Transmission belt tensioning device and mower

Abstract

The utility model discloses a transmission belt tensioning device and a mowing machine, and relates to the technical field of mowing machines, a first inhaul cable of a first-stage tensioning assembly is used for driving a first tensioning block to move so as to enable a tensioning installation frame to move, and first-stage adjustment of a pressing wheel assembly is achieved; a second inhaul cable of the second-stage tensioning assembly is connected to the height adjusting assembly, the tensioning state of the second inhaul cable is adjusted along with adjustment of the height adjusting assembly, and when the height adjusting assembly adjusts the height of the cutter head assembly, the second inhaul cable is driven by the height adjusting assembly to drive a second tensioning block to move so that a tensioning installation frame can move. Therefore, the tightness state of the transmission belt is changed, and secondary adjustment of the pressing wheel assembly is achieved. The height adjusting assembly can drive the second inhaul cable to adjust the pressing wheel assembly while adjusting the cutter head, self-adaptive second-stage tensioning adjustment is achieved on the basis of first-stage tensioning adjustment, the tensioning force of the belt is kept within a proper range when the height of the cutter head assembly is adjusted, and the problem that the belt is too tight or too loose is solved.

Description

Technical Field

[0001] This utility model relates to the field of lawnmower technology, and more specifically to a transmission belt tensioning device and a lawnmower. Background Technology

[0002] A lawnmower is a type of garden machinery. It is mainly used for garden trimming, lawn greening trimming, urban street trimming, greening scenic spots, field trimming, field weeding, especially for lawns and grasslands in parks, football fields and other grassy areas, private villa gardens, and vegetation maintenance in agricultural, forestry and livestock farms.

[0003] Lawn mowers use an engine or similar structure as a power source, and drive a blade disc to rotate and cut the grass using belt transmission. Lawn mowers are equipped with a height adjustment mechanism, allowing adjustment of the blade disc's height to change the cutting height.

[0004] The belt drive has two pulleys and a tensioner. At different cutting heights, the center distance between the pulleys changes, thus affecting the belt tension. When the cutter head descends to its lowest position, one pulley connected to the cutter head descends synchronously, while the other pulley remains stationary, and the belt tension reaches its maximum.

[0005] Currently, the traditional lawnmower blade clutch tensioning mechanism relies on a fixed lever mechanism for tensioning, and the position of the tensioning pulley can hardly be changed. When the two pulleys are at the same height and the belt tension is properly adjusted, the belt tension may be too high when the cutter head is at its lowest position, resulting in a significant reduction in belt life and excessive vibration of the entire vehicle.

[0006] For those skilled in the art, how to keep the belt tension within a suitable range is a technical problem that needs to be solved. Utility Model Content

[0007] The core of this utility model lies in providing a transmission belt tensioning device. A primary tensioning component is used to adjust the initial tension of the transmission belt, achieving a first-level adjustment. A secondary tensioning component is used to adaptively change the tension of the transmission belt as the height adjustment component rises and falls, achieving a second-level adjustment, thus maintaining the belt tension within a suitable range. The specific solution is as follows:

[0008] A transmission belt tensioning device includes a primary tensioning assembly, a secondary tensioning assembly, and a pressure roller assembly. The pressure roller assembly includes a tensioning guide rail, a tensioning mounting bracket, and a tensioning roller. The tensioning mounting bracket is linearly slidably mounted on the tensioning guide rail, and the tensioning roller is rotatably mounted on the tensioning mounting bracket around a rotating shaft. The tensioning roller is used to contact the transmission belt of the cutter head assembly.

[0009] The primary tensioning assembly includes a first cable and a first tensioning block, wherein the first cable is used to drive the first tensioning block to move, thereby moving the tensioning mounting frame;

[0010] The secondary tensioning assembly includes a second cable and a second tensioning block. The second cable is connected to the height adjustment assembly. When the height adjustment assembly adjusts the height of the cutter head assembly, the second cable is driven by the height adjustment assembly to drive the second tensioning block to move, thereby moving the tensioning mounting bracket to change the tension of the transmission belt.

[0011] Optionally, the pressure roller assembly is provided as a set, and the primary tensioning assembly and the secondary tensioning assembly apply force to the same tensioning mounting frame.

[0012] Optionally, when the cutter head assembly is in its lowest position, the drive belt maintains a suitable tension, and the cutter head assembly moves upward to relax the drive belt;

[0013] The direction of the force exerted by the second tensioning block on the tensioning mounting frame is the same as the direction of the force exerted by the first tensioning block on the tensioning mounting frame.

[0014] Optionally, when the cutter head assembly is in its highest position, the drive belt maintains a suitable tension, and the cutter head assembly moves downward to tension the drive belt;

[0015] The direction of the force exerted by the second tensioning block on the tensioning mounting frame is opposite to the direction of the force exerted by the first tensioning block on the tensioning mounting frame.

[0016] Optionally, the first tensioning block is rotatably mounted via a first hinge shaft, and the second tensioning block is rotatably mounted via a second hinge shaft.

[0017] Optionally, the tensioning mounting bracket is slidably mounted on the tensioning guide rail along a straight line.

[0018] Optionally, the tensioning mounting bracket is provided with a drive pin;

[0019] The first tension block is provided with a first slot, the length and width of which are both greater than twice the diameter of the drive pin;

[0020] The second tension block is provided with a second slot, the length of which is greater than twice the diameter of the drive pin, and the width of which is slightly greater than the diameter of the drive pin.

[0021] Optionally, the second cable is connected to a cable spring, which is used to apply a tension force to the second cable.

[0022] Optionally, the pressure roller assembly is provided in two sets, and the primary tensioning assembly and the secondary tensioning assembly apply force to different tensioning mounting frames respectively.

[0023] This utility model also provides a lawnmower, including the transmission belt tensioning device described in any of the above claims. Its height adjustment component includes a height adjustment toothed plate and a hanging shaft mechanism installed on the frame. The hanging shaft mechanism is driven to rotate by a height adjustment handle to adjust the height of the cutter head assembly. The height adjustment handle is used to engage with the stop teeth on the height adjustment toothed plate for limiting the position.

[0024] This invention provides a transmission belt tensioning device. The tensioning guide rail of the pressure roller assembly provides guidance, and the tensioning mounting frame drives the tensioning roller to move along the tensioning guide rail. The tensioning roller contacts the transmission belt of the cutter head assembly, adjusting the tension of the transmission belt. The first cable of the primary tensioning assembly drives the first tensioning block to move, causing the tensioning mounting frame to move, thus achieving primary adjustment of the pressure roller assembly. The second cable of the secondary tensioning assembly is connected to the height adjustment component, and its tension is adjusted according to the height adjustment component. When the height adjustment component adjusts the height of the cutter head assembly, the second cable is driven by the height adjustment component to drive the second tensioning block to move, causing the tensioning mounting frame to move, thereby changing the tension of the transmission belt, achieving secondary adjustment of the pressure roller assembly. When adjusting the height of the cutter head assembly, the height adjustment component also drives the second cable to adjust the pressure roller assembly, achieving adaptive secondary tension adjustment based on primary tension adjustment. This keeps the belt tension within a suitable range when adjusting the height of the cutter head assembly, avoiding the problem of the belt being too tight or too loose. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the overall structure of the transmission belt tensioning device of this utility model;

[0027] Figure 2 for Figure 1 A schematic diagram showing the removal of some structures from the basic design.

[0028] Figure 3 A schematic diagram of the structure of the primary tensioning assembly and the secondary tensioning assembly in conjunction with the adjusting pressure roller assembly;

[0029] Figure 4This is a schematic diagram showing that the direction of the force exerted by the second tensioning block on the tensioning mounting frame is the same as the direction of the force exerted by the first tensioning block on the tensioning mounting frame.

[0030] Figure 5 This is a schematic diagram showing that the direction of the force exerted by the second tensioning block on the tensioning mounting frame is opposite to the direction of the force exerted by the first tensioning block on the tensioning mounting frame.

[0031] The image includes:

[0032] Primary tensioning assembly 10; first cable 101; first tensioning block 102; first slot 1021; first tension return spring 1022; first hinge pin 103; clutch operating handle 104;

[0033] Secondary tensioning assembly 20; second cable 201; second tensioning block 202; second slot 2021; second hinge shaft 203; cable spring 204;

[0034] Pressure roller assembly 30; tension guide rail 301; tension mounting bracket 302; drive pin 3021; ​​tension roller 303;

[0035] Cutter head assembly 40; drive belt 401; driven pulley 402; drive pulley 403;

[0036] Height adjustment component 50; height adjustment gear plate 501; stop gear 5011; hanging shaft mechanism 502; height adjustment handle 503. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solution of this utility model, the transmission belt tensioning device of this utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] This utility model discloses a transmission belt tensioning device, applicable to machinery such as lawnmowers. The machinery includes a cutter head assembly 40, on which cutting blades are mounted. Driven by a height adjustment component 50, the cutter head assembly 40 can be raised and lowered to adjust its height, thereby changing the cutting height of the cutting blades. The cutting blades of the cutter head assembly 40 are driven to rotate by a driven pulley 402, which is rotatably mounted on the cutter head assembly 40. For example… Figure 1 , Figure 2 As shown, the driven pulley 402 is installed in the central area of ​​the cutter head assembly 40. When the cutter head assembly 40 rises and falls, it drives the driven pulley 402 to rise and fall synchronously.

[0039] A drive pulley 403 is rotatably mounted on the frame of a lawnmower or similar machine. The drive pulley 403 is connected to the output of a drive motor, and power is transmitted between the drive pulley 403 and the driven pulley 402 via a transmission belt 401. When the height of the cutter head assembly 40 is adjusted, the driven pulley 402 rises and falls synchronously with the cutter head assembly 40, while the height of the drive pulley 403 remains fixed. This creates a height difference between the drive pulley 403 and the driven pulley 402, thus affecting the tension of the transmission belt 401. When the heights of the drive pulley 403 and the driven pulley 402 are equal, the center distance between them is minimal; when there is a height difference between the drive pulley 403 and the driven pulley 402, the center distance between them increases.

[0040] Taking a specific scenario as an example: when the cutter head assembly 40 is at its highest position, the height of the driving pulley 403 is level with the height of the driven pulley 402; when the cutter head assembly 40 moves down to its lowest position, the height difference between the driving pulley 403 and the driven pulley 402 reaches its maximum. When the cutter head assembly 40 is at its highest position, the transmission belt 401 is adjusted to a suitable tension; a descent of the cutter head assembly 40 will cause excessive tension in the transmission belt 401. Conversely, when the cutter head assembly 40 is at its lowest position, the transmission belt 401 is adjusted to a suitable tension; an ascent of the cutter head assembly 40 will cause insufficient tension in the transmission belt 401.

[0041] The transmission belt tensioning device of this utility model achieves adaptive adjustment through the two-stage tensioning component 20. When the height of the cutter head assembly 40 is adjusted, the tension of the transmission belt 401 is changed synchronously to avoid the transmission belt 401 being too loose or too tight, so that the transmission belt 401 can always be kept at a suitable tension.

[0042] Combination Figure 1 , Figure 2 As shown, this utility model provides a transmission belt tensioning device, including a primary tensioning assembly 10, a secondary tensioning assembly 20, and a pressure roller assembly 30. The primary tensioning assembly 10 and the secondary tensioning assembly 20 can independently adjust the pressure roller assembly 30. The pressure roller assembly 30 is used to change the tension of the transmission belt 401, and can tension or loosen the transmission belt 401.

[0043] The pressure roller assembly 30 includes a tension guide rail 301, a tension mounting bracket 302, and a tension roller 303. The tension guide rail 301 is fixedly mounted on the cutter head assembly 40, meaning that the pressure roller assembly 30 as a whole will rise and fall with the cutter head assembly 40. Both ends of the tension guide rail 301 can be fixed to the cutter head assembly 40 by bolts or welding.

[0044] The tensioning mounting bracket 302 is linearly slidably mounted on the tensioning guide rail 301. The tensioning guide rail 301 plays a sliding guiding role for the tensioning mounting bracket 302, allowing the tensioning mounting bracket 302 to move in a straight line.

[0045] The tensioning wheel 303 is rotatably mounted on the tensioning mounting bracket 302 around a rotating shaft, and the tensioning wheel 303 can rotate relative to the tensioning mounting bracket 302. Figure 1 As shown, the tensioning pulley 303 has a vertical shaft, aligned with the lifting direction of the cutter head assembly 40. The tensioning pulley 303 contacts the drive belt 401 of the cutter head assembly 40, applying pressure to the drive belt 401. The tensioning mounting bracket 302 moves laterally, with a horizontal displacement perpendicular to the lifting direction of the cutter head assembly 40, but it is also allowed to move in an inclined direction. When the tensioning mounting bracket 302 drives the tensioning pulley 303 to translate, it can move closer to or further away from the drive belt 401, thereby tightening or loosening the drive belt 401.

[0046] The primary tensioning assembly 10 includes a first cable 101 and a first tensioning block 102. The first cable 101 drives the first tensioning block 102 to move, thereby moving the tensioning mounting bracket 302. The first cable 101 also serves as a transmission mechanism, connecting... Figure 1 As shown, one end of the first cable 101 is connected to the clutch operating handle 104, and the other end is connected to the first tension block 102. The clutch operating handle 104 is rotatably mounted on the frame and is used by the operator to manually operate it, thereby transmitting power through the first cable 101 to move the first tension block 102. The first tension block 102 then drives the tension mounting bracket 302 to move. The first tension block 102 can be rotatably mounted on the cutter head assembly 40 or slidably mounted on the cutter head assembly 40. Of course, the clutch operating handle 104 can also adopt a knob structure. A first tension return spring 1022 is provided between the first tension block 102 and the cutter head assembly 40. When the tension of the first cable 101 is released, the first tension return spring 1022 causes the first tension block 102 to automatically return to its original position.

[0047] The primary tensioning assembly 10 is used to adjust the pretension of the drive belt 401, ensuring that the drive belt 401 reaches a suitable tension when the cutter head assembly 40 is at a specific height position. For example, when the cutter head assembly 40 is at its highest or lowest position, operating the primary tensioning assembly 10 changes the position of the tensioning wheel 303 of the pressure wheel assembly 30, thereby achieving a suitable tension for the drive belt 401.

[0048] The secondary tensioning assembly 20 includes a second cable 201 and a second tensioning block 202. The second cable 201 serves a transmission function, adjusting the state of the second tensioning block 202. The second cable 201 is connected to the height adjustment assembly 50, meaning one end of the second cable 201 is connected to the height adjustment assembly 50 and the other end is connected to the second tensioning block 202. The height adjustment assembly 50 can change the height of the cutter head assembly 40 and maintain the adjusted height of the cutter head assembly 40. The specific structure of the height adjustment assembly 50 can refer to existing technology. Figure 1 Taking the structure shown as an example, the height adjustment assembly 50 includes a hanging shaft mechanism 502 rotatably mounted on the frame, and a height adjustment handle 503 mounted on the hanging shaft mechanism 502. The height adjustment handle 503 is used for hand gripping, thereby driving the hanging shaft mechanism 502 to rotate. The height adjustment gear plate 501 is provided with multiple stop teeth 5011, which can limit the height adjustment handle 503 to different stop positions.

[0049] When the height adjustment component 50 adjusts the height of the cutter head assembly 40, it pulls the second cable 201. The second cable 201 is driven by the height adjustment component 50 to move the second tension block 202, causing the tension mounting bracket 302 to move and change the tension of the transmission belt 401. A second tension return spring (not shown in the attached figure) can be provided between the second tension block 202 and the cutter head assembly 40. When the tension of the second cable 201 is released, the second tension return spring causes the second tension block 202 to automatically return to its original position.

[0050] The secondary tensioning component 20 is used to adaptively adjust the tension of the transmission belt 401 when the height position of the cutter head assembly 40 changes, so as to avoid the tension being too large or too small after the position of the cutter head assembly 40 changes.

[0051] The transmission belt tensioning device of this utility model adjusts the initial tension of the transmission belt 401 through the primary tensioning component 10. When adjusting the height of the cutter head assembly, the tension of the transmission belt 401 is automatically adjusted by the secondary tensioning component 20 without human intervention, always keeping the transmission belt 401 within a suitable tension range. Both the primary tensioning component 10 and the secondary tensioning component 20 can adjust the position of the tensioning wheel 303 of the pressure wheel assembly 30. While adjusting the cutter head assembly 40, the height adjustment component 50 also adjusts the position of the tensioning wheel 303 through the second cable 201. Based on the primary tension adjustment, adaptive secondary tension adjustment is achieved, keeping the belt tension within a suitable range when adjusting the height of the cutter head assembly, avoiding the problem of the belt being too tight or too loose.

[0052] In some specific embodiments, the transmission belt tensioning device of this utility model is equipped with a pressure roller assembly 30, and the primary tensioning assembly 10 and the secondary tensioning assembly 20 apply force to the same tensioning mounting frame 302. Combined with... Figure 1 , Figure 2 , Figure 3 As shown, the structures displayed all feature a single pressure roller assembly 30. The first tensioning block 102 of the primary tensioning assembly 10 and the second tensioning block 202 of the secondary tensioning assembly 20 both act on the same tensioning mounting frame 302. Using only one pressure roller assembly 30 simplifies the overall product structure.

[0053] Of course, this utility model does not exclude the possibility of setting two sets of pressure roller assemblies 30. In the case where the second tensioning block 202 further tensions the transmission belt 401 under the tensioning action of the first tensioning block 102, two sets of pressure roller assemblies 30 can also be set. The two sets of pressure roller assemblies 30 are respectively located at two opposite segments of the transmission belt 401, and are arranged in opposite directions. The second tensioning block 202 and the first tensioning block 102 each apply force to the tensioning mounting bracket 302 of one set of pressure roller assemblies 30. Alternatively, the two sets of pressure roller assemblies 30 can be arranged side-by-side in the same segment of the transmission belt 401, with the two sets of pressure roller assemblies 30 arranged side-by-side in the same direction.

[0054] Based on the above description, the adjustment of the secondary tensioning component 20 includes two scenarios:

[0055] 1) When the cutter head assembly 40 is in its lowest position, the drive belt 401 maintains appropriate tension. The cutter head assembly 40 moves upward to loosen the drive belt 401. (Combined) Figure 4 As shown, in this case, the direction of the force exerted by the second tensioning block 202 on the tensioning mounting bracket 302 is the same as the direction of the force exerted by the first tensioning block 102 on the tensioning mounting bracket 302. That is, under the tensioning action of the first tensioning block 102 on the transmission belt 401, the second tensioning block 202 further tensions the transmission belt 401.

[0056] The drive belt 401 is pre-tensioned when the cutter head assembly 40 is in its lowest position. When the cutter head assembly 40 rises, the drive belt 401 will loosen. At this time, the secondary tensioning assembly 20 should apply a further tensioning force to the drive belt 401, further tightening it. When the height adjustment assembly 50 drives the cutter head assembly 40 upward, it applies a tensioning force to the second cable 201. The second cable 201 then drives the second tensioning block 202 to move. The force exerted by the second tensioning block 202 on the tensioning mounting bracket 302 is in the same direction as the force exerted by the first tensioning block 102 on the tensioning mounting bracket 302. The force of the second tensioning block 202 is superimposed on the force of the first tensioning block 102, and the two forces together tension the drive belt 401.

[0057] The rise of the cutter head assembly 40 is positively correlated with the force exerted by the second tensioning block 202 on the tensioning mounting bracket 302. The higher the rise of the cutter head assembly 40, the greater the force exerted by the second tensioning block 202 on the tensioning mounting bracket 302, resulting in a greater superimposed tension force on the transmission belt 401. As the transmission belt 401 relaxes, the pushing force from the tensioning pulley 303 is greater, keeping the transmission belt 401 within a suitable tension range.

[0058] 2) When the cutter head assembly 40 is in its highest position, the drive belt 401 maintains a suitable tension. The cutter head assembly 40 moves downward to tension the drive belt 401. (Combined) Figure 5 As shown, the direction of the force exerted by the second tensioning block 202 on the tensioning mounting bracket 302 is opposite to the direction of the force exerted by the first tensioning block 102 on the tensioning mounting bracket 302. That is, under the tensioning action of the first tensioning block 102 on the transmission belt 401, the second tensioning block 202 relaxes the transmission belt 401.

[0059] The drive belt 401 is pre-tensioned when the cutter head assembly 40 is at its highest position. When the cutter head assembly 40 descends, the drive belt 401 will become tense. At this time, the secondary tensioning assembly 20 should loosen the drive belt 401 to reduce its tension. When the height adjustment assembly 50 drives the cutter head assembly 40 downward, it applies tension to the second cable 201. The second cable 201 then drives the second tensioning block 202 to move. The force exerted by the second tensioning block 202 on the tensioning mounting bracket 302 is opposite to the force exerted by the first tensioning block 102 on the tensioning mounting bracket 302. The second tensioning block 202 resists the tension of the first tensioning block 102, thus loosening the tension of the drive belt 401.

[0060] The descent of the cutter head assembly 40 is positively correlated with the force exerted by the second tensioning block 202 on the tensioning mounting bracket 302. The lower the cutter head assembly 40 descends, the greater the force exerted by the second tensioning block 202 on the tensioning mounting bracket 302, and the greater the reverse thrust of the second tensioning block 202 on the first tensioning block 102. As the cutter head assembly 40 descends, the transmission belt 401 is tensioned, and the thrust of the tensioning pulley 303 on the transmission belt 401 decreases, thereby keeping the transmission belt 401 within a suitable tension range.

[0061] Combining the two cases 1) and 2) above, the direction of the force exerted by the first tensioning block 102 on the tensioning mounting frame 302 is always consistent, while the direction of the force exerted by the second tensioning block 202 on the tensioning mounting frame 302 is different in both cases 1) and 2).

[0062] Combination Figure 1 , Figure 2 , Figure 3 As shown, the first tension block 102 is rotatably mounted on the cutter head assembly 40 via the first hinge shaft 103, and the second tension block 202 is rotatably mounted on the cutter head assembly 40 via the second hinge shaft 203. The first tension block 102 and the second tension block 202 act as levers. One end of the first tension block 102 is connected to the first cable 101, and the other end applies a force to the tension mounting frame 302. Both ends of the first tension block 102 rotate around the first hinge shaft 103. One end of the second tension block 202 is connected to the second cable 201, and the other end applies a force to the tension mounting frame 302. Both ends of the second tension block 202 rotate around the second hinge shaft 203.

[0063] It should be noted that the first tension block 102 and the second tension block 202 can be installed independently on the cutter head assembly 40. When only one set of pressure roller assembly 30 is provided, and the first tension block 102 and the second tension block 202 exert the same force on the tension mounting bracket 302, the second tension block 202 can be rotatably installed on the first tension block 102, that is, the second hinge shaft 203 is installed on the first tension block 102.

[0064] In some embodiments, the tension mounting bracket 302 is slidably mounted on the tension guide rail 301 along a straight line. However, it should not be excluded that the tension mounting bracket 302 may be slidably mounted on the tension guide rail 301 along a curve. These specific configurations should all be included within the protection scope of this utility model.

[0065] Combination Figure 3 As shown, in some embodiments, the tensioning mounting bracket 302 is provided with a drive pin 3021, which is fixed on the tensioning mounting bracket 302. The drive pin 3021 is a columnar or conical structure, and the length extension direction of the drive pin 3021 is perpendicular to the displacement direction of the tensioning mounting bracket 302.

[0066] The first tension block 102 has a first slot 1021, the length and width of which are both greater than twice the diameter of the drive pin 3021; ​​the second tension block 202 has a second slot 2021, the length of which is greater than twice the diameter of the drive pin 3021, and the width of which is slightly greater than the diameter of the drive pin 3021. Combined Figure 3 As shown, L1 represents the length of the first slot 1021, L2 represents the length of the second slot 2021, and W2 represents the width of the second slot 2021. The second tension block 202 is located above the first tension block 102, obscuring a portion of the first tension block 102. The lengths L1 and L2 of the first and second slots 1021 are approximately equal, while the width of the first slot 1021 is greater than the width W2 of the second slot 2021. The width W2 of the second slot 2021 is only slightly larger than the diameter of the drive pin 3021, allowing the drive pin 3021 to slide freely relative to the second slot 2021. When the first tension block 102 rotates, the drive pin 3021 can move relative to it along its length within the first slot 1021; when the second tension block 202 rotates, the drive pin 3021 can move relative to it along its length within the second slot 2021.

[0067] The width of the first slot 1021 is greater than twice the diameter of the drive pin 3021. When the second slot 2021 moves the drive pin 3021, it provides a range of motion for the drive pin 3021 in the width direction of the first slot 1021. Figure 4 For example, the first tension block 102 applies a downward force to the drive pin 3021, and the upper edge of the first slot 1021 contacts the drive pin 3021; ​​when the second tension block 202 further applies a downward force to the drive pin 3021, the drive pin 3021 contacts the upper edge of the second slot 2021, and the drive pin 3021 moves away from the upper edge of the first slot 1021 within the first slot 1021. The width of the first slot 1021 defines the movement limit range of the first tension block 102.

[0068] Combination Figure 1 , Figure 2 , Figure 3 As shown, the second cable 201 is connected to the cable spring 204, which in turn connects the second cable 201 and the lifting shaft mechanism 502. The cable spring 204 applies tension to the second cable 201. The cable spring 204 has a large elastic coefficient k. When the secondary tensioning assembly 20 normally adjusts the force of the transmission belt 401, the cable spring 204 is not stretched. When the rotational displacement of the second tensioning block 202 exceeds the required maximum displacement, the second tensioning block 202 is restricted to a set limit position. At this time, the cable spring 204 is stretched, protecting the second cable 201 from maximum stress and improving the comfort of the cutter head operation.

[0069] In some embodiments, the pressure roller assembly 30 is provided in two sets, with the primary tensioning assembly 10 and the secondary tensioning assembly 20 applying forces to different tensioning mounting brackets 302 respectively. This can be applied when both the primary tensioning assembly 10 and the secondary tensioning assembly 20 are used to tension the drive belt 401. Combined with... Figure 3 As shown, a pressure roller assembly 30 is provided only on one side of the drive belt 401, and a pressure roller assembly 30 can also be provided on the opposite side. One pressure roller assembly 30 is driven by the primary tensioning assembly 10, and the other pressure roller assembly 30 is driven by the secondary tensioning assembly 20.

[0070] This utility model also provides a lawnmower, including the aforementioned transmission belt tensioning device, wherein a height adjustment component 50 is provided. The height adjustment component 50 includes a height adjustment toothed plate 501 mounted on the frame and a hanging shaft mechanism 502. A height adjustment handle 503 is mounted on the hanging shaft mechanism 502, and the hanging shaft mechanism 502 can rotate relative to the frame. The hanging shaft mechanism 502 is driven to rotate by the height adjustment handle 503 to adjust the height of the cutter head assembly 40. That is, operating the height adjustment handle 503 will drive the hanging shaft mechanism 502 to rotate, thereby changing the height of the cutter head assembly 40. Figure 1 As shown, the height adjustment handle 503 is used to engage with the stop teeth 5011 on the height adjustment tooth plate 501 for positioning. A gap is provided between two adjacent stop teeth 5011, and the height adjustment handle 503 can be engaged into this gap to achieve positioning, keeping the blade assembly 40 at a specific height. This lawnmower can achieve the technical effects described above.

[0071] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A transmission belt tensioning device, characterized in that, It includes a primary tensioning assembly (10), a secondary tensioning assembly (20), and a pressure roller assembly (30). The pressure roller assembly (30) includes a tensioning guide rail (301), a tensioning mounting bracket (302), and a tensioning wheel (303). The tensioning mounting bracket (302) is linearly slidably mounted on the tensioning guide rail (301). The tensioning wheel (303) is rotatably mounted on the tensioning mounting bracket (302) around a rotating shaft. The tensioning wheel (303) is used to contact the drive belt (401) of the cutter head assembly (40). The primary tensioning assembly (10) includes a first cable (101) and a first tensioning block (102), wherein the first cable (101) is used to drive the first tensioning block (102) to move, thereby moving the tensioning mounting bracket (302); The secondary tensioning assembly (20) includes a second cable (201) and a second tensioning block (202). The second cable (201) is connected to the height adjustment assembly (50). When the height adjustment assembly (50) adjusts the height of the cutter head assembly (40), the second cable (201) is driven by the height adjustment assembly (50) to drive the second tensioning block (202) to move, thereby moving the tensioning mounting bracket (302) to change the tension of the transmission belt (401).

2. The transmission belt tensioning device according to claim 1, characterized in that, The pressure roller assembly (30) is provided in one set, and the primary tensioning assembly (10) and the secondary tensioning assembly (20) apply force to the same tensioning mounting frame (302).

3. The transmission belt tensioning device according to claim 2, characterized in that, When the cutter head assembly (40) is in its lowest position, the drive belt (401) maintains a suitable tension, and the cutter head assembly (40) moves upward to relax the drive belt (401). The direction of the force exerted by the second tensioning block (202) on the tensioning mounting frame (302) is the same as the direction of the force exerted by the first tensioning block (102) on the tensioning mounting frame (302).

4. The transmission belt tensioning device according to claim 2, characterized in that, When the cutter head assembly (40) is in its highest position, the drive belt (401) maintains a suitable tension, and the cutter head assembly (40) moves downward to tension the drive belt (401). The direction of the force exerted by the second tensioning block (202) on the tensioning mounting frame (302) is opposite to the direction of the force exerted by the first tensioning block (102) on the tensioning mounting frame (302).

5. The transmission belt tensioning device according to any one of claims 1 to 4, characterized in that, The first tension block (102) is rotatably mounted via the first hinge (103), and the second tension block (202) is rotatably mounted via the second hinge (203).

6. The transmission belt tensioning device according to claim 5, characterized in that, The tensioning mounting bracket (302) is slidably mounted on the tensioning guide rail (301) along a straight line.

7. The transmission belt tensioning device according to claim 5, characterized in that, The tensioning mounting bracket (302) is provided with a drive pin (3021); The first tension block (102) is provided with a first slot (1021), the length and width of the first slot (1021) are both greater than twice the diameter of the drive pin (3021); The second tension block (202) is provided with a second slot (2021), the length of which is greater than twice the diameter of the drive pin (3021), and the width is slightly greater than the diameter of the drive pin (3021).

8. The transmission belt tensioning device according to claim 7, characterized in that, The second cable (201) is connected to a cable spring (204), which is used to apply a tensioning force to the second cable (201).

9. The transmission belt tensioning device according to claim 1, characterized in that, The pressure roller assembly (30) is provided in two sets, and the primary tensioning assembly (10) and the secondary tensioning assembly (20) apply force to different tensioning mounting frames (302).

10. A lawnmower, characterized in that, The transmission belt tensioning device according to any one of claims 1 to 9 includes a height adjustment component (50) comprising a height adjustment toothed plate (501) mounted on the frame and a hanging shaft mechanism (502). The hanging shaft mechanism (502) is driven to rotate by a height adjustment handle (503) to adjust the height of the cutter head assembly (40). The height adjustment handle (503) is used to engage with a stop tooth (5011) on the height adjustment toothed plate (501) for limiting the movement.

Images