Integral driven synchronous gear of oil-free double-screw compressor

Abstract

The utility model discloses an integral driven synchronous gear of an oil-free double-screw compressor. The integral driven synchronous gear comprises a hub and a gear ring, the hub comprises a hub body and a protruding ring part protruding from the peripheral face of the hub body in the radial direction, and the hub body is provided with a shaft hole penetrating in the axial direction. The gear ring is provided with a stepped through hole extending in the axial direction, the stepped through hole comprises a small-diameter through hole and a large-diameter through hole, and a stepped surface is formed between the small-diameter through hole and the large-diameter through hole; the gear ring is arranged outside the hub in a sleeving mode and connected with the hub, the convex ring part at least partially extends into the large-diameter through hole in the axial direction, the hole wall of the large-diameter through hole abuts against the outer circumferential face of the convex ring part, and the step face abuts against the end face, close to one end of the step face, of the convex ring part. The oil-free double-screw compressor is easy to assemble, high in transmission precision and capable of guaranteeing that the meshing clearance of the rotors of the oil-free double-screw compressor is within the design range.

Description

Technical Field

[0001] The utility model relates to the technical field of compressors, in particular to a synchronous gear of a twin-screw compressor. Background Art

[0002] In the field of chemical machinery, particularly in the petrochemical industry, screw compressors offer advantages such as simple structure, reliable operation, and easy operation, and thus have broad application prospects. Oil-free twin-screw compressors, which require no oil lubrication during the compression process, can be used as steam compressors or process compressors. The screw rotors and synchronous gears are their core components. The rotors do not directly contact each other, but rather have a certain meshing clearance between them. The male rotor drives the female rotor through the synchronous gears, which transmit power while ensuring the meshing clearance between the rotors, thus guaranteeing the proper operation of the compressor.

[0003] In oil-free twin-screw compressors, the meshing clearance between the rotors and the drive accuracy are crucial to the compressor's performance and efficiency. In existing oil-free twin-screw compressors, the passive synchronous gear in the synchronous gearing typically adopts a split (adjustable) structure. In this structure, both the small and large ring gears are mounted on the hub. By adjusting the small ring gear so that it is slightly offset from the large ring gear, the meshing clearance between the small and large ring gears and the active synchronous gear in the synchronous gearing can be reduced, thereby ensuring meshing clearance between the rotors. After the gear clearance is properly adjusted, the small and large ring gears are positioned relative to the hub using tapered pins, and then the large and small ring gears and the hub are secured with bolts. Summary of the Invention

[0004] The technical problem to be solved by the utility model is to provide a passive synchronous gear for an oil-free twin-screw compressor, which is easy to assemble, has high transmission accuracy, and can ensure that the meshing clearance of the rotor of the oil-free twin-screw compressor is within the design range.

[0005] According to an embodiment of the utility model, an integral passive synchronous gear of an oil-free twin-screw compressor includes a hub and a ring gear; the hub includes a hub body and a convex ring portion radially protruding from the outer peripheral surface of the hub body, and the hub body has an axial hole passing through in the axial direction; the ring gear has a stepped through hole extending in the axial direction, and the stepped through hole includes a small-diameter through hole and a large-diameter through hole, and a step surface is formed between the small-diameter through hole and the large-diameter through hole; the ring gear is sleeved on the outside of the hub and connected to the hub, wherein the convex ring portion at least partially extends into the large-diameter through hole in the axial direction, the hole wall of the large-diameter through hole abuts the outer peripheral surface of the convex ring portion, and the step surface abuts the end face of the convex ring portion adjacent to one end of the step surface.

[0006] In the above-mentioned integral passive synchronous gear of the oil-free twin-screw compressor, the ring gear and the convex ring portion are connected to each other by a plurality of bolts. A locking washer is provided between each bolt and the ring gear, and each two adjacent bolts share one locking washer.

[0007] In the above-mentioned integral passive synchronous gear of the oil-free twin-screw compressor, two ends of the anti-loosening gasket are bent toward each other and respectively pressed on the heads of two bolts sharing the anti-loosening gasket.

[0008] The above-mentioned integral passive synchronous gear of the oil-free twin-screw compressor is made of 42CrMo.

[0009] Compared with the prior art, the present invention has the following advantages:

[0010] 1. Simplified assembly process: The embodiment of the utility model changes the passive synchronous gear of the oil-free twin-screw compressor to an integral (non-adjustable) structure (the integral structure here means that the ring gear is an integral part), which no longer requires the small ring gear and the large ring gear to be staggered by a small angle, thereby reducing the meshing clearance between the small ring gear and the active synchronous gear, simplifying the assembly process, improving work efficiency, and reducing labor costs;

[0011] 2. Improve transmission accuracy: The advantage of the integral passive synchronous gear is its high transmission accuracy. Since there is no need to adjust the angle between the small gear ring and the large gear ring, the meshing clearance can be ensured directly through high-precision processing, thereby reducing the meshing error and making the gear meshing clearance and the rotor meshing clearance more stable. This can ensure the normal operation of the oil-free twin-screw compressor and improve the mechanical performance and efficiency of the compressor.

[0012] 3. Ensure rotor meshing clearance: The integral passive synchronous gear can ensure that the rotor meshing clearance is within the design range. When the compressor encounters abnormal conditions such as reverse rotation, it avoids the rotor tooth contact caused by excessive gear clearance and collision, which affects the stable operation of the unit.

[0013] 4. High gear strength: The integral passive synchronous gear of the embodiment of the utility model is made of 42CrMo material, and the active synchronous gear is made of 20CrMnTi material. After quenching and tempering treatment, it has a high fatigue limit and impact resistance, improves the strength and durability of the gear, and extends the service life. At the same time, it can ensure the size and shape accuracy of the gear and improve the transmission efficiency;

[0014] 5. Low maintenance cost: The synchronous gear structure of the embodiment of the utility model is more stable and the meshing clearance is smaller, thereby reducing the maintenance and replacement costs caused by gear wear or damage, and improving the reliability and economy of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A three-dimensional schematic diagram of an integral passive synchronous gear of an oil-free twin-screw compressor according to an embodiment of the present utility model is shown (bolts and locating pins are not shown in the figure).

[0016] Figure 2 A front schematic diagram of an integral passive synchronous gear of an oil-free twin-screw compressor according to an embodiment of the present utility model is shown.

[0017] Figure 3 Shown Figure 2 AA cross-sectional view of .

[0018] Figure 4 and Figure 5 Shown respectively Figure 3 Schematic diagram of partial enlargement of part I and part II. DETAILED DESCRIPTION

[0019] The inventors of the present application have found in practice that although the existing split-type passive synchronous gear structure can ensure the normal operation of the oil-free twin-screw compressor to a certain extent, there are some problems in actual operation. First, the assembly process of this structure is relatively complicated. The small gear ring and the large gear ring need to be offset by a small angle, and then positioned and fixed. This requires high adjustment accuracy and increases assembly time and labor costs. Secondly, since the small gear ring and the large gear ring can move relative to each other, if the gear clearance is not adjusted properly, the meshing clearance of the rotor will change. Therefore, the transmission accuracy of this structure is relatively low, which may affect the mechanical performance and efficiency of the compressor. Finally, if the meshing clearance between the synchronous gears is too large, when the compressor encounters abnormal conditions such as reversal, the male rotor will enter an idling state for a period of time, which will cause the long-side meshing clearance and short-side meshing clearance between the rotors to deviate from the design value, and even cause the rotor teeth to contact and rub, affecting the stable operation of the unit.

[0020] See also Figures 1 to 3 The integral passive synchronous gear of the oil-free twin-screw compressor according to the embodiment of the present invention includes a hub 1 and a ring gear 2 .

[0021] The hub 1 comprises a hub body 11 and a raised annular portion 12 radially extending from the outer circumference of the hub body 11. The hub body 11 is cylindrical and has an axial hole 10 extending axially therethrough. The wall of the axial hole 10 is provided with a keyway 101 for keying the hub 1 to the female rotor shaft of the oil-free twin-screw compressor.

[0022] Ring gear 2 has an axially extending stepped through-hole 20, which includes a smaller diameter through-hole 201 and a larger diameter through-hole 202. A stepped surface 203 is formed between the smaller diameter through-hole 201 and the larger diameter through-hole 202. The tooth width W of ring gear 2 is equal to the tooth width of the active synchronous gear of the oil-free twin-screw compressor.

[0023] The ring gear 2 is sleeved on the outside of the wheel hub 1 and connected to the wheel hub 1, wherein the convex ring portion 12 at least partially extends into the large-diameter through hole 202 along the axial direction, the hole wall of the large-diameter through hole 202 abuts the outer peripheral surface of the convex ring portion 12, and the step surface 203 abuts the end surface 123 of the convex ring portion 12 adjacent to one end of the step surface 203.

[0024] Preferably, a groove 202a is provided at the junction of the large-diameter through hole 202 and the stepped surface 203, and a chamfer 12a is provided at the top of the end of the convex ring portion 12 adjacent to the stepped surface 203. A groove 12b is provided at the junction of the bottom of the end of the convex ring portion 12 adjacent to the stepped surface 203 and the hub body 11, and a chamfer 201a is provided at the junction of the small-diameter through hole 201 and the stepped surface 203. This structure ensures that the wall of the large-diameter through hole 202 is in close contact with the outer circumferential surface of the convex ring portion 12, and that the end surface 123 of the convex ring portion 12 adjacent to the stepped surface 203 is in close contact with the stepped surface 203.

[0025] In this embodiment, the ring gear 2 and the raised ring portion 12 are connected by a plurality of bolts 3. A locking washer 4 is provided between each bolt 3 and the ring gear 2. Every two adjacent bolts 3 share a locking washer 4, which prevents the bolts 3 from loosening. To further prevent loosening, the two ends of the locking washer 4 are bent toward each other and press against the heads of the two bolts 3 sharing the same locking washer.

[0026] In this embodiment, the entire convex ring portion 12 extends into the large diameter through hole 202 in the axial direction, the end face 124 of the other end of the convex ring portion 12 away from the step surface 203 is flush with the end face 24 of the end of the ring gear 2 adjacent to the large diameter through hole 202, and the hole wall of the small diameter through hole 201 abuts the outer peripheral surface of the hub body 11.

[0027] In this embodiment, the integral passive synchronous gear includes a positioning pin 5; the ring gear 2 is provided with a first positioning hole 25, the convex ring portion 12 is provided with a second positioning hole 126, and the positioning pin 5 is inserted into the first positioning hole 25 and the second positioning hole 126. Preferably, the positioning pin 5 is a conical positioning pin.

[0028] In this embodiment, the material of the integral passive synchronous gear is 42CrMo, and the material of the active synchronous gear meshing therewith is 20CrMnTi.

[0029] The embodiment of the present utility model solves the problem that the existing split synchronous gear structure may cause the rotor meshing clearance to deviate from the design value. In the prior art, if the meshing clearance between the synchronous gears is too large, the long side clearance and the short side clearance in the meshing clearance between the rotors will deviate from the design value, which may cause the male rotor to enter an idling state when the compressor is reversed, and even cause the rotor teeth to contact and rub. The embodiment of the present utility model adopts an integral passive synchronous gear structure to ensure the accuracy of the meshing clearance and avoid the occurrence of the above-mentioned problems. The meshing clearance of the integral passive synchronous gear structure is small. When the compressor reverses or other abnormal conditions occur, it can avoid the male rotor from entering an idling state and the rotor teeth from contacting and rubbing, thereby improving the stability and reliability of the equipment and ensuring the stable operation of the compressor unit.

[0030] The manufacturing process of the integral passive synchronous gear of the embodiment of the utility model mainly includes the following steps:

[0031] Step 1: Material processing. The active synchronous gear is made of 20CrMnTi, and the passive synchronous gear is made of 42CrMo. The forging material should comply with the relevant provisions of Q / ZB 71-73 and be inspected according to Group IV. Other technical requirements should comply with the relevant provisions of GB / T 3077-2015. The active synchronous gear forging is normalized to a surface hardness of HB160-200.

[0032] Step 2: Gear machining. First, the active and passive synchronous gears are machined with high precision. After finishing, the active synchronous gear undergoes magnetic particle inspection and surface carburizing and quenching, achieving a hardness of HRC56-62 and an effective carburized layer depth of 0.6-0.9mm on the tooth surface. Then, the ring gear 2 and hub 1 of the passive synchronous gear undergo quenching and tempering, achieving a hardness of HB260-300 and a fatigue limit of 600-800MPa. After semi-finishing, the inner surface of hub 1 is quenched to a hardness of HRC45-52.

[0033] Step 3: Assembly process. At the beginning, the pin hole (first positioning hole 25) is reserved in advance for the ring gear 2, and the wheel hub 1 does not have a pin hole; use the assembly tools and tooling holes to heat-seal the active synchronous gear and the passive synchronous gear onto the rotor shaft at the same time, and the heat-seal temperature is 150-200°C. Then adjust the positioning, make marks, punch the pin hole (second positioning hole 126) and hinge the pin hole for the wheel hub 1, and then put the locating pin 5 into the pin hole of the ring gear 2 and the wheel hub 1 to achieve precise positioning. Finally, place the anti-loosening gasket 4 between the bolt 3 and the ring gear 2, fix the ring gear 2 and the wheel hub 1 with the bolt 3, and fold the corners of the anti-loosening gasket over the bolt head and press it tightly. Its function is to prevent the bolt 3 from loosening and ensure the reliable fixation of the gear.

[0034] The present invention and its manufacturing process have the following advantages and features:

[0035] 1. Integral synchronous gear structure: The embodiment of the utility model changes the passive synchronous gear of the oil-free twin-screw compressor synchronous gear into an integral (non-adjustable) structure. It is no longer necessary to stagger the small gear ring and the large gear ring by a small angle as in the split passive synchronous gear. The meshing clearance with the active synchronous gear is small, the transmission accuracy is high, and the assembly process is simplified. However, it has higher requirements for the processing accuracy of the gear.

[0036] 2. High-precision gear processing: The passive synchronous gear of the embodiment of the utility model is made of 42CrMo material, which has a high fatigue limit and impact resistance after quenching and tempering. The active synchronous gear is made of 20CrMnTi material. 20CrMnTi is a carburized steel with good machinability, small machining deformation, and good fatigue resistance. This material selection can ensure the strength and toughness of the gear, while also helping to improve the machinability and service life of the gear. Using high-precision gear processing methods can ensure the size and shape accuracy of the gear, improve transmission efficiency, and extend service life;

[0037] 3. Precise Assembly Process: The assembly process of this embodiment is relatively simple. After the active and passive synchronous gears are simultaneously shrink-fitted onto the rotor shaft, the ring gear and hub are positioned using tapered locating pins, and then bolted together. This assembly process ensures accurate meshing clearance between the synchronous gears and the rotor, avoiding degradation of mechanical performance and efficiency due to improper assembly.

Claims

1. An integral passive synchronous gear for an oil-free twin-screw compressor, characterized in that: The integral passive synchronous gear includes a hub and a ring gear; The wheel hub comprises a wheel hub body and a convex ring portion radially protruding from the outer peripheral surface of the wheel hub body, wherein the wheel hub body has an axial hole extending therethrough in the axial direction; The gear ring has a stepped through hole extending in the axial direction, the stepped through hole includes a small-diameter through hole and a large-diameter through hole, and a step surface is formed between the small-diameter through hole and the large-diameter through hole; The gear ring is sleeved outside the wheel hub and connected to the wheel hub, wherein the convex ring portion at least partially extends into the large-diameter through hole in the axial direction, the hole wall of the large-diameter through hole abuts the outer peripheral surface of the convex ring portion, and the step surface abuts the end surface of the convex ring portion adjacent to one end of the step surface.

2. The integral passive synchronous gear of the oil-free twin-screw compressor according to claim 1, characterized in that: The ring gear and the raised ring portion are connected to each other by a plurality of bolts.

3. The integral passive synchronous gear of the oil-free twin-screw compressor according to claim 2, characterized in that: An anti-loosening washer is provided between each of the bolts and the gear ring, and every two adjacent bolts share one anti-loosening washer.

4. The integral passive synchronous gear of the oil-free twin-screw compressor according to claim 3, characterized in that: The two ends of the anti-loosening gasket are bent toward each other and respectively pressed on the heads of two bolts sharing the anti-loosening gasket.

5. The integral passive synchronous gear of the oil-free twin-screw compressor according to claim 1, characterized in that: The integral passive synchronous gear includes a positioning pin; The gear ring is provided with a first positioning hole, the convex ring portion is provided with a second positioning hole, and the positioning pin is inserted into the first positioning hole and the second positioning hole.

6. The integral passive synchronous gear of the oil-free twin-screw compressor according to claim 1, characterized in that: A keyway is provided on the wall of the shaft hole of the hub.

7. The integral passive synchronous gear of the oil-free twin-screw compressor according to claim 1, characterized in that: The hole wall of the small-diameter through hole abuts against the outer peripheral surface of the hub body.

8. The integral passive synchronous gear of the oil-free twin-screw compressor according to claim 1, characterized in that: The material of the integral passive synchronous gear is 42CrMo.

9. The integral passive synchronous gear of the oil-free twin-screw compressor according to claim 1, characterized in that: The tooth width of the ring gear is equal to the tooth width of the active synchronous gear of the oil-free twin-screw compressor.

10. The integral passive synchronous gear of the oil-free twin-screw compressor according to claim 1, characterized in that: A groove is provided at the junction of the large diameter through hole and the step surface, and a chamfer is provided at the top of one end of the convex ring portion adjacent to the step surface, and A groove is provided at the junction of the bottom of one end of the convex ring portion adjacent to the step surface and the hub body, and a chamfer is provided at the junction of the small-diameter through hole and the step surface.

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