High-speed high-performance screw vacuum pump

Abstract

The utility model provides a high-speed high-performance screw vacuum pump, and belongs to the technical field of machinery. The problem of how to increase the rotating speed of the screw vacuum pump is solved. The high-speed high-performance screw vacuum pump comprises two screws and a motor, the front end of one of the screws extends into a shell of the motor and is fixedly connected with a rotor or a stator of the motor through a front locking bolt, the rear ends of the two screws are in transmission connection through a gear, the rear ends of the two screws are connected with a locking assembly, and the locking assembly is connected with the motor. The locking assembly locks the gear to the rear end of the screw rod in the axial direction of the screw rod. The high-speed high-performance screw vacuum pump can effectively improve the rotating speed.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical technology and relates to a high-speed, high-performance screw vacuum pump. Background Technology

[0002] A screw vacuum pump is a pumping device that uses a pair of screws (or rotors) to generate suction and exhaust by rotating synchronously and at high speed in opposite directions within a pump casing. A drive shaft connects to the driving rotor, which in turn drives the driven rotor via a synchronous gear. The normal operation of the screw vacuum pump is achieved through the cooperation of the driving and driven rotors.

[0003] For example, a variable pitch double-headed screw vacuum pump disclosed in Chinese Patent (Authorization Announcement No. CN203308712U) has a pair of double-headed screw rotors with symmetrical end face profiles and opposite rotation directions, wherein the active rotor (9) and the driven rotor (10) are meshed and installed in the pump body (7), and the pitch gradually decreases from the intake port to the exhaust port. As the active rotor (9) and the driven rotor (10) rotate synchronously, the gas is compressed step by step and discharged from the pump chamber and pump body (7). According to the text of paragraph 0024 of its specification, the active rotor 9 and the driven rotor 10 are supported by the front bearing 5 and the rear bearing 11 respectively, and are driven to rotate by a pair of synchronous gears 3. The motor 1 is connected to the active rotor 9 through the coupling 2.

[0004] However, in actual operation, the torque that the coupling can transmit often does not meet the actual requirements, and its service life cannot be guaranteed after long-term load. Secondly, in the current technology, whether it is the gear on the driving rotor or the gear on the driven rotor, its positioning is often achieved by a key. This causes a certain deviation in the coaxiality between the gear and the driving or driven rotor. When the speed reaches a certain value, the gear on the driving rotor and the gear on the driven rotor are very prone to slippage or tooth stripping, which cannot meet the conditions for efficient operation of the screw vacuum pump. In severe cases, it can also cause irreversible damage to the screw vacuum pump. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a high-speed, high-performance screw vacuum pump. The technical problem this invention aims to solve is: how to increase the rotational speed of the screw vacuum pump.

[0006] The objective of this utility model can be achieved through the following technical solution: a high-speed, high-performance screw vacuum pump, comprising two screws and a motor, characterized in that the front end of one of the screws extends into the housing of the motor and is connected and fixed to the rotor or stator of the motor by a front locking bolt, the rear ends of the two screws are connected by gear transmission, and a locking assembly is connected to the rear ends of the two screws, and the locking assembly locks the gear along the axial direction of the screw at the rear ends of the screw.

[0007] It should be noted beforehand that, as existing technology, this high-speed, high-performance screw vacuum pump has two screws installed, which are arranged side by side and slightly offset along the axial direction, allowing the external threads of the two screws to mesh. These two screws can be referred to as the driving screw and the driven screw, respectively. The driving screw is fixedly connected to the rotor or stator of the motor and is driven to rotate by the motor rotor. The driven screw and the driving screw are driven and transmitted through a pair of gears, thus achieving synchronous rotation of the two screws. Based on this structure, the difference between this application and the existing technology is that: firstly, this application eliminates the coupling, directly inserting the front end of the screw (the driving screw) into the motor housing, and using a front locking bolt to screw it into the motor rotor or stator, thus directly driving the motor rotor or stator. The active screw rotates, eliminating the need for a complex transmission mechanism between the two components. The motor directly drives the screw, ensuring higher rotation speeds. A gear is connected to the rear end of the screw (which can be considered a sleeve), and a locking assembly clamps it along the screw's axial direction. This ensures a secure connection between the gear and screw. Because the gear is locked along the screw's axial direction, it avoids the misalignment of the gear relative to the screw that occurs with keyed connections in existing technologies. This ensures coaxiality between the gear and screw. This design prevents gear misalignment and vibration during high-speed screw rotation, thus avoiding tooth slippage and wear on the gears of the two screws during transmission. This ensures the pump screw vacuum pump operates at higher speeds.

[0008] In the aforementioned high-speed, high-performance screw vacuum pump, the pump further includes a pump housing and a rear cover fixed to the pump housing. Each screw is rotatably connected in the pump housing, with its rear end passing through the rear cover. A rear bearing is fixed to the rear cover, and the inner ring of the rear bearing is locked to the screw. The locking assembly presses the gear onto the inner ring of the rear bearing. As a further embodiment, the rear cover engages with the rear bearing inside it to achieve circumferential positioning of the screw, thereby ensuring that the screw's axis will not shift at any time. Furthermore, the inner ring of the rear bearing acts as the load-bearing component, replacing the screw in bearing the pressure applied to the gear by the locking assembly. This ensures stable gear installation and prevents excessive stress on the screw.

[0009] In the aforementioned high-speed, high-performance screw vacuum pump, the locking assembly includes a rear locking bolt and a rear end cap sleeved outside the rear locking bolt. The rear locking bolt is screwed to the rear end of the screw, and the rear end cap presses the gear onto the inner ring of the rear bearing. The screwed connection between the rear locking bolt and the rear end of the screw, via a threaded engagement, ensures the coaxiality of the gear and the screw by pressing the rear end cap against the gear, thus guaranteeing the coaxiality of the gear and the screw.

[0010] In the aforementioned high-speed, high-performance screw vacuum pump, the locking assembly further includes an annular and elastic expansion sleeve. A groove surrounding the screw is provided on the side of the gear facing away from the rear pressure cover. The expansion sleeve is embedded in the groove, and the rear pressure cover presses the expansion sleeve against the bottom wall of the groove. The groove allows the expansion sleeve to be inserted. Furthermore, the rear pressure cover has a U-shaped cross-section along the screw axis. During the tightening of the rear locking bolt, the open end of the rear pressure cover can be inserted into the groove and continuously press against the expansion sleeve, causing the expansion sleeve to elastically deform within the groove. The elastic force generated by this deformation ensures that the gear receives sufficient force, thereby ensuring a more secure connection between the gear and the screw while maintaining coaxiality.

[0011] In the aforementioned high-speed, high-performance screw vacuum pump, a front cover fixed to the pump housing is further included. The motor is fixed to the outer wall of the front cover. Two front bearings are fixed within the front cover. The front ends of the two screws pass through the front cover and are engaged with the inner rings of the two front bearings. The front bearings within the front cover, with their inner rings engaging with the outer wall of the screw front ends, ensure circumferential positioning of the screws and guarantee the coaxiality of the screw front ends and the motor rotor or stator.

[0012] In the aforementioned high-speed, high-performance screw vacuum pump, a front end cap is fixedly installed in the rotor of the motor. The front end of one of the screws extends into the rotor of the motor and abuts against the front end cap. A front locking bolt passes through the front end cap and is screwed and locked to the front end of the screw. This ensures the connection stability between the screw front end and the motor rotor.

[0013] Compared with existing technologies, this high-speed, high-performance screw vacuum pump has the following advantages:

[0014] The front end of the screw extends directly into the motor housing and abuts against the front end cap in the motor rotor, and is locked in place by a front locking bolt. This direct-drive method ensures that the screw can achieve a higher speed. The gear is positioned at the rear end of the screw along the screw axis through a locking assembly, ensuring a strong connection and higher coaxiality, preventing issues such as slippage and tooth breakage, and ensuring that the screw vacuum pump can achieve a higher speed. Attached Figure Description

[0015] Figure 1 This is a simplified cross-sectional view of this high-speed, high-performance screw vacuum pump.

[0016] Figure 2 yes Figure 1 A magnified view of a portion of point A in the middle.

[0017] Figure 3 yes Figure 1 A magnified view of a section at point B in the middle.

[0018] In the diagram, 1 is the screw; 2 is the motor; 21 is the front end cover; 3 is the gear; 31 is the slot; 4 is the front locking bolt; 5 is the locking assembly; 51 is the rear locking bolt; 52 is the rear end cover; 53 is the expansion sleeve; 6 is the pump housing; 61 is the front side cover; 611 is the front bearing; 62 is the rear side cover; and 621 is the rear bearing. Detailed Implementation

[0019] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0020] like Figure 1 As shown, this high-speed, high-performance screw vacuum pump includes a cylindrical pump casing 6. Two parallel screws 1 are rotatably connected inside the pump casing 6. The two ends of the two screws 1 extend from the two ends of the pump casing 6, respectively. A front cover 62 is fixed to one end of the pump casing 6 by screws, and a rear cover 61 is fixed to the other end by screws. A front bearing 621 is fixed in the front cover 62. The front end of the screw 1 passes through the front cover 62 and its outer wall is engaged with the inner ring of the front bearing 621. A rear bearing 611 is fixed in the rear cover 61. The rear end of the screw 1 passes through the rear bearing 611 and its outer wall is engaged with the inner ring of the rear bearing 611.

[0021] Combination Figure 2 A motor 2 is fixed to the outer wall of the front cover 62 by screws. The motor 2 is a permanent magnet shielded motor. A channel is provided in the rotor inside the motor 2, and a front end cover 21 is fixed in the channel along the radial direction of any one of the screws 1. The front end of one of the screws 1 extends into the housing of the motor 2 and is inserted into the channel to abut against the front end cover 21. The front locking bolt 4 passes through the opening on the front end cover 21 and the threaded hole opened at the front end of the screw 1 to lock it in place, so that the front end of the screw 1 and the rotor of the motor 2 are firmly fixed together.

[0022] Combination Figure 3The rear end of the screw 1 is fitted with a gear 3. A locking assembly 5 is also located at the rear end of the screw 1. Specifically, the locking assembly 5 includes a rear locking bolt 51, a rear end cap 52, and an annular expansion sleeve 53 made of elastic material. A groove 31 surrounding the screw 1 is formed on the side of the gear 3 facing away from the rear cover 61. The expansion sleeve 53 is fitted into the groove 31. The rear end cap 52 has a U-shaped cross-section along the axial direction of the screw 1 and is fitted onto the rear locking bolt. The open end of screw 51 is inserted into the slot 31 and the expansion sleeve 53 and tightened. The rear locking bolt 51 is screwed into the threaded hole at the rear end of screw 1. As the rear locking bolt 51 is tightened, the rear end cover 52 continuously squeezes the expansion sleeve 53, causing it to elastically deform in the slot 31. With the transmission of force, the gear 3 is pressed against the outer wall of the inner ring of the rear bearing 611, ensuring the stable connection of the gear 3 and the screw 1 while maintaining a high degree of coaxiality. In addition, the two screws 1 set in the pump housing 6 are driven by the gears 3. When the motor 2 starts, its rotor drives one of the screws 1 to rotate. The gear 3 on the screw 1 cooperates with the gear 3 on the other screw 1 to achieve synchronous rotation of the other screw 1.

[0023] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

[0024] Although this document frequently uses terms such as screw 1, motor 2, front end cap 21, gear 3, slot 31, front locking bolt 4, locking assembly 5, rear locking bolt 51, rear end cap 52, expansion sleeve 53, pump housing 6, front side cover 61, front bearing 611, rear side cover 62, and rear bearing 621, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any additional limitation would contradict the spirit of this utility model.

Claims

1. A high-speed, high-performance screw vacuum pump, comprising two screws (1) and a motor (2), characterized in that, One of the screws (1) has its front end inserted into the housing of the motor (2) and is connected and fixed to the rotor or stator of the motor (2) by a front locking bolt (4). The rear ends of the two screws (1) are connected by a gear (3). The rear ends of the two screws (1) are connected to a locking assembly (5), and the locking assembly (5) locks the gear (3) along the axial direction of the screw (1) at the rear end of the screw (1).

2. The high-speed, high-performance screw vacuum pump according to claim 1, characterized in that, This high-speed, high-performance screw vacuum pump also includes a pump housing (6) and a rear cover (61) fixed on the pump housing (6). Each screw (1) is rotatably connected in the pump housing (6) and its rear end passes through the rear cover (61). A rear bearing (611) is fixed on the rear cover (61). The inner ring of the rear bearing (611) is locked with the screw (1). The locking assembly (5) presses the gear (3) onto the inner ring of the rear bearing (611).

3. The high-speed, high-performance screw vacuum pump according to claim 2, characterized in that, The locking assembly (5) includes a rear locking bolt (51) and a rear end cap (52) sleeved on the rear locking bolt (51). The rear locking bolt (51) is screwed to the rear end of the screw (1) and the gear (3) is pressed onto the inner ring of the rear bearing (611) by the rear end cap (52).

4. The high-speed, high-performance screw vacuum pump according to claim 3, characterized in that, The locking assembly (5) also includes an annular and elastic expansion sleeve (53). The gear (3) has a slot (31) on the side opposite to the rear end cover (52) surrounding the screw (1). The expansion sleeve (53) is embedded in the slot (31), and the rear end cover (52) presses the expansion sleeve (53) against the bottom wall of the slot (31).

5. The high-speed, high-performance screw vacuum pump according to claim 2, 3, or 4, characterized in that, This high-speed, high-performance screw vacuum pump also includes a front cover (62) fixed on the pump housing (6), the motor (2) is fixed on the outer wall of the front cover (62), two front bearings (621) are fixed in the front cover (62), and the front ends of the two screws (1) pass through the front cover (62) and are clamped to the inner rings of the two front bearings (621).

6. The high-speed, high-performance screw vacuum pump according to claim 5, characterized in that, A front end cap (21) is fixed in the rotor of the motor (2), and the front end of one of the screws (1) extends into the rotor of the motor (2) and abuts against the front end cap (21), and the front locking bolt (4) passes through the front end cap (21) and is screwed and locked to the front end of the screw (1).

Images