Pallet fork cooperatively driven by gear and rack

Abstract

The utility model provides a pallet fork cooperatively driven by a gear and a rack, which comprises a lower fork, a middle fork and an upper fork which are sequentially arranged in a butt joint mode, a gear assembly is installed on the lower fork and the middle fork in a combined mode, a rack assembly is installed on the lower fork, the middle fork and the upper fork in a combined mode, and the gear assembly is meshed with the rack assembly. When the gear assembly is driven to rotate, the rack assembly drives the middle fork and the upper fork to move relative to the lower fork. The pallet fork cooperatively driven by the gear and the rack is higher in transmission efficiency and positioning accuracy, higher in bearing capacity and stability, compact in structure, high in adaptability, high in adaptability to the working environment, high in reliability, easy and rapid to maintain and higher in bidirectional movement speed and flexibility.

Description

Technical Field

[0001] This utility model relates to the technical field of logistics and warehousing equipment, and more precisely to a rack and pinion driven fork. Background Technology

[0002] With the continuous development of the logistics industry and logistics technology, the frequency of cargo turnover and the volume and weight of cargo are constantly increasing. The requirements for forklifts and other transfer mechanisms are also getting higher and higher, requiring forks to have higher strength, greater load capacity and high-intensity reciprocating motion.

[0003] The transmission structure of forks is crucial to their performance. Common transmission structures for existing forks are single-gear and chain drives. This structure concentrates the load on a localized area of ​​the gear teeth, leading to uneven wear over time and shortening service life. The single-gear design lacks lateral restraint, making the forks prone to lateral shift under heavy or uneven loads, requiring additional guiding mechanisms (such as roller guides) for compensation, increasing structural complexity. Some existing forks also use chain and belt drives. In this structure, the chain or belt is prone to elastic elongation under heavy loads, causing transmission lag; the belt may also slip due to insufficient friction. Chains require regular lubrication, and belts need to be protected against oil and aging, resulting in high maintenance costs and a high risk of breakage due to wear. They cannot withstand instantaneous impact loads (such as sudden fork stops), easily causing vibration or shaking, affecting cargo stability. In addition, some existing forks use hydraulic systems as their transmission structure. However, the energy conversion efficiency of hydraulic systems is only 60%-70%, and they require continuous power supply to maintain pressure. Their energy consumption is much higher than that of mechanical transmission. Aging of seals or damage to oil circuits can lead to hydraulic oil leakage, polluting the environment and requiring downtime for maintenance. The viscosity of hydraulic oil is greatly affected by temperature, making it difficult to start at low temperatures and prone to overheating at high temperatures, which limits its application in extreme environments.

[0004] In summary, existing forks generally cannot meet the requirements of high efficiency and high intensity of use with a relatively simple structure. There is a need in this field for a fork with a simpler structure that can meet performance requirements. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a rack and pinion driven fork, which achieves transmission through the cooperation of the gear assembly and the rack assembly, thereby improving the performance of the fork with a relatively simple structure.

[0006] To achieve the above objectives, this utility model provides a rack and pinion driven fork, comprising a lower fork, a middle fork, and an upper fork sequentially connected together. A gear assembly is mounted on the lower fork and the middle fork, and a rack assembly is mounted on the lower fork, the middle fork, and the upper fork. The gear assembly meshes with the rack assembly. When the gear assembly is driven to rotate, it drives the middle fork and the upper fork to move relative to the lower fork through the rack assembly.

[0007] Preferably, the gear assembly includes a first gear set mounted in conjunction with the lower fork and a second gear set mounted in conjunction with the middle fork, and the rack assembly includes a lower rack mounted on the lower fork, a middle rack mounted on the middle fork and an upper rack mounted on the upper fork, wherein the first gear set meshes with the middle rack and the second gear set meshes with both the lower rack and the upper rack.

[0008] Preferably, the moving distance of the upper fork is twice the moving distance of the middle fork.

[0009] Preferably, the lower fork is composed of a first lower fork side plate and a second lower fork side plate on both sides, the first gear set is installed between the first lower fork side plate and the second lower fork side plate, and the lower rack is fixedly connected to the first lower fork side plate or the second lower fork side plate.

[0010] Preferably, the middle part of the fork has a slot, and the top of the second gear set extends out of the top of the fork through the slot and meshes with the upper rack.

[0011] Preferably, both the first gear set and the second gear set are composed of several large gears and small gears arranged alternately, wherein the large gears mesh with the rack assembly, and the small gears do not mesh with the rack assembly.

[0012] Preferably, the gear assembly is driven by a servo motor or an encoder.

[0013] Compared with the prior art, the advantages of the rack and pinion driven fork disclosed in this utility model are: the rack and pinion driven fork has higher transmission efficiency and positioning accuracy, stronger load-bearing capacity and stability, more compact structure and stronger adaptability, stronger applicability to working environment, higher reliability and simple and quick maintenance, and higher speed and flexibility in bidirectional movement. Attached Figure Description

[0014] 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.

[0015] like Figure 1 The diagram shown is a structural schematic of a rack and pinion driven fork according to this application.

[0016] like Figure 2 The figure shown is a side cross-sectional view of a rack and pinion driven fork according to this application.

[0017] like Figure 3 The figure shown is a cross-sectional view of a rack and pinion driven fork according to this application. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] like Figures 1 to 3 As shown, this application discloses a rack and pinion driven fork comprising a lower fork 11, a middle fork 12, and an upper fork 13 sequentially connected together. Gear assemblies are mounted on the lower fork 11 and the middle fork 12, and rack assemblies are mounted on the lower fork 11, the middle fork 12, and the upper fork 13. The gear assemblies mesh with the rack assemblies. When the gear assemblies are driven to rotate, the rack assemblies drive the middle fork 12 and the upper fork 13 to move relative to the lower fork 11, thereby realizing the extension and retraction of the forks.

[0020] The gear and rack assembly meshing transmission method provides linear motion with power transmission without intermediate links, achieving a transmission efficiency of over 90% and low energy loss. Preferably, the gear assembly is driven by a servo motor or encoder. Due to the fixed rack pitch, ultra-high repeatability positioning accuracy can be achieved. The rigid contact between the gear and rack assemblies, compared to flexible transmission methods such as belts and chains, can withstand high loads and impacts, and the meshing transmission is slip-free, making it suitable for applications requiring high synchronization. The gear and rack co-drive fork structure is compact and highly adaptable. The linear rack can be directly integrated into the equipment guide rail or base, eliminating the need for additional transmission components and saving installation space. By splicing multiple rack segments, infinitely long linear motion can be achieved. The gear and rack co-drive fork has high reliability and simple maintenance. Both the gear and rack assemblies are made of high-strength alloy steel (such as 45 steel, 20CrMnTi, etc.) and are hardened, resulting in high wear resistance and a lifespan of tens of thousands of hours. Lubrication requirements are low (simply apply grease periodically), and there are fewer potential failure points, making maintenance costs lower than hydraulic or pneumatic systems. The rack and pinion driven forks offer bidirectional movement and speed flexibility. By changing the rotation direction of the gears, the rack can achieve bidirectional linear movement (such as fork extension and retraction, stacker crane lifting). When paired with a variable frequency motor, the rack can adapt to various needs ranging from low-speed heavy loads (0.1 m / s) to high-speed light loads (10 m / s). The rack and pinion driven forks are highly adaptable to different environments; the rack and pinion drive is less sensitive to changes in temperature, humidity, dust, and other environmental factors, making it suitable for outdoor high-temperature and high-humidity environments (such as port cranes and mining equipment).

[0021] Specifically, the gear assembly includes a first gear set 21 mounted to the lower fork 11 and a second gear set 22 mounted to the middle fork 12. The rack assembly includes a lower rack 31 mounted on the lower fork 11, a middle rack 32 mounted on the middle fork 12, and an upper rack 33 mounted on the upper fork 13. The first gear set 21 meshes with the middle rack 32, and the second gear set 22 meshes with both the lower rack 31 and the upper rack 33. When the first gear set 21 is driven to rotate, it drives the middle fork 12 and the upper fork 13 to move via the middle rack 32, and simultaneously drives the second gear set 22 to move. The second gear set 22 is driven to rotate by the lower rack 33, and the second gear set 22 drives the upper fork 13 to move relative to the middle fork 12 via the upper rack 33. The moving distance of the upper fork 13 is twice the moving distance of the middle fork 12.

[0022] The lower fork 11 is composed of a first side plate 111 and a second side plate 112 on both sides. A first gear set 21 is installed between the first side plate 111 and the second side plate 112. The lower rack 31 is fixedly connected to the first side plate 111 or the second side plate 112.

[0023] The middle fork 12 has a slot in the middle, and the top of the second gear set 22 extends out of the top of the middle fork 12 through the slot and meshes with the upper rack 33.

[0024] Preferably, both the first gear set 21 and the second gear set 22 are composed of several large and small gears arranged alternately. The large gears mesh with the rack assembly, and the small gears realize the transmission between the large gears. The small gears do not mesh with the rack assembly. This structure can ensure the normal operation of the motion, and each gear set and rack form a closed chain, forming a closed meshing trajectory, avoiding situations where the gears cannot be locked or cannot be installed due to improper meshing spacing design.

[0025] 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 rack and pinion driven fork, characterized in that, The device includes a lower fork, a middle fork, and an upper fork that are sequentially connected. Gear assemblies are mounted on the lower fork and the middle fork. Rack assemblies are mounted on the lower fork, the middle fork, and the upper fork. The gear assemblies mesh with the rack assemblies. When the gear assemblies are driven to rotate, the rack assemblies drive the middle fork and the upper fork to move relative to the lower fork.

2. The rack and pinion driven fork as described in claim 1, characterized in that, The gear assembly includes a first gear set mounted in conjunction with the lower fork and a second gear set mounted in conjunction with the middle fork. The rack assembly includes a lower rack mounted on the lower fork, a middle rack mounted on the middle fork, and an upper rack mounted on the upper fork. The first gear set meshes with the middle rack, and the second gear set meshes with both the lower rack and the upper rack.

3. The rack and pinion driven fork as described in claim 2, characterized in that, The upper fork moves a distance twice that of the middle fork.

4. The rack and pinion driven fork as described in claim 2, characterized in that, The lower fork is composed of a first side plate and a second side plate on both sides. The first gear set is installed between the first side plate and the second side plate. The lower rack is fixedly connected to the first side plate or the second side plate.

5. The rack and pinion driven fork as described in claim 2, characterized in that, The middle part of the fork has a slot, and the top of the second gear set extends out of the top of the middle fork through the slot and meshes with the upper rack.

6. The rack and pinion driven fork as described in claim 2, characterized in that, Both the first gear set and the second gear set are composed of several large gears and small gears arranged alternately. The large gears mesh with the rack assembly, while the small gears do not mesh with the rack assembly.

7. The rack and pinion driven fork as described in claim 1, characterized in that, The gear assembly is driven by a servo motor or an encoder.

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