Novel fixed shaft type linear motor

Abstract

The utility model discloses a novel fixed shaft type linear motor, which is characterized in that a rotor assembly is matched with a stator assembly, a front bearing is sleeved at one end of the rotor assembly and is fixed with the rotor assembly, a rear bearing is sleeved at the other end of the rotor assembly and is fixed with the rotor assembly, a front end cover is matched with the front bearing, and a rear end cover is matched with the rear bearing. The nut is located in the rotor assembly and fixed to the rotor assembly, the screw penetrates through the nut and is in threaded connection with the nut, one end of the shaft is fixed to the screw, a groove is formed in the circumferential face of the shaft, the outer barrel surrounds the shaft, the outer barrel is fixed to the front end cover, the inner barrel is located in the outer barrel and fixed to the outer barrel, and the inner barrel is provided with a ball. An assembling groove is formed in the inner wall face of the inner cylinder body, the balls are matched with the assembling groove, and the balls are further matched with a groove in the shaft. According to the utility model, the friction force between the projecting shaft and the guide component can be reduced.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, specifically to a novel fixed-axis linear motor. Background Technology

[0002] Linear motion mechanisms, as the basic unit of linear motion control, are widely used in various fields of industrial production. With industrial development and technological progress, their application environments have become more diversified.

[0003] Fixed-axis linear motors typically refer to through-axis linear motors. A through-axis linear motor is a type of motor in which a nut is built into the motor body, and a lead screw can pass through the motor to achieve linear motion. This design requires the lead screw to have its rotation restricted to produce linear motion. Through-axis motors generally have a stroke between 30-200mm, and their advantage lies in allowing for greater installation coaxiality errors and tolerating larger system errors.

[0004] Traditional fixed-axis linear motors utilize a screw spline assembly passing through a rotary motor, such as Figure 4 As shown, a guide device 1 with an extended shaft is installed on the front cover of the motor. The guide device 1 is made of aluminum alloy. An injection-molded spline groove 2 is formed on the inner wall of the left end through an injection molding process. The injection-molded spline groove 2 is made of plastic. An external thread 3 is machined on the right end of the guide device 1. The guide device is fixed to the front cover of the motor through the external thread 3. The injection-molded spline groove 2 prevents the screw spline assembly from rotating, thereby realizing the conversion of rotational motion to linear motion. There is sliding friction between the spline groove and the screw spline assembly, resulting in high frictional resistance. Furthermore, the fit clearance between the injection-molded spline groove and the screw spline is large, and the guiding accuracy is also poor because the guide device is connected to the front cover of the motor by threads. Utility Model Content

[0005] This invention provides a novel fixed-axis linear motor, which can reduce the friction between the protruding shaft and the guide component.

[0006] The technical solutions to the above technical problems are as follows:

[0007] A novel fixed-axis linear motor includes a stator assembly, a rotor assembly, a front bearing, a rear bearing, a front end cover, a rear end cover, a nut, a screw, a shaft, and an outer cylinder. The rotor assembly passes through the stator assembly. The front bearing is fitted onto one end of the rotor assembly and fixed thereto. The rear bearing is fitted onto the other end of the rotor assembly and fixed thereto. The front end cover mates with the front bearing, and the rear end cover mates with the rear bearing. The nut is located inside the rotor assembly and fixed thereto. The screw passes through the nut and is threadedly connected to the nut. One end of the shaft is fixed to the screw. A groove is provided on the circumferential surface of the shaft. The outer cylinder surrounds the shaft and is fixed to the front end cover. The motor also includes an inner cylinder and balls. The inner cylinder is located inside the outer cylinder and fixed thereto. An assembly groove is provided on the inner wall of the inner cylinder. The balls mate with the assembly groove and also with the groove on the shaft.

[0008] This invention reduces the gap between the inner cylinder and the extending shaft, while also reducing the friction between them, thus improving the guiding accuracy and efficiency of the motor. Based on physical properties, the rolling friction coefficient is much smaller than the sliding friction coefficient. By replacing the injection-molded plastic spline groove with a ball spline groove, the transition from sliding friction to rolling friction is achieved, thereby fulfilling the requirements of small gap and low friction between the extending shaft and the inner cylinder. Attached Figure Description

[0009] Figure 1 This is a structural diagram of the fixed-axis linear motor of this utility model.

[0010] Figure 2 This is an exploded view of the fixed-axis linear motor of this utility model.

[0011] Figure 3 This is a sectional view of the outer and inner cylinders after assembly.

[0012] Figure 4 This is a structural diagram of a guide device for an extended shaft in the prior art.

[0013] Labels in the attached diagram:

[0014] Stator assembly 1, rotor assembly 2, first shoulder 2a, front bearing 3, rear bearing 4, front end cover 5, rear end cover 6, nut 7, screw 8, protruding shaft 9, groove 9a, outer cylinder 10, first keyway 10a, inner cylinder 11, assembly groove 11a, second keyway 11b, ball bearing 12, key 12a, washer 13, preload nut 14, screw 15, limiting component 16. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0016] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0017] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0018] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0019] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0020] like Figures 1 to 3As shown, this utility model discloses a novel fixed-axis linear motor, comprising a stator assembly 1, a rotor assembly 2, a front bearing 3, a rear bearing 4, a front end cover 5, a rear end cover 6, a nut 7, a screw 8, an extension shaft 9, an outer cylinder 10, an inner cylinder 11, and ball bearings 12. The rotor assembly 2 is fitted to the stator assembly 1 and passes through the stator assembly 1. The front bearing 3 is fitted onto one end of the rotor assembly 2 and fixed thereto. The rear bearing 4 is fitted onto the other end of the rotor assembly 2 and fixed thereto. The front end cover 5 is fitted to the front bearing 3 and has a first bearing chamber. The front bearing 3 fits into the first bearing chamber on the front end cover 5. The rear end cover 6 is fitted to the rear bearing 4 and has a second bearing chamber. The rear bearing 4 fits into the second bearing chamber on the rear end cover 6. Screws 15 are threaded through the rear end cover 6, the stator assembly 1, and the front end cover 5 to fasten the rear end cover 6, the stator assembly 1, and the front end cover 5 into a single unit.

[0021] Nut 7 is located inside rotor assembly 2 and fixed to rotor assembly 2. Rotor assembly 2 consists of rotor core and rotor shaft. Rotor core is sleeved on rotor shaft and fixed to rotor shaft. Rotor shaft is hollow shaft. Radial through hole is provided on the circumferential surface of the shaft. Nut 7 is located inside rotor shaft and is interference-fitted with radial through hole, thereby fixing nut 7 to rotor shaft as one.

[0022] The screw 8 passes through the nut 7 and is threadedly connected to the nut 7. One end of the protruding shaft 9 is fixed to the screw 8. A groove 9a is provided on the circumferential surface of the protruding shaft 9, and the groove 9a is arranged along the axial direction of the protruding shaft 9. A limiting member 16 is installed between the screw 8 and the protruding shaft 9. The limiting member 16 is annular. After the screw 8 and the protruding shaft 9 are threadedly connected, the limiting member 16 is clamped between the screw 8 and the protruding shaft 9.

[0023] The outer cylinder 10 surrounds the protruding shaft 9 and is fixed to the front end cover 5. In this embodiment, the outer cylinder 10 and the front end cover 5 are integrally formed. The inner cylinder 11 is located inside the outer cylinder 10 and is fixed to the outer cylinder 10. The length of the inner cylinder 11 is less than the length of the outer cylinder 10, which is less than half the length of the outer cylinder 10. The inner wall surface of the inner cylinder 11 is provided with an assembly groove 11a. The ball bearing 12 cooperates with the assembly groove 11a and also cooperates with the groove 9a on the protruding shaft 9.

[0024] This utility model also includes a key 12a. The outer cylinder 10 is provided with a first keyway 10a, and the inner cylinder 11 is provided with a second keyway 11b. After the key 12a is engaged with the first keyway 10a and the second keyway 11b respectively, the outer cylinder 10 and the inner cylinder 11 are fixed together.

[0025] This utility model also includes a washer 13 and a preload nut 14 located inside the front cover 5. The rotor assembly 2 is provided with a first shoulder 2a. One end of the front bearing 3 is engaged with the first shoulder 2a. One end of the washer 13 abuts against the other end of the front bearing 3. The other end of the washer 13 abuts against the preload nut 14. The preload nut 14 is threadedly connected to the front cover 5.

[0026] In this invention, the front cover 5 and the outer cylinder 10 are directly formed into a single piece using a die-casting mold, eliminating the need for threaded connections and ensuring high guiding accuracy. The inner cylinder 11 is tightly and securely fixed to the inner wall of the outer cylinder 10 via a key 12a. Several ball bearings 12 are fitted into the mounting groove 11a on the inner cylinder 11, and the groove 9a on the surface of the protruding shaft 9 further engages with the ball bearings 12, preventing rotation while also providing rolling friction. This eliminates the gap between the protruding shaft 9 and the inner cylinder 11, improving efficiency and guiding accuracy.

Claims

1. A novel fixed-axis linear motor, comprising a stator assembly (1), a rotor assembly (2), a front bearing (3), a rear bearing (4), a front end cover (5), a rear end cover (6), a nut (7), a screw (8), an extension shaft (9), and an outer cylinder (10). The rotor assembly (2) is fitted with the stator assembly (1). The front bearing (3) is fitted onto one end of the rotor assembly (2) and fixed to the rotor assembly (2). The rear bearing (4) is fitted onto the other end of the rotor assembly (2) and fixed to the rotor assembly (2). The front end cover (5) is fitted with the front bearing (3), the rear end cover (6) is fitted with the rear bearing (4), the nut (7) is located inside the rotor assembly (2) and fixed to the rotor assembly (2), the screw (8) passes through the nut (7) and is threadedly connected to the nut (7), one end of the protruding shaft (9) is fixed to the screw (8), the circumferential surface of the protruding shaft (9) is provided with a groove (9a), the outer cylinder (10) surrounds the protruding shaft (9), and the outer cylinder (10) is fixed to the front end cover (5). The characteristic of this design is that... It also includes an inner cylinder (11) and a ball (12). The inner cylinder (11) is located inside the outer cylinder (10) and fixed to the outer cylinder (10). The inner wall surface of the inner cylinder (11) is provided with an assembly groove (11a). The ball (12) cooperates with the assembly groove (11a) and the ball (12) also cooperates with the groove (9a) on the extension shaft (9).

2. A novel fixed-axis linear motor according to claim 1, characterized in that, The outer cylinder (10) and the front end cover (5) are integrally formed.

3. A novel fixed-axis linear motor according to claim 1, characterized in that, It also includes a key (12a). The outer cylinder (10) is provided with a first keyway (10a), and the inner cylinder (11) is provided with a second keyway (11b). After the key (12a) is engaged with the first keyway (10a) and the second keyway (11b) respectively, the outer cylinder (10) and the inner cylinder (11) are fixed together.

4. A novel fixed-axis linear motor according to claim 1, characterized in that, It also includes a washer (13) and a preload nut (14) located inside the front cover (5). The rotor assembly (2) is provided with a first shoulder (2a). One end of the front bearing (3) is engaged with the first shoulder (2a). One end of the washer (13) abuts against the other end of the front bearing (3). The other end of the washer (13) abuts against the preload nut (14). The preload nut (14) is threadedly connected to the front cover (5).

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