Pedal type fitness machine

Abstract

The utility model relates to the technical field of sports equipment, in particular to a pedal type fitness machine which comprises two pedal assemblies and a double-crank transmission mechanism, the double-crank transmission mechanism comprises two crank assemblies, one crank assembly is connected with the pedal assemblies through an elastic adjusting structure, and the other crank assembly is connected with the pedal assemblies. The elastic adjusting structure enables the crank assembly and the pedal assembly which are connected to the elastic adjusting structure to form elastic connection with relative translation in the length direction of the pedal assembly, so that when the pedal assembly and the double-crank transmission mechanism form instrument locking due to insufficient precision, the pedal assembly and the double-crank transmission mechanism are locked. The pedal assembly and the crank assemblies form relative movement by means of the elastic force of the elastic adjusting structure to unlock the instrument, the angle of the pedal assembly can be changed to meet the walking gait of a user, meanwhile, the pulling force between the two crank assemblies is reduced, and the service life is prolonged. During treading, the instant force in contact with the pedal assembly can be absorbed by the elastic adjusting structure, so that the exercise injury of the knee joint is reduced; the structural design of the whole machine is optimized, the size of the whole machine is reduced, and space and cost of a user are saved.

Description

Technical Field

[0001] The utility model relates to the technical field of sports equipment, in particular to a pedal type fitness machine. Background Art

[0002] Most of the foot pedals of the existing pedal type fitness machines (such as elliptical machines) on the market are driven by a single crank mechanism, that is, the foot pedals are driven by a set of crank mechanisms. The application of the single crank drive mechanism on commercial large elliptical machines and household small elliptical machines can be further divided into the mechanism of single crank plus swing rod and the mechanism of single crank plus roller. Refer to Figure 1 As shown, large elliptical machines usually use the drive mechanism of single crank 200 plus swing rod 300. One end of the foot pedal 100 is connected to the swing rod 300, and the other end is connected to the single crank 200, forming a structure that can rotate in an elliptical motion. However, the overall size of the elliptical machine designed by this structure is large and cannot be further reduced for two reasons: (1) In order to conform to ergonomics, when the connected crank is perpendicular to the ground, the maximum horizontal angle of one side of the foot pedal cannot be greater than 21.5 degrees, and the maximum horizontal angle of the other side of the foot pedal cannot be greater than 4 degrees; (2) When a person is exercising, the front and rear foot spacing is at least 300 mm (more than 150 mm for the crank) to have the feeling of normal walking.

[0003] Refer to Figure 2 As shown, there is also a mini elliptical machine on the market at present, which adopts the drive mechanism of single crank 200 plus roller 400. One end of the foot pedal 100 is connected to the single crank 200, and the other end is connected to the roller 400 that can roll on the bottom plate. In order to reduce the overall size of this elliptical machine and also to conform to ergonomics, limited by the maximum angle of the foot pedal, it can only be designed with a front and rear foot spacing of about 150 mm (75 mm for the crank), and the movement amplitude is too small to achieve the exercise effect.

[0004] There are also fitness machines (such as elliptical machines) with a double crank drive mechanism in the prior art, which can balance the movement amplitude and the miniaturization of the equipment. For example, refer to the patent application number: TW104203057U. The two double cranks in this patent are synchronously driven by a synchronous belt to drive the two foot pedals to rotate synchronously. The internal structure is complex, the whole machine is wider, resulting in a larger distance between the two foot pedals, uncomfortable movement, and high cost at the same time. For example, refer to the patent application number: CN202410157165.3. The two double cranks are synchronously driven by a rigid connection through a connecting rod to drive the two foot pedals to rotate synchronously. The installation accuracy requirements for each component of the drive mechanism are relatively high. Even a small welding deformation or dimensional processing error will cause the instrument to lock, and the actual production difficulty is large and the cost is high. The two foot pedals of the fitness machines disclosed in the above two patents have always moved in parallel, and cannot meet the walking gait matching of the user (the walking gait includes the state with the toes facing up and the toes facing down and the state between the toes facing up and the toes facing down).

[0005] In addition, most of the pedal plates of existing elliptical machines have rigid contact during the pedaling process, which causes greater harm to knee joint movement. Summary of the Invention

[0006] The purpose of the present utility model is to provide a pedal-type fitness machine to solve the problems existing in the above-mentioned existing elliptical machines, such as large overall size, small movement step distance of mini elliptical machines, complex structure of elliptical machines with synchronous belt transmission between double cranks and wide distance between two pedal plates, easy locking of elliptical machines with rigid connection between double cranks through connecting rods, and the problem that the movement angle change of their two pedal plates does not conform to the walking gait of users and the rigid contact during pedaling.

[0007] To achieve the above purpose, the technical solution of the present utility model is: a pedal-type fitness machine, including a frame and two pedal assemblies and a double crank transmission mechanism arranged on the frame. The double crank mechanism includes two crank assemblies arranged at intervals. The ends of the two crank assemblies are respectively rotatably connected to the pedal assemblies. The pedal assemblies are used for users to step on and move along a predetermined trajectory under the action of the users' stepping and the rotation of the crank assemblies. The pedal assemblies are strip-shaped. One of the crank assemblies is connected to the pedal assembly through an elastic adjustment structure. The elastic adjustment structure makes the crank assembly connected to the elastic adjustment structure form an elastic connection with the pedal assembly having relative translation along the length direction of the pedal assembly.

[0008] In one embodiment, the elastic adjustment structure includes an adjustment track and an elastic member. The extension direction of the adjustment track is parallel to the length direction of the pedal assembly. The elastic member forms a connection relationship with the adjustment track that can elastically deform along the adjustment track. The end of the crank assembly connected to the elastic adjustment structure is provided with a first rolling bearing. The first rolling bearing and the elastic member are arranged in sequence along the adjustment track. And the adjustment track forms a relatively fixed connection relationship with the pedal assembly. The crank assembly connected to the elastic adjustment structure forms an elastic sliding connection with the adjustment track along the extension direction of the adjustment track under the elastic force of the first rolling bearing and the elastic member, thereby forming the elastic connection with the pedal assembly.

[0009] In one embodiment, a plurality of elastic members are provided. On both sides of the first rolling bearing in the extension direction of the adjustment track, a plurality of the elastic members are arranged.

[0010] In one embodiment, the elastic member is a compression spring, and there are two compression springs. The two compression springs are respectively arranged on both sides of the first rolling bearing along the extension direction of the adjustment track. A force transmission member is provided between the compression spring and the first rolling bearing. The force transmission member includes a force transmission part, and a contact plane is provided on the side of the force transmission part facing the compression spring. The compression spring indirectly contacts the outer peripheral surface of the first rolling bearing by contacting the contact plane of the force transmission part, and the radial dimension of the contact plane of the compression spring is larger than the outer diameter of the compression spring.

[0011] In one embodiment, a bearing abutment surface is provided on the side of the force transmission part facing the first rolling bearing, and in the process of the first rolling bearing sliding along the adjustment track, the bearing abutment surface of the force transmission part is always in contact with the outer peripheral surface of the first rolling bearing, and the abutment plane of the force transmission part is always in contact with the compression spring.

[0012] In one embodiment, the force transmission member further includes a guide portion, the guide portion is arranged on a side of the force transmission portion facing the compression spring, and the compression spring is sleeved outside the guide portion.

[0013] In one embodiment, the end of the compression spring away from the force transmission member is defined as the distal end of the compression spring, and the outer diameter of the distal end of the compression spring is larger than the outer diameter of other parts of the compression spring, so that the outer side of the distal end of the compression spring abuts against the inner wall of the adjustment track to eliminate abnormal noise during operation.

[0014] In one embodiment, the elastic adjustment structure further includes limiting portions arranged at both ends of the adjustment track, and the limiting portions are respectively arranged on both sides of the first rolling bearing, thereby forming a movement limit of the first rolling bearing along the length direction of the adjustment track.

[0015] In one embodiment, one of the crank assemblies is connected to a belt transmission mechanism, and the belt transmission mechanism is also drivingly connected to an inertia resistance wheel assembly, so that the inertia resistance wheel assembly provides motion inertia and resistance to the pedal assembly through the belt transmission mechanism.

[0016] In one embodiment, it further comprises a handle assembly disposed on the frame, wherein the handle assembly has two gripping parts for being held by a user.

[0017] In one embodiment, the frame includes a main frame and a base connected to the main frame. The two pedal assemblies are respectively arranged on both sides of the main frame. The arrangement direction of the two pedal assemblies is defined as the Y-axis direction, the arrangement direction of the main frame relative to the base is defined as the Z-axis direction, and the direction perpendicular to the Y-axis and the Z-axis is defined as the X-axis direction. The two crank assemblies are arranged on the main frame at intervals along the X-axis direction and penetrate the main frame along the Y-axis direction. The two pedal assemblies are respectively rotatably connected to both ends of the crank assemblies in the Y-axis direction, so that the two pedal assemblies move synchronously along an elliptical trajectory.

[0018] The beneficial effects of the present utility model are as follows: By arranging an elastic adjustment structure between one of the crank assemblies and the pedal assembly, the crank assembly and the pedal assembly are relatively movably connected. Thus, when the pedal assembly and the double-crank transmission mechanism are locked due to insufficient precision, the pedal assembly and the crank assembly move relatively to release the locking of the instrument, and the pedal assembly and the crank assembly move relatively relying on the elastic force of the elastic adjustment structure. The two pedal assemblies move synchronously along an elliptical trajectory. Correspondingly, under the action of the elastic force of the elastic adjustment structure, the change in the movement angle of the two pedal assemblies conforms to the walking gait of the user, and the force transmitted from the pedal assembly to the user is also softer, which helps to protect the user's knees and reduce knee joint movement injuries. Description of the Drawings

[0019] Figure 1 is a three-dimensional view of an existing large elliptical machine.

[0020] Figure 2 is a three-dimensional view of an existing mini elliptical machine.

[0021] Figure 3 is a three-dimensional view of Embodiment 1 of the present utility model.

[0022] Figure 4 is a three-dimensional view of Embodiment 1 of the present utility model without a housing and foot pedals.

[0023] Figure 5 is a three-dimensional view of the front crank assembly of Embodiment 1 of the present utility model.

[0024] Figure 6 is a three-dimensional view of the rear crank assembly and flange of Embodiment 1 of the present utility model.

[0025] Figure 7 is a connection structure diagram of the front crank assembly, elastic adjustment structure and pedal assembly of Embodiment 1 of the present utility model.

[0026] Figure 8 is a three-dimensional view of the force transmission member of Embodiment 1 of the present utility model.

[0027] Figure 9is an embodiment of the present utility model Figure 7 which is a cross-sectional view of the connection structure shown

[0028] Figure 10 which is a perspective view of the compression spring of the embodiment of the present utility model

[0029] Figure 11 which is a perspective view of another embodiment of the elastic adjustment structure of the present utility model

[0030] Figure 12 which is a side view of the pedal assembly of Embodiment 1 of the present utility model when it moves to a position close to the horizontal position

[0031] Figure 13 which is a perspective view of Embodiment 2 of the present utility model

[0032] Wherein: 1 is the frame, 11 is the main frame, 12 is the base, 13 is the housing, 2 is the pedal assembly, 21 is the foot pedal, 22 is the pedal fixing member, 3 is the double crank mechanism, 30 is the crank assembly, 31 is the front crank assembly, 311 is the front middle shaft, 312 is the front split crank, 313 is the front bearing fixing shaft, 314 is the first rotating bearing, 32 is the rear crank assembly, 321 is the rear middle shaft, 322 is the rear split crank, 323 is the rear bearing fixing shaft, 4 is the elastic adjustment structure, 41 is the adjustment track, 42 is the elastic member, 420 is the distal end of the compression spring, 421 is the first compression spring, 422 is the second compression spring, 43 is the force transmission member, 431 is the force transmission part, 4311 is the abutting plane, 4312 is the bearing abutting surface, 432 is the guiding part, 44 is the limiting part, 5 is the belt transmission mechanism, 50 is the flange, 51 is the belt, 52 is the belt pulley, 6 is the inertial resistance wheel assembly, 61 is the inertial resistance wheel, 7 is the handle assembly, 70 is the holding part Detailed implementation manners

[0033] To further illustrate each embodiment, the present utility model provides drawings. These drawings are part of the disclosure of the present utility model, mainly used to illustrate the embodiments, and can be combined with the relevant descriptions in the specification to explain the operating principle of the embodiments. With reference to these contents, those of ordinary skill in the art should be able to understand other possible implementation manners and the advantages of the present utility model. The components in the drawings are not drawn to scale, and similar component symbols are usually used to represent similar components

[0034] Embodiment 1

[0035] Referring to Figures 3 to 4 as shown, the present utility model discloses a pedal type fitness machine, including a frame 1, the frame 1 includes a main frame 11 and a base 12 connected to the main frame 11, there are two pedal assemblies 2 and a double crank transmission mechanism 3 provided on the frame 1, the two pedal assemblies 2 are respectively arranged on both sides of the main frame 11, the arrangement direction of the two pedal assemblies 2 is defined as the Y-axis direction, the arrangement direction of the main frame 11 relative to the base 12 is defined as the Z-axis direction, and the direction perpendicular to the Y-axis and the Z-axis is defined as the X-axis direction

[0036] The double-crank mechanism 3 includes two crank assemblies 30 arranged at intervals. The two crank assemblies 30 are arranged on the main frame 11 at intervals in the X-axis direction and penetrate the main frame 11 in the Y-axis direction. The two pedal assemblies 2 are respectively rotatably connected to both ends of the crank assemblies 30 in the Y-axis direction. The pedal assemblies 2 are used for users to step on and move along a predetermined trajectory under the stepping of the users and the rotation of the crank assemblies 30. Thus, the two pedal assemblies 2 move synchronously along the predetermined trajectories respectively. Define the direction that the user faces when using the fitness machine as the front, and the direction opposite thereto as the rear, and the front and rear directions are parallel to the X-axis direction. The two crank assemblies 30 are divided into a front crank assembly 31 and a rear crank assembly 32.

[0037] The frame 1 further includes a housing 13. The two pedal assemblies 2 are respectively arranged on both sides of the housing 13, and a part of the double-crank transmission mechanism 3 is arranged inside the housing 13. Each pedal assembly 2 includes a foot pedal 21 and a pedal fixing member 22. The pedal assemblies 2 are respectively connected to the two crank assemblies 30 by means of the pedal fixing members 22.

[0038] Refer to Figure 4 As shown, the rear crank assembly 32 is connected with a belt transmission mechanism 5, and the belt transmission mechanism 5 is also drivingly connected to an inertial resistance wheel assembly 6. Thus, the inertial resistance wheel assembly 6 provides motion inertia and resistance to the pedal assembly 2 through the belt transmission mechanism 5. The inertial resistance wheel assembly 6 in this example is a magnetic resistance wheel with adjustable resistance, and the principle of its resistance adjustment is the prior art and will not be elaborated here. The belt 51 of the belt transmission mechanism 5 is wound around the belt pulley 52 and the inertial resistance wheel 61 of the inertial resistance wheel assembly 6. The belt pulley 52 of the belt transmission mechanism 5 is connected to the rear middle shaft 321 of the rear crank assembly 32. More specifically, a flange 50 is provided on the rear middle shaft, and the belt pulley 52 is fixedly connected to the flange 50 and thus indirectly connected to the rear middle shaft 321. Thus, the inertial resistance wheel 61 transfers inertia and resistance to the rear crank assembly 32 through the belt transmission mechanism 5, and finally forms the motion inertia and resistance of the pedal assembly 2.

[0039] It should be noted that the rotational connection between the pedal assembly 2 and the crank assembly 30 includes the direct connection between the pedal assembly 2 and the crank assembly 30, and also includes the indirect connection formed by other connection structures between the pedal assembly 2 and the crank assembly 30. In this example, one of the crank assemblies 30 is directly connected to the pedal fixing member 22 of the pedal assembly 2, and the other crank assembly 30 is indirectly connected to the pedal fixing member 22 of the pedal assembly 2 through an elastic adjustment structure 4. The front crank assembly 31 in this example is indirectly connected to the pedal assembly 2 through the elastic adjustment structure 4, and the rear crank assembly 32 is directly connected to the pedal assembly 2. In other embodiments, it may also be that the rear crank assembly 32 is indirectly connected to the pedal assembly 2 through the elastic adjustment structure 4, and the front crank assembly 31 is directly connected to the pedal assembly 2.

[0040] The following takes the elastic adjustment structure 4 being arranged on the front crank assembly 31 as an example for illustration. If the elastic adjustment structure 4 is arranged on the rear crank assembly 32, its connection structure is the same as that of the front crank assembly 31.

[0041] The pedal assembly 2 is strip-shaped. The front crank assembly 31 and the pedal assembly are connected by the elastic adjustment structure 4. The elastic adjustment structure 4 enables the front crank assembly 31 and the pedal assembly 2 to form an elastic connection with relative translation along the length direction of the pedal assembly 2.

[0042] By arranging the elastic adjustment structure 4 between the front crank assembly 31 and the pedal assembly 2, the present utility model enables the front crank assembly 31 and the pedal assembly 2 to form a relative motion connection. Thus, when the pedal assembly 2 and the double-crank transmission mechanism 3 are locked due to welding deformation or insufficient machining accuracy, the pedal assembly 2 and the front crank assembly 31 move relatively to release the locking of the instrument. Moreover, the pedal assembly 2 and the front crank assembly 31 rely on the elastic force of the elastic adjustment structure 4 to form relative movement, so that an included angle is formed between the front crank assembly 31 and the rear crank assembly 32, reducing the tension between the front central shaft 311 and the rear central shaft 321, and causing less wear to the pedal assembly 2 and the double-crank transmission mechanism 3. Also, due to the existence of the elastic force, a force transmission is formed between the pedal assembly 2 and the double-crank transmission mechanism 3, ensuring the synchronous movement of the two pedal assemblies. Correspondingly, under the action of the elastic force of the elastic adjustment structure 4, the force transmitted from the pedal assembly 2 to the user is also softer, which helps to protect the user's knees and reduce knee joint movement injuries.

[0043] Refer to Figures 5 to 6 As shown in the figure, the front crank assembly 31 includes a front central shaft 311 passing through the main frame 11. The front central shaft 311 passes through the bearings on both sides of the main frame 11. Its two ends are respectively fixedly connected to one end of a front split crank 312. The other end of the front split crank 312 is fixedly connected to a front bearing fixed shaft 313. A first rotating bearing 314 is arranged at the end of the front bearing fixed shaft 313 away from the front split crank 312. Thus, the first rotating bearing 314 is located at the end of the front crank assembly 31. The elastic adjustment structure 4 is connected to the front crank assembly 31 through the first rotating bearing 314, thereby forming an indirect connection between the pedal assembly 2 and the front crank assembly 31.

[0044] The rear crank assembly 32 includes a rear center shaft 321 passing through the main frame 11. The rear center shaft 321 passes through the bearings on both sides of the main frame 11, and its two ends are respectively fixedly connected to one end of a rear split crank 322. The other end of the rear split crank 322 is fixedly connected to a rear bearing fixing shaft 323. The second rotating bearing is arranged at the end of the rear bearing fixing shaft 323 away from the rear split crank 322, so that the second rotating bearing is located at the end of the rear crank assembly 32. The pedal assembly 2 is connected to the rear crank assembly 32 through the second rotating bearing, thus forming the connection between the pedal assembly 2 and the rear crank assembly 32.

[0045] Referring to Figures 7 to 10 As shown, the elastic adjustment structure 4 includes an adjustment track 41 and an elastic member 42. The extending direction of the adjustment track 41 is parallel to the length direction of the pedal assembly 2. The elastic member 42 is arranged in the adjustment track 41. The first rolling bearing 314 at the end of the front crank assembly 31 and the elastic member 42 are arranged in the adjustment track 41 in sequence. Thus, the elastic member 42 and the adjustment track 41 form a connection relationship that can elastically deform along the adjustment track 41, and the adjustment track 41 and the pedal assembly 2 form a relatively fixed connection relationship. The front crank assembly 31 forms an elastic sliding connection along the extending direction of the adjustment track 41 with the adjustment track 41 under the elastic force of the first rolling bearing 314 and the elastic member 42, thus forming an elastic connection with the pedal assembly 2. Preferably, a plurality of elastic members 42 are provided. In the extending direction of the adjustment track 41, the plurality of elastic members 42 are arranged on both sides of the first rolling bearing 314. The elastic members 42 are arranged on both sides of the first rolling bearing 314 respectively. Thus, during the rotation of the front crank assembly 31, under the stepping action of the user, the pedal assembly 2 and the front crank assembly 31 can form a relative movement along the extending direction of the adjustment track 41 and respectively towards both sides of the first rolling bearing 314.

[0046] In this example, the elastic member 42 is a compression spring, and there are two compression springs. The two compression springs are respectively arranged on both sides of the first rolling bearing 314 along the extending direction of the adjusting track 41. A force transmission member 43 is provided between the compression spring and the first rolling bearing 314. The force transmission member 43 includes a force transmission portion 431. An abutting plane 4311 is provided on one side of the force transmission portion 431 facing the compression spring. The compression spring indirectly abuts against the outer peripheral surface of the first rolling bearing 314 by abutting against the abutting plane 4311 of the force transmission portion 431, and the dimension of the abutting plane 4311 in the radial direction of the compression spring is larger than the outer diameter of the compression spring. Since the outer peripheral surface of the first rolling bearing 314 is an arc surface, if the compression spring directly abuts against the outer peripheral surface of the first rolling bearing 314, it may bend and deform along the arc direction of the arc surface when the compression spring is compressed by force, making the elastic force direction of the compression spring uncontrollable. Therefore, in this example, the abutting plane 4311 on the force transmission portion 431 enables the compression spring and the first rolling bearing 314 to form an indirect contact. The compression spring will not bend and deform due to compression when contacting the plane, making the elastic force direction controllable, ensuring the reliability of the elastic force, and contributing to the reliable and stable movement of the two pedal assemblies 2. The force transmission portion 431 in this example is cylindrical. One end face forms an abutting plane 4311 for the compression spring to abut against, and the other end face abuts against the first rolling bearing to form a bearing abutting top surface 4312. The bearing abutting top surface 4312 in this example is an arc surface, an arc surface matching the outer peripheral surface of the first rolling bearing 314, so as to increase the contact area between the bearing abutting top surface 4312 and the outer peripheral surface of the first rolling bearing 314 and the stability of the abutting.

[0047] In order to further improve the controllability of the compression spring deformation, the force transmission member 43 further includes a guiding portion 432. The guiding portion 432 is arranged on the side of the force transmission portion 431 facing the compression spring, and the compression spring is sleeved outside the guiding portion 432. Preferably, the guiding portion 432 is a frustum of a cone with an inclined outer peripheral surface, which has a large end and a small end. The small end of the guiding portion 432 is inserted into the compression spring to play a role in guiding the deformation of the compression spring.

[0048] It should be noted that the fit between the guiding portion 432 of the force transmission member 43 and the compression spring is relatively tight. Thus, during the deformation process of the compression spring, the guiding portion 432 and the compression spring always remain sleeved, preventing them from colliding and making noise when reconnecting after being disconnected.

[0049] In this example, in order to further reduce the abnormal noise caused by the friction between the compression spring and the adjustment track 41, the outer diameter of one end of the compression spring away from the guiding portion 432 is larger. Define the end of the compression spring away from the guiding portion 432 as the distal end 420 of the compression spring. That is, the outer diameter of the distal end 420 of the compression spring is greater than the outer diameter of other parts of the compression spring. More specifically, the outer diameters of one to two turns at the end of the distal end 420 of the compression spring are larger. Thus, the outer side of the distal end of the compression spring can contact the inner wall of the adjustment track 41, and it is ensured that there is a certain distance between the part with a smaller outer diameter of the compression spring and the inner wall of the adjustment track 41, preventing the abnormal noise caused by the friction between the compression spring and the adjustment track 41. Of course, in other embodiments, it is also feasible to keep the outer diameter of the compression spring consistent.

[0050] In addition, when the first rolling bearing 314 translates in the adjustment track 41 and compresses the compression spring on one side of the first rolling bearing 314, the compression spring on the other side will elongate, and the elongating compression spring can at most elongate to its natural state without pressure. If the compression spring on one side is compressed to the limit, then the compression spring on the other side cannot continue to elongate when it elongates to the natural state, and it is possible that the abutting plane 4311 of the force transmission part 431 is disengaged from the compression spring. Taking the example where the first compression spring 421 is compressed by the pressure of the first rolling bearing 314, the second compression spring 422 is not stressed and naturally elongates, and the force transmission part 43 is disengaged from the first rolling bearing 314. At this time, there is no direct or indirect interaction force between the first rolling bearing 314 and the second compression spring 422. When the first rolling bearing 314 moves reversely towards the second compression spring 422, there will be a situation where the first rolling bearing 314 impacts the force transmission part 43, and the force transmission part 43 impacts the second compression spring 422, generating abnormal noise. The above is the situation where the first compression spring 421 is compressed and the second compression spring 422 is disengaged from the first rolling bearing 314. Vice versa, that is, the principle of the second compression spring 422 being compressed and the first compression spring 421 being disengaged from the first rolling bearing 314 is the same, only the direction is opposite. To overcome this problem, the lengths of the two compression springs and the thickness of the force transmission part 431 of the force transmission part 43 (that is, the dimension of the force transmission part 431 in the length direction of the compression spring) should be such that the outer peripheral surface of the first rolling bearing 314 and the bearing abutting surface 4312 of the force transmission part 43 are always in abutment. The specific values of the lengths of the compression springs and the thickness of the force transmission part 431 are determined by those skilled in the art according to parameters such as the length of the adjustment track 41, the spring constant of the compression spring, the maximum use weight, the outer diameter of the first rolling bearing 314, the movement trajectory of the pedal assembly 2, etc. and the prior art. The specific calculation method belongs to the conventional technology in this field and is not the content protected by the present utility model, so it will not be elaborated here.

[0051] The elastic adjustment structure 4 also includes a limit portion 44 disposed at both ends of the adjustment track 41, and the limit portions 44 are respectively disposed on both sides of the first rolling bearing 314, thereby forming a movement limit of the first rolling bearing 314 along the length direction of the adjustment track 41. The provision of the limit portion 44 can prevent the first rolling bearing 314 from excessively moving on the adjustment track 41, thereby preventing the first rolling bearing 314 from being disengaged from abutting against one of the compression springs. The limit portion 44 in this example is formed by a bolt fixedly disposed outside the adjustment track 41.

[0052] The elastic member 42 in this example is a compression spring. In other embodiments, the elastic member 42 can also be a bent spring leaf (such as a V-shaped or U-shaped bent spring leaf) or a buffer pad (such as a elastomeric rubber pad, etc.), and the elastic member 42 arranged on one side of the first rolling bearing 314 can be either a spring leaf or a buffer pad or a plurality of spring leaves or a plurality of buffer pads spliced together.

[0053] See also Figure 11 As shown, in other embodiments, the elastic member 42 may also be a tension spring, the two ends of which are respectively hooked on one end of the adjustment track 42 and the front bearing fixing shaft 313, and are extended or restored as the first bearing 314 slides on the adjustment track 41. Of course, it is also feasible to replace the tension spring with other tension belts, and the principle of providing elastic force is similar to that of the tension spring, which will not be repeated here.

[0054] The usage process of the present utility model is as follows: Taking the two crank assemblies in the vertical direction as the initial position, that is, the front split crank 312 and the rear split crank 322 of the two crank assemblies are respectively in the vertical direction. At this time, the two pedal assemblies 2 are respectively at the highest position and the lowest position, and the rolling bearing 314 is located at the middle position of the adjustment track 41, that is, the first compression spring 421 and the second compression spring 422 are subjected to the same or similar forces, and the two pedal assemblies 2 are respectively in the horizontal direction. When the user continuously steps on the pedals, under the inertial action of the high-speed rotation of the inertial resistance wheel 61 on the double-crank mechanism, the pedal assembly 2 at the highest position (defined as the first pedal assembly) moves forward and downward, and the pedal assembly 2 at the lowest position (defined as the second pedal assembly) synchronously moves backward and upward. At this time, most of the person's weight is on the second pedal assembly. The front end of the first pedal assembly tilts upward under the action of the elastic adjustment structure 4, and the first rolling bearing 314 at the first pedal assembly moves backward along the adjustment track 41, and the compression spring located behind the first rolling bearing 314 is compressed; the front end of the second pedal assembly tilts downward under the action of the elastic adjustment structure 4, and the first rolling bearing 314 at the second pedal assembly moves forward along the adjustment track 41, and the compression spring located in front of the first rolling bearing 314 is compressed. When the first pedal assembly moves to be close to horizontal with the front split crank 312, at this time, most of the person's weight and the downward pedaling force are instantaneously switched to the first pedal assembly, and a downward force will be applied to the first pedal assembly. The first pedal assembly moves downward and backward, and the front end of the first pedal assembly tilts downward under the action of the elastic adjustment structure 4. The first rolling bearing 314 at the first pedal assembly moves forward along the adjustment track 41, and the compression spring located in front of the first rolling bearing 314 is compressed; the second pedal assembly moves upward and forward, and the front end of the second pedal assembly tilts upward under the action of the elastic adjustment structure 4. At this time, the first rolling bearing 314 at the second pedal assembly moves backward along the adjustment track 41, and the compression spring located behind the first rolling bearing 314 is compressed. Until the first pedal assembly moves to the lowest position and returns to the horizontal direction again, and the second pedal assembly moves to the highest position and returns to the horizontal direction again, just completing a half-circle movement. Then the first pedal assembly repeats the movement trajectory of the second pedal assembly in the first half-circle, and the second pedal assembly repeats the movement trajectory of the first pedal assembly in the first half-circle until the movement trajectory of one circle is completed. The movement trajectories of the two pedal assemblies 2 form an ellipse, and this pedal-type fitness machine is also called an elliptical machine. During the movement process, the change in the tilt angle of the pedal just conforms to the angle change of the sole of a person's foot when walking, making it more stable and less likely to fall when standing on the machine platform, and also more comfortable.

[0055] The present utility model sets an elastic adjustment structure 4 between one of the crank assemblies 30 and the pedal assembly 2, and its advantages include:

[0056] 1. During the process of the user stepping on the pedal assembly 2 for exercise, since the user's feet simulate the gait of walking, the direction of the pressure exerted by the user on the two pedal assemblies 2 changes constantly. Along with this pressure change, the elastic adjustment structure 4 enables one of the crank assemblies 30 (the front crank assembly 31 in Embodiment 1) to translate relative to the pedal assembly 2. Firstly, it avoids the locking of the equipment during rotation, preventing the locking of the equipment caused by reasons such as welding deformation and machining errors of each assembled part, making the movement of the pedal assembly 2 smoother; secondly, it enables the front end of the pedal assembly 2 to switch between tilting upward and tilting downward, matching the user's walking gait (the walking gait includes the state of the toes facing upward, the toes facing downward, and the state between the toes facing upward and the toes facing downward).

[0057] 2. Without the elastic adjustment structure 4, the pedal assembly 2 cannot tilt upward or downward. At this time, when the user steps on the pedal assembly 2, the high-speed rotating inertial resistance wheel 61 generates a huge kinetic energy, which is transmitted to the rear crank assembly 32 through the belt 51 and the belt pulley 52. The rear crank assembly 32 is transmitted to the front crank assembly 31 through the pedal assembly 2. At the same time, under the action of the person's weight, the front crank assembly 31 will generate a downward force. To raise the person's center of gravity and rotate past, the resultant force received by the front crank assembly 31 must be upward. However, when the rear crank assembly 32 and the front crank assembly 31 both rotate to be parallel or nearly parallel to the horizontal direction, the rear crank assembly 32 transmits a force vertically or nearly vertically upward in the horizontal direction, and the front crank assembly 31 generates a downward force under the action of the person's weight. These two forces will generate a large mutual pulling force between the two crank assemblies, reducing the service life of the whole machine. The utility model forms that when the pedal assembly 2 is stepped on, under the action of gravity, the moving speeds of the two crank assemblies 30 are different through the elastic adjustment structure 4, so that a certain included angle will be formed between the two crank assemblies 30 (refer to Figure 12 as shown), so that the pulling force generated between the two crank assemblies 30 will be reduced, improving the service life.

[0058] 3. In the existing elliptical machine, the pedal assembly 2 and the transmission mechanism are in rigid contact. Therefore, when the user applies force to the pedal assembly 2, the reaction force exerted by the pedal assembly 2 on the user is also relatively large, that is, the exercise injury to the knee joint is relatively large; after installing the elastic adjustment structure 4, the acting force between the pedal assembly 2 and the double-crank transmission mechanism 3 is transmitted to the elastic adjustment structure 4 and absorbed by the elastic member, thereby reducing the reaction force transmitted from the pedal assembly 2 to the user and reducing the degree of knee joint injury.

[0059] 4. The two crankshaft assemblies of the utility model are connected by relying on the pedal assembly and the elastic adjustment structure 4, without other transmission structures. Therefore, the distance between the two pedal assemblies 2 can be reduced, the exercise comfort can be improved, the overall structure of the whole machine can be optimized, the size of the whole machine can be reduced, and the use space and cost of the user can be reduced.

[0060] Example 2

[0061] Referring to Figure 13 as shown, the difference between this example and Example 1 is that this example is provided with a handle assembly 7, and the handle assembly 7 is provided with two holding portions 70 for the user to hold by hand. The handle assembly 7 is arranged on the frame 1, so during use, the handle assembly 7 is not linked with the pedal assembly 2, and the movement is more stable.

[0062] The other parts not described in this example are the same as those in Example 1 and will not be elaborated here.

[0063] Although the present utility model has been specifically shown and described in conjunction with the preferred embodiments, those skilled in the art should understand that the other parts not described are the prior art, and various changes made to the present utility model in form and details without departing from the spirit and scope of the present utility model defined by the appended claims all fall within the protection scope of the present utility model.

Claims

1. A pedal-type fitness machine, comprising a frame and two pedal assemblies and a double-crank mechanism arranged on the frame. The double-crank mechanism includes two crank assemblies arranged at intervals. The ends of the two crank assemblies are respectively rotatably connected to the pedal assemblies. The pedal assemblies are used for a user to step on and move along a predetermined trajectory under the action of the user's stepping and the rotation of the crank assemblies. It is characterized in that: The pedal assembly is strip-shaped, and one of the crank assemblies is connected to the pedal assembly through an elastic adjustment structure. The elastic adjustment structure enables the crank assembly connected to the elastic adjustment structure and the pedal assembly to form an elastic connection with relative translation along the length direction of the pedal assembly.

2. The pedal type fitness machine according to claim 1, wherein: The elastic adjustment structure includes an adjustment track and an elastic member. The extending direction of the adjustment track is parallel to the length direction of the pedal assembly. The elastic member forms a connection relationship with the adjustment track that can elastically deform along the adjustment track. A first rolling bearing is provided at the end of the crank assembly connected to the elastic adjustment structure. The first rolling bearing and the elastic member are arranged in sequence along the adjustment track, and the adjustment track forms a relatively fixed connection relationship with the pedal assembly. The crank assembly connected to the elastic adjustment structure forms an elastic sliding connection with the adjustment track along the extending direction of the adjustment track under the elastic force of the first rolling bearing and the elastic member, thereby forming the elastic connection with the pedal assembly.

3. The pedal type fitness machine according to claim 2, characterized in that: A plurality of the elastic members are provided. Along the extending direction of the adjustment track, the plurality of elastic members are arranged on both sides of the first rolling bearing.

4. A pedal-type fitness machine according to claim 3, characterized in that: The elastic member is a compression spring, and there are two compression springs. The two compression springs are respectively arranged on both sides of the first rolling bearing along the extending direction of the adjustment track. A force transmission member is provided between the compression spring and the first rolling bearing. The force transmission member includes a force transmission portion. One side of the force transmission portion facing the compression spring is provided with an abutting plane. The compression spring indirectly abuts against the outer peripheral surface of the first rolling bearing by abutting against the abutting plane of the force transmission member, and the dimension of the abutting plane in the radial direction of the compression spring is larger than the outer diameter of the compression spring.

5. The pedal type fitness machine according to claim 4, wherein: One side of the force transmission portion facing the first rolling bearing is provided with a bearing abutting top surface. During the process of the first rolling bearing sliding along the adjustment track, the bearing abutting top surface of the force transmission portion always abuts against the outer peripheral surface of the first rolling bearing, and the abutting plane of the force transmission portion always abuts against the compression spring.

6. The pedal type fitness machine according to claim 4, characterized in that: The force transmission member further includes a guiding portion. The guiding portion is arranged on one side of the force transmission portion facing the compression spring, and the compression spring is sleeved outside the guiding portion.

7. A pedal type fitness machine according to claim 4, characterized in that: Define the end of the compression spring far from the force transmission member as the distal end of the compression spring. The outer diameter of the distal end of the compression spring is larger than the outer diameter of other parts of the compression spring, so that the outer side of the distal end of the compression spring abuts against the inner wall of the adjustment track to eliminate abnormal running noise.

8. The pedal type fitness machine according to claim 2, characterized in that: The elastic adjustment structure further includes limiting portions arranged at both ends of the adjustment track. The limiting portions are respectively arranged on both sides of the first rolling bearing, thereby forming a movement limit for the first rolling bearing along the length direction of the adjustment track.

9. A pedal type fitness machine according to claim 1, wherein: One of the crank assemblies is connected to a belt transmission mechanism, and the belt transmission mechanism is also drivingly connected to an inertial resistance wheel assembly. Thus, the inertial resistance wheel assembly provides movement inertia and resistance to the pedal assembly through the belt transmission mechanism.

10. A pedal type fitness machine according to claim 1, characterized in that: It further includes a handle assembly disposed on the frame, and the handle assembly is provided with two holding portions for the user to hold by hand; and / or, The frame includes a main frame and a base connected to the main frame. The two pedal assemblies are respectively disposed on both sides of the main frame. The arrangement direction of the two pedal assemblies is defined as the Y-axis direction, the arrangement direction of the main frame relative to the base is defined as the Z-axis direction, and the direction perpendicular to the Y-axis and the Z-axis is defined as the X-axis direction. The two crank assemblies are arranged on the main frame at intervals along the X-axis direction and penetrate through the main frame along the Y-axis direction. The two pedal assemblies are respectively rotatably connected to both ends of the crank assemblies in the Y-axis direction, so that the two pedal assemblies move synchronously along an elliptical trajectory.

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