Lower shaft assembly and single crystal furnace

Abstract

The embodiment of the utility model provides a lower shaft assembly and a single crystal furnace, the lower shaft assembly comprises a lower shaft support and a crucible shaft, the lower shaft assembly further comprises a first corrugated pipe, and the first corrugated pipe is sleeved outside the crucible shaft; the supporting seat is connected to the lower shaft bracket and can ascend and descend relative to the lower shaft bracket; one end of the first corrugated pipe is connected with the supporting seat in a sealing manner; the weighing sensor is arranged in the supporting seat; and the weighing sensor is used for supporting the crucible shaft. In the embodiment of the invention, in the process that the first corrugated pipe is deformed along with the lifting of the crucible shaft, the tension or pressure generated by the deformation of the first corrugated pipe can be directly transmitted to the sliding base, so that the tension or pressure generated by the first corrugated pipe is prevented from influencing the measurement result of the weighing sensor; and the measurement accuracy of the weighing sensor on the weight of the crucible and the silicon liquid is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photovoltaics, and particularly relates to a lower shaft assembly and a single crystal furnace. BACKGROUND

[0002] The existing lower shaft assembly of a single crystal furnace comprises a lower shaft support and a crucible shaft, the crucible shaft is used for supporting a crucible, and the lower shaft support is used for supporting the crucible shaft.

[0003] When a single crystal furnace is used to draw a crystal bar, the weight of the silicon liquid in the crucible needs to be obtained so as to better control the lifting speed of the crucible and the lifting speed of the crystal bar in the single crystal furnace. At present, one of the weighing methods for the silicon liquid in the crucible is to calculate the silicon material in the crucible and the silicon material subsequently added, then measure the weight of the crystal bar through the upper bearing load sensor of the single crystal furnace in the crystal drawing process, and the weight of the remaining silicon liquid in the crucible is calculated through the difference between the total silicon material in the crucible and the crystal bar. This way of indirectly obtaining the weight of the silicon liquid in the crucible has a certain hysteresis and cannot meet the requirements of the process and safety. CONTENT OF THE UTILITY MODEL

[0004] The application aims to provide a lower shaft assembly and a single crystal furnace, so as to at least partially solve the hysteresis and the measurement accuracy of the above-mentioned melt measurement.

[0005] In order to solve the above technical problems, the application is implemented as follows:

[0006] In a first aspect, the application discloses a lower shaft assembly, which comprises a lower shaft support and a crucible shaft mounted on the lower shaft support; the lower shaft assembly further comprises,

[0007] A first bellows is sleeved outside the crucible shaft;

[0008] A support seat is connected to the lower shaft support and can be lifted relative to the lower shaft support; one end of the first bellows is sealingly connected to the support seat;

[0009] A weighing sensor is arranged in the support seat; the weighing sensor supports the crucible shaft.

[0010] Optionally, the support seat comprises a bellows support and a sliding base; wherein,

[0011] The bellows support is sleeved outside the crucible shaft and is arranged between the first bellows and the sliding base; the lower end of the bellows support is connected to the sliding base; the sliding base is lifted relative to the lower shaft support;

[0012] The lower end of the first bellows is sealingly connected to the upper end of the bellows support.

[0013] Optionally, the support base further comprises a second fixing plate, the second fixing plate supporting the load sensor.

[0014] The second fixing plate is connected to the sliding base.

[0015] Optionally, the support base further comprises a second bellows and a first fixing plate; wherein,

[0016] The load sensor is arranged between the second fixing plate and the first fixing plate.

[0017] The second bellows is sleeved on the crucible shaft;

[0018] The upper end of the second bellows is connected to the bellows support, and the lower end is connected to the first fixing plate.

[0019] Optionally, the support base further comprises a sealing member; wherein,

[0020] The lower end of the second bellows is connected to the sealing member;

[0021] The sealing member is sleeved on the lower end of the crucible shaft and connected to one side of the first fixing plate, and the other side of the first fixing plate is connected to the load sensor.

[0022] Optionally, the number of load sensors is at least two, and the at least two load sensors are distributed around the axis of the crucible shaft and mounted on the second fixing plate.

[0023] Optionally, in the case where the number of load sensors is two, the two load sensors are arranged asymmetrically with respect to the axis of the crucible shaft.

[0024] Optionally, the lower shaft assembly further comprises a lead screw and a nut; wherein,

[0025] The lead screw is connected to the lower shaft support;

[0026] The nut is fixedly connected to the sliding base and engaged with the lead screw.

[0027] Optionally, the lower shaft assembly further comprises a guide rail and a sliding block; wherein,

[0028] The guide rail is connected to the lower shaft support, and the guide rail is parallel to the lead screw;

[0029] The sliding block is fixedly connected to the sliding base and slidingly connected to the guide rail.

[0030] In another aspect, a single crystal furnace is provided, comprising a furnace body and a lower shaft assembly as described above; wherein,

[0031] The lower shaft assembly is located below the furnace body, and a crucible shaft of the lower shaft assembly passes through the bottom of the furnace body; and the upper end of the first bellows of the lower shaft assembly is connected with the bottom of the furnace body.

[0032] In the embodiment, the weighing sensor is arranged in the lower shaft assembly, and the weighing sensor is arranged between the sliding base and the crucible shaft.

[0033] In the embodiment, the first bellows is arranged outside the crucible shaft, and the upper end of the first bellows is connected with the bottom of the furnace body, and the lower end of the first bellows is connected with the sliding base.

[0034] Additional aspects and advantages of the present application will be described in the following description and become apparent from the description or can be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0035] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0036] Figure 1 is one of the structure schematic diagrams of the lower shaft assembly in the embodiment of the present application;

[0037] Figure 2 is the second structure schematic diagram of the lower shaft assembly in the embodiment of the present application;

[0038] Figure 3 is the third structure schematic diagram of the lower shaft assembly in the embodiment of the present application;

[0039] Figure 4 is the fourth structure schematic diagram of the lower shaft assembly in the embodiment of the present application.

[0040] Reference numerals: 1 - lower shaft support, 2 - screw rod, 3 - nut, 4 - sliding base, 5 - guide rail, 6 - sliding block, 7 - second fixed plate, 8 - load cell, 9 - first fixed plate, 10 - sealing element, 11 - second bellows, 12 - bellows support, 13 - first bellows, 14 - crucible shaft, 15 - vacuum cavity. DETAILED DESCRIPTION

[0041] The embodiments of the present application will be described in detail below, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only, and are used only for explaining the present application, and cannot be understood as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0042] The terms "first", "second" in the description and claims of the present application can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / ", generally indicates that the front and rear associated objects are in a "or" relationship.

[0043] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0044] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0045] The embodiment of the present application provides a lower shaft assembly which can be used in a single crystal furnace. Specifically, the lower shaft assembly can be arranged below the single crystal furnace, and a crucible shaft in the lower shaft assembly can pass through the bottom of the single crystal furnace and be connected with a crucible in the single crystal furnace. The lower shaft assembly can be used for supporting the crucible and driving the crucible to lift. A load cell in the lower shaft assembly can be used for weighing the crucible to directly measure the weight of silicon liquid in the crucible. Referring to Figure 1 , one of structural schematic diagrams of the lower shaft assembly is shown, referring to Figure 2 , another structural schematic diagram of the lower shaft assembly is shown; referring to Figure 3 , a third structural schematic diagram of the lower shaft assembly is shown; referring to Figure 4 , a fourth structural schematic diagram of the lower shaft assembly is shown.

[0046] The lower shaft assembly provided by the embodiment of the present application comprises a first bellows 13 sleeved outside a crucible shaft 14. A support seat is connected to the lower shaft support 1 and can be lifted relative to the lower shaft support 1. One end of the first bellows 13 is sealingly connected with the support seat, and a load cell 8 is arranged in the support seat. The load cell 8 supports the crucible shaft 14.

[0047] As shown in Figures 1 to 4 , the lower shaft assembly specifically can comprise a lower shaft support 1 and a crucible shaft. The support seat comprises a sliding base 4 which is liftable connected to the lower shaft support 1. A load cell is connected to the sliding base 4. The lower end of the crucible shaft 14 is connected to the load cell, and the upper end of the crucible shaft 14 is used for passing through the bottom of the furnace body and being connected with the crucible. The first bellows 13 is sleeved outside the crucible shaft 14, and the upper end of the first bellows 13 is connected with the bottom of the furnace body, and the lower end of the first bellows 13 is connected with the sliding base 4.

[0048] In the embodiment of the present application, the lower shaft assembly is provided with a weighing sensor, which is arranged between the sliding base 4 and the crucible shaft 14. The crucible shaft 14 can pass through the bottom of the furnace body and be connected with the crucible. The weight of the crucible can be transmitted to the weighing sensor through the crucible shaft 14, so as to realize the direct weighing of the crucible and the silicon liquid in the crucible by the weighing sensor. In the process of the first bellows following the deformation of the crucible shaft in lifting, the pulling force or pressure generated by the deformation of the first bellows can be directly transmitted to the sliding base, avoiding the pulling force or pressure generated by the deformation of the first bellows from being transmitted to the weighing sensor, which affects the measurement result of the weighing sensor and improves the measurement accuracy of the weighing sensor for the weight of the crucible and the silicon liquid.

[0049] Since the upper end of the first bellows 13 is connected to the bottom of the furnace body and the lower end is connected to the sliding base 4, in the process of the first bellows 13 following the deformation of the crucible shaft 14 in lifting, the first bellows 13 will deform following the lifting of the crucible shaft 14, so as to form a sealed space outside the crucible shaft 14, avoiding the air outside entering the furnace body through the gap between the crucible shaft 14 and the furnace body, which affects the stability of the air flow in the furnace body. The pulling force or pressure generated by the deformation can be directly transmitted to the sliding base 4, avoiding the pulling force or pressure generated by the deformation of the first bellows 13 from affecting the measurement result of the weighing sensor, which improves the measurement accuracy of the weighing sensor for the weight of the crucible and the silicon liquid.

[0050] In specific applications, the lower shaft support 1 serves as the structural main body of the lower shaft assembly and can be used to support components such as the sliding base 4 and the crucible shaft 14. In the case of application of the lower shaft support 1 to the single crystal furnace, the lower shaft support 1 can be installed below the furnace body of the single crystal furnace. The sliding base 4 can be slidingly connected to the lower shaft support 1 and can be lifted and lowered on the lower shaft support 1. The upper end of the sliding base 4 can drive the crucible shaft 14 to lift. The crucible shaft 14 can extend into the furnace body from the bottom of the furnace body and support the crucible. The crucible shaft 14 can be used to drive the crucible to lift or rotate. The first bellows 13 can be sleeved outside the crucible shaft. In the process of the sliding base 4 driving the crucible shaft 14 to lift, the first bellows 13 can be lifted and lowered accordingly following the sliding base 4.

[0051] Specifically, since the weighing sensor is connected below the crucible shaft 14, the weighing sensor can directly measure the weight of the silicon liquid in the crucible. Moreover, during the process of lifting or lowering the crucible shaft 14 by the sliding base 4, the first bellows 13 correspondingly rises or falls with the sliding base 4, forming internal tension or pressure. Since the lower end of the first bellows 13 is connected to the sliding base 4, the tension or pressure generated by the first bellows 13 acts on the sliding base 4, without interfering with the weighing result of the weighing sensor. In this way, the weighing result of the weighing sensor can be consistent with the actual weight result, greatly improving the measurement accuracy of the weighing sensor.

[0052] As shown in Figures 1 to 3 The lower shaft assembly can further include a lead screw 2 and a nut 3. The lead screw 2 is connected to the lower shaft support 1, and the nut 3 is fixed to the sliding base 4 and engaged with the lead screw 2. Since the nut 3 is engaged with the lead screw 2 and fixedly connected to the sliding base 4, the nut 3 and the sliding base 4 can be lifted or lowered along the axial direction of the lead screw 2 when the lead screw 2 rotates.

[0053] In actual application, the lower shaft assembly can further include a driving member connected to the lead screw 2 to drive the lead screw 2 to rotate. The driving member can be arranged on the top or bottom of the lower shaft support 1 as needed, and the specific mounting position of the driving member is not limited in the embodiments of the present application. The driving member can include, but is not limited to, a motor, an electric motor, etc., and the specific form of the driving member is not limited in the embodiments of the present application.

[0054] Optionally, the lower shaft assembly can further include a guide rail 5 and a sliding block 6. The guide rail 5 is connected to the lower shaft support 1 and parallel to the lead screw 2, and the sliding block 6 is fixed to the sliding base 4 and slidingly connected to the guide rail 5. During the process of lifting or lowering the sliding base 4 by the lead screw 2, the sliding block 6 can be correspondingly driven to slide along the guide rail 5. Due to the limiting and guiding effect of the guide rail 5, the sliding base 4 can only be lifted or lowered along the axial direction of the guide rail 5 and the lead screw 2, so as to improve the movement accuracy of the sliding base 4. Moreover, the guide rail 5 can also be used to balance the bending moment caused by the misalignment of the axis of the lower shaft assembly and the axis of the lead screw 2, reduce the stress suffered by the sliding base 4 during the lifting or lowering process, and improve the smoothness of the movement of the sliding base 4.

[0055] In the embodiment of the present application, the nut 3 and the sliding block 6 are connected to the sliding base 4, so that the friction between the sliding block 6 and the guide rail 5 during the lifting of the sliding base 4 is transmitted to the sliding base 4, and is not transmitted to the weighing sensor, thereby avoiding the interference of the friction on the measurement result of the weighing sensor, and further improving the measurement accuracy of the weighing sensor.

[0056] In actual application, the nut 3 and the sliding block 6 can be connected to the sliding base 4 by screws, bolts and other fasteners, or can be connected to the sliding base 4 by welding, clamping and other connection methods. The embodiment of the present application does not make specific limitation on the connection method of the nut 3 and the sliding block 6 on the sliding base 4.

[0057] In some optional embodiments of the present application, as shown in Figure 1 and Figure 2 The support seat can further include a corrugated pipe support 12 connected to the sliding base 4. The corrugated pipe support 12 is sleeved outside the crucible shaft 14 and is arranged between the first corrugated pipe 13 and the sliding base 4. The lower end of the first corrugated pipe 13 is connected to the upper end of the corrugated pipe support 12, and the lower end of the corrugated pipe support 12 is connected to the sliding base 4. In specific application, the corrugated pipe support 12 can be used to support the first corrugated pipe 13 and transmit the force generated by the deformation of the first corrugated pipe 13 to the sliding base 4, so as to avoid the influence of the pulling force or pulling down of the deformation of the first corrugated pipe 13 on the accuracy of the weighing sensor 8.

[0058] In some optional embodiments of the present application, as shown in Figure 1 and Figure 2 The support seat can further include a second corrugated pipe 11. The second corrugated pipe 11 is sleeved outside the crucible shaft 14. The upper end of the second corrugated pipe 11 is connected to the corrugated pipe support 12, and the lower end is connected to the weighing sensor 8. The second corrugated pipe 11 can offset the slight deformation of the weighing sensor 8 under stress, and since the deformation amount is very small, the pulling and pressing force caused by the deformation of the second corrugated pipe 11 is also very small, which has negligible influence on the weighing result of the weighing sensor 8.

[0059] In practical applications, the load sensor 8 can be a pressure load sensor, i.e., the weight measurement is realized under pressure. Since the gravity of the crucible shaft 14, the crucible and the silicon liquid in the crucible directly acts on the load sensor, the load sensor forms a weight measurement result under pressure, and the load sensor can be slightly deformed under pressure. In the embodiment of the present application, the second bellows 11 can be deformed correspondingly when the load sensor is deformed. The deformation of the second bellows 11 can offset the deformation of the load sensor.

[0060] In some optional embodiments of the present application, the support seat comprises a second bellows 11 and a first fixed plate 9; wherein the load sensor 8 is arranged between the second fixed plate 7 and the first fixed plate 9; the second bellows 11 is sleeved on the crucible shaft 14; the upper end of the second bellows 11 is connected to the bellows support 12, and the lower end is connected to the first fixed plate 9.

[0061] In some optional embodiments of the present application, the support seat can further comprise a first fixed plate 9 and a sealing element 10; wherein the lower end of the second bellows 11 is connected to the sealing element 10; the sealing element 10 is sleeved on the lower end of the crucible shaft 14 and connected to one side of the first fixed plate 9, and the other side of the first fixed plate 9 is connected to the load sensor 8. The sealing element 10 can be used to realize the sealing of the crucible shaft 14, so as to form a vacuum cavity 15 between the crucible shaft 14, the first bellows 13 and the furnace body, to avoid the air outside entering the furnace body through the gap between the crucible shaft 14 and the furnace body. Specifically, the sealing element 10 of the present embodiment is a magnetic fluid transmission sealing element.

[0062] In practical applications, the upper and lower ends of the first bellows 13 and the second bellows 11 can be respectively provided with mounting flanges. The upper end flange of the first bellows 13 can be connected to the bottom of the furnace body, and the lower end flange of the first bellows 13 can be connected to the bellows support 12 and connected to the sliding base 4 through the bellows support 12. The upper end flange of the second bellows 11 can be connected to the bellows support 12, and the lower end flange of the second bellows 11 can be connected to the mounting flange of the sealing element 10, and the mounting flange of the sealing element 10 can be connected to the first fixed plate 9.

[0063] In some optional embodiments of the present application, the support base can further comprise a second fixing plate 7, which is arranged opposite to the first fixing plate 9 and connected to the sliding base 4, and the load sensor is arranged between the second fixing plate 7 and the first fixing plate 9. The second fixing plate 7 can be used to support and fix the load sensor, which is conducive to the layout of the load sensor on the sliding base 4.

[0064] Optionally, the second fixing plate 7 and the sliding base 4 are an integrally formed structure, that is, the second fixing plate 7 and the sliding base 4 can be made by an integrally forming process. In this way, the connection reliability between the second fixing plate 7 and the sliding base 4 can be enhanced, and the operation of separately processing the second fixing plate 7 and the sliding base 4 and then assembling them can be avoided, thereby simplifying the processing technology of the second fixing plate 7 and the sliding base 4.

[0065] Of course, in actual applications, those skilled in the art can also connect the second fixing plate 7 to the sliding base 4 by using fasteners such as bolts and screws, or connect the second fixing plate 7 to the sliding base 4 by using connection methods such as welding and clamping, and the embodiments of the present application do not make specific limitations on the connection method of the second fixing plate 7 on the sliding base 4.

[0066] In some optional embodiments of the present application, the number of load sensors can be at least two, and the at least two load sensors are arranged around the axial direction of the crucible shaft 14 and installed on the second fixing plate 7. In actual applications, at least two load sensors are arranged, and the load sensors are arranged at different positions on the second fixing plate 7.

[0067] For example, the number of load sensors can be 2, 3 or 4, and the embodiments of the present application do not make specific limitations on the number of load sensors.

[0068] As shown in Figure 4 When the number of load sensors is two, the two load sensors are arranged asymmetrically relative to the axis of the crucible shaft 14, so as to avoid the deflection of the crucible shaft 14 caused by the deformation of the load sensors under stress.

[0069] In actual applications, the load sensors may be slightly deformed under pressure. If the two load sensors are arranged symmetrically relative to the axis of the crucible shaft 14, the two load sensors may be deformed on the same side due to the pressure, which can cause the crucible shaft 14 to be deflected to the side under pressure, thereby affecting the stability of the crucible shaft 14 supporting the crucible.

[0070] In the embodiment of the present application, the two weighing sensors are asymmetrically arranged relative to the crucible shaft 14, which can greatly improve the support reliability of the crucible shaft 14 for the crucible.

[0071] In a specific application, after the polycrystalline silicon material is loaded into the crucible of the single crystal furnace, the weight of the polycrystalline silicon material is transmitted to the sealing member 10 through the crucible shaft 14, and then transmitted to the weighing sensor 8 through the first fixing plate 9 connected with the mounting flange of the sealing member 10. After the weighing sensor is used for weighing and peeling, the accurate weight of the polycrystalline silicon material in the crucible can be obtained. Since the first bellows 13 is connected with the bellows support 12, which is directly mounted on the sliding base 4, the tension or pressure generated by the stretching or compression of the first bellows 13 will not be transmitted to the weighing sensor, and has no influence on the weight measurement accuracy. The slight deformation of the weighing sensor caused by the pressure of the polycrystalline silicon material is offset by the deformation of the second bellows 11, and the deformation amount is very small, which has negligible influence on the measurement accuracy of the weighing sensor.

[0072] In summary, the lower shaft assembly described in the embodiment of the present application can have at least the following advantages:

[0073] In the embodiment of the present application, the lower shaft assembly is provided with a weighing sensor, which is arranged between the sliding base and the crucible shaft. The crucible shaft can pass through the bottom of the furnace body and be connected with the crucible. The weight of the crucible can be transmitted to the weighing sensor through the crucible shaft, so as to realize the direct weighing of the crucible and the silicon liquid in the crucible by the weighing sensor. Since the upper end of the first bellows is connected to the bottom of the furnace body, and the lower end is connected to the sliding base, during the deformation of the first bellows following the lifting of the crucible shaft, the tension or pressure generated by the first bellows can be directly transmitted to the sliding base, avoiding the influence of the tension or pressure generated by the first bellows on the measurement result of the weighing sensor, and improving the measurement accuracy of the weighing sensor for the weight of the crucible and the silicon liquid.

[0074] The embodiment of the present application also provides a single crystal furnace, which can specifically include a furnace body and the lower shaft assembly described in any of the above embodiments. The crucible is arranged in the furnace body. The lower shaft assembly is located below the furnace body, and the crucible shaft 14 of the lower shaft assembly passes through the bottom of the furnace body and is connected with the crucible in the single furnace. The crucible shaft 14 can be used to support the crucible and drive the crucible to lift or rotate.

[0075] In the embodiment of the present application, the lower shaft assembly of the single crystal furnace is provided with a load cell, which is arranged between the sliding base and the crucible shaft, and the crucible shaft can pass through the bottom of the furnace body and be connected with the crucible. The weight of the crucible can be transmitted to the load cell through the crucible shaft, so as to realize the weighing of the load cell for the crucible and the silicon liquid in the crucible. Since the upper end of the first bellows is connected to the bottom of the furnace body, and the lower end is connected to the sliding base, during the deformation of the first bellows following the lifting of the crucible shaft, the tension or pressure generated by the first bellows can be directly transmitted to the sliding base, avoiding the influence of the tension or pressure generated by the first bellows on the measurement result of the load cell, and improving the measurement accuracy of the load cell for the weight of the crucible and the silicon liquid.

[0076] It should be noted that in the embodiment of the present application, the structure of the lower shaft assembly is the same as that of the lower shaft assembly described in any of the above embodiments, and the beneficial effects are similar, which will not be repeated here.

[0077] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0078] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A lower shaft assembly comprising a lower shaft support (1) and a crucible shaft (14), characterized in that, The lower shaft assembly further comprises a first bellows (13) sleeved outside the crucible shaft (14); A support base connected to the lower shaft support (1) and capable of lifting relative to the lower shaft support (1); one end of the first bellows (13) is sealingly connected to the support base; A load cell (8) arranged in the support base; the load cell (8) supports the crucible shaft (14); The support base comprises a bellows support (12) and a sliding base (4); wherein, The bellows support (12) is sleeved outside the crucible shaft (14) and arranged between the first bellows (13) and the sliding base (4); the lower end of the bellows support (12) is connected to the sliding base (4); the sliding base (4) lifts relative to the lower shaft support (1); The lower end of the first bellows (13) is sealingly connected to the upper end of the bellows support (12).

2. The lower axle assembly of claim 1, wherein, The support base further comprises a second fixing plate (7) supporting the load cell (8); The second fixing plate (7) is connected to the sliding base (4).

3. The lower shaft assembly of claim 2, wherein, The support base further comprises a second bellows (11) and a first fixing plate (9); wherein, The second bellows (11) is sleeved outside the crucible shaft (14); the upper end of the second bellows (11) is connected to the bellows support (12) and the lower end is connected to the first fixing plate (9); The load cell (8) is arranged between the second fixing plate (7) and the first fixing plate (9).

4. The lower axle assembly of claim 3, wherein, The support base further comprises a sealing member (10); wherein, The lower end of the second bellows (11) is connected to the sealing member (10); The sealing member (10) is sleeved at the lower end of the crucible shaft (14) and connected to one side of the first fixing plate (9); the other side of the first fixing plate (9) is connected to the load cell (8).

5. The lower shaft assembly of claim 2, wherein, The number of load cells is at least two; the at least two load cells are distributed around the axis of the crucible shaft (14) and mounted on the second fixing plate (7).

6. The lower shaft assembly of claim 5, wherein, In the case where the number of load cells is two, the two load cells are asymmetrically arranged relative to the axis of the crucible shaft (14).

7. The lower shaft assembly of claim 1, wherein, The lower shaft assembly further comprises a lead screw (2) and a nut (3); wherein, The lead screw (2) is connected to the lower shaft support (1); The nut (3) is fixedly connected to the sliding base (4) and engaged with the lead screw (2).

8. The lower shaft assembly of claim 7, wherein, The lower shaft assembly further comprises a guide rail (5) and a sliding block (6); wherein, The guide rail (5) is connected to the lower shaft support (1) and parallel to the lead screw (2); The sliding block (6) is fixedly connected to the sliding base (4) and slidingly connected to the guide rail (5).

9. A single crystal furnace characterized by comprising: The single crystal furnace comprises a furnace body and the lower shaft assembly according to any one of claims 1 to 8; wherein, The lower shaft assembly is located below the furnace body, and a crucible shaft (14) of the lower shaft assembly penetrates through the bottom of the furnace body; an upper end of a first bellows (13) of the lower shaft assembly is connected with the bottom of the furnace body.

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