Roller screw

Abstract

The utility model discloses a roller screw which comprises a screw body extending in the axial direction, screw teeth with the same screw pitch are arranged on a spiral disc on the screw body, a spiral raceway is formed between the screw teeth, a roller with the outer wall face attached to the inner wall face of the raceway is connected to the screw teeth in a rotating mode, and the roller can roll relative to the raceway. And the tangent plane of the thread is matched with the tangent plane of the roller path. According to the screw, original sliding friction formed when the screw makes contact with a nut is converted into rolling friction, friction force is reduced, meanwhile, mechanism transmission is more stable, the application field is wide, good economic benefits are achieved, the overall function is complete, and practicability is high.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical transmission, and more specifically, to a roller screw. Background Art

[0002] There are two commonly used linear transmission methods in the world: mechanical transmission or linear motor direct transmission. Mechanical transmission includes screw nut transmission, ball screw transmission, gear rack transmission, worm gear transmission, screw nut transmission. These transmission methods have their own advantages and disadvantages as follows:

[0003] Screw nuts and screw nut strips are mainly used in large transmission equipment. They have the advantages of large torque transmission and easy installation. The disadvantages are large friction coefficient, slow rotation speed, and slow movement speed. There is reverse clearance, it cannot be accurately positioned, and it will move during processing, so a locking mechanism is required. Now that global equipment has entered the era of digital control, this transmission method has been gradually eliminated.

[0004] Ball screws and gear racks are the main mechanical transmission methods for current digital equipment. Ball screws can achieve zero gap after being pre-loaded with steel balls. Because of rolling friction, they have the advantages of low friction coefficient, fast transmission speed, high precision, and high efficiency. They are adopted by most equipment. However, since the ball screw is a cylindrical ball circulation structure, the two ends of the screw are fixed and the nut moves in the middle. When the transmission distance is too long, the screw will bend due to its own weight, resulting in poor accuracy. Various screw supports have also appeared on the market, or the screw is fixed and the nut is rotated to reduce the distortion of the screw. However, when the aspect ratio of the transmission exceeds 10 times, the effect of these support methods is still not ideal, because the screw with a larger aspect ratio is greatly affected by temperature changes. Also, when the moving distance is more than 12 meters, it is difficult for the ball screw to ensure the moving positioning accuracy. At this time, most equipment uses gear racks as the transmission method. Because most racks are one for every 1 meter, they can be infinitely long in theory. However, the gear racks are intermittent line transmissions, and the circumferential length is converted into a straight line length, which has a large inherent error. In addition, since the gear transmission must have a tooth gap, the transmission error is increased. Therefore, a complex clearance elimination structure is required for gear rack transmission, which makes installation difficult. When the gear rack is driven, because the gear rotates in a circle, at most 3 tooth profiles can be stressed at the same time, and the stress is uneven and small. The gear rotates one circle, the moving distance is too large, and a large-scale reduction mechanism needs to be installed. Therefore, the installation method of the gear rack is limited, and the installation cost is too high. It is only forced to be used when the ball screw cannot meet the requirements. Accordingly, the utility model proposes a roller screw. Utility Model Content

[0005] The purpose of the utility model is to overcome the deficiencies in the prior art and provide a roller screw.

[0006] In order to solve the above technical problems, the purpose of the utility model is achieved as follows: the utility model involves a roller screw, including a screw body extending in the axial direction, a spiral disk on the screw body is provided with screw teeth with equal pitches, and a spiral raceway is formed between the screw teeth. A roller with an outer wall surface attached to the inner wall surface of the raceway is rotatably connected to the screw teeth, and the roller can roll relative to the raceway.

[0007] The utility model is further configured such that: the cut surface of the screw thread matches the cut surface of the raceway.

[0008] The utility model is further configured as follows: the section of the screw thread is in an isosceles trapezoidal shape, and the roller is in a truncated cone shape.

[0009] The utility model is further configured that: the spacing between two adjacent rollers is equal.

[0010] To sum up, the utility model has the following beneficial effects: the roller screw involved in the utility model converts the sliding friction originally formed by the contact with the nut into rolling friction, thereby reducing the friction force and making the transmission of the mechanism smoother. It has a wide range of applications, good economic benefits, complete overall functions and strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0012] Figure 2 It is a structural schematic diagram of the utility model from another viewing angle. DETAILED DESCRIPTION

[0013] In order to enable those skilled in the art to better understand the technical solution of the utility model, the preferred implementation scheme of the utility model is described below in conjunction with specific embodiments, but it should be understood that these descriptions are only for further illustrating the features and advantages of the utility model, rather than limiting the patent requirements of the utility model. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the utility model.

[0014] The utility model is further described below in conjunction with the accompanying drawings and preferred embodiments.

[0015] Example 1

[0016] See also Figure 1 and Figure 2As shown, a roller screw involved in this embodiment includes a screw body 1 extending in the axial direction, a spiral disk on the screw body 1 is provided with screw teeth 2 with equal pitches, and a spiral raceway 3 is formed between the screw teeth 2. A roller 4 with an outer wall surface attached to the inner wall surface of the raceway 3 is rotatably connected to the screw teeth 2, and the roller 4 can roll relative to the raceway 3.

[0017] Furthermore, the cross section of the screw thread 2 matches the cross section of the raceway 3 .

[0018] Furthermore, the cross section of the screw thread 2 is an isosceles trapezoid, and the roller 4 is a truncated cone.

[0019] Furthermore, the distance between two adjacent rollers 4 is equal.

[0020] The roller screw involved in the utility model converts the sliding friction originally formed by contact with the nut into rolling friction, thereby reducing the friction force and making the transmission of the mechanism more stable. It has a wide range of applications, good economic benefits, perfect overall functions and strong practicality.

[0021] Unless otherwise specified, in the present invention, the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicating orientation or positional relationship are based on the orientation or positional relationship actually shown, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the orientation or positional relationship in the present invention are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood in combination with the embodiments and according to specific circumstances.

[0022] Unless otherwise clearly specified and limited, in the present invention, the terms "disposed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] The preferred specific embodiments of the utility model are described in detail above. It should be understood that ordinary technicians in this field can make many modifications and changes based on the concept of the utility model without creative work. Therefore, all technical solutions that can be obtained by technicians in this technical field based on the concept of the utility model through logical analysis, reasoning or limited experiments on the basis of the existing technology should be within the scope of protection determined by the claims.

Claims

1. A roller screw, comprising a screw body extending in the axial direction, a spiral disk on the screw body having screw teeth with equal pitches, and a spiral raceway formed between the screw teeth, characterized in that: The screw thread is rotatably connected to a roller whose outer wall surface is attached to the inner wall surface of the raceway, and the roller can roll relative to the raceway.

2. The roller screw according to claim 1, characterized in that: The cut surface of the thread tooth matches the cut surface of the raceway.

3. The roller screw according to claim 2, characterized in that: The cross section of the screw thread is in the shape of an isosceles trapezoid, and the roller is in the shape of a truncated cone.

4. The roller screw according to claim 3, characterized in that: The distances between two adjacent rollers are equal.

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