OHT trolley walking structure stable in turning

Abstract

The stable-turning OHT trolley walking structure comprises a trolley frame, walking wheels and a track, and a front rotating shaft and a rear rotating shaft are arranged at the two ends of the trolley frame respectively; the traveling wheels are respectively mounted at two ends of the front rotating shaft and the rear rotating shaft; auxiliary wheels coaxial with the walking wheels are arranged on the outer sides of the walking wheels, and the auxiliary wheels are fixedly connected with the walking wheels. The track can be matched with the walking wheel, and a cushion strip capable of being matched with the auxiliary wheel is arranged on a bent track of the track. The traveling wheels and the auxiliary wheels are matched with the filler strips on the bent rails, so that linear running and turning running of the OHT trolley are separated when the OHT trolley runs; when the OHT turns, the auxiliary wheel is in contact with the filler strip to be stressed, the OHT tilts towards one side, at the moment, the auxiliary wheel is in contact fit with the filler strip, the walking wheel is separated from the track, and the walking wheel turns by means of the auxiliary wheel on one side; the influence caused by the differential speed problem of the front and rear wheels can be greatly reduced through the turning mode; the gap between the auxiliary wheel and the filler strip can be adjusted by adjusting the number of the gaskets, and debugging is convenient.

Description

Technical Field

[0001] The present invention belongs to the technical field of logistics equipment, and in particular relates to a traveling structure of an OHT cart with stable cornering. Background Art

[0002] Overhead Hoist Transporters (OHTs) have been widely used in semiconductor manufacturing plants for transporting wafer boxes; in the field of semiconductor manufacturing, the process of transporting wafer boxes requires very high stability of the OHT operation.

[0003] As Figure 1 shown, the traveling wheels of the existing OHTs in the prior art are usually arranged in a layout of two wheels on the front axle + two wheels on the rear axle, and each of the front axle and the rear axle is driven by a motor; there are various types of traveling tracks for OHTs, but generally they are divided into two categories: straight tracks and curved tracks; when the OHT travels on a straight track, the rotational speeds of the motors on the front and rear axles are the same, the rotational speeds of the front axle and the rear axle are the same, and the front and rear axles are in a synchronous state; when the OHT starts to enter a curved track, there is a state where the front axle has entered the curved track and the rear axle is still on the straight track. At this time, with the same rotational speeds of the motors on the front and rear axles, the rotational speeds of the front and rear wheels are also the same, and the linear speeds of the front and rear wheels are the same. However, since the front wheels rotate on the curved track and the rear wheels rotate on the straight track, there will always be a situation where the front and rear wheels drag each other, which will cause problems such as vehicle body jitter, decreased positioning accuracy, and abnormal noise in the transmission system. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a traveling structure of an OHT cart with stable cornering to solve the above-mentioned technical problems existing in the prior art.

[0005] The technical solution adopted by the present invention to solve the above technical problems is as follows: A traveling structure of an OHT cart with stable cornering, comprising: A vehicle frame, with a front rotating shaft and a rear rotating shaft respectively arranged at both ends of the vehicle frame; Traveling wheels, which are respectively installed at both ends of the front rotating shaft and the rear rotating shaft; an auxiliary wheel coaxial with the traveling wheel is arranged on the outer side of the traveling wheel, and the auxiliary wheel is fixedly connected to the traveling wheel; A track, which can cooperate with the traveling wheels, and a cushion strip capable of cooperating with the auxiliary wheels is arranged on the curved track of the track.

[0006] Further, the diameter of the auxiliary wheel is 0.6 - 0.8 times the diameter of the traveling wheel.

[0007] Further, connecting pieces are respectively arranged at both ends of the cushion strip, the connecting pieces are connected to the track by connecting members, and a transition surface is arranged between the connecting piece and the upper surface of the cushion strip.

[0008] Further, a gasket is arranged between the cushion strip and the curved track.

[0009] Further, hinge shafts are respectively arranged in the middle parts of the front rotating shaft and the rear rotating shaft, and the front rotating shaft and the rear rotating shaft are respectively installed on both sides of the vehicle frame by means of the hinge shafts.

[0010] Compared with the prior art, the present invention has the following advantages: In the present invention, the traveling wheels and the auxiliary wheels of the large and small wheel structure, together with the cushion strips on the curved rails, enable the separation of the straight running and the turning running of the OHT cart during operation. When the OHT turns, the auxiliary wheels contact and receive force from the cushion strips, causing the OHT to tilt to one side. At this time, the auxiliary wheels contact and cooperate with the cushion strips, and the traveling wheels are separated from contact with the track, and the OHT turns by relying on the auxiliary wheels on one side; through this turning method, the influence caused by the differential problem between the front and rear wheels can be greatly reduced; the gap between the auxiliary wheels and the cushion strips can be adjusted by adjusting the number of shims, which is convenient for debugging; the structure of the present invention is simple, has strong practicability, is reasonably designed, is small in size, has a high degree of standardization, is easy to disassemble and repair, and ensures the stability of the device. Description of the Drawings

[0011] Figure 1 is a layout diagram of the conventional OHT wheels in the prior art; Figure 2 is a schematic diagram of the overall structure of the present invention; Figure 3 is a schematic diagram of the track part structure of the present invention; Figure 4 is a schematic diagram of the front rotating shaft part structure of the present invention.

[0012] In the figure: 1, vehicle frame; 2, front rotating shaft; 3, rear rotating shaft; 4, traveling wheel; 5, auxiliary wheel; 6, track; 7, curved rail; 8, connecting piece; 9, connecting member; 10, shim; 11, hinge shaft; 12, cushion strip; 13, transition surface. Detailed Embodiment

[0013] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings.

[0014] This embodiment provides a traveling structure of an OHT cart with stable turning, which includes a vehicle frame 1, traveling wheels 4 and a track 6. The vehicle frame 1 provides an installation space for each component of the OHT cart, and the track 6 is installed in the factory. The vehicle frame 1 can move on the track 6 through the cooperation of the traveling wheels 4 and the track 6; As Figures 2 - 4 shown, front rotating shafts 2 and rear rotating shafts 3 are respectively arranged at both ends of the vehicle frame 1; The traveling wheels 4 are respectively installed at both ends of the front rotating shaft 2 and the rear rotating shaft 3; an auxiliary wheel 5 coaxial with the traveling wheel 4 is arranged outside the traveling wheel 4, and the auxiliary wheel 5 is fixedly connected to the traveling wheel 4; The track 6 can cooperate with the traveling wheels 4, and a cushion strip 12 that can cooperate with the auxiliary wheels 5 is provided on the curved track 7 of the track 6; When the OHT cart travels straight, it moves by relying on the cooperation between the traveling wheels 4 and the track 6. The speeds of the front rotating shaft 2 and the rear rotating shaft 3 are kept consistent, and there is no contact between the auxiliary wheels 5 and the track 6. When turning, the auxiliary wheels 5 contact the cushion strip 12 on the curved track 7 to produce cooperation. At this time, the traveling wheels 4 are disengaged from the track 6, and the cart turns by relying on the auxiliary wheels 5 on one side.

[0015] Furthermore, the diameter of the auxiliary wheels 5 is 0.6 - 0.8 times the diameter of the traveling wheels 4. The diameter of the auxiliary wheels 5 is smaller than that of the traveling wheels 4 to avoid the auxiliary wheels 5 affecting the cooperation between the traveling wheels 4 and the track 6 during straight-line travel.

[0016] Furthermore, connecting pieces 8 are respectively arranged at both ends of the cushion strip 12. The connecting pieces 8 are connected to the track 6 by connecting members 9, and a transition surface 13 is arranged between the upper surface of the connecting pieces 8 and the cushion strip 12.

[0017] Furthermore, a gasket 10 is arranged between the cushion strip 12 and the curved track 7, and the gap between the auxiliary wheels 5 and the cushion strip 12 can be adjusted by adjusting the number of gaskets 10.

[0018] Furthermore, hinge shafts 11 are respectively arranged in the middle parts of the front rotating shaft 2 and the rear rotating shaft 3. The front rotating shaft 2 and the rear rotating shaft 3 are respectively installed at both ends of the vehicle frame 1 by means of the hinge shafts 11.

[0019] Working principle: In the present invention, the OHT cart's straight-line travel and turning motions are separated by the auxiliary wheels 5 and the traveling wheels 4 with different diameters. The cooperation between the auxiliary wheels 5 and the cushion strip 12 is used for turning to avoid the influence of the differential problem on the OHT's turning. Specifically: When the OHT cart travels straight, it moves by relying on the cooperation between the traveling wheels 4 and the track 6. The speeds of the front rotating shaft 2 and the rear rotating shaft 3 are kept consistent, and there is no contact between the auxiliary wheels 5 and the track 6. When turning, the auxiliary wheels 5 contact the cushion strip 12 on the curved track 7 to produce cooperation, and the auxiliary wheels 5 are stressed. At this time, the traveling wheels 4 are disengaged from the track 6, and the cart turns by relying on the auxiliary wheels 5 on one side. The gap between the auxiliary wheels 5 and the cushion strip 12 can be adjusted by adjusting the number of gaskets 10. The turning method of the present invention can greatly reduce the influence caused by the differential problem between the front and rear wheels and improve the running stability of the OHT.

[0020] It can be understood that the above embodiments are only exemplary embodiments adopted to illustrate the principle of the present invention, and the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

1. An OHT trolley running structure with stable cornering, characterized in that, Comprising: A frame (1), with a front rotating shaft (2) and a rear rotating shaft (3) respectively arranged at both ends of the frame (1); Traveling wheels (4), which are respectively installed at both ends of the front rotating shaft (2) and the rear rotating shaft (3); an auxiliary wheel (5) coaxial with the traveling wheel (4) is arranged on the outer side of the traveling wheel (4), and the auxiliary wheel (5) is fixedly connected to the traveling wheel (4); A track (6), which can cooperate with the traveling wheel (4), and a cushion strip (12) capable of cooperating with the auxiliary wheel (5) is arranged on the curved track (7) of the track (6).

2. The traveling structure of the OHT cart according to claim 1, wherein The diameter of the auxiliary wheel (5) is 0.6 - 0.8 times the diameter of the traveling wheel (4).

3. The traveling structure of the OHT cart according to claim 1, wherein Connection pieces (8) are respectively arranged at both ends of the cushion strip (12), the connection pieces (8) are connected to the track (6) by connecting members (9), and a transition surface (13) is arranged between the upper surface of the connection piece (8) and the cushion strip (12).

4. The traveling structure of the OHT cart according to claim 1, characterized in that A gasket (10) is arranged between the cushion strip (12) and the curved track (7).

5. The traveling structure of the OHT cart according to claim 1, characterized in that, Hinge shafts (11) are respectively arranged in the middle of the front rotating shaft (2) and the rear rotating shaft (3), and the front rotating shaft (2) and the rear rotating shaft (3) are respectively installed at both ends of the frame (1) by means of the hinge shafts (11).

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