Bearing system, screw assembly, electric cylinder

Abstract

This disclosure provides a bearing system, a lead screw assembly, and an electric cylinder. The bearing system includes a first bearing, a second bearing, and a housing. The first bearing and the second bearing are coaxially disposed within the housing and are used to fix the lead screw. The bearing system also includes a force-receiving element sandwiched between the first and second bearings, used to detect the axial force acting on the first and second bearings along the axial direction coaxial with them. This disclosure integrates the force-receiving element into the bearing system, directly detecting the force on the lead screw, which improves the real-time performance and accuracy of estimating the remaining life, load level, and efficiency trend of linear motion products such as electric cylinders.

Description

Technical Field

[0001] This disclosure relates to the field of mechanical equipment technology, and in particular to a bearing system, a lead screw assembly, and an electric cylinder. Background Technology

[0002] In linear motion products such as electric cylinders, the force on the lead screw needs to be measured to estimate remaining life, load level, and efficiency trend. Force measurement in linear motion products like electric cylinders is generally performed indirectly, for example, by measuring the motor current to indirectly calculate the force on the lead screw. This process requires one or more calculations during data transmission, making it complex and prone to errors, and making it difficult to guarantee the real-time performance and accuracy of estimates for remaining life, load level, and efficiency trend. Utility Model Content

[0003] This disclosure provides a bearing system, a lead screw assembly, and an electric cylinder.

[0004] In a first aspect, embodiments of this disclosure provide a bearing system including a first bearing, a second bearing, and a housing. The first bearing and the second bearing are coaxially disposed within the housing. The first bearing and the second bearing are used to fix a lead screw. The bearing system further includes a force-receiving element, which is clamped between the first bearing and the second bearing and is used to detect the axial force acting on the first bearing and the second bearing in the axial direction coaxial with the first bearing and the second bearing.

[0005] In some embodiments, the force-receiving element is coupled to the outer ring of the first bearing and the second bearing respectively, and the force-receiving element is used to detect the axial force applied along the axial direction.

[0006] In some embodiments, the bearing system further includes a preload nut, which is coaxial with the first bearing and the second bearing, with one side of the preload nut contacting the second bearing, and the preload nut is used to adjust the gap between the first bearing and the second bearing.

[0007] In some embodiments, a nut mounting hole is provided on the housing along the axial direction, the preload nut is disposed in the nut mounting hole, and the external thread of the preload nut and the internal thread of the nut mounting hole form a threaded engagement; one side of the preload nut contacts the outer ring of the second bearing.

[0008] In some embodiments, the preload nut includes a body portion and a protrusion extending from the body portion along the axial direction, wherein the protrusion portion near the second bearing side contacts the outer ring of the second bearing.

[0009] In some embodiments, the distance between the first bearing and the second bearing when not subjected to axial force along the axial direction is smaller than the axial dimension of the force-bearing element in the unforced state.

[0010] In some embodiments, a first stepped structure is provided on the inner wall of the housing at one end relative to the nut mounting hole; the outer ring of the first bearing contacts the first stepped structure.

[0011] In some embodiments, the bearing system further includes a positioning nut and a bearing sleeve; the positioning nut is coaxial with the first bearing and the second bearing, the positioning nut is located on the side of the first bearing away from the second bearing and contacts the first bearing, and the internal thread of the positioning nut is used to form a threaded engagement with the external thread of the lead screw; the outer rings of the first bearing and the second bearing are fixed in the housing, the inner rings of the first bearing and the second bearing are sleeved on the outer periphery of the bearing sleeve, and the inner hole of the bearing sleeve is used to engage with the lead screw; the force-bearing element is disposed in the cavity formed by the bearing sleeve, the first bearing, the second bearing, and the housing.

[0012] In some embodiments, the positioning nut has a first stepped portion on the side facing the first bearing; a first elastic support member is provided in the first stepped portion, and the two sides of the first elastic support member are in contact with the inner ring of the first bearing and the positioning nut, respectively.

[0013] In some embodiments, the bearing sleeve includes a tubular portion and a flange portion extending outward from one end of the tubular portion; the inner rings of the first bearing and the second bearing are sleeved on the outer periphery of the tubular portion; the flange portion is located on the side of the second bearing away from the first bearing; the flange portion contacts the inner ring of the second bearing.

[0014] In some embodiments, a second step is provided on the side of the flange facing the second bearing; a second elastic support is provided in the second step, and the two sides of the second elastic support contact the inner ring of the second bearing and the flange, respectively.

[0015] In some embodiments, the housing is further provided with a guide hole at one end relative to the nut mounting hole, and the positioning nut is disposed in the guide hole; a second stepped structure is provided on the inner wall of the housing near the guide hole; a sealing ring is provided in the second stepped structure, and the sealing ring contacts the outer periphery of the positioning nut.

[0016] In a second aspect, embodiments of this disclosure provide a lead screw assembly, the lead screw assembly including a lead screw and a bearing system according to the first aspect of embodiments of this disclosure, wherein the lead screw is coupled to the inner rings of a first bearing and a second bearing in the housing of the bearing system.

[0017] In some embodiments, the bearing system further includes a bearing sleeve, the inner rings of the first bearing and the second bearing are sleeved on the outer periphery of the bearing sleeve, and the inner hole of the bearing sleeve engages with the lead screw; the bearing system further includes a positioning nut, the internal thread of the positioning nut engaging with the external thread of the lead screw.

[0018] Thirdly, embodiments of this disclosure provide an electric cylinder, including a driver and the lead screw assembly described in the second aspect of embodiments of this disclosure.

[0019] In this embodiment of the disclosure, a force-bearing element is integrated into the bearing system, which can directly detect the axial force acting on the first and second bearings in the axial direction, that is, directly measure the force on the lead screw without the need for a complicated calculation process. The measurement results are more accurate and precise, thereby helping to improve the real-time performance and accuracy of estimating the remaining life, load level, efficiency trend, etc. of linear motion products such as electric cylinders. Attached Figure Description

[0020] Figure 1 This is a three-dimensional cross-sectional structural diagram of a bearing system according to an embodiment of this disclosure.

[0021] Figure 2 This is a three-dimensional structural schematic diagram of a bearing system according to an embodiment of the present disclosure.

[0022] Figure 3 This is a cross-sectional structural diagram of a bearing system according to an embodiment of this disclosure.

[0023] Figure 4 This is a three-dimensional structural diagram of a lead screw assembly according to an embodiment of the present disclosure.

[0024] Figure 5 This is a cross-sectional structural diagram of a lead screw assembly according to an embodiment of this disclosure.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1. First bearing; 2. Second bearing; 3. Housing; 4. Force-bearing element; 5. Lead screw; 6. Bearing sleeve; 61. Tubular part; 62. Flange part; 7. Sealing ring; 81. Guide hole; 82. Nut mounting hole; 9. Blind hole; 10. First elastic support; 20. Second elastic support; 11. Positioning nut; 12. Preload nut. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions of this disclosure, the technical solutions of this disclosure will be described in detail below with reference to the accompanying drawings.

[0028] Exemplary embodiments will be described more fully below with reference to the accompanying drawings; however, these exemplary embodiments may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will enable those skilled in the art to fully understand the scope of this disclosure.

[0029] Where there is no conflict, the various embodiments of this disclosure and the features thereof in the embodiments may be combined with each other.

[0030] As used herein, the term “and / or” includes any and all combinations of one or more related enumerated entries.

[0031] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It will also be understood that when the terms “comprising” and / or “made of” are used in this specification, the presence of the stated feature, integral, step, operation, element, and / or component is specified, but the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof is not excluded.

[0032] The embodiments described herein can be described with reference to plan views and / or cross-sectional views using the ideal schematic diagrams of this disclosure. Therefore, the example illustrations can be modified according to manufacturing techniques and / or tolerances. Therefore, the embodiments are not limited to those shown in the drawings, but include modifications to configurations formed based on manufacturing processes. Therefore, the areas illustrated in the drawings are schematic in nature, and the shapes of the areas shown in the figures illustrate specific shapes of areas of an element, but are not intended to be limiting.

[0033] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and will not be interpreted as having an idealized or overly formal meaning, unless expressly so defined herein.

[0034] The inventors of this disclosure have discovered that directly measuring the force on the lead screw using force sensors or other force-feeding components can improve the real-time performance and accuracy of estimating the remaining life, load level, and efficiency trends of linear motion products such as electric cylinders. However, linear motion products such as electric cylinders have compact structures and limited internal space, making it difficult to embed force-feeding components without affecting the stroke or load capacity. Determining an appropriate installation location to integrate force sensors or other force-feeding components into linear motion products such as electric cylinders for direct measurement of the force on the lead screw is quite challenging.

[0035] Therefore, this disclosure aims to provide a solution for integrating force-receiving elements such as force sensors into bearing systems of linear motion products such as electric cylinders, and to provide a bearing system with force-receiving elements. In some embodiments, the bearing system is a bearing housing used to fix the lead screw, that is, for axial positioning and radial support of the lead screw. Figure 1 This is a three-dimensional cross-sectional structural diagram of a bearing system according to an embodiment of this disclosure. Figure 2 This is a three-dimensional structural schematic diagram of a bearing system according to an embodiment of the present disclosure.

[0036] Reference Figure 1 , Figure 2 The bearing system includes a first bearing 1, a second bearing 2, a housing 3, and a force-bearing element 4. The first bearing 1 and the second bearing 2 are coaxially arranged within the housing 3, as shown below. Figure 3 As shown, the first bearing 1 and the second bearing 2 are used to fix the lead screw 5. In this embodiment, the axial direction refers to the direction coaxial with the first bearing 1 and the second bearing 2, which is also the direction in which the lead screw 5 extends. When... Figure 1 , Figure 2 When the bearing system shown is applied to the lead screw assembly, the axial force generated by the axial load on the lead screw 5 will be transmitted to the bearing system through the lead screw 5, causing the first bearing 1 and the second bearing 2 to be subjected to axial force. In this embodiment, the force-bearing element 4 is clamped between the first bearing 1 and the second bearing 2, so that the axial force on the first bearing 1 and the second bearing 2 can be detected by detecting the pressure action between the first bearing 1 and the second bearing 2 in the axial direction, thus achieving the purpose of directly measuring the axial force on the lead screw 5.

[0037] In this embodiment of the disclosure, the force-receiving element 4 refers to an element used to directly measure the force applied to the first bearing and the second bearing. This disclosure does not specifically limit the type of force-receiving element. In some embodiments, the force-receiving element 4 is a force sensor, for example, a piezoelectric force sensor, a piezoresistive force sensor, etc.

[0038] Taking force sensor 4 as an example, the detection process of axial force in a bearing system is explained. Figure 1 , Figure 3As shown, the force sensor is clamped between the first bearing 1 and the second bearing 2. When the lead screw 5 is subjected to an axial load and receives an axial force to the right as shown in the figure, this axial force is transmitted to the first bearing 1, causing the first bearing 1 to press against the force sensor to the right. The second bearing 2 provides a reverse support force through the axial limiting structure. At this time, the axial force between the first bearing 1 and the second bearing 2 detected by the force sensor is the axial force to the right of the lead screw 5. When the lead screw 5 is subjected to an axial load and receives an axial force to the left as shown in the figure, this axial force is transmitted to the second bearing 2, causing the second bearing 2 to press against the force sensor to the left. The first bearing 1 provides a reverse support force through the axial limiting structure. At this time, the axial force between the first bearing 1 and the second bearing 2 detected by the force sensor is the axial force to the left of the lead screw 5. Direct detection of the force on the lead screw 5 is achieved through the force-receiving element 4 integrated into the bearing system.

[0039] In this embodiment of the disclosure, by integrating the force-bearing element 4 into the bearing system, the force on the lead screw 5 can be directly measured, making the measurement results more accurate and precise. This helps to estimate the remaining life of the lead screw in real time, observe situations exceeding the static load level, and determine the overall efficiency trend of the lead screw by comparing the power consumption and output power of the lead screw.

[0040] In some embodiments, the force-receiving element 4 is coupled to the outer rings of the first bearing 1 and the second bearing 2 respectively, and the force-receiving element 4 is capable of detecting the axial force acting along the axial direction.

[0041] In some embodiments, the force-receiving element 4 is a force sensor that detects pressure by deformation, and the deformation of the force sensor is proportional to the magnitude of the applied force. For example, as... Figure 1 As shown, the force-bearing element 4 can deform along the axial direction, thereby enabling the detection of axial force along the axial direction.

[0042] In this embodiment, the inner rings of the first bearing 1 and the second bearing 2 are used to cooperate with the lead screw 5. When the lead screw 5 rotates, the inner rings of the first bearing 1 and the second bearing 2 rotate together with the bearing 5, while the outer rings of the first bearing 1 and the second bearing 2 remain stationary relative to the housing 3. Coupling the force-bearing element 4 to the outer rings of the first bearing 1 and the second bearing 2 respectively keeps the force-bearing element 4 stationary within the housing 3, facilitating installation; it also avoids contact between the force-bearing element 4 and the inner rings of the first bearing 1 and the second bearing 2, thus preventing resistance.

[0043] In this embodiment, the coupling of the force-receiving element 4 to the outer rings of the first bearing 1 and the second bearing 2 means that the force-receiving element 4 is directly or indirectly connected to the outer rings of the first bearing 1 and the second bearing 2, respectively, to achieve force transmission, thereby enabling the force-receiving element to detect the axial force on the first bearing and the second bearing. In some embodiments, the force-receiving element 4 is directly connected to the outer rings of the first bearing 1 and the second bearing 2. For example, the force-receiving element 4 abuts against the outer rings of the first bearing 1 and the second bearing 2, or the force-receiving element 4 is connected to the outer rings of the first bearing 1 and the second bearing 2. In some embodiments, the force-receiving element 4 can be indirectly connected to the outer rings of the first bearing 1 and the second bearing 2 through a force transmission medium.

[0044] In this embodiment, the force-receiving element 4 can be directly connected to / in contact with the outer rings of the first bearing 1 and the second bearing 2, or it can be indirectly connected to / in contact with the outer rings of the first bearing 1 and the second bearing 2, as long as force transmission can be achieved. This embodiment does not impose any special limitations on this.

[0045] In some embodiments, such as Figure 1 , Figure 3 As shown, the bearing system also includes a preload nut 12, which is coaxial with the first bearing 1 and the second bearing 2. One side of the preload nut 12 contacts the second bearing 2 and is used to adjust the distance between the first bearing 1 and the second bearing 2, thereby adjusting the initial force on the force-bearing element 4 when the lead screw 5 is unloaded.

[0046] In some embodiments, the other end of the housing 3 is provided with a nut mounting hole 82, and a preload nut 12 is disposed in the nut mounting hole 82, wherein the external thread of the preload nut 12 and the internal thread of the nut mounting hole 82 form a threaded engagement.

[0047] In this embodiment, the nut mounting hole 82 is located at the end of the housing 3 where the second bearing 2 is mounted. The preload nut 12 has an external thread on its outer periphery and an internal thread in the nut mounting hole 82, thus achieving a threaded connection between the preload nut 12 and the housing 3. When the preload nut 12 rotates in the nut mounting hole 82, it will move axially under the action of the thread, pushing the second bearing 2 to move axially, thereby achieving the purpose of adjusting the distance between the first bearing 1 and the second bearing 2.

[0048] Taking a force sensor with force-receiving element 4 that detects pressure through deformation as an example, force-receiving element 4 is clamped between the first bearing 1 and the second bearing 2. When the distance between the first bearing 1 and the second bearing 2 is less than the axial dimension of force-receiving element 4 in the non-stressed state (i.e., the state without deformation), force-receiving element 4 will undergo axial deformation, thereby detecting axial force. The axial dimension of force-receiving element 4 refers to the dimension of force-receiving element 4 in the axial direction, and the axial deformation refers to the deformation generated by force-receiving element 4 in the axial direction.

[0049] In some embodiments, the distance between the first bearing 1 and the second bearing 2 when not subjected to axial force in the axial direction is smaller than the axial dimension of the force-bearing element 4 in the non-forced state.

[0050] In the initial state, i.e., when the lead screw 5 is unloaded, by tightening or loosening the preload nut 12, the preload nut 12 is moved axially towards or away from the force-bearing element 4 to adjust the distance between the first bearing 1 and the second bearing 2. This ensures that the distance between the first bearing 1 and the second bearing 2, when not subjected to axial force, is smaller than the axial dimension of the force-bearing element 4 in the unloaded state. At this time, the force-bearing element 4 will deform. By setting the reading of the force-bearing element 4 to 0, when the lead screw 5 bears a load causing further deformation of the force-bearing element 4, the reading of the force-bearing element 4 becomes the actual force on the lead screw 5, thus allowing the force-bearing element 4 to operate in the high-range range. Since the detection accuracy of the force-bearing element is not high when it is working in the low range, but is higher when it is working in the high range, by adjusting the distance between the first bearing 1 and the second bearing 2 when they are not subjected to axial force in the axial direction by tightening the preload nut 12, making it smaller than the axial dimension of the force-bearing element 4 in the non-stressed state, the force-bearing element 4 can be made to work in the high range, thereby improving the detection accuracy of the force-bearing element 4, and thus making the force measurement result of the lead screw 5 more accurate.

[0051] In some embodiments, the axial side of the preload nut 12 is provided with at least one blind hole 9, which can be used to rotate the preload nut 12 by inserting a tool into the blind hole 9. The side of the blind hole 9 that contacts the second bearing 2 is not open, which can prevent contaminants or other particles from entering between the inner and outer rings of the second bearing 2, thereby reducing wear and extending the service life of the bearing.

[0052] In some embodiments, such as Figure 3 As shown, the preload nut 12 includes a body and a protrusion that protrudes from the body in the axial direction. The protrusion near the second bearing 2 contacts the outer ring of the second bearing 2.

[0053] In some embodiments, such as Figure 3 As shown, a first stepped structure is provided on the inner wall of the end of the housing 3 opposite to the nut mounting hole 82; the outer ring of the first bearing 1 is in contact with the first stepped structure.

[0054] In some embodiments, such as Figure 1 , Figure 3 As shown, the bearing system also includes a positioning nut 11, which is coaxial with the first bearing 1 and the second bearing 2, and one side of the positioning nut 11 is in contact with the first bearing 1.

[0055] In some embodiments, a guide hole 81 is provided at one end of the housing 3, and a positioning nut 11 is disposed in the guide hole 81. The internal thread of the positioning nut 11 is used to form a threaded engagement with the external thread of the lead screw 5.

[0056] After the positioning nut 11 is threadedly connected to the lead screw 5, by rotating the positioning nut 11, the positioning nut 11 will move axially closer to or away from the force-bearing element 4 under the action of the thread, which can also play the role of adjusting the distance between the first bearing 1 and the second bearing 2.

[0057] In some embodiments, such as Figure 3 As shown, the positioning nut 11 has a first step on the side facing the first bearing 1; a first elastic support 10 is provided in the first step, and the two sides of the first elastic support 10 are in contact with the inner ring of the first bearing 1 and the positioning nut 11, respectively.

[0058] In some embodiments, the first elastic support 10 is a wave spring.

[0059] In some embodiments, such as Figure 1 As shown, the bearing system also includes a bearing sleeve 6, which is used to fix the first bearing 1 and the second bearing 2. The outer rings of the first bearing 1 and the second bearing 2 are fixed to the housing 3 by sliding connection through preload shims. The inner rings of the first bearing 1 and the second bearing 2 are sleeved on the outer periphery of the bearing sleeve 6. The inner hole of the bearing sleeve 6 is used to cooperate with the lead screw 5. The force-bearing element 4 is set in the cavity formed by the bearing sleeve 6, the first bearing 1, the second bearing 2, and the housing 3.

[0060] In some embodiments, such as Figure 3 As shown, the bearing sleeve 6 includes a tubular portion 61 and a flange portion 62 extending outward from one end of the tubular portion 61; the inner rings of the first bearing 1 and the second bearing 2 are sleeved on the outer periphery of the tubular portion 61; the flange portion 62 is located on the side of the second bearing 2 away from the first bearing 1; the flange portion 62 is in contact with the inner ring of the second bearing 2.

[0061] In some embodiments, such as Figure 3 As shown, a second step is provided on the side of the flange portion 62 facing the second bearing 2; a second elastic support member 20 is provided in the second step portion, and the two sides of the second elastic support member 20 are in contact with the inner ring and the flange portion of the second bearing 2, respectively.

[0062] In some embodiments, the second elastic support 20 is a wave spring.

[0063] In some embodiments, a sealing ring 7 is also provided in the housing 3 to prevent contaminants or other particles from entering between the inner and outer rings of the first bearing 1, thereby reducing wear and extending the service life of the bearing.

[0064] In some embodiments, such as Figure 1 , Figure 3 As shown, a second stepped structure is provided on the inner wall of the housing 3 near the guide hole 81. The second stepped structure and the first stepped structure are arranged sequentially in the axial direction away from the guide hole 81. A sealing ring 7 is provided in the second stepped structure. The sealing ring 7 contacts the outer periphery of the positioning nut 11 to seal.

[0065] In some embodiments, the positioning nut 11 also serves as a guide, guiding the lead screw 5 to move axially. The positioning nut 11 is sleeved on the outer circumference of the lead screw 5. Under the guiding action of the positioning nut 11, guide hole 81, and sealing ring 7, the lead screw 5 can only move axially, preventing it from deviating from the axial direction and increasing its stability during axial reciprocating motion. Simultaneously, the positioning nut 11 and sealing ring 7 cooperate to bear the radial force of the lead screw 5, preventing direct contact between the lead screw 5 and the housing 3, and reducing friction and wear.

[0066] This disclosure provides a lead screw assembly. Figure 4 This is a three-dimensional structural diagram of a lead screw assembly according to an embodiment of this disclosure. Figure 5 This is a cross-sectional structural diagram of a lead screw assembly according to an embodiment of this disclosure.

[0067] Reference Figure 4 , Figure 5 The lead screw assembly includes a lead screw 5 and a bearing system. The bearing system includes a first bearing 1, a second bearing 2, a housing 3, and a force-receiving element 4. The first bearing 1 and the second bearing 2 are coaxially disposed within the housing 3 and are used to fix the lead screw 5. In this embodiment, the axial direction refers to the direction coaxial with the first bearing 1 and the second bearing 2, which is also the direction in which the lead screw 5 extends. The axial force generated by the axial load on the lead screw 5 is transmitted to the bearing system through the lead screw 5, causing the first bearing 1 and the second bearing 2 to be subjected to axial force. In this embodiment, the force-receiving element 4 is clamped between the first bearing 1 and the second bearing 2, so that the axial force on the first bearing 1 and the second bearing 2 can be detected by detecting the pressure action between the first bearing 1 and the second bearing 2 in the axial direction, thus achieving the purpose of directly measuring the axial force on the lead screw 5.

[0068] This disclosure does not specifically limit the type of force-receiving element. In some embodiments, the force-receiving element 4 is a force sensor, such as a piezoelectric force sensor, a piezoresistive force sensor, etc.

[0069] In this embodiment of the disclosure, by integrating the force-bearing element 4 into the bearing system, the force on the lead screw 5 can be directly measured, making the measurement results more accurate and precise. This helps to estimate the remaining life of the lead screw in real time, observe situations exceeding the static load level, and determine the overall efficiency trend of the lead screw by comparing the power consumption and output power of the lead screw.

[0070] In some embodiments, the force-receiving element 4 is coupled to the outer rings of the first bearing 1 and the second bearing 2 respectively, and the force-receiving element 4 is capable of detecting the axial force acting along the axial direction.

[0071] In some embodiments, the force-receiving element 4 is a force sensor that detects pressure by deformation, and the deformation of the force sensor is proportional to the magnitude of the applied force. For example, as... Figure 5 As shown, the force-bearing element 4 can deform along the axial direction, thereby enabling the detection of axial force along the axial direction.

[0072] In this embodiment, the coupling of the force-receiving element 4 to the outer rings of the first bearing 1 and the second bearing 2 means that the force-receiving element 4 is directly or indirectly connected to the outer rings of the first bearing 1 and the second bearing 2, respectively, to achieve force transmission, thereby enabling the force-receiving element to detect the axial force on the first bearing and the second bearing. In some embodiments, the force-receiving element 4 is directly connected to the outer rings of the first bearing 1 and the second bearing 2. For example, the force-receiving element 4 abuts against the outer rings of the first bearing 1 and the second bearing 2, or the force-receiving element 4 is connected to the outer rings of the first bearing 1 and the second bearing 2. In some embodiments, the force-receiving element 4 can be indirectly connected to the outer rings of the first bearing 1 and the second bearing 2 through a force transmission medium.

[0073] In some embodiments, such as Figure 5 As shown, the bearing system also includes a preload nut 12, which is coaxial with the first bearing 1 and the second bearing 2. One side of the preload nut 12 contacts the second bearing 2 and is used to adjust the distance between the first bearing 1 and the second bearing 2, thereby adjusting the initial force on the force-bearing element 4 when the lead screw 5 is unloaded.

[0074] In some embodiments, the other end of the housing 3 is provided with a nut mounting hole 82, and a preload nut 12 is disposed in the nut mounting hole 82, wherein the external thread of the preload nut 12 and the internal thread of the nut mounting hole 82 form a threaded engagement.

[0075] In this embodiment, the nut mounting hole 82 is located at the end of the housing 3 where the second bearing 2 is mounted. The preload nut 12 has an external thread on its outer periphery and an internal thread in the nut mounting hole 82, thus achieving a threaded connection between the preload nut 12 and the housing 3. When the preload nut 12 rotates in the nut mounting hole 82, it will move axially under the action of the thread, pushing the second bearing 2 to move axially, thereby achieving the purpose of adjusting the distance between the first bearing 1 and the second bearing 2.

[0076] In some embodiments, the distance between the first bearing 1 and the second bearing 2 when not subjected to axial force in the axial direction is smaller than the axial dimension of the force-bearing element 4 in the non-forced state.

[0077] In the initial state, i.e. when the lead screw 5 is unloaded, by tightening or loosening the preload nut 12, the preload nut 12 is moved closer to or further away from the force-bearing element 4 in the axial direction, so as to adjust the distance between the first bearing 1 and the second bearing 2. This allows the distance between the first bearing 1 and the second bearing 2 when they are not subjected to axial force in the axial direction to be smaller than the axial dimension of the force-bearing element 4 in the unloaded state.

[0078] In some embodiments, the axial side of the preload nut 12 is provided with at least one blind hole 9, which can be used to rotate the preload nut 12 by inserting a tool into the blind hole 9. The side of the blind hole 9 that contacts the second bearing 2 is not open, which can prevent contaminants or other particles from entering between the inner and outer rings of the second bearing 2, thereby reducing wear and extending the service life of the bearing.

[0079] In some embodiments, such as Figure 5 As shown, the preload nut 12 includes a body and a protrusion that protrudes from the body in the axial direction. The protrusion near the second bearing 2 contacts the outer ring of the second bearing 2.

[0080] In some embodiments, such as Figure 5 As shown, a first stepped structure is provided on the inner wall of the end of the housing 3 opposite to the nut mounting hole 82; the outer ring of the first bearing 1 is in contact with the first stepped structure.

[0081] In some embodiments, such as Figure 5 As shown, the bearing system also includes a positioning nut 11, which is coaxial with the first bearing 1 and the second bearing 2, and one side of the positioning nut 11 is in contact with the first bearing 1.

[0082] In some embodiments, a guide hole 81 is provided at one end of the housing 3, and a positioning nut 11 is disposed in the guide hole 81. The internal thread of the positioning nut 11 is used to form a threaded engagement with the external thread of the lead screw 5.

[0083] After the positioning nut 11 is threadedly connected to the lead screw 5, by rotating the positioning nut 11, the positioning nut 11 will move axially closer to or away from the force-bearing element 4 under the action of the thread, which can also play the role of adjusting the distance between the first bearing 1 and the second bearing 2.

[0084] In some embodiments, such as Figure 5 As shown, the positioning nut 11 has a first step on the side facing the first bearing 1; a first elastic support 10 is provided in the first step, and the two sides of the first elastic support 10 are in contact with the inner ring of the first bearing 1 and the positioning nut 11, respectively.

[0085] In some embodiments, the first elastic support 10 is a wave spring.

[0086] In some embodiments, such as Figure 5 As shown, the bearing system also includes a bearing sleeve 6, which is used to fix the first bearing 1 and the second bearing 2. The outer rings of the first bearing 1 and the second bearing 2 are fixed in the housing 3, and the inner rings of the first bearing 1 and the second bearing 2 are sleeved on the outer periphery of the bearing sleeve 6. The inner hole of the bearing sleeve 6 is engaged with the lead screw 5. The force-bearing element 4 is set in the cavity formed by the bearing sleeve 6, the first bearing 1, the second bearing 2, and the housing 3.

[0087] In some embodiments, such as Figure 5 As shown, the bearing sleeve 6 includes a tubular portion 61 and a flange portion 62 extending outward from one end of the tubular portion 61; the inner rings of the first bearing 1 and the second bearing 2 are sleeved on the outer periphery of the tubular portion 61; the flange portion 62 is located on the side of the second bearing 2 away from the first bearing 1; the flange portion 62 is in contact with the inner ring of the second bearing 2.

[0088] In some embodiments, such as Figure 5 As shown, a second step is provided on the side of the flange portion 62 facing the second bearing 2; a second elastic support member 20 is provided in the second step portion, and the two sides of the second elastic support member 20 are in contact with the inner ring and the flange portion of the second bearing 2, respectively.

[0089] In some embodiments, the second elastic support 20 is a wave spring.

[0090] In some embodiments, a sealing ring 7 is also provided in the housing 3 to prevent contaminants or other particles from entering between the inner and outer rings of the first bearing 1, thereby reducing wear and extending the service life of the bearing.

[0091] In some embodiments, such as Figure 5 As shown, a second stepped structure is provided on the inner wall of the housing 3 near the guide hole 81. The second stepped structure and the first stepped structure are arranged sequentially in the axial direction away from the guide hole 81. A sealing ring 7 is provided in the second stepped structure, and the sealing ring 7 is in contact with the outer periphery of the positioning nut 11.

[0092] In some embodiments, the positioning nut 11 also serves as a guide, guiding the lead screw 5 to move axially. The positioning nut 11 is sleeved on the outer circumference of the lead screw 5. Under the guiding action of the positioning nut 11, guide hole 81, and sealing ring 7, the lead screw 5 can only move axially, preventing it from deviating from the axial direction and increasing its stability during axial reciprocating motion. Simultaneously, the positioning nut 11 and sealing ring 7 cooperate to bear the radial force of the lead screw 5, preventing direct contact between the lead screw 5 and the housing 3, and reducing friction and wear.

[0093] This disclosure also provides an electric cylinder, including a driver and a lead screw assembly provided in this disclosure.

[0094] Example embodiments have been disclosed herein, and while specific terminology has been used, it is for illustrative purposes only and should be construed as such, and is not intended to be limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in connection with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in connection with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of this disclosure as set forth by the appended claims.

Claims

1. A bearing system comprising a first bearing (1), a second bearing (2), and a housing (3), wherein the first bearing (1) and the second bearing (2) are coaxially disposed within the housing (3), and the first bearing (1) and the second bearing (2) are used to fix a lead screw (5), characterized in that, The bearing system also includes a force-bearing element (4). The force-bearing element (4) is sandwiched between the first bearing (1) and the second bearing (2) and is used to detect the axial force acting on the first bearing (1) and the second bearing (2) in the axial direction coaxial with the first bearing (1) and the second bearing (2).

2. The bearing system according to claim 1, characterized in that, The force-receiving element (4) is coupled to the outer ring of the first bearing (1) and the second bearing (2) respectively, and the force-receiving element (4) is used to detect the axial force along the axial direction.

3. The bearing system according to claim 2, characterized in that, The bearing system also includes a preload nut (12), which is coaxial with the first bearing (1) and the second bearing (2). One side of the preload nut (12) is in contact with the second bearing (2). The preload nut (12) is used to adjust the distance between the first bearing (1) and the second bearing (2).

4. The bearing system according to claim 3, characterized in that, The housing (3) is provided with a nut mounting hole (82) along the axial direction. The preload nut (12) is disposed in the nut mounting hole (82). The external thread of the preload nut (12) and the internal thread of the nut mounting hole (82) form a threaded engagement. One side of the preload nut (12) contacts the outer ring of the second bearing (2).

5. The bearing system according to claim 4, characterized in that, The preload nut (12) includes a body portion and a protrusion portion that protrudes from the body portion along the axial direction. The protrusion portion near the second bearing (2) contacts the outer ring of the second bearing (2).

6. The bearing system according to claim 3, characterized in that, The distance between the first bearing (1) and the second bearing (2) when not subjected to axial force along the axial direction is smaller than the axial dimension of the force-bearing element (4) in the non-forced state.

7. The bearing system according to claim 4 or 5, characterized in that, The inner wall of the housing (3) at one end relative to the nut mounting hole (82) is provided with a first stepped structure; the outer ring of the first bearing (1) is in contact with the first stepped structure.

8. The bearing system according to claim 4 or 5, characterized in that, The bearing system also includes a positioning nut (11) and a bearing sleeve (6); the positioning nut (11) is coaxial with the first bearing (1) and the second bearing (2), the positioning nut (11) is located on the side of the first bearing (1) away from the second bearing (2) and is in contact with the first bearing (1), and the internal thread of the positioning nut (11) is used to form a threaded engagement with the external thread of the lead screw (5); The outer rings of the first bearing (1) and the second bearing (2) are fixed in the housing (3), and the inner rings of the first bearing (1) and the second bearing (2) are sleeved on the outer periphery of the bearing sleeve (6). The inner hole of the bearing sleeve (6) is used to cooperate with the lead screw (5). The force-bearing element (4) is disposed in the cavity formed by the bearing sleeve (6), the first bearing (1), the second bearing (2), and the housing (3).

9. The bearing system according to claim 8, characterized in that, The positioning nut (11) has a first step on the side facing the first bearing (1); a first elastic support (10) is provided in the first step, and the two sides of the first elastic support (10) are in contact with the inner ring of the first bearing (1) and the positioning nut (11) respectively.

10. The bearing system according to claim 8, characterized in that, The bearing sleeve (6) includes a tubular portion (61) and a flange portion (62) extending outward from one end of the tubular portion (61); the inner rings of the first bearing (1) and the second bearing (2) are sleeved on the outer periphery of the tubular portion (61); the flange portion (62) is located on the side of the second bearing (2) away from the first bearing (1); the flange portion (62) is in contact with the inner ring of the second bearing (2).

11. The bearing system according to claim 10, characterized in that, The flange portion (62) is provided with a second step portion on the side facing the second bearing (2); a second elastic support member (20) is provided in the second step portion, and the two sides of the second elastic support member (20) are in contact with the inner ring of the second bearing (2) and the flange portion (62) respectively.

12. The bearing system according to claim 8, characterized in that, The housing (3) is provided with a guide hole (81) at one end relative to the nut mounting hole (82), and the positioning nut (11) is disposed in the guide hole (81); a second stepped structure is provided on the inner wall of the housing (3) near the guide hole (81); a sealing ring (7) is provided in the second stepped structure, and the sealing ring (7) contacts the outer periphery of the positioning nut (11).

13. A lead screw assembly, characterized in that, The lead screw assembly includes a lead screw (5) and a bearing system according to any one of claims 1 to 12, wherein the lead screw (5) is coupled to the inner rings of a first bearing (1) and a second bearing (2) in the housing (3) of the bearing system.

14. The lead screw assembly according to claim 13, characterized in that, The bearing system also includes a bearing sleeve (6), the inner rings of the first bearing (1) and the second bearing (2) are sleeved on the outer periphery of the bearing sleeve (6), and the inner hole of the bearing sleeve (6) is engaged with the lead screw (5); the bearing system also includes a positioning nut (11), the internal thread of the positioning nut (11) is engaged with the external thread of the lead screw (5).

15. An electric cylinder, characterized in that, Includes a driver and a lead screw assembly as claimed in claim 13 or 14.

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