Torque sensor device for a resistance system

Abstract

Torque sensor device for a resistance system, wherein the resistance system comprises: a support frame (20) comprising a left side plate (20L) and a right side plate (20R) which are connected to form a unit by means of several positioning rods (24), wherein an axle bore (21) is provided in the opposite positions of the left and right side plates (20L, 20R); a flywheel (30) having an axle of the flywheel (31) which is rotatably mounted in the axle bores (21) via a left bearing (32), a right bearing (32) and a bearing housing (50), so that the flywheel (30) can rotate on the support frame (20); and a coil-magnetic resistance system (40) arranged on one side of the outer circumference of the flywheel (30) and exerting a magnetic force on the flywheel (30), wherein the magnetic force is proportional to the applied current; characterized in that - that the bearing housing (50) has a first ring body (51) on the outer circumference of which a positioning groove (511) is provided, and on the inner surface of which a second ring body (52) with a larger outer diameter is arranged; - that the axle bores (21) of the left and right side plate (20L, 20R) are designed as oval openings with a long groove (23), so that the first ring body (51) of the bearing housing (50) can be inserted into the axle bore (21) from the inside out, the second ring body (52) serving as a positioning surface on the inside and a positioning element (53) being inserted into the positioning groove (511) on the outside, whereby the bearing housing (50) is not rigidly fixed in the axle bore (21), but is mounted in a floating arrangement; - that a torque sensor (60) has a strain gauge block (61) which is installed in the elongated groove (23) on the side of the shaft bore (21), wherein the strain gauge block (61) is aligned in line with the axis of the flywheel (31) and the center of the coil magnetoresistive system (40), and whose upper end forms a transverse projection plate (62) whose upper surface (621) is in contact with the second ring body (52) of the bearing housing (50), while the underside (622) of the projection plate (62) is provided with a resistive strain gauge (63) and associated connecting leads (64), wherein the resistive strain gauge (63) generates different resistance values ​​depending on the deformation of the strain gauge block (61); and - that a control circuit (80) receives the resistance changes of the torque sensor (60), from which the change in the applied resistance and the difference between the desired and actual resistance can be determined in order to adjust the applied resistance and to bring the desired resistance into line with the actual resistance.

Description

[0001] The present invention relates to a torque sensor device for a resistance system, in particular a device for detecting magnetic forces based on changes in electrical resistance. The detected magnetic force data are used to compensate for and correct the output current.

[0002] As in Fig. Figure 1A discloses the conventional, widely used electromagnetic resistance device 10A, comprising a flywheel 11 mounted on a support frame 13 via its axis 12. At least one coil 14 is attached to the side of the flywheel 11. When current is passed through the coil 14, a magnetic field is generated which, due to the magnetic conductivity of the flywheel material, forms a magnetic circuit between the coil core and the flywheel 11 as soon as the coil 14 is energized. According to Lenz's law, when the flywheel 11 rotates, the device generates a rotational resistance force that acts opposite to the direction of rotation and whose magnitude corresponds to the rotation of the flywheel.

[0003] As in Fig. Figure 1B describes a conventional, widely used self-generating resistance system 10B, which has a similar structure to the previously mentioned electromagnetic resistance system 10A. The difference is that the coil 14 of the electromagnetic resistance system 10A requires an external power supply. In the self-generating resistance system, however, a current-generating device 15 is integrated inside the flywheel 11. This device generates current through the rotation of the flywheel 11, thereby providing the power supply required for the coil 14 to generate the necessary resistance.

[0004] The two resistance (or voltage) systems mentioned above, 10A and 10B, are established products and represent the state of the art; therefore, a detailed description of their function and properties is unnecessary. Such resistance (or voltage) systems have already been discussed in various publications, such as the Chinese publication CN201204540 "Hybrid Generator with Integrated Eddy-Current Magnetic Resistance," the Taiwanese publication M420342 "Self-Generating Resistance Device for Fitness and Rehabilitation Equipment," and US Patent No. 6,084,325 "Brake Device with a Combination of Power Generation and Eddy-Current Magnetic Resistance."

[0005] The resistance (or voltage) systems described above control the strength of the generated magnetic force by regulating the current supply to coil 14. The magnitude of the magnetic force (magnetic force = current x number of coil windings) determines the level of the generated resistance or voltage.

[0006] Without a measuring sensor for feedback, precise control of the magnetic force (i.e., the resistance or voltage) is difficult, as shown in Fig. Figure 1C illustrates this. In conventional control methods, after the resistance system has been manufactured, the resistance curve of the device is typically determined. Parameters such as current, speed, and power are measured and compiled in a power table. To control the resistance, the current speed of the device is first determined. The required current for the desired resistance (or voltage) level is then looked up in the power table as a function of the speed. By controlling the current, the corresponding resistance can be generated in systems 10A or 10B.

[0007] This indicates that these systems are "open-loop systems," meaning they lack feedback and compensation to correct the result. In the 10A or 10B resistor systems, numerous factors can influence the strength of the magnetic force during resistance generation. These include operating time, flywheel temperature, coil temperature, and the distance between the flywheel and iron core. These influences can alter the strength of the magnetic field lines, the magnetic resistance, and the electrical resistance of the coil, potentially leading to significant deviations between the actual resistance generated and the desired value.

[0008] To reduce these deviations, switching to a closed-loop system with feedback is one of the most effective methods. Direct feedback of the magnetic force offers the greatest effectiveness. In such a closed-loop control system, the measured magnetic force is continuously fed back to the control system and compared with the defined setpoint value. If deviations occur, the supplied current can be adjusted immediately to meet the specified requirements.

[0009] The invention is based on the objective of providing a torque sensor device for resistance systems that improves the accuracy of resistance control and thus enables more precise control of the resistance in order to meet the requirements of highly developed devices.

[0010] Another object of the invention is to offer a torque sensor device for resistance systems that ensures precise resistance control and integrates the torque sensor and the resistance generator in a common unit to achieve a simplified overall structure.

[0011] This problem is solved according to the invention by a torque sensor device for a resistance system, which has the features specified in claim 1. Further advantageous embodiments of the invention will become apparent from the features of the dependent claims.

[0012] According to the invention, a torque sensor device is provided for a resistance system, wherein the resistance system comprises the following: a support frame comprising a left side plate and a right side plate connected to form a unit by means of several positioning rods, wherein an axle bore is provided in the opposite positions of the left and right side plates; a flywheel comprising a flywheel axle which is rotatably mounted in the axle bores via a left bearing, a right bearing and a bearing housing, so that the flywheel can rotate on the support frame; and a coil magnetoresistive system arranged on one side of the outer circumference of the flywheel and exerting a magnetic force on the flywheel, the magnetic force being proportional to the applied current.

[0013] According to the invention, the bearing housing comprises a first ring body with a positioning groove on its outer circumference and a second ring body with a larger outer diameter arranged on its inner surface. The axle bores of the left and right side plates are designed as oval openings with an elongated groove, allowing the first ring body of the bearing housing to be inserted into the axle bore from the inside out. The second ring body serves as a positioning surface on the inside, and a positioning element is inserted into the positioning groove on the outside, thus enabling the bearing housing to be mounted in a floating arrangement rather than rigidly fixed in the axle bore.A torque sensor has a strain gauge block installed in the elongated groove on the side of the axle bore, the strain gauge block being aligned in a line with the axis of the flywheel and the center of the coil magnetoresistance system, and its upper end forming a transverse projection plate, the upper surface of which is in contact with the second ring body of the bearing housing, while the underside of the projection plate is provided with a resistive strain gauge and associated connecting leads, the resistive strain gauge generating different resistance values ​​depending on the deformation of the strain gauge block.A control circuit receives the resistance changes from the torque sensor, from which the change in the applied resistance is calculated and the difference between the desired and actual resistance can be determined in order to adjust the applied resistance and bring the desired resistance into line with the actual resistance.

[0014] The invention and its embodiments are explained in more detail below with reference to the drawing. The drawing shows: Fig. 1A a perspective view of a conventional electromagnetic resistance system; Fig. 1B a perspective view of a conventional self-generating resistance system; Fig. 1C a sequence of resistance control steps of a conventional open control system; Fig. 2 a perspective exploded view of an embodiment of the present invention; Fig. 3 an enlarged view of a right side plate of a support frame according to an embodiment of the invention; Fig. 4A a perspective view of a torque sensor according to an embodiment of the invention; Fig. 4B a perspective view of the torque sensor from a different viewpoint according to an embodiment of the invention; Fig. 5A a perspective view of the right side of the resistance device according to the invention in the assembled state; Fig. 5B a perspective view of the left side of the resistance device according to the invention in the assembled state; Fig. 6A a perspective exploded view of the bearing housing and the torque sensor in an embodiment of the invention; Fig. 6B a perspective assembly view of the bearing housing and the torque sensor in an embodiment of the invention; Fig. 7A a side view of an embodiment of the present invention; Fig. 7B an enlarged cross-sectional view of part of the structure made of Fig. 7A; Fig. 8 a schematic flow diagram of the resistance control process in the closed control system of the present invention; Fig. 9 a schematic representation of an application example of the resistance device according to the invention in a fitness and rehabilitation device; and Fig. 10 a schematic representation of another application example of the resistance device according to the invention in the fitness and rehabilitation device.

[0015] First, attention will be drawn to the in the Fig. 2 to Fig. Reference is made to Figure 8, which illustrates a preferred, practical implementation of the "torque sensor device for a resistance system" according to the invention. In principle, the proposed resistance system of this invention is applicable to both electromagnetic and self-generating systems. Although these two resistance systems differ in their power supply (one uses an external power source, the other a self-generating power supply), the structure for implementing magnetic force feedback using a strain gauge remains largely identical in both cases. Therefore, the structure of the electromagnetic resistance system is explained by way of example in the following embodiment.

[0016] The resistance device 70 according to the invention comprises a support frame 20, a flywheel 30, a coil magnetic resistance system 40, a torque sensor 60 and a control circuit 80.

[0017] The support frame 20 consists of a left and a right side plate 20L, 20R, which are connected to form a unit by means of several positioning rods 24. An axle bore 21 is located at the opposite positions of the left and right side plates 20L, 20R.

[0018] The flywheel 30 has an axle 31 and is rotatably mounted on the support frame 20 in the axle bores 21 via two bearings 32 and bearing housings 50, so that the flywheel 30 can rotate on the support frame 20. In this embodiment, one end of the axle 31 of the flywheel 30 is fixed by a first nut 33 and a first screw 34, while the other end is provided with a pulley 35, which is also fastened by a second nut 36 and a second screw 37.

[0019] The coil-magnetic resistance system 40 is mounted on one side of the outer circumference of the flywheel 30 and exerts a magnetic force on the flywheel 30. This magnetic force is proportional to the applied current. In this embodiment, the coil-magnetic resistance system 40 comprises an iron core 41 and a coil 42 wound thereon. Since these components are part of the prior art, they are not part of the invention and do not require further description.

[0020] The main features of the present invention are that the bearing housing 50 has a first ring body 51, on the outer circumference of which a positioning groove 511 is formed. Furthermore, a second ring body 52 with a larger outer diameter is arranged on the inner surface of the first ring body 51. In this embodiment, the outer diameter of the second ring body 52 is larger than that of the axle bore 21.

[0021] The axle bores 21 of the left and right side plates 20L, 20R are designed as oval openings with an elongated groove 23, allowing the first ring body 51 of the bearing housing 50 to be inserted into the axle bore 21 from the inside out. On the inside, the second ring body 52 serves as a positioning surface, while on the outside, a positioning element 53 is inserted into the positioning groove 511, thus preventing the bearing housing 50 from being rigidly connected to the axle bore 21, but rather allowing it to be mounted in a floating arrangement within the axle bore 21. In this embodiment, the positioning element 53 comprises a retaining ring or a positioning ring that is inserted into the positioning groove 511 to secure the bearing housing 50 in the axle bore 21.

[0022] As in Fig. Figure 3, an enlarged schematic representation of the right side plate 20R of the support frame 20, shows that in a preferred embodiment, when the first ring body 51 of the bearing housing 50 is inserted into the axle bore 21, a clearance 22 is created between the axle bore 21 and the elongated groove 23. The dashed line “A” shows the position of an ideal circle, which would represent the position of the first ring body 51. However, the actual axle bore 21, as shown at position “B”, is not circular, but has a clearance 22. This allows the bearing housing 50 to adjust its position when the compressive force P acting on it changes. Thus, the bearing housing 50 can react flexibly to changes in force with every change in pressure, as shown in Fig. 7A and Fig. 7B illustrates this.

[0023] As in the Fig. 4A and Fig. As shown in Figure 4B, the torque sensor 60 has an expansion block 61 which is mounted in the elongated groove 23 on the side of the shaft bore 21. The expansion block 61 is, as shown in the Fig. 7A and Fig. Figure 7B shows the expansion block 61 aligned along the same XX reference line with the axis 31 of the flywheel 30 and the center of the coil magnetoresistive system 40. The upper end of the expansion block 61 extends inwards, forming a transverse projection plate 62. The upper surface 621 of the projection plate is designed to contact the second ring body 52 of the bearing housing 50. A resistive strain gauge 63 with associated connecting leads 64 is mounted on the opposite underside 622 of the projection plate 62. The resistive strain gauge 63 generates different resistance values ​​depending on the deformation of the expansion block 61.

[0024] In this embodiment, the torque sensor 60 is attached to the left and right side plates 20L, 20R by means of a third screw 65. As shown in the Fig. 6A and Fig. As shown in Figure 6B, the extended end of the projection plate 62 at the upper end of the expansion block 61 is a free end without a fixed connection, thus possessing elastic deformation capability. The projection plate 62 is free and rests against the outer edge of the second ring body 52 to absorb the compressive force P acting upon it.

[0025] In this embodiment, the following applies: the greater the current in the coil-magnetic resistance system 40, the stronger the magnetic force; the smaller the current, the weaker the magnetic force. The magnetic force generated by the coil-magnetic resistance system 40 forms a magnetic circuit with the flywheel 30, which is made of a magnetizable material, and attracts the flywheel 30. Since the flywheel 30 is movable due to its floating mounting in the support frame 20, it is pulled towards the coil-magnetic resistance system 40 when the magnetic force is applied. This causes the expansion block 61 to come under pressure and deform, thereby generating a change in the resistance value of the resistance strain gauge 63. The greater the magnetic force on the flywheel 30, the greater the deformation of the expansion block 61. Conversely, the lower the magnetic force on the flywheel 30, the lower the pressure on the expansion block 61 and thus also its deformation.

[0026] The control circuit 80 receives the resistance changes from the torque sensor 60 and calculates the change in the applied resistance from this. It then compares the desired resistance force with the actual resistance force and adjusts the applied force accordingly so that the desired resistance matches the actual resistance.

[0027] As in Fig. Figure 8 illustrates the process for resistance control of the closed-loop control system of this invention. The steps include: S1: Input of the desired resistance or voltage. S2: Comparison of the desired resistance with the actual resistance. S3: Calculation of the required current so that the control circuit 80, based on the resistance change 81, adjusts the required current 82 to change the magnetic force of the coil magnetoresistance system 40. S4: Generation of the corresponding resistance. S5: Measurement of the actual resistance, then return to step S2 to compare the desired resistance with the actual resistance.

[0028] According to the "closed-loop control system" described above, feedback is used to compensate for and correct the result. The technical solution of the present invention lies in the use of the torque sensor 60 as a magnetic force detection device, wherein the change in electrical resistance serves to measure the magnetic force. The detected magnetic force data are used to compensate for and correct the output current. In this way, the numerous factors that influence the resistance or voltage can be reduced to a minimum.

[0029] Fig. Figure 9 shows a schematic representation of the application of the resistance system 70 according to the invention in fitness and rehabilitation equipment 90. The resistance system 70 can be connected to the fitness or rehabilitation equipment 90 via the pulley 35. The control circuit 80 can be integrated into the control panel of the device. In fitness and medical rehabilitation equipment, especially in sophisticated training equipment for professional training, there is a high demand for the precision of the training data.

[0030] Trainees must be able to create and implement detailed training plans and receive precise feedback on the results achieved in order to evaluate performance and adjust future training plans accordingly. Therefore, the precise acquisition and implementation of training data is crucial. The resistance system 70 according to the invention, with a closed-loop control system, in combination with the control circuit 80, enables highly precise resistance control that meets the requirements of advanced equipment and supports the precise execution of training programs.

[0031] Fig.Figure 10 shows a further schematic representation of the application of the resistance system 70 according to the invention in a clamping device 100. The resistance system 70 can be connected to the clamping device 100 via the pulley 35, while the control circuit 80 can be installed in the vicinity of the clamping device 100. For devices requiring precise voltage regulation, the resistance system 70 according to the invention, with its closed-loop control system, in combination with the control circuit 80, provides a feedback device for the resistance change 81 and the possibility of adjusting the output current 82. This creates a closed-loop control system for the braking system that effectively fulfills the required control requirements. This embodiment can optimally provide the necessary functionalities in such demanding applications.

[0032] The present invention achieves the following improvements through the technical measures described above: 1. The invention utilizes the torque sensor 60, which is arranged along the axis of the flywheel 31 and in line with the coil-magnetic resistance system 40. This sensor serves as a magnetic force detection device by using resistance changes to measure the magnetic force. The detected magnetic force data are used to compensate for and correct the output current. This significantly improves the precision of the resistance control of the resistance system 70, enabling more precise resistance control and meeting the requirements of sophisticated devices. 2. The torque sensor 60 and the coil-magnetic resistance system 40, which generates the resistance or voltage, are integrated into the same mechanical structure of the resistance system 70. This simplifies the overall structure and increases the efficiency of the system. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 201204540

[0004] US 6,084,325

[0004]

Claims

[1] A torque sensor device for a resistance system, the resistance system comprising: a support frame (20) having a left side plate (20L) and a right side plate (20R) connected to form a unit by means of a plurality of positioning rods (24), wherein an axle hole (21) is provided in each of the opposite positions of the left and right side plates (20L, 20R); a flywheel (30) having a flywheel axle (31) which is rotatably mounted in the axle bores (21) via a left bearing (32), a right bearing (32) and a bearing housing (50) so that the flywheel (30) can rotate on the support frame (20); and a coil magnetoresistance system (40) disposed on one side of the outer circumference of the flywheel (30) and exerting a magnetic force on the flywheel (30), the magnetic force being proportional to the applied current; characterized by , - that the bearing housing (50) has a first annular body (51), on the outer circumference of which a positioning groove (511) is provided, and on the inner surface of which a second annular body (52) with a larger outer diameter is arranged; - that the axle bores (21) of the left and right side plates (20L, 20R) are designed as oval openings with a long groove (23), so that the first annular body (51) of the bearing housing (50) can be inserted into the axle bore (21) from the inside to the outside, wherein the second annular body (52) serves as a positioning surface on the inside and a positioning element (53) is inserted into the positioning groove (511) on the outside, whereby the bearing housing (50) is not rigidly fastened in the axle bore (21), but is mounted in a floating arrangement; - that a torque sensor (60) has a strain block (61) installed in the long groove (23) on the side of the axle bore (21), the strain block (61) being aligned with the axis of the flywheel (31) and the center of the coil magneto-resistance system (40), and the upper end of which forms a transversely extending projection plate (62), the upper surface (621) of which is in contact with the second annular body (52) of the bearing housing (50), while the underside (622) of the projection plate (62) is provided with a resistance strain gauge (63) and associated connecting leads (64), the resistance strain gauge (63) generating different resistance values depending on the deformation of the strain block (61); and - that a control circuit (80) receives the resistance changes of the torque sensor (60), from which the change in the applied resistance and the difference between the desired and actual resistance can be determined in order to adjust the applied resistance and to bring the desired resistance into agreement with the actual resistance. [2] Torque sensor device for a resistance system according to claim 1, characterized by that when the first annular body (51) of the bearing housing (50) is inserted into the axle bore (21), a movement clearance (22) is created which is located between the axle bore (21) and the long groove (23) and enables a displacement of the bearing housing (50) in the direction of the expansion block (61). [3] Torque sensor device for a resistance system according to claim 2, characterized bythat the extended end of the projection plate (62) at the upper end of the expansion block (61) is designed as a free end without a fixing element being attached thereto, whereby the projection plate (62) has elastic deformation properties. [4] Torque sensor device for a resistance system according to claim 1, characterized by that the positioning element (53) is selected from a group comprising a retaining ring and a positioning ring, wherein the positioning element (53) engages in the positioning groove (511) in order to fix the bearing housing (50) in the axle bore (21). [5] Torque sensor device for a resistance system according to claim 1, characterized by that one end of the axis of the flywheel (31) is fixed with a first nut (33) and a first screw (34), while the other end is provided with a pulley (35) and secured by a second nut (36) and a second screw (37). [6] Torque sensor device for a resistance system according to claim 1, characterized by that the torque sensor (60) is attached to the left and right side plates (20L, 20R) with a third screw (65).

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