WINDING SHAFT FIXTURE, WINDING DEVICE, AND METHOD FOR PREPARING ELECTRODE ASSEMBLY

The present application discloses a winding shaft fixture, a winding device, and a method for preparing an electrode assembly. The winding shaft fixture includes a clamping mechanism and a tensioning mechanism. The clamping mechanism is used to clamp or release an end of a winding shaft. The tensioning mechanism is connected to the clamping mechanism, and the tensioning mechanism is configured to apply a pulling force to the clamping mechanism when the clamping mechanism clamps the end of the winding shaft, so as to apply the pulling force to the winding shaft. According to the technical solutions of the present application, the winding shaft can be allowed to have a higher winding speed to improve the production efficiency of the electrode assembly.

TECHNICAL FIELD

The present application relates to the field of battery production technology, and in particular, to a winding shaft fixture, a winding device, and a method for preparing an electrode assembly.

BACKGROUND ART

Achieving energy conservation and emission reduction is the key to the sustainable development of the automotive industry. Electric vehicles have become an important part of the sustainable development of the automotive industry due to their advantages in energy conservation and being environmentally friendly. For the electric vehicles, the battery technology is an important factor to their development.

In battery production, a wound electrode assembly is formed by winding an electrode plate and a separator by means of a winding shaft, and the winding speed directly affects the production efficiency of the electrode assembly and a battery. However, in the prior art, it is easy to produce unqualified electrode assemblies by simply increasing the winding speed.

SUMMARY

In view of the above problem, embodiments of the present application provide a winding shaft fixture, a winding device, and a method for preparing an electrode assembly, which can allow a winding shaft to have a higher winding speed to improve the production efficiency of the electrode assembly.

In a first aspect, the present invention provides a winding shaft fixture, including: a clamping mechanism for clamping or releasing an end of a winding shaft; and a tensioning mechanism connected to the clamping mechanism, the tensioning mechanism being configured to apply a pulling force to the clamping mechanism when the clamping mechanism clamps the end of the winding shaft, so as to apply the pulling force to the winding shaft.

In the technical solution of the embodiments of the present application, one end of the winding shaft is mounted on a mounting base and the other end thereof is clamped by the clamping mechanism; when the clamping mechanism clamps the end of the winding shaft, the tensioning mechanism applies a pulling force to the clamping mechanism so as to apply the pulling force to the end of the winding shaft by means of the clamping mechanism to tension the winding shaft, thereby reducing the deflection deformation of the winding shaft, ensuring the winding quality of the electrode assembly, and allowing the winding speed to be increased to improve the production efficiency of the electrode assembly.

In some embodiments, the clamping mechanism includes: a housing having an opening for the winding shaft to extend through; and a clamping assembly provided in the housing and rotatably connected to the housing about an axis of the winding shaft, the clamping assembly being used to clamp or release the end of the winding shaft; where the tensioning mechanism is connected to the housing.

The end of the winding shaft extends into the housing through the opening and is clamped by the clamping assembly, and the tensioning mechanism pulls the housing to tension the winding shaft. Since the clamping assembly is arranged to be rotatably connected to the housing about the axis of the winding shaft, the clamping assembly may actively rotate to match the rotation of the winding shaft or may be driven to rotate by the winding shaft, and the housing and the tensioning mechanism are not required to rotate with the winding shaft, so that manufacturing cost of the winding shaft fixture and operation cost for winding can be effectively reduced.

In some embodiments, the clamping assembly includes a transmission member and a plurality of clamping members, the plurality of clamping members being distributed about the axis of the winding shaft, and each of the clamping members being in wedged fit with the transmission member; and the clamping mechanism further includes: a first drive unit provided in the housing, the first drive unit being used to drive the transmission member to move in an axial direction of the winding shaft, so that the plurality of clamping members are closed in a radial direction of the winding shaft to clamp the end of the winding shaft.

When the first drive unit is operated to drive the transmission member to move along the axis of the winding shaft, due to a wedged fit between the transmission member and the clamping members, the transmission member can effectively drive all the clamping members to radially close, and a clamping force of the clamping members to the end of the winding shaft can be ensured. Moreover, transmission between the transmission member and the clamping members described above is carried out in a simple way, which can ensure the power transmission efficiency and reduce the difficulty of designing the transmission member and the clamping members.

In some embodiments, the clamping assembly further includes a base, the base being rotatably mounted in the housing about the axis of the winding shaft, and the transmission member being movably mounted on the base in the axial direction of the winding shaft.

The base capable of rotating about the axis of the winding shaft is provided, so that the transmission member can not only move along the axis of the winding shaft, but can also rotate about the axis of the winding shaft, so as to synchronously rotate with the winding shaft.

In some embodiments, the transmission member passes through the base in the axial direction of the winding shaft, one end of the transmission member is in wedged fit with the plurality of clamping members, and the other end of the transmission member is connected to the first drive unit.

The transmission member is located between the clamping member and the first drive unit in the axial direction of the winding shaft, so that the transmission member can be driven by the first drive unit to drive the clamping members to close in the radial direction of the winding shaft in a shortest path, so as to quickly clamp the winding shaft. Moreover, the clamping members, the transmission member and the first drive unit are arranged in the axial direction of the winding shaft, which facilitates the spatial arrangement of the individual structures in the clamping mechanism.

In some embodiments, the base is provided with a plurality of guide grooves, the plurality of guide grooves are distributed at intervals in a circumferential direction of the base, and each of the guide grooves extends in an axial direction of the base; and the transmission member includes a connecting portion and a plurality of transmission portions, the transmission portions are arranged corresponding to the guide grooves, each of the transmission portions is slidably provided in the corresponding guide groove, one end of each transmission portion is in wedged fit with the corresponding clamping member, the other end of each transmission portion is connected to the connecting portion, and the connecting portion is connected to the first drive unit.

The plurality of transmission portions are slidably provided in the corresponding guide grooves, and with the connecting portion, the first drive unit can drive all the transmission portions to slide simultaneously, so that all the clamping members are synchronously closed in the radial direction of the winding shaft under the action of the corresponding transmission portions, ensuring a clamping effect and clamping coaxiality of the winding shaft.

In some embodiments, the clamping assembly further includes a base, the base being rotatably mounted in the housing about the axis of the winding shaft, and the base being configured to abut against the clamping members to prevent the clamping members from moving in the axial direction of the winding shaft.

The base capable of rotating about the axis of the winding shaft is provided, so that it can be ensured that the clamping members are prevented from moving in the axial direction of the winding shaft while the clamping members can rotate about the axis of the winding shaft, so as to avoid the situation in which the clamping members do not clamp the winding shaft due to the offset of the clamping members caused by the wedged fit during transmission of the transmission member.

In some embodiments, one end surface of the base is provided with an accommodating recess, a part of each of the clamping members is located in the accommodating recess, and the other part of the clamping member is located outside the accommodating recess and in wedged fit with the transmission member.

The base has a simple structure and is easily manufactured. Since a part of the clamping member abuts in the accommodating recess, when moving in the axial direction of the winding shaft, the transmission member can easily drive the clamping member to radially slide along the accommodating recess, so that the winding shaft is clamped by the clamping members.

In some embodiments, the clamping mechanism further includes: a bearing, the base being mounted in the housing by means of the bearing.

With the bearing, the base can be stably rotated in the housing, ensuring stability of the winding shaft during winding.

In some embodiments, one of the base and the bearing is provided with a limiting protrusion and the other one is provided with a limiting groove, and the limiting protrusion and the limiting groove are engaged with each other to prevent the base from moving in the axial direction of the winding shaft.

The base and the bearing are engaged with each other by means of the limiting protrusion and the limiting groove, and the base is limited in the axial direction of the winding shaft, so that the base cannot be displaced due to a movement of the transmission member, ensuring that the winding shaft is successfully clamped by the clamping members.

In some embodiments, the clamping assembly further includes: an elastic element configured to apply an elastic force to the plurality of clamping members, so that the plurality of clamping members are opened in the radial direction of the winding shaft to release the end of the winding shaft.

When the first drive unit drives the transmission member to move back, that is, the transmission member no longer acts on the clamping members, the plurality of clamping members can be radially opened under the action of the elastic element to release the winding shaft, which facilitates withdrawing of the winding shaft.

In some embodiments, the clamping mechanism further includes: a connector provided in the housing, the first drive unit being connected to the connector to drive the connector to move in the axial direction of the winding shaft; and a second drive unit fixed to the connector and connected to the transmission member, the second drive unit being used to drive the transmission member to rotate about the axis of the winding shaft.

The first drive unit drives the transmission member to drive the clamping members to clamp the winding shaft, the second drive unit drives the transmission member and the clamping members to actively rotate, so that two ends of the winding shaft rotate at the same speed, ensuring the winding quality of the electrode assembly. Moreover, the problem of breakage of the winding shaft due to excessive torque on one end of the winding shaft can be solved by means of active rotation. The connector is provided, so that the first drive unit is prevented from rotating when the second drive unit achieves active rotation, effectively controlling a work load of the winding shaft fixture, and saving the operation cost.

In some embodiments, the clamping mechanism further includes: a guide rod fixed in the housing and extending parallel to the axial direction of the winding shaft; where the connector is slidably sleeved around the guide rod.

The guide rod is provided, so that the base can be driven by the first drive unit to move stably in the axial direction of the winding shaft, ensuring that the transmission member successfully drives the clamping members to radially close.

In some embodiments, the clamping mechanism further includes: a second drive unit provided in the housing, the second drive unit being used to drive the clamping assembly to rotate about the axis of the winding shaft.

The second drive unit provides a torque, so that the two ends of the winding shaft rotate at the same speed, ensuring the winding quality of the electrode assembly; Moreover, the problem of breakage of the winding shaft due to excessive torque on one end of the winding shaft can be solved by means of active rotation.

In some embodiments, the clamping assembly includes a plurality of clamping members, each of the clamping members having a first bevel that is used to be attached to the end of the winding shaft.

The end of the winding shaft is sharp. The first bevel of the clamping member can be effectively attached to a bevel of the end of the winding shaft, ao as to ensure interaction interfaces between all the clamping members and the end of the winding shaft when the clamping members are closed and effectively clamp the winding shaft, avoiding the situation in which the clamping mechanism slips off the winding shaft when the winding shaft is tensioned.

In some embodiments, the clamping assembly includes a plurality of clamping members, each of the clamping members being provided with a protrusion that is used to be embedded in a recess provided at the end of the winding shaft.

With the protrusion and the recess respectively provided on the clamping member and the end of the winding shaft, the clamping members firmly grip the winding shaft when clamping the end of the winding shaft, so as to ensure a clamping force of the clamping member to the end of the winding shaft, avoiding the situation in which the clamping mechanism slips off the winding shaft when the winding shaft is tensioned.

In a second aspect, the present invention provides a winding device, including: a mounting base; a winding shaft with one end mounted on the mounting base; and a winding shaft fixture according to any one of the foregoing embodiments, where the clamping mechanism is used to clamp the other end of the winding shaft.

In the foregoing implementation, the mounting base is connected to one end of the winding shaft and drives the winding shaft to carry out winding. The clamping mechanism clamps the other end of the winding shaft, the tensioning mechanism applies a pulling force to the winding shaft, so that the rigidity of the winding shaft can be effectively improved, the deflection deformation of the winding shaft can be reduced, and the winding quality of the electrode assembly can be ensured.

In a third aspect, the present invention provides a winding device, including a mounting base; a winding shaft with one end mounted on the mounting base; and a tensioning mechanism configured to apply a pulling force to the winding shaft at the other end of winding shaft.

In the foregoing implementation, the tensioning mechanism applies a pulling force to the winding shaft, so that the rigidity of the winding shaft can be effectively improved, the deflection deformation of the winding shaft can be reduced, and the winding quality of the electrode assembly can be ensured.

In a fourth aspect, the present invention provides a method for preparing an electrode assembly, including:applying a pulling force to an end of a winding shaft; androtating the winding shaft to wind an electrode plate and a separator that are stacked so as to form the electrode assembly.

In the foregoing implementation, the pulling force is applied to the end of the winding shaft to improve the rigidity of the winding shaft, and when the winding shaft is rotated to wind the electrode plate and the separator that are stacked, the deflection deformation of the winding shaft can be effectively reduced, ensuring a winding effect of the electrode assembly.

LIST OF REFERENCE SIGNS

DETAILED DESCRIPTION

In order to make the objects, technical solutions and advantages of embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the embodiments described are some of, rather than all of, the embodiments of the present application. Generally, the assemblies of the embodiments of the present application described and illustrated in the accompanying drawings herein may be arranged and designed in a variety of different configurations.

Thus, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application as claimed, but is merely representative of the selected embodiments of the present application. All the other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

It should be noted that like numerals and letters refer to like items in the following accompanying drawings, so once an item is defined in one accompanying drawing, it does not require further definition and explanation in subsequent accompanying drawings.

In the description of the embodiments of the present application, it should be understood that orientations or positional relationships indicated by the terms “center”, “upper”, “lower”, “left”, “right”, “vertical”, “horizontal”, “inside”, “outside”, etc. are based on the orientations or positional relationships shown in the accompanying drawings or are orientations or positional relationships in which a product of the present application is conventionally placed when in use, or the orientations or positional relationships commonly understood by those skilled in the art, and are intended to facilitate the description of the present application and simplify the description only, rather than indicating or implying that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation, and will not to be interpreted as limiting the present application.

In the description of the embodiments of the present application, it should also be noted that the terms “provided”, “mounting”, “connecting”, and “connection” should be interpreted in the broad sense unless explicitly defined and limited otherwise. For example, the terms may mean a fixed connection, a detachable connection, or an integral connection, or may be a direct connection, an indirect connection by means of an intermediate medium, or internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the terms mentioned above in the present application can be construed according to specific circumstances.

It should be noted that the embodiments in the present application and features in the embodiments may be combined with each other without conflicts.

The technical solution of the present application will be described below with reference to the accompanying drawings.

At present, from the perspective of the development of the market situation, the traction batteries are used more and more widely. The traction batteries are not only used in energy storage power systems such as hydroelectric power plants, thermal power plants, wind power plants and solar power plants, but also widely used in electric transportation means such as electric bicycles, electric motorcycles and electric vehicles and in many fields such as military equipment and aerospace. With the continuous expansion of the application field of traction batteries, the market demand for the traction batteries is also expanding.

In battery production, a wound electrode assembly is formed by winding an electrode plate and a separator by means of a winding shaft, and the winding speed directly affects the production efficiency of the electrode assembly and a battery. However, in the prior art, it is easy to produce unqualified electrode assemblies by simply increasing the winding speed.

After research, the inventor found that the cause of the above problem lies in the insufficient rigidity of the winding shaft. The winding shaft may have the deflection deformation when it is only affected by dead weight, and it may also be affected by tension of the electrode plate and separator during winding, which greatly increases the deformation amount of the winding shaft, and in such a state, the electrode assembly produced by winding will have various quality problems. In order to produce qualified electrode assemblies in this case, the winding speed is required to be reduced, which leads to a great reduction in the battery production efficiency.

Based on the above considerations, in order to meet the demand of increasing the winding speed and to solve the problem of a low winding quality due to insufficient rigidity of the winding shaft, the inventor, after an intensive study, found the following.

It can be seen from the beam deflection deformation that in the absence of a pretension force, that is, one end of the winding shaft is connected to a mounting base (the mounting base can drive the winding shaft to rotate to produce an electrode assembly by winding), and the other end of the winding shaft is in a free state, the deformation of the winding shaft refers to the deformation of a cantilever beam with one end fixed, and the deflection deformation equation is

and when a pretension force is applied to the other end of the winding shaft, that is, when one end of the winding shaft is connected to the mounting base, and the other end thereof is fixed and provided with a pulling force, the deflection deformation equation is

where F is a resultant force of the tension of the electrode plate and separator and the dead weight to the winding shaft, L is a length of the winding shaft, E is an elastic modulus of the winding shaft, and D is a diameter of the winding shaft. It can be seen from the above two equations that a bending deformation value when the pretension force is applied is equivalent to 20% of the deformation of the cantilever beam with one end fixed, so the rigidity of the winding shaft can be significantly improved after the pretension force is applied, thereby improving the winding rate and quality of the electrode assembly.

To this end, the inventor proposes a design thinking. Referring toFIG.1,FIG.1is a schematic diagram of a design thinking of a winding shaft fixture13provided in the present application. One end of a winding shaft10is fixed to a mounting base11, and the other end of the winding shaft10is inserted into a front support12. The mounting base11can drive the winding shaft10to rotate about an axis of the winding shaft10to wind an electrode plate and a separator that are stacked on the winding shaft10so as to form an electrode assembly. Considering that after the end of the winding shaft10is inserted into the front support12, the winding shaft has a high degree of freedom and may move backward and forward in an insertion direction of the winding shaft10, the winding shaft10is deformed and bent by an external force and the dead weight, so that the end thereof may be displaced within the front support12. Therefore, by fixing and clamping the end of the winding shaft10that is away from the mounting base11, a large deformation of the winding shaft10can be avoided. Then, a pulling force N is applied in an axial direction of the winding shaft10to tension the winding shaft10. When the winding shaft10is deformed due to the resultant force F of the tension of the electrode plate and separator and the dead weight, the pulling force N produces two components, where a component N1is in a direction opposite the resultant force F, and a component N2is in a direction in which the winding shaft10moves backward and forward. At this point, the component N1offsets part of the resultant force F, reducing the impact of the tension of the electrode plate and separator and the dead weight on the deformation of the winding shaft10, thereby ensuring the winding speed and quality of the electrode assembly.

Based on the above design thinking, some embodiments of the present application provide a winding shaft fixture13. Referring toFIG.2,FIG.2is a schematic diagram of a winding shaft fixture13according to some embodiments of the present application.

The winding shaft fixture13includes a clamping mechanism20and a tensioning mechanism30. The clamping mechanism20is used to clamp or release an end of the winding shaft10. The tensioning mechanism30is connected to the clamping mechanism20, the tensioning mechanism30is configured to apply a pulling force to the clamping mechanism20when the clamping mechanism20clamps the end of the winding shaft10, so as to apply the pulling force to the winding shaft10. As shown, N is directed in a direction in which the pulling force is applied to the winding shaft10by the tensioning mechanism30.

The “end of the winding shaft10” refers to an end of the winding shaft10that is away from the mounting base11. The mounting base11is connected to one end of the winding shaft10and can drive the winding shaft10to rotate to wind an electrode plate and a separator that are stacked so as to form an electrode assembly. In an actual working condition, the winding shaft10is located between the mounting base11and the clamping mechanism20, and two ends of the winding shaft10are fixed respectively by the mounting base11and the clamping mechanism20. The tensioning mechanism30applies a pulling force to the winding shaft10by means of the clamping mechanism20to improve the rigidity of the winding shaft10and reduce the impact of the tension of the electrode plate and separator (the electrode plate and separator that are stacked) and the dead weight of the winding shaft10on the deformation of the winding shaft10. It is to be understood that the clamping mechanism20includes a power device capable of performing a clamping action, a power source of which is not limited to a commonly used electric motor, cylinder or electro-pneumatic power element. The tensioning mechanism30includes a power device providing pulling traction, a power source of which is not limited to a commonly used electric motor, cylinder or electro-pneumatic power element.

In the foregoing implementation, when the clamping mechanism20clamps the end of the winding shaft10, the tensioning mechanism30applies a pulling force to the winding shaft10to tension the winding shaft10, thereby reducing the deflection deformation of the winding shaft10, ensuring the winding quality of the electrode assembly, and allowing the winding speed to be increased to improve the production efficiency of the electrode assembly.

According to some embodiments of the present application, optionally, referring toFIG.3,FIG.3is a diagram of an internal structure of a clamping mechanism20according to some embodiments of the present application. The clamping mechanism20includes a housing21and a clamping assembly22. The housing21has an opening210for the winding shaft10to extend through. The clamping assembly22is provided in the housing21and is rotatably connected to the housing21about the axis of the winding shaft10. The clamping assembly22is used to clamp or release the end of the winding shaft10. The tensioning mechanism30is connected to the housing21.

The clamping assembly22is connected to the housing21, that is, when the tensioning mechanism30applies a pulling force to the housing21, the pulling force can act on the clamping assembly22, so that the tensioning mechanism30can apply the pulling force to the winding shaft10clamped by the clamping assembly22. The clamping assembly22is provided inside the housing21and can rotate relative to the housing21about the axis of the winding shaft10, that is, the clamping assembly22can rotate with the winding shaft10when clamping the winding shaft10, ensuring that the winding shaft10carries out winding. The end of the winding shaft10extends into the housing21through the opening210of the housing21, and the part of the winding shaft10extending into the housing21can be clamped and fixed by the clamping assembly22.

The end of the winding shaft10extends into the housing21through the opening210and is clamped by the clamping assembly22, and the tensioning mechanism30pulls the housing21to tension the winding shaft10. Since the clamping assembly22is designed to be rotatably connected to the housing21about the axis of the winding shaft10, the clamping assembly22may actively rotate to match the rotation of the winding shaft10or may be driven to rotate by the winding shaft10, and the housing21and the tensioning mechanism30are not required to rotate with the winding shaft10, so that manufacturing cost of the winding shaft fixture13and operation cost for winding can be effectively reduced.

According to some embodiments of the present application, optionally, referring toFIGS.4to6,FIG.4is a schematic structural diagram of a clamping mechanism20according to some embodiments of the present application,FIG.5is a partial sectional view of a clamping mechanism20according to some embodiments of the present application, andFIG.6is an enlarged view of part VI inFIG.5. The clamping assembly22includes a transmission member220and a plurality of clamping members221. The plurality of clamping members221are distributed about the axis of the winding shaft10, and each of the clamping members221is in wedged fit with the transmission member220. The clamping mechanism20further includes: a first drive unit23provided in the housing21. The first drive unit23is used to drive the transmission member220to move in the axial direction of the winding shaft10, so that the plurality of clamping members221are closed in a radial direction of the winding shaft10to clamp the end of the winding shaft10.

Two or more clamping members221may be provided to provide a clamping force to the winding shaft10in the radial direction of the winding shaft10to firmly clamp the winding shaft10. Optionally, two clamping members221are provided, where one of the clamping members221provides a clamping force to an upper surface of the winding shaft10and the other clamping member221provides a clamping force to a lower surface of the winding shaft10, and the two clamping forces are co-linear and pass through the center of the winding shaft10, so that the winding shaft10can be stably clamped. Optionally, a spacer40may be provided between the clamping members221, the spacer40is inserted between two parts of the winding shaft10to avoid the situation in which when the clamping members221clamp the winding shaft, a gap of the winding shaft10becomes smaller to make the winding shaft10deformed into an oval, which affects the winding quality. Referring toFIG.6, “wedged fit” means that an interaction interface between the clamping member221and the transmission member220is inclined. When the first drive unit23drives the transmission member220to move along the axis of the winding shaft10, the transmission member220displaces the clamping members221toward the winding shaft10along the interaction interface in the radial direction of the winding shaft10to be radially closed, thereby clamping the winding shaft10. It is to be understood that the first drive unit23may include a device capable of outputting linear motion such as a cylinder or a linear electric motor. Of course, in other embodiments, the clamping assembly22may be other devices capable of performing a clamping action, such as a manipulator or jaws.

When the first drive unit23is operated to drive the transmission member220to move along the axis of the winding shaft10, due to a wedged fit between the transmission member220and the clamping members221, the transmission member220can effectively drive all the clamping members221to radially close, and a clamping force of the clamping members221to the end of the winding shaft10can be ensured. Moreover, transmission between the transmission member220and the clamping members221described above is carried out in a simple way, which can ensure the power transmission efficiency and reduce the difficulty of designing the transmission member220and the clamping members221.

According to some embodiments of the present application, optionally, referring toFIG.5, the clamping assembly22further includes a base222, where the base222is rotatably mounted in the housing21about the axis of the winding shaft10, and the transmission member220is movably mounted on the base222in the axial direction of the winding shaft10.

The transmission member220is mounted on the base222, is supported by the base222and can move in the axial direction of the winding shaft10to act on the clamping members221, thereby driving the clamping members221to radially close. The base222is mounted in the housing21and can rotate about the axis of the winding shaft10, so that the transmission member220can rotate about the axis of the winding shaft10under the support of the base222to match the rotation of the winding shaft10or to be driven to rotate by the winding shaft10.

The base222capable of rotating about the axis of the winding shaft10is provided, so that the transmission member220can not only move along the axis of the winding shaft10, but can also rotate about the axis of the winding shaft10, so as to synchronously rotate with the winding shaft10, thereby ensuring the normal operation of the winding shaft10.

According to some embodiments of the present application, optionally, referring toFIG.5, the transmission member220passes through the base222in the axial direction of the winding shaft10, one end of the transmission member220is in wedged fit with the plurality of clamping members221, and the other end of the transmission member220is connected to the first drive unit23.

In the axial direction of the winding shaft10, the transmission member220is located between the clamping member221and the first drive unit23, that is, the three are arranged along the axis of the winding shaft10.

The transmission member220is designed to be located between the clamping members221and the first drive unit23in the axial direction of the winding shaft10, so that the transmission member220can be driven by the first drive unit23to drive the clamping members221to close in the radial direction of the winding shaft10in a shortest path, so as to quickly clamp the winding shaft10. Moreover, the clamping members221, the transmission member220and the first drive unit23are arranged in the axial direction of the winding shaft10, which facilitates the spatial arrangement of the individual structures in the clamping mechanism20.

According to some embodiments of the present application, referring toFIGS.5,6, and7,FIG.7is a schematic diagram of a base222according to some embodiments of the present application. The base222is provided with a plurality of guide grooves2220, the plurality of guide grooves2220are distributed at intervals in a circumferential direction of the base222, and each of the guide grooves2220extends in an axial direction of the base222. The transmission member220includes a connecting portion2200and a plurality of transmission portions2201, the transmission portions2201are arranged corresponding to the guide grooves2220, each of the transmission portions2201is slidably provided in the corresponding guide groove2220, one end of each transmission portion2201is in wedged fit with the corresponding clamping member221, the other end of each transmission portion2201is connected to the connecting portion2200, and the connecting portion2200is connected to the first drive unit23.

The number of guide grooves2220corresponds to the number of transmission portions2201, and each transmission portion2201can slide in the corresponding guide groove2220in the axial direction of the winding shaft10. The number of transmission portions2201is the same as the number of clamping members221, and the two correspond to each other on a one-to-one basis. A wall surface of the transmission portion2201located at the end of the transmission portion that is away from the first drive unit23and facing the clamping member221is provided with a second bevel2202, a wall surface of the clamping member221facing the transmission portion2201is provided with a third bevel2210, and the second bevel2202abuts against the third bevel2210, so that the clamping member221is in wedged fit with the transmission portion2201, and thus each transmission portion2201can drive the corresponding clamping member221to move in the radial direction of the winding shaft10. All of the transmission portions2201are connected to the first drive unit23by means of the connecting portion2200, that is, when in operation, the first drive unit23can drive all the transmission portions2201to slide in the corresponding guide grooves2220, so to drive the corresponding clamping members221to radially move, so that all the clamping members221are radially closed to clamp the winding shaft10.

With the connecting portion2200, the first drive unit23can drive all the transmission portions2201to slide simultaneously, so that all the clamping members221are synchronously closed in the radial direction of the winding shaft10under the action of the corresponding transmission portions2201, ensuring a clamping effect and clamping coaxiality of the winding shaft10, where the clamping coaxiality means that the center lines of all the clamping members221in the axial direction of the winding shaft10coincide with the axis of the winding shaft10when all the clamping members221are radially closed.

Optionally, referring toFIGS.8and9,FIG.8is a sectional view of a clamping mechanism20according to some embodiments of the present application, andFIG.9is a schematic diagram of a clamping member221and a transmission member220according to some embodiments of the present application. The transmission member220includes a disc-shaped block2203. The disc-shaped block2203is provided with wedge grooves2204, and the number of wedge grooves2204is the same as the number of clamping members221. A wedge block2211is provided at an end of each clamping member221, and the wedge block2211is embedded in the corresponding wedge groove2204to realize a wedged fit between the clamping member221and the transmission member220. The base222includes a sleeve2221, and the transmission member220passes through the sleeve2221and is in wedged fit with the clamping member221. When the first drive unit23is operated to drive the transmission member220to move along the axial direction of the winding shaft, the wedge groove2204pushes the wedge block2211, driving all the clamping members221to radially close to clamp the end of the winding shaft10.

According to some embodiments of the present application, optionally, the clamping assembly22further includes a base222, where the base222is rotatably mounted in the housing21about the axis of the winding shaft10, and the base222is configured to abut against the clamping members221to prevent the clamping members221from moving in the axial direction of the winding shaft10.

The clamping members221abut against the base222in the axial direction of the winding shaft10, realizing limiting in the axial direction of the winding shaft10. When the transmission member220moves in the axial direction of the winding shaft10, it can be ensured that the clamping members221cannot move in the axial direction of the winding shaft10, but moves only in the radial direction of the winding shaft10, thereby clamping or releasing the end of the winding shaft10. Since the base222is mounted in the housing21and can rotate about the axis of the winding shaft10, the clamping members221can rotate about the axis of the winding shaft10under the support of the base222to match the rotation of the winding shaft10or to be driven to rotate by the winding shaft10.

The base222capable of rotating about the axis of the winding shaft10is provided, so that it can be ensured that the clamping members221are prevented from moving in the axial direction of the winding shaft10while the clamping members221can rotate about the axis of the winding shaft10, so as to avoid the situation in which the clamping members221do not clamp the winding shaft10due to the offset of the clamping members221caused by the wedged fit during transmission of the transmission member220.

According to some embodiments of the present application, optionally, referring toFIG.6, one end surface of the base222is provided with an accommodating recess2222, a part of each of the clamping members221is located in the accommodating recess2222, and the other part of the clamping member is located outside the accommodating recess2222and in wedged fit with the transmission member220.

A part of the clamping member221is located in the accommodating recess2222and an end of the clamping member221abuts against a bottom surface of the accommodating recess2222. In the radial direction of the winding shaft10, the accommodating recess2222also has extra space to allow the clamping member221to move in the radial direction of the winding shaft10to clamp or release the winding shaft10.

The design of the accommodating recess2222enable the base222to have a simple structure and be easily manufactured. Since a part of the clamping member221abuts in the accommodating recess2222, when moving in the axial direction of the winding shaft10, the transmission member220can easily drive the clamping members221to slide toward the winding shaft10along the bottom surface of the accommodating recess2222, so that the winding shaft10is clamped by the clamping members221.

Optionally, referring toFIGS.8,9, and10,FIG.10is a schematic diagram of a base222and clamping members221in the clamping mechanism20provided inFIG.8. The base222includes two support blocks2223. The two support blocks2223are interconnected into a disc-like support structure, and the two support blocks2223are fixed to the sleeve2221. The disc-shaped block2203that is in wedged fit with the clamping members221is accommodated in a cavity between the two support blocks2223. The two support blocks2223jointly form a slide slot2224in the radial direction of the winding shaft10. The clamping member221is provided with a small section2212that is in slide fit with the slide slot2224, where the clamping member221may be regarded as a sequential connection of a large section2213, the small section2212, and the wedge block2211in the axial direction of the winding shaft10. The large section2213is used to provide a clamping force to the winding shaft10and the large section2213has a greater size than the slide slot2224to abut against a surface of the support block2223, thereby prevent the clamping members221from moving in the axial direction of the winding shaft10. The small section2212is used to enable the clamping member221to slide in the radial direction of the winding shaft10, so as to clamp or release the winding shaft10. The wedge block2211is engaged with the wedge groove2204of the disc-shaped block2203to be driven by the transmission member220, thereby enabling the clamping member221to perform a clamping action.

With the above design, the clamping members221can stably move in the radial direction of the winding shaft10and effectively prevent the clamping members221from moving along the axis of the winding shaft10, ensuring that the clamping members221clamp the winding shaft10along a correct movement track.

According to some embodiments of the present application, optionally, the clamping mechanism20further includes a bearing24, where the base222is mounted in the housing21by means of the bearing24.

Optionally, referring toFIG.5, an outer race of the bearing24is fixed to an inner wall of the housing21, and the base222is fixed to an inner race of the bearing24. The base222can rotate about the axis of the winding shaft10under the action of the bearing24, so as to rotate with the winding shaft10.

Optionally, referring toFIG.8, the outer race of the bearing24is fixed to the inner wall of the housing21, and the sleeve2221of the base222is fixed to the inner race of the bearing24, so that the base222can rotate about the axis of the winding shaft10, so as to rotate with the winding shaft10.

With the bearing24, the base222can be stably rotated in the housing21, ensuring stability of the winding shaft10during winding.

According to some embodiments of the present application, optionally, one of the base222and the bearing24is provided with a limiting protrusion2225and the other one is provided with a limiting groove, and the limiting protrusion2225and the limiting groove are engaged with each other to prevent the base222from moving in the axial direction of the winding shaft10.

The limiting protrusion2225and the limiting groove are arranged in at least two manners, one is that the limiting protrusion2225is provided on a surface of the base222and the limiting groove is provided in the inner race of the bearing24. The other one is that the limiting protrusion2225is provided on the inner race of the bearing24and the limiting groove is provided in a surface of the base222. It is to be understood that another conceivable arrangement manner is that a surface of the base222is provided with a limiting protrusion2225and a limiting groove, the inner race of the bearing24is provided with a limiting groove and a limiting protrusion2225, the limiting protrusion2225of the base222is engaged with the limiting groove of the bearing24, and the limiting groove of the base222is engaged with the limit protrusion2225of the bearing24. Referring toFIG.7, two limiting protrusions2225are provided on a surface of the base222, and correspondingly, two limiting grooves (not shown in the figure) are provided in the inner race of the bearing24to effectively prevent the base222from moving in the axial direction of the winding shaft10.

The base222and the bearing24are engaged with each other by means of the limiting protrusion2225and the limiting groove, and the base222is limited in the axial direction of the winding shaft10, so that the base222cannot be displaced along the axis of the winding shaft10due to a movement of the transmission member220, ensuring that the winding shaft10is successfully clamped by the clamping members221.

According to some embodiments of the present application, optionally, referring toFIG.11,FIG.11is a schematic diagram of clamping members221and an elastic element223according to some embodiments of the present application. The clamping assembly22further includes an elastic element223. The elastic element223is configured to apply an elastic force to the plurality of clamping members221, so that the plurality of clamping members221are opened in the radial direction of the winding shaft10to release the end of the winding shaft10.

The elastic element223provides the elastic force in the radial direction for the clamping members221, so that the plurality of clamping members221have a tendency to radially open relative to each other. When the first drive unit23is operated to drive the transmission member220to move in the axial direction of the winding shaft10, it is necessary to overcome the elastic force of the elastic element223to radially close the clamping members221to clamp the winding shaft10. When the transmission member220does not act on the clamping members221, the clamping members221are opened in the radial direction of the winding shaft10to release the end of the winding shaft10. As shown inFIG.11, the elastic element223includes a plurality of springs, and the plurality of springs are provided at the edges of the two clamping members221to provide elastic forces in the radial direction for the clamping members221.

When the first drive unit23drives the transmission member220to move back, the transmission member220no longer acts on the clamping members221, the plurality of clamping members221can be radially opened under the action of the elastic element223to release the winding shaft10, facilitating withdrawing of the winding shaft10and also preparing for the next insertion of the winding shaft10.

According to some embodiments of the present application, optionally, referring toFIGS.12and13,FIG.12is a schematic diagram of a clamping mechanism20according to some embodiments of the present application, andFIG.13is a sectional view of a clamping mechanism20according to some embodiments of the present application. The clamping mechanism20further includes a connector25and a second drive unit26. The connector25is provided in the housing21, and the first drive unit23is connected to the connector25to drive the connector25to move in the axial direction of the winding shaft10. The second drive unit26is fixed to the connector25and is connected to the transmission member220, and the second drive unit26is used to drive the transmission member220to rotate about the axis of the winding shaft10.

Referring toFIG.13, one end of the connector25is rotatably connected to the connecting portion2200of the transmission member220, and the rotatable connection manner may be achieved in the form of sleeving with balls. The connecting portion2200is supported by the connector25to ensure that the transmission member220rotates stably about the axis of the winding shaft10. The first drive unit23and the second drive unit26are connected to the other end of the connector25, and an execution end of the second drive unit26passes through the connector25and is connected to the connecting portion2200, so that when in operation, the second drive unit26can drive the connecting portion2200to rotate, so as to drive the transmission portion2201, the clamping members221and the winding shaft10to rotate. When in operation, the first drive unit23can drive the connector25, the transmission portion2201and the second drive unit26to move in the axial direction of the winding shaft10, so that the winding shaft10is clamped by the clamping members221.

The first drive unit23drives the clamping members221by means of the transmission member220to clamp the winding shaft10, the second drive unit26drives the transmission member220and the clamping members221to actively rotate, so that two ends of the winding shaft10rotate at the same speed, ensuring the winding quality of the electrode assembly. Moreover, the problem of breakage of the winding shaft due to excessive torque on one end of the winding shaft10can be solved by means of active rotation. The connector25is provided, so that the first drive unit23is not required to rotate with the winding shaft10when the second drive unit26achieves active rotation, effectively controlling a work load of the winding shaft fixture13, and saving the operation cost.

It is to be understood that the second drive unit26may include an electric motor or other devices capable of outputting a torque.

It is to be understood that, referring toFIG.5, as described above, one end of the connector25is rotatably connected to the connecting portion2200of the transmission member220, and the rotatable connection manner may be in the form of sleeving with balls. The connecting portion2200is supported by the connector25to ensure that the transmission member220rotates stably about the axis of the winding shaft10. The first drive unit23is connected to the other end of the connector25to drive the transmission member220to move along the axis of the winding shaft10, and also to ensure that the transmission member220and the clamping members221rotate about the axis of the winding shaft10.

It is to be understood that the clamping mechanism20shown inFIG.8may also include a connector25, where one end of the connector25is rotatably connected to the transmission member220, and the first drive unit23is connected to the other end of the connector25to drive the transmission member220to move along the axis of the winding shaft10, and also to ensure that the transmission member220and the clamping members221rotate about the axis of the winding shaft10.

According to some embodiments of the present application, optionally, referring toFIG.12, the clamping mechanism20further includes a guide rod27fixed in the housing21and extending parallel to the axial direction of the winding shaft10. Here, the connector25is slidably sleeved around the guide rod27.

The clamping mechanism20further includes a first supporting plate28and a second supporting plate29. The first supporting plate28and the second supporting plate29are fixed inside the housing21and spaced apart from each other in the axial direction of the winding shaft10. The guide rod27is fixed between the first supporting plate28and the second supporting plate29in a direction parallel to the axial direction of the winding shaft10and used to guide the connector25, so that the connector25is driven by the first drive unit23to move stably in the axial direction of the winding shaft10. It is to be understood that the number of guide rods is not limited, but may be one, two or three, etc., in order to guide the connector25.

The guide rod27is provided, so that the base222can be driven by the first drive unit23to move stably in the axial direction of the winding shaft10, ensuring that the transmission member220successfully drives the clamping members221to radially close so as to clamp the winding shaft10.

It is to be understood that, referring toFIG.12, the first drive unit23may include a plurality of electric telescopic rods. The plurality of telescopic rods are fixed to the second supporting plate29, and telescopic ends of the telescopic rods are connected to the connector25to drive the connector25to move in the axial direction of the winding shaft10. It is to be understood that, in other embodiments, the first drive unit23may also include other devices capable of outputting linear motion, such as a combination of a movable telescopic rod and a cylinder.

According to some embodiments of the present application, optionally, the clamping mechanism20further includes a second drive unit26provided in the housing21, the second drive unit26being used to drive the clamping assembly22to rotate about the axis of the winding shaft10.

It is to be understood that the second drive unit26can drive the first drive unit23, the transmission member220and the clamping member221to rotate together.

The second drive unit26provides a torque, so that the two ends of the winding shaft10rotate at the same speed, ensuring the winding quality of the electrode assembly.

Moreover, the problem of breakage of the winding shaft due to excessive torque on one end of the winding shaft10can be solved by means of active rotation.

According to some embodiments of the present application, optionally, the clamping assembly22includes a plurality of clamping members221, where each of the clamping members221has a first bevel that is used to be attached to the end of the winding shaft10.

The end of the winding shaft10is sharp. The first bevel of the clamping member221can be effectively attached to the end of the winding shaft10, so as to ensure interaction interfaces between all the clamping members221and the end of the winding shaft10when all the clamping members are closed and effectively clamp the winding shaft10, avoiding the situation in which the clamping mechanism20slips off the winding shaft10when the winding shaft10is tensioned.

According to some embodiments of the present application, optionally, referring toFIGS.6,14, and15,FIG.14is a schematic diagram of clamping members221and a winding shaft10according to some embodiments of the present application, andFIG.15is a schematic diagram of clamping members221and a winding shaft10according to some embodiments of the present application. The clamping assembly22includes a plurality of clamping members221, where each of the clamping members221is provided with a protrusion that is used to be embedded in a recess provided at the end of the winding shaft10.

The protrusion and the recess have an embedded relationship, that is, when the clamping members221clamp the end of the winding shaft10, the protrusion can be embedded in the recess, so that the clamping members221“grip” the winding shaft10to ensure the clamping effect of the clamping members221to the winding shaft10. Referring toFIG.6, inFIG.6, the protrusion of the clamping member221includes a plurality of tooth structures, the recess of the winding shaft10includes a plurality of groove structures corresponding to the tooth structures. When the clamping members221clamp the winding shaft10, the plurality of tooth structures are embedded in the plurality of groove structures, thereby improving the clamping effect of the clamping members221to the winding shaft10. Referring toFIG.14, the protrusion of the clamping member221includes a skewed-tooth structure2214, and the recess of the winding shaft10includes a skewed-slot structure corresponding to the skewed-tooth structure2214. When the clamping members221clamp the winding shaft10, the skewed-tooth structure2214is embedded in the skewed-slot structure. If the clamping members221are not radially opened, the winding shaft10cannot be disengaged from the clamping members221because of the cooperation between the skewed-tooth structure2214and the skewed-slot structure, thereby improving the clamping effect of the clamping members221to the winding shaft10. Referring toFIG.15, the protrusion of the clamping member221includes a blocky structure2215, and the recess of the winding shaft10includes a square-groove structure corresponding to the blocky structure2215. When the clamping members221clamp the winding shaft10, the blocky structure2215is embedded in the square-groove structure. If the clamping members221are not radially opened, the winding shaft10can not be disengaged from the clamping members221because of the cooperation between the blocky structure2215and the square-groove structure, thereby improving the clamping effect of the clamping member221to the winding shaft10.

With the protrusion and the recess respectively provided on the clamping member221and the end of the winding shaft10, the clamping members221firmly grip the winding shaft10when clamping the end of the winding shaft10, so as to ensure a clamping force of the clamping members221to the end of the winding shaft10, avoiding the situation in which the clamping mechanism20slips off the winding shaft10when the winding shaft10is tensioned.

According to some embodiments of the present application, the present application further provides a winding device. Referring toFIG.2, the winding device includes a mounting base11, a winding shaft10, and a winding shaft fixture13according to any of the above solutions. One end of the winding shaft10is mounted on the mounting base11. A clamping mechanism20is used to clamp the other end of the winding shaft10.

The mounting base11is connected to one end of the winding shaft10and drives the winding shaft10to carry out winding. The clamping mechanism20clamps the other end of the winding shaft10, the tensioning mechanism30applies a pulling force to the winding shaft10, so that the rigidity of the winding shaft10can be effectively improved, the deflection deformation of the winding shaft10can be reduced, and the winding quality of the electrode assembly can be ensured.

According to some embodiments of the present application, the present application further provides a winding device, including a mounting base11, a winding shaft10, and a tensioning mechanism30. One end of the winding shaft10is mounted on the mounting base11. The tensioning mechanism30is configured to apply a pulling force to the winding shaft10at the other end of winding shaft10.

The tensioning mechanism30applies a pulling force to the winding shaft10, so that the rigidity of the winding shaft10can be effectively improved, the deflection deformation of the winding shaft10can be reduced, the winding quality of the electrode assembly can be ensured, and the winding speed can be allowed to be increased to improve the production efficiency of the electrode assembly. It is necessary for the tensioning mechanism30to be connected to the winding shaft10to apply a pulling force to the winding shaft10. The connection relationship between the tensioning mechanism30and the winding shaft10is not limited to the way of clamping the winding shaft10by the clamping mechanism20as described above, and the end of the winding shaft10may also be fixed by other ways. For example, the tensioning mechanism may be connected to the winding shaft10by means of pin fixation, that is, a pin hole is provided at each of an end of the winding shaft10and an end of the tensioning mechanism30, and the winding shaft is connected to the tensioning mechanism by means a pin; and when in operation, the tensioning mechanism30can pull the winding shaft10closer, thereby improving the rigidity of the winding shaft10. It is to be understood that the tensioning mechanism30may also be connected to the end of the winding shaft10by means of snap-fitting, and when in operation, the tensioning mechanism30can pull the winding shaft10closer, thereby improving the rigidity of the winding shaft10.

According to some embodiments of the present application, the present application further provides a method for preparing an electrode assembly. Referring toFIG.16,FIG.16is a flowchart of a method for preparing an electrode assembly according to some embodiments of the present application. The method includes the following steps: S1: applying a pulling force to an end of a winding shaft10; and S2: rotating the winding shaft10to wind an electrode plate and a separator that are stacked so as to form the electrode assembly.

At step S1, the pulling force is applied to the end of the winding shaft10to improve the rigidity of the winding shaft10, and when step S2is performed, that is, when the winding shaft10is rotated to wind the electrode plate and the separator that are stacked, the deflection deformation of the winding shaft10can be effectively reduced, ensuring a winding effect of the electrode assembly, and allowing the winding speed to be increased to improve the production efficiency of the electrode assembly.

It is to be understood that, in conjunction with the second drive unit26described above, the method for preparing an electrode assembly, in some embodiments, may further include providing power to each end of the winding shaft10, so that the two ends of the winding shaft10rotate at the same speed. By providing power to each end of the winding shaft10, the rotational speeds of the two ends are synchronized to prevent inconsistent speeds at the front and rear ends of the winding shaft10, which may lead to breakage of the winding shaft10.

According to some embodiments of the present application, reference is made toFIGS.4to7. The present application provides a winding shaft fixture13.

The winding shaft fixture13includes a clamping mechanism20and a tensioning mechanism30. The clamping mechanism20includes a housing21, a clamping assembly22, a first drive unit23, a connector25, and a bearing24. The housing21has an opening210for the winding shaft10to extend through. The clamping assembly22includes a transmission member220, clamping members221, a base222and an elastic element223(seeFIG.11). The transmission member220includes a connecting portion2200and a plurality of transmission portions2201. The base222is mounted in the housing21by means of the bearing24, and the bearing24and the base222are engaged with each other by means of a limiting protrusion2225and a limiting groove to prevent the base222from moving in the axial direction of the winding shaft10. The base222is provided with a plurality of guide grooves2220extending along the axis of the winding shaft10. The transmission portions2201are slidably provided in the guide grooves2220respectively. All the transmission portions2201are connected to the connecting portion2200. The connecting portion2200is rotatably connected to the connector25. The first drive unit23is connected to the connector25, and the connector25can move stably in the axial direction of the winding shaft10under the guiding of the guide rod27. Each connecting portion2200is in wedged fit with the corresponding clamping member221. One end surface of the base222is provided with an accommodating recess2222, and a part of the clamping member221is located in the accommodating recess2222. Since the base222abuts against the clamping member, the clamping member221is limited in the axial direction of the winding shaft10. Due to the accommodating recess2222, the clamping member221is allowed to move in the radial direction of the winding shaft10.

When in operation, the first drive unit23drives the connector25to move along the axis of the winding shaft10, and drives all the transmission portions2201to move in the axial direction of the winding shaft10by means of the connecting portion; then, all the clamping members221are radially closed under the action of the transmission portions2201to clamp the winding shaft10; and the tensioning mechanism30is operated to apply a pulling force to the winding shaft10to tension the winding shaft10, thereby effectively improving the rigidity of the winding shaft10, reducing the deflection deformation of the winding shaft10, ensuring the winding quality of the electrode assembly, and allowing the winding speed to be increased to improve the production efficiency of the electrode assembly.

When the first drive unit23is reset, the transmission portions2201withdraw the action on the clamping members221, and the clamping members221can be radially opened under the action of the elastic element223to release the end of the winding shaft10, so that the winding shaft10can be pulled out of the winding shaft fixture13.

The foregoing descriptions are merely preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, various modifications and variations may be made to the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present application should fall within the scope of protection of the present application.