20221 have the same dimensions, as do the first and second ball bearings 130 and 70. However, the balancing weight 50 connected to the first stepped shaft 20211 is in contact with the end surface of the first stepped shaft 20211, and the first ball bearing 130 has a clearance fit with both the balancing weight 50 and the first stepped shaft 20211. In contrast, the balancing weight 50 connected to the second stepped shaft 20221 has a clearance fit with the end surface of the second stepped shaft 20221, and the second ball bearing 70 has a surface contact with both the balancing weight 50 and the second stepped shaft 20221. Therefore, by making the first stepped shaft 20211 longer than the second stepped shaft 20221, the balancing weight 50, in conjunction with the first ball bearing 130 and the balancing weight 50, can prevent axial over-positioning.

[0089] Please refer to Figure 16 , Figure 16 for Figure 3 Schematic diagram of the structure of the middle signal disk 60.

[0090] like Figure 16 As shown, the signal disk 60 has a signal disk mounting hole 601a in the middle, and a signal disk positioning surface 6012 is provided on one side of the signal disk 60 along the axial direction. The rotating shaft 202 is provided with a signal disk positioning step 20213 (shown in FIG. Figure 8). Obviously, the diameter of the signal disk mounting hole 601a should not be larger than the shaft diameter of the signal disk mounting section on the rotating shaft 202, so that the signal disk 60 can be press-fitted to the rotating shaft 202 through the signal disk mounting hole 601a, and the signal disk positioning surface 6012 and the signal disk positioning step 20213 are axially abutted, and the other side of the signal disk 60 is axially abutted against the first balance shaft housing 30, making the positioning of the signal disk 60 more stable and reliable. The signal disk 60 should be set close to the speed signal sensor 104 (shown in Figure 6 、 7 ), in this embodiment, the speed signal sensor 104 is close to the first shaft portion 2021, so the signal disk 60 should be set on the first shaft portion 2021. Obviously, if the speed signal sensor 104 is close to the second shaft portion 2022, the signal disk 60 should be set on the second shaft portion 2022.

[0091] Furthermore, the signal disk 60 includes a signal disk main body 601 and a circle of tooth structures 602 arranged on the outer edge of the signal disk main body 601. The circle of tooth structure 602 has a notch at a certain position. The circle of tooth structure 602 includes a plurality of tooth structures evenly distributed along the circumferential direction. By removing one of the tooth structures or processing one less tooth structure, a tooth-missing portion 602a can be formed.

[0092] like Figure 6 and Figure 7 As shown, the motor housing assembly 10 also includes a speed signal sensor 104 and a motor control module 103, both of which are arranged on the outside of the motor housing assembly 10. The speed signal sensor 104 can be used in conjunction with the signal disk 60 to read the speed and phase information of the rotating shaft 202. The motor control module 103 can control the relevant parameters of the rotating shaft 202 based on the information obtained, thereby achieving the purpose of balancing the unbalanced force or torque of the electric balancing shaft device. Since the signal disk 60 has a toothless portion 602a, there are requirements for the phase of the toothless portion 602a relative to the plug connectors at both ends of the rotating shaft 202 during installation. It should be set according to actual needs, and the signal disk 60 should be vertically aligned with the speed signal sensor 104 after assembly is completed, so as to ensure the accuracy of phase reading and subsequent adjustment.

[0093] The detailed adjustment method is as follows:

[0094] S101. Install the signal disk 60 according to actual needs so that it can accurately read the phase information of the rotating shaft 202 and the engine crankshaft (not shown in the drawings of this embodiment);

[0095] S102: After the electric balance shaft device is fixed outside the engine, the phase of the rotating shaft 202 is locked with the phase of the crankshaft on the engine so that the phase of the rotating shaft 202 is consistent with the phase of the crankshaft;

[0096] S103, before the engine is started, the first rotation shaft phase signal and the first crankshaft phase signal are obtained by the rotation speed signal sensor 104 and the signal disk 60;

[0097] S104, determining whether the obtained first rotation shaft phase signal is consistent with the first crankshaft phase signal;

[0098] S105: If the first rotating shaft phase signal and the first crankshaft phase signal are inconsistent, the motor control module 103 adjusts the phase of the rotating shaft 202 so that the rotating shaft phase and the crankshaft phase are consistent;

[0099] S106: After the engine is started, the phase difference between the rotating shaft phase and the crankshaft phase is compensated according to the difference between the rotating shaft phase signal and the crankshaft phase signal read in real time;

[0100] S107, after the engine is shut down, obtaining a second rotation shaft phase signal and a second crankshaft phase signal through the speed signal sensor 104 and the signal disk 60;

[0101] S108, determining whether the obtained second rotation shaft phase signal and the second crankshaft phase signal are consistent;

[0102] S109 , if the second shaft phase signal and the second crankshaft phase signal are inconsistent, adjust the shaft phase through the motor control module 103 to make the shaft phase consistent with the crankshaft phase, and record the adjusted balance shaft phase and crankshaft phase.

[0103] By means of this adjustment and control method, the function of the electric balancing shaft device to balance unbalanced forces or torques can be realized relatively simply.

[0104] Please refer to Figure 17 , Figure 17 Schematic diagram of the structure of the hollow positioning pin 110.

[0105] Depend on Figure 6 and Figure 7It can be seen that the motor housing assembly 10 has a first end face 105 and a second end face 107 along the axial direction, both of which are annular. A plurality of threaded holes evenly distributed along the circumference are provided on the first end face 105 and the second end face 107, which can be respectively defined as first threaded holes 105a and second threaded holes 107a. At least one positioning pin hole is also provided on the first end face 105 and the second end face 107, which can be respectively defined as first positioning pin hole 105b and second positioning pin hole 107b. The first positioning pin hole 105b and the second positioning pin hole 107b are respectively coaxially connected to one of the first threaded holes 105a and the second threaded holes 107a to form a stepped hole. The apertures of the first positioning pin hole 105b and the second positioning pin hole 107b are respectively larger than the apertures of the corresponding first threaded holes 105a and the second threaded holes 107a. That is, when processing the first end face 105 and the second end face 107, the first threaded hole 105a and the second threaded hole 107a should be processed first, and then at least one is selected from the multiple first threaded holes 105a and the second threaded holes 107a respectively located on the first end face 105 and the second end face 107 to be processed into the first positioning pin hole 105b and the second positioning pin hole 107b. If the lengths of the first positioning pin hole 105b and the second positioning pin hole 107b are smaller than the corresponding first threaded hole 105a and the second threaded hole 107a, the first threaded hole 105a and the second threaded hole 105b of the first positioning pin hole 105b and the second positioning pin hole 107b are processed at the same time, which can be used to insert the hollow positioning pin 110 and the connecting screw 120.

[0106] Recombination Figure 12 and Figure 13To illustrate, one end of the first balance shaft housing 30 serves as the bearing mounting portion, while the other end serves as the mounting end surface 303. Mounting end surface 303 includes a fixing hole 303a corresponding to the first threaded hole 105a and the second threaded hole 107a. Also provided on mounting end surface 303 are pin holes 303b corresponding to the first locating pin holes 105b and the second locating pin holes 107b. Similar to the machining of the first and second end surfaces 105 and 107, when machining the mounting end surface 303 of the first balance shaft housing 30, the fixing hole 303a (which can be a threaded hole or a plain hole) should be machined first, followed by the pin hole 303b. Pin hole 303b should be coaxial with one of the fixing holes 303a, and the diameter of pin hole 303b should be larger than that of fixing hole 303a. Accordingly, the second balance shaft housing 40 has a bearing mounting portion at one end and a mounting end surface 403 at the other. Mounting end surface 403 includes a fixing hole 403a corresponding to the first threaded hole 105a and the second threaded hole 107a. Also provided on mounting end surface 403 are pin holes 403b corresponding to the first locating pin holes 105b and the second locating pin holes 107b. Similar to the machining of the first and second end surfaces 105 and 107, when machining the mounting end surface 403 of the second balance shaft housing 40, fixing hole 403a (which can be a threaded hole or a plain hole) should be machined first, followed by pin hole 403b. Pin hole 403b should be coaxial with one of the fixing holes 403a, and the diameter of pin hole 403b should be larger than that of fixing hole 403a. It should be noted that the sizes of the pin holes 303b, 403b and the first positioning pin hole 105b and the second positioning pin hole 107b are not completely consistent. The apertures of the pin holes 303b and 403b should be larger than the apertures of the first positioning pin hole 105b and the second positioning pin hole 107b.

[0107] The electric balancing shaft device also includes a hollow locating pin 110 and a second connecting bolt 120. The hollow locating pin 110 can be inserted into the first locating pin hole 105b and the pin hole 303b, or into the second locating pin hole 107b and the pin hole 403b. The sizes of the first locating pin hole 105b, the second locating pin hole 107b, and the pin holes 303b and 403b can be configured to be inconsistent. Specifically, the hollow locating pin 110 and the first locating pin hole 105b and the second locating pin hole 107b have an interference fit, while the hollow locating pin 110 and the pin holes 303b and 403b have a small clearance fit or a transition fit. This configuration not only ensures a more secure fixation between the first and second balancing shaft housings 30 and 40 and the motor housing assembly 10, but also facilitates installation and removal of the first and second balancing shaft housings 30 and 40. The second connecting bolt 120 can be inserted into the first threaded hole 105a and the fixing hole 303a, or into the second threaded hole 107a and the fixing hole 403a. For example, the first threaded hole 105a and the positioning pin hole 105b machined based on the second threaded hole 107a, as well as the matching fixing hole 303a and the pin hole 303b machined based on the fixing hole 303a, in this case, the hollow positioning pin 110 is first inserted into the positioning pin hole 105b and the pin hole 303b to connect the motor housing assembly 10 and the first balance shaft housing 30, and then the second connecting bolt 120 is inserted into the threaded hole 105a and the fixing hole 303a. As mentioned above, the hollow structure of the hollow positioning pin 110 allows the second connecting bolt 120 to penetrate.

[0108] In this embodiment, the first balance shaft housing 30 and the second balance shaft housing 40 are identical. The first threaded hole 105a and the first locating pin hole 105b on the first end surface 105 are arranged symmetrically with the second threaded hole 107a and the second locating pin hole 107b on the second end surface 107. This arrangement allows the first balance shaft housing 30 to be connected to either the first end surface 105 or the second end surface 107. Similarly, the second balance shaft housing 40 can be connected to either end surface. This allows the balance shaft housings to have identical structures, reducing the number of parts. In this embodiment, the first balance shaft housing 30 is connected to the first end surface 105, and the second balance shaft housing 40 is connected to the second end surface 107.

[0109] Furthermore, the first end surface 105 and the second end surface 107 can each be provided with an even number of first positioning pin holes 105b and second positioning pin holes 107b, and all first positioning pin holes 105b on the first end surface 105 and all second positioning pin holes 107b on the second end surface 107 can be distributed symmetrically along the radial direction. This arrangement can also achieve a more reliable positioning connection. For example, in this embodiment, two symmetrical first positioning pin holes 105b and two symmetrical second positioning pin holes 107b are distributed on the same end surface.

[0110] The motor housing assembly 10 is provided with a mounting base 106 (shown in FIG. Figure 6 、 7 ), a plurality of threaded holes 106a are provided on the mounting base 106. Similarly, for the first balancing shaft housing 30 and the second balancing shaft housing 40, a first mounting base 304 and a second mounting base 404 are provided on their exteriors (shown in FIG. Figure 12 、 13 ), first and second threaded holes 304a, 404a are also provided on the first mounting base 304 and the second mounting base 404, respectively. This arrangement allows for threaded connection with a mechanical interface on the engine, thereby securing the entire electric balance shaft device to the exterior of the engine. This significantly impacts the internal dimensions of the engine and does not restrict the electric balance shaft device to engine specifications, making it more versatile. Furthermore, if parts of the electric balance shaft device are damaged or if the balance weight 50 needs to be replaced, there is no need to disassemble the engine, making replacement and maintenance more convenient.

[0111] like Figure 3 As shown, one group of balancing blocks 50 and another group of balancing blocks 50 are respectively connected to the first shaft portion 2021 and the second shaft portion 2022. The center of mass direction of this pair of balancing blocks 50 can be set to 0 degrees or 180 degrees according to actual needs, depending on whether it is force or torque that needs to be balanced.

[0112] As previously mentioned, the electric balance shaft device in this embodiment can be used to balance unbalanced forces or torques generated by an engine. For a three-cylinder engine, which primarily generates first-order reciprocating inertia torque, the center of mass of the two sets of balance weights 50 at either end of the rotating shaft 202 can be set at 180 degrees, and an electric balance shaft device can be fixed to the outside of the engine. For a four-cylinder engine, which primarily generates second-order reciprocating inertia forces, the center of mass of the two sets of balance weights 50 can be set at 0 degrees, and two electric balance shaft devices can be fixed to the outside of the engine. This method can balance unbalanced forces or torques in the engine.

[0113] from Figure 3 As can be seen in the figure, the electric balancing shaft device in this embodiment further includes a cover 100. The cover 100 is located at the left and right ends of the entire electric balancing shaft device along the first direction and can be embedded in the ends of the first balancing shaft housing 30 and the second balancing shaft housing 40. This arrangement can better protect the entire device.

[0114] When assembling the electric balance shaft device in this embodiment, the following steps should be followed:

[0115] First, install the first ball bearing 130 and the second ball bearing 70 into the bearing mounting groove 301 and the bearing mounting groove 401 of the first balance shaft housing 30 and the second balance shaft housing 40, respectively, until the end faces of the first ball bearing 130 and the second ball bearing 70 contact the bearing positioning surfaces. Then, install the first bearing retaining ring 140 and the second bearing retaining ring 80 into the retaining ring retaining groove 302 and the retaining ring retaining groove 402 of the first balance shaft housing 30 and the second balance shaft housing 40, respectively.

[0116] Then, all hollow locating pins 110 are press-fitted into the first locating pin holes 105b and the second locating pin holes 107b of the first end surface 105 and the second end surface 107, respectively. The second balancing shaft housing 40 is installed toward the second end surface 107, so that the hollow locating pins 110 are also inserted into the pin holes 403b located on the mounting end surface 403 of the second balancing shaft housing 40. At this time, the mounting end surface 403 of the second balancing shaft housing 40 is ensured to be in contact with the second end surface 107 (i.e., the side close to the motor control module 103), and all holes are aligned one by one. The second connecting bolts 120 are inserted into the second threaded holes 107a and the fixing holes 403a and tightened.

[0117] The signal disc 60 is then press-fitted onto the signal disc positioning step 20213 on the rotating shaft 202 with the signal disc positioning surface 6012 contacting and pressing the step surface. During installation, the toothed portion 602a of the signal disc 60 and the first plug connector 20212 and the second plug connector 20222 have a phase requirement. The specific phase requirement is set according to the actual requirements of the engine.

[0118] Then, install the motor rotor assembly 20 into the housing cavity 40a of the motor housing assembly 10 and the second balance shaft housing 40, aligning the signal disk 60 with the speed signal sensor 104 on the same side of the motor housing assembly 10, and insert the second stepped shaft 20221 into the inner hole of the second ball bearing 70;

[0119] Then install the first balance shaft housing 30. Similarly, insert the hollow positioning pin 110 first, so that the installation end surface 303 of the first balance shaft housing 30 is aligned with the first end surface 105 (i.e., the side close to the speed signal sensor 104). Secure and tighten with the second connecting bolt 120.

[0120] After that, install the balancing weight 50 by inserting it into the first plug connector 20212 and the second plug connector 20222 respectively and tightening the first connecting bolt 90. The center of mass position angle of the balancing weight 50 on both sides can be adjusted to 180 degrees and 0 degrees according to the needs. For a three-cylinder engine, when installing the balancing weight 50, it is necessary to ensure that the center of mass position of the two balancing weights is 180 degrees; for a four-cylinder engine, the installation angle of the balancing weight is 0 degrees. After the balancing weight 50 is assembled, the assembly status of the two ends of the shaft 202 is as follows Figures 14 to 16As shown, the balancing weight 50 on one side of the second shaft portion 2022 is clearance-fitted with the axial end surface of the second shaft portion 2022, and the two end surfaces of the inner ring of the second ball bearing 70 are respectively in contact with the balancing weight 50 and the second step surface 202211; while the balancing weight 50 on one side of the first shaft portion 2021 is surface-fitted with the axial end surface of the first shaft portion 2021, and the two end surfaces of the inner ring of the first ball bearing 130 are clearance-fitted with the first step surface 202111 and the balancing weight 50, thereby avoiding axial over-positioning;

[0121] Then, the blind covers 100 at both ends are press-fitted into the first balance shaft housing 30 and the second balance shaft housing 40 respectively. During press-fitting, the press-fitting depth must be controlled to avoid interference between the blind covers 100 and rotating parts.

[0122] During use, corresponding mounting points are designed on the outside of the engine. The motor is secured to the outside of the engine via mounting base 106, first mounting base 304, and second mounting base 404. During installation, the initial phase must be set according to the engine's requirements. During operation, the speed signal sensor 104 reads the speed and phase of the electric balance shaft device via the signal disk 60 and transmits the relevant information to the engine control module via a wiring harness. The engine control module analyzes and compares the engine speed and phase signals and the balance shaft speed and phase signals. The motor control module 103 on the motor housing 102 controls and adjusts the speed and phase of the rotor 201, thereby balancing the unbalanced forces or unbalanced torques of the engine.

[0123] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. An electric balance shaft device, characterized in that: The invention comprises a motor housing assembly (10), a first balancing shaft housing (30), a second balancing shaft housing (40), and a motor rotor assembly (20); the motor rotor assembly (20) comprises a rotor (201) and a rotating shaft (202), and the rotor (201) is located in the motor housing assembly (10); the motor housing assembly (10) and the first balancing shaft housing (30), and the motor housing assembly (10) and the second balancing shaft housing (40) are detachably fixedly connected; The rotating shaft (202) includes a first shaft portion (2021) and a second shaft portion (2022) extending axially from the motor housing assembly (10); the electric balancing shaft device further includes two groups of balancing blocks (50); the first shaft portion (2021) and one group of balancing blocks (50) are located in the first balancing shaft housing (30); and the second shaft portion (2022) and the other group of balancing blocks (50) are located in the second balancing shaft housing (40); The first shaft portion (2021) and the second shaft portion (2022) are both connected to a set of balancing blocks (50), and the balancing blocks (50) are provided with connecting holes (50a), and the ends of the first shaft portion (2021) and the second shaft portion (2022) are inserted into the corresponding connecting holes (50a) and are circumferentially limited with the connecting holes (50a); The electric balancing shaft device further comprises a first connecting bolt (90), and the first shaft portion (2021) and the corresponding balancing block (50), as well as the second shaft portion (2022) and the corresponding balancing block (50), are all connected via the corresponding first connecting bolt (90).

2. The electric balance shaft device according to claim 1, characterized in that: The hole wall of the connecting hole (50a) comprises a first curved wall and a first straight wall connected to each other, the first shaft portion (2021) and the second shaft portion (2022) respectively comprise a first plug connector (20212) and a second plug connector (20222), and the outer peripheral walls of the first plug connector (20212) and the second plug connector (20222) comprise a second curved wall adapted to the first curved wall and a second straight wall adapted to the first straight wall.

3. The electric balance shaft device according to claim 1, characterized in that: The balancing weight (50) comprises a sector-shaped balancing weight body (501) and a mounting portion (502), wherein the mounting portion (502) protrudes from the inner end of the balancing weight body (501) along the radial direction of the balancing weight body (501).

4. The electric balance shaft device according to any one of claims 1 to 3, characterized in that: The electric balancing shaft device further comprises a first ball bearing (130) and a first bearing retaining ring (140), and a second ball bearing (70) and a second bearing retaining ring (80), wherein the first ball bearing (130) is arranged between the first balancing shaft housing (30) and the first shaft portion (2021), and the second ball bearing (70) is arranged between the second balancing shaft housing (40) and the second shaft portion (2022); The first balancing shaft housing (30) and the second balancing shaft housing (40) both include bearing mounting grooves, the groove sidewalls of the bearing mounting grooves having retaining ring grooves, the first ball bearing (130) and the second ball bearing (70) being mounted in the corresponding bearing mounting grooves, and the first bearing retaining ring (140) and the second bearing retaining ring (80) being mounted in the corresponding retaining ring grooves.

5. The electric balance shaft device according to claim 4, characterized in that: The ends of the first shaft portion (2021) and the second shaft portion (2022) are respectively provided with a first stepped shaft (20211) and a second stepped shaft (20221); the first stepped shaft (20211) has a first stepped surface (202111), and the second stepped shaft (20221) has a second stepped surface (202211); One axial end of the inner ring of the first ball bearing (130) is clearance-fitted with a group of the balancing blocks (50), the other axial end of the inner ring of the first ball bearing (130) is clearance-fitted with the first step surface (202111), and the axial end surface of the first step shaft (20211) is in axial contact with a group of the balancing blocks (50); One axial end of the inner ring of the second ball bearing (70) abuts against another group of the balancing blocks (50) in the axial direction, the other axial end of the inner ring of the second ball bearing (70) abuts against the second step surface (202211), and the axial end surface of the second step shaft (20221) is clearance-fitted with another group of the balancing blocks (50).

6. The electric balance shaft device according to claim 5, characterized in that: The length of the first step shaft (20211) is greater than the length of the second step shaft (20221).

7. The electric balance shaft device according to any one of claims 1 to 3, characterized in that: The electric balancing shaft device further comprises a signal disk (60), wherein a signal disk mounting hole (601a) is provided in the middle of the signal disk (60), and a signal disk positioning surface (6012) is provided on one side of the signal disk (60) along the axial direction; a signal disk positioning step (20213) is provided on the rotating shaft (202); the signal disk (60) is sleeved on the rotating shaft (202), and the signal disk positioning surface (6012) and the signal disk positioning step (20213) are in axial contact with each other, and the other side of the signal disk (60) is in axial contact with the first balancing shaft housing (30).

8. The electric balance shaft device according to claim 7, characterized in that: The signal disk (60) comprises a signal disk main body (601) and a toothed structure (602) arranged on the outer edge of the signal disk main body (601), wherein the toothed structure (602) has a toothed portion (602a); The motor housing assembly (10) further comprises a rotational speed signal sensor (104) and a motor control module (103), wherein the rotational speed signal sensor (104) and the motor control module (103) are arranged outside the motor housing assembly (10), and the rotational speed signal sensor (104) cooperates with the signal disk (60).

9. The electric balance shaft device according to any one of claims 1 to 3, characterized in that: The motor housing assembly (10) has a first end face (105) and a second end face (107) which are respectively annular in the axial direction, and a plurality of threaded holes uniformly distributed along the circumferential direction are respectively provided on the first end face (105) and the second end face (107); the first end face (105) and the second end face (107) are provided with at least one positioning pin hole, the positioning pin hole and one of the threaded holes are coaxially connected to form a stepped hole, and the aperture of the positioning pin hole is larger than the aperture of the threaded hole; The first balancing shaft housing (30) and the second balancing shaft housing (40) further include mounting end surfaces, each of the mounting end surfaces having a fixing hole corresponding to the threaded hole and a pin hole corresponding to the positioning pin hole; It also includes a hollow positioning pin (110) and a second connecting bolt (120), wherein the hollow positioning pin (110) is inserted into the positioning pin hole and the pin hole; and the second connecting bolt (120) is inserted into a corresponding set of fixing holes and the threaded hole.

10. The electric balance shaft device according to claim 9, characterized in that: Both the first end surface (105) and the second end surface (107) are provided with an even number of positioning pin holes, and the even number of positioning pin holes are symmetrically distributed along the radial direction.

11. The electric balance shaft device according to any one of claims 1 to 3, characterized in that: The motor housing assembly (10), the first balance shaft housing (30) and the second balance shaft housing (40) are all provided with mounting bases on their exteriors, and a plurality of threaded holes are provided on the mounting bases for connection with the exterior of the engine.

12. The electric balance shaft device according to any one of claims 1 to 3, characterized in that: The centers of mass of one group of balancing weights (50) and another group of balancing weights (50) are arranged in the same direction or in opposite directions.

13. An engine system, characterized in that: The electric balancing shaft device comprises the electric balancing shaft device according to any one of claims 1 to 12, wherein the electric balancing shaft device is installed outside the engine.

14. The engine system according to claim 13, wherein: The engine is a three-cylinder engine, and a set of the electric balance shaft devices is installed outside the engine; or, the engine is a four-cylinder engine, and two sets of the electric balance shaft devices are installed outside the engine.

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